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HAND PAIN
156 Chapter 21 HAND PAIN
Chapter 21
HAND PAIN Joseph M. Bellapianta, William F. Lavelle, Elizabeth Demers Lavelle, Ike Onyedika, Demetri Economedes, and Richard Whipple
INTRODUCTION The hand is a complex anatomic structure that has been in part credited with the development of modern people. Tendons, nerves, blood vessels, and small bones allow for the seemingly fluid function of the hand, yet all of these structures may fall victim to pathology and become sources of hand pain. The diagnosis of hand pain requires a working knowledge of functional hand anatomy and an understanding of the processes that may lead to pain. Hand pain may be primary or referred from other areas.
NERVE ETIOLOGIES OF HAND PAIN Carpal Tunnel Syndrome Carpal tunnel syndrome (CTS) is the most common compression neuropathy of the upper extremity. It is caused by compression of the median nerve at the wrist through the carpal tunnel. It may be acute or chronic in nature. Any space-occupying lesion in the carpal tunnel or a reduction of the space inside the tunnel from external compression will result in reduced space for the median nerve. Pressure on the nerve may result from swelling of the lining of the flexor tendons, joint dislocations, fractures, and inflammatory arthritis (Box 21–1). The root cause of the compression is often unknown. Occupational hazards such as keeping the wrist bent for long periods of time have also been speculated to cause CTS. Wrist and distal radius fractures can often produce acute CTS because of swelling or immobilization of the wrist in a flexed position. Repetitive flexion/extension of the wrist, repetitive motion of the fingers, the repetitive and forceful squeezing and releasing of a tool, and vibration exposure have all been implicated. Patients will often complain of symptoms when driving a car or reading a newspaper. Swelling and symptoms can also develop from pregnancy, thyroid disorder, and diabetes. CTS may present with paresthesia, hypothesia, anesthesia, or pain on the surfaces of the hand innervated by the median nerve, which includes the palmar and the dorsal distal phalangeal aspects of the lateral three and a half digits (Fig. 21–1). With prolonged median nerve compression, weakness and atrophy will be seen in the thenar muscles as a result of denervation. The pain, paresthesia, hypothesia, and anesthesia associated with CTS tend to be more severe at night and often interrupt sleep. This is due to elevated carpal tunnel pressures and lower systemic blood pressures causing acute ischemia. Patients will often awake with pain and dangle or shake out the hand to increase blood flow. Patients with CTS usually complain of pain and paresthesia in the hand or wrist, but pain
proximal to the wrist (radiating toward the shoulder) has been frequently reported as well.1 The presence of proximal pain may represent a clinical marker of mild median nerve damage and appears to be related to ‘‘extramedian spread of symptoms in the hand, from peripheral or central nervous system mechanisms.’’1 A careful history and physical examination should be performed with the addition of certain specific tests to reveal median nerve neuropathy (Box 21–2). Electromyography/nerve conduction velocity studies can be helpful in confounding cases in which other causes for symptoms need to be ruled out, such as compression at a higher level. In some cases of CTS, the only complaints are deep hand pain and aching, but no numbness. Treatment for CTS should always begin with conservative measures. Conservative therapy includes splinting the wrist in a neutral position, oral anti-inflammatory drugs to reduce synovitis, diuretics to reduce edema, and treatment of any underlying medical condition. Corticosteroid injections can also be tried; however, only a small percentage of patients will be symptom-free 12 months later. Noninvasive treatment approaches for mild to moderate CTS with median motor nerve distal latencies of more than 4.2 msec but less than 7.0 msec have been advocated with mixed results. The use of laser therapy for mild to moderate CTS may be beneficial2–4 or without dramatic success.5 Differences in treatment technique may be at least partly responsible for varied results. Another noninvasive treatment strategy for CTS that may be beneficial is the use of the lidocaine 5% patch.6,7 Injections can also be used for diagnostic purposes to predict surgeon outcome. Patients with typical symptoms but normal nerve tests, who improve with injections, may be candidates for surgical release. Injections may also be used for atypical patients with only hand pain but no numbness. Injections can help to distinguish fixed neuropathy versus compressive neuropathy. The steroid, if placed in the carpal tunnel, will shrink the synovium and lower the carpal tunnel pressure. If noninvasive measures fail, surgical release of the transverse carpal ligament is generally recommended. Sectioning of the transverse carpal ligament decompresses the median nerve, thus relieving the symptoms. The point of compression on the median nerve can often be seen with a hyperemic epineurium and changing nerve diameter in the carpal tunnel. This procedure can be done open or endoscopically with similar long-term results.
Guyon’s Canal or UlnarTunnel Syndrome In the palm, the ulnar nerve passes under the pisohamate ligament, which is a fascial band between the pisiform and the hamate. This tunnel is called Guyon’s canal. Guyon’s canal contains the ulnar artery and vein and the ulnar nerve. Patients with ulnar tunnel syndrome complain of paresthesias and decreased sensation in the little finger and half of the ring finger. Unlike CTS, it is not caused directly by tendinitis because no tendons run through the tunnel. Compression may be induced by activities such as using the palm of the hand as a hammer or with repetitive use of tools such as a screwdriver or pliers. Ulnar tunnel syndrome is also more common in long-distance cyclers. The compression may be the result of a cyst in the canal, swelling of the ulnar artery, or a fracture of the hook of the hamate. Hamate fractures are seen in golfers as the result of hitting the firm ground instead of the golf ball while swinging. These are also seen in racquet sports. Treatment options for ulnar neuropathy at the wrist include avoiding provocative activities, splinting, anti-inflammatory medication, steroid injections, and occupational therapy. If these are
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Box 21^1 CAUSES OF CARPAL TUNNEL SYNDROME Anatomic Causes Due to Decreased Size Carpal bone abnormalities Thickened transverse carpal ligaments Anatomic Causes Due to Increased Contents of Canal Neuroma, lipoma, myeloma, persistent median artery, anomalous muscles in the tunnel Hypertrophic synovium, distal radial fractures, post-traumatic osteophyte, hematoma Neuropathic Causes Diabetes, alcoholism, proximal lesion of median nerve
Median nerve
Inflammatory Causes Tenosynovitis, rheumatoid arthritis, infection, gout
Ulnar nerve
Alteration of Fluid Balance Pregnancy, eclampsia, myxedma, long-term hemodialysis, horizontal position and muscle relaxation, Raynaud’s disease, obesity Congenital Mucopolysaccharidosis, mucolipidosis, Down’s syndrome, achondroplasia
unsuccessful, surgery to decompress the nerve may be needed. The tunnel may be directly decompressed for isolated ulnar nerve symptoms or in combination with a release of the carpal tunnel.
Cubital Tunnel Syndrome Cubital tunnel syndrome is the most common site of ulnar nerve entrapment and the second most common peripheral compression neuropathy. Cubital tunnel syndrome affects men more often than women. The ulnar nerve enters the cubital tunnel by passing deep to the arcuate ligament (Osborne’s ligament), which connects the ulnar and the humeral heads of the flexor carpi ulnaris (FCU) muscle. The nerve then passes between the two heads of the FCU before heading deep to the flexor pronator aponeurosis. Compression or injury may develop because of repetitive elbow motion, prolonged elbow flexion, direct compression, or childhood elbow fractures with subsequent abnormal growth and alignment (tardy ulnar nerve palsy) (Box 21–3). Patients with this condition commonly exhibit symptoms of intermittent pain on the medial side of the elbow and paresthesias of the fourth and fifth digits. An associated aching discomfort along the inner forearm or elbow may be present. If nerve damage persists, there is loss of sensation in the fourth and fifth digits. Eventually, there is loss of pinch and grip strength owing to atrophy of the muscle of the hand because the ulnar nerve is responsible for innervation of most of the intrinsic hand muscles. The major diagnostic tests for cubital tunnel syndrome include an elbow flexion test, Tinel’s test, and the pressure provocative test. In the elbow flexion test, patients are positioned with their arms at their side, and elbows flexed approximately 1208. The patient maintains that position for 3 minutes in an attempt to reproduce the symptoms. In Tinel’s test, the groove between the olecranon process and the medial epicondyle through which the ulnar nerve passes is palpated and tapped. Similarly to a Tinel test at the carpal tunnel, a positive test is characterized by a tingling sensation in the ulnar distribution of the forearm and hand distal to the tapping point (see Fig. 21–2). The pressure provocative test for cubital tunnel syndrome involves applying pressure proximal to the cubital tunnel, with the elbow flexed 208 and the forearm in a supine position. Anterior subluxation of the ulnar nerve should also be identified by direct palpation with flexion of the elbow. Nonoperative treatment of cubital tunnel syndrome includes immobilization with long arm splints to prevent elbow flexion at night, a padded elbow brace during the day, and avoidance of
Transverse carpal ligament
A Median nerve
Radial nerve
Ulnar nerve
B Figure 21^1. A, Nerves of the palm of the hand. B, Nerves of
the dorsal hand.
activities with repetitive elbow movements. The use of nonsteroidal anti-inflammatory drugs may be beneficial. Steroid injections are rarely used. If nonoperative treatments are ineffective, surgical procedures may be entertained. The goal of surgery is to relieve compression of the ulnar nerve. The methods used to decompress the ulnar nerve
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Box 21^2 TESTS USED TO CONFIRM THE DIAGNOSIS OF CARPAL TUNNEL SYNDROME *Phalen’s test: Patient places elbow on table, forearm vertical, wrists flexed. The test is positive when paresthesias develop on the radial side digits within 60 sec (Fig. 21^2). Reverse Phalen’s with wrist extended can also be done. *Tinel’s test: Examiner lightly taps along median nerve at the wrist, proximal to distal. Positive if tingling develops in fingers at site of compression. *Carpal tunnel compression test: Examiner compresses median nerve. If paresthesias develop within 30 sec, test is positive. Hand diagram: Patient marks signs of pain or paresthesias on diagram of hand. Hand-volume stress test: Measure hand volume by water displacement, repeat after stress test and10 min rest. Measurement of carpal tunnel pressure: Measure carpal tunnel pressure via infusion catheter. Positive if pressure reaches 25 mm Hg or more. Static two-point discrimination: Determine minimum separation of two points on the palmer aspect of the hand. Test is positive if one fails to discriminate points more than 6 mm apart. Moving two-point discrimination: Similar to static two-point discrimination. Positive if patient fails to discriminate points more than 5 mm apart. Vibrometry: Head of vibrometer is placed on palmar side of the digit. An amplitude of 120 Hz is increased to threshold of perception. It is then compared with the median and ulnar nerves in both hands. Test is positive if there is asymmetry with contralateral hand or between radial and ulnar digits. Semmes-Weinstein monofilament test: Monofilaments of increasing lengths are touched to the palmar side of digit until patient can tell which digit is touched. Positive if value is greater than 2.83 in radial digit. *Electromyogaphy: Needle electrodes placed in muscle.Fibrillation potentials, sharp waves, increased insertional activity. Nerve conduction velocities can also be useful. *Commonly used tests.
Box 21^3 CAUSES OF CUBITAL TUNNEL SYNDROME Compression of the ulnar nerve Entrapment in distal humeral fracture or elbow dislocation Cubitus valgus, cubitus varus, malunion, nonunion Aberrant or abnormal musculature of forearm musculature Osteoarthritis Inflammatory arthritis Synovial chondromatosis Bands, vascular and fascial, musculotendinous variations around the medial epicondyle, aberrant muscle anomalies. The ulnar nerve may be compressed at different levels including the medial intermuscular septum or posterior compartment of the arm (e.g., arcade [or ligament] of Struthers) and soft tissue of bony abnormalities of the cubital tunnel (e.g., epitrochleoanconeus muscle [anconeus epitrochlearis muscle], thick arcuate ligament of Osbourne [‘‘Osborne’s band’’]). Space-occupying lesions, e.g., tumors
include in situ decompression, in situ decompression with medial epicondylectomy, and anterior transposition. Transpositions may be completed in a subcutaneous or submuscular fashion. Decompression of the nerve usually leads to symptom resolution.
Radial Tunnel Syndrome Proximal radial compression neuropathy occurs infrequently and is diagnosed correctly even less frequently (Rinker, 2004). The radial nerve emerges from the intermuscular septum on the lateral arm and descends distally along the border of the brachialis muscle (Rinker, 2004). Roughly 2 cm distal to the elbow, the radial nerve divides into the posterior interosseous nerve (PIN) and the superficial sensory divisions.8 The PIN courses under the fibrous proximal margin of the supinator muscle, known as the arcade of Frohse, and bifurcates to innervate the extensor carpi ulnaris muscle and the digital extensor muscles.8
Figure 21^2. Tinel’s test.
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Table 21^1. Dorsal Compartment Tendons Compartment
Tendons
I
II
III
1. Extensor pollicis 1. Extensor carpi radialis brevis longus (EPL) (ECRB) 2. Abductor pollicis brevis 2. Extensor carpi radialis longus (APB) (ECRL)
IV
Extensor pollicis longus (EPL)
In 1979, Lister and colleagues9 suggested four possible sites of radial nerve compression: (1) the fibrous bands anterior to the radial head; (2) the ‘‘radial recurrent fan’’ of vessels described by Henry; (3) the tendinous margin of the extensor carpi radialis brevis (ECRB); and (4) the arcade of Frohse.8,9 Symptoms and signs depend on the site of compression, however; the most common symptoms were deep aching pain in the lateral forearm (from compression of the PIN), pain radiation to the neck and shoulder, and a ‘‘heavy’’ sensation of the affected arm.8 The most common physical findings were tenderness over the radial nerve at the supinator muscle level, pain on resisted supination, and the presence of Tinel’s sign over the radial forearm.8 Furthermore, the radial nerve may be compressed between the brachialis and the brachioradialis muscles (e.g., in a manual worker)10; may mimic epicondylitis lateralis humeri (‘‘tennis elbow’’); or present with lateral upper arm pain, local tenderness, and tingling sensations at the distal end of the upper arm when the radial nerve is percussed in the mid third of the upper arm (Tinel’s sign), without clinical muscular weakness.11 Surgical decompression in cases refractory to conservative therapy may yield good results.8
REFERRED HAND PAIN
V
Extensor digiti 1. Extensor minimi (EDM) digitorum communis (EDC) 2. Extensor indicis proprius (EIP)
VI
Extensor carpi ulnaris (ECU)
Scalenotomy or first rib resections may be done to relieve symptoms, although the prognosis is guarded.
Double Crush Carpal tunnel and cervical root compression may coexist, causing what is frequently called the double crush. CTS may cause pain above the hand but never numbness above the carpal tunnel. If the work-up reveals a double crush, injections of the carpal tunnel may help to determine the more primary lesion. Generally speaking, the carpal tunnel is released prior to a cervical procedure because the risk of disability is much less.
Cardiac Disease Do not forget that acute and chronic cardiac disease may present with hand and arm pain. The patient may describe tingling in the hand with activity. Do not be misled. Family history and risk factors should always be assessed.
TENDON DISORDERS OF THE HAND
Cervical Entrapment More proximal nerve compression may produce hand pain. Cervical disk disease or stenosis may produce pain radiating down the arm into the hand. Numbness and pain typically follow a radicular pattern based on the root that is compressed. Reflexes may be diminished along with proximal strength. Diagnosis is confirmed with magnetic resonance imaging (MRI). Conservative treatment with traction therapy, steroids, and pain management injections may help initially. Decompression with fusion may be indicated for intractable pain or progressive weakness. Symptoms may be relieved by placing the hand above the head.
Thoracic Outlet Syndrome Thoracic outlet syndrome may produce arm pain and numbness, especially on the ulnar side of the hand. Symptoms are exacerbated by overhead activity. Diagnosis may be difficult because nerve testing may be inconclusive. Pancoast’s tumors of the lung should be ruled out because they can mimic thoracic outlet syndrome.
Diagnosing and treating tendon related disorders of the hand require an understanding of the anatomy, course, and function of both the volar and the dorsal tendons of the hand. The dorsal aspect of the hand has six compartments as described in Table 21–1. A helpful memory aide is ‘‘2-2-1-2-1-1.’’ The volar, or flexor, aspect of the hand is not as neatly compartmentalized; however, zones of injury are often discussed to describe injuries and develop a treatment plan. Anatomic landmarks divide the zones from distal to proximal. Table 21–2 describes the flexor zones and their boundaries. Of highest regards is zone 2, which is often referred to as ‘‘No man’s land.’’ This name developed owing to the difficulties encountered by the pioneers of hand surgery. Surgical interventions within the fibro-osseus sheath of the palm resulted in large numbers of postsurgical complications, particularly adhesions. Through improved surgical techniques and postoperative hand therapy protocols, hand surgeons have realized better functional outcomes after zone 2 injuries. Zone 2 injuries present this management difficulty because both the flexor digitorum superficialis (FDS) and the flexor digitorum profundus (FDP) tendons enter the fibro-osseous tunnel at the midpalm level, making repair difficult. The primary
Table 21^2. Flexor Zones of the Hand and Their Respective Landmarks Zone
Landmarks
1
Flexor digitorum superficialis insertion to tip of finger
2
3
4
5
Distal palmar crease to insertion of flexor digitorum superficialis
Distal edge of transverse carpal ligament to distal palmar crease
Carpal tunnel (transverse carpal ligament)
Proximal to carpal tunnel
160 Chapter 21 HAND PAIN postoperative complication of repair is formation of adhesions to the flexor tendon sheaths. Physicians managing hand pain after an operative repair should emphasize aggressive occupational therapy with passive range of motion. A balance between therapies that protect the repaired tendons from the forces of active flexion yet allow for excursion of the tendon in the fibro-osseous sheath is necessary.
Extensor Compartment Hand PainçExtensor Tenosynovitis Compartment1 The most common etiology of pain within this compartment is due to DeQuervain’s tenosynovitis. This is caused by inflammation and stenosis of the synovial sheath surrounding the extensor pollicis longus (EPL) and abductor pollicis brevis (APB) tendons. Patients may experience an acute exacerbation, but symptoms are far more commonly chronic in nature and caused by repetitive motion. The Finklestein test is used for confirmation of diagnosis (Fig. 21–3). In this test, the patient flexes the thumb of the affected hand while making a fist around ther thumb. The patient then ulnarly deviates the hand. A positive test elicits increased pain over this compartment. Local injection of corticosteroids into this compartment may confirm the diagnosis. Rest and nonsteroidal anti-inflammatory drugs (NSAIDs) are a first line of treatment. Immobilization techniques include thumb spica casting or bracing for up to 1 month; however, shorter durations of immobilization are more common. Surgical decompression of the first dorsal compartment is reserved for recalcitrant pain but has an excellent prognosis. Persistent pain after surgery may be due to inadequate release, subluxation of the tendons, or radial nerve injury.
Compartment 2 Far less common than pain within the first dorsal compartment is pain within the second. If the patient is experiencing pain within this compartment, however, intersection or cross-over syndrome
must be considered. This is a syndrome by which the tendons of the first dorsal compartment cross over the tendons of the second, causing a site of irritation proximal to the extensor retinaculum. This occurs proximal to the wrist in the distal forearm. This condition commonly affects patients who do repeated wrist actions such as shoveling or raking. Conservative management is again first-line treatment. Hand surgeons will typically recommend activities that emphasize neutral wrist alignment. Corticosteroid injection within the second dorsal compartment at the intersection point may be offered. Surgery is rarely necessary to treat intersection syndrome. In extremely difficult cases, a hand surgeon may remove some of the thickened tenosynovium around the irritated tendons.
Compartments 3 to 6 The EPL tendon is alone in the third extensor compartment. It deviates sharply around Lister’s tubercle to provide extension of the thumb. Lister’s tubercle is a palpable bony landmark on the dorsal radius. It acts as a fulcrum to prevent radial subluxation of the EPL tendon. Tendinitis can occur in this compartment and is usually treated without surgery. Rupture of the EPL can also occur and is discussed further in the section ‘‘Degenerative Joint Disease of the Wrist and Hand,’’ later. The fourth compartment has the extensor digitorum communis (EDC) and extensor indicis proprius (EIP) tendons. It is a broad compartment that is often violated during dorsal approaches to the wrist. Distally, the EDC can be avulsed off of the distal phalynx, which is called ‘‘mallet finger.’’ This injury to the distal extensor tendon insertion is usually treated with immobilization of the distal interphalangeal (DIP) joint in extension for approximately 8 weeks. Compartment 5 has the extensor digiti minimi (EDM) tendon, which provides independent fifth finger extension. Compartment 6 contains the extensor carpi ulnaris (ECU) tendon, which is closely associated with the triangular fibrocartilage complex (TFCC) of the ulnar wrist. The ECU tendon can sublux with wrist motion, leading to tendinitis and ulnar wrist pain. Treatment is initially conservative with rest and anti-inflammatory medication.
Figure 21^3. Finklestein’s test.
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Tendon Lacerations
Table 21^3. Classification of Flexor Digitorum Profundus Avulsion Injuries
Lacerations to the extensor tendons that are less than 50% of the tendon substance generally do not have to be repaired, and early gentle motion can be started. Tendon lacerations that are greater than 50% are usually repaired. There are a variety of suture techniques for tendon repair. Of the utmost importance, however, is the number of strands of suture that cross the repair site, with increasing number of sutures providing a stronger repair. Tendon repair has been proved to be strongest when four to six sutures cross the repair site. Protected gentle active motion may be started with multisuture repairs, which lessen adhesions and increase mobility.
Proximal Location of Palm interphalangeal retracted joint tendon Timing of Within 7–10 4 wk repair days
FLEXOR ASPECT HAND PAIN
Type 1
Type 2
Type 3
Distal interphalangeal joint 4 wk
avulsion, classically known as ‘‘Jersey finger,’’ injuries are classified based on the location of tendon retraction, as illustrated in Table 21–3. This is most common in the ring finger and is diagnosed by lack of flexion at the DIP joint.
Anatomy The two extrinsic flexors of the fingers are the FDS and the FDP. As the FDS approaches the metacarpophalangeal (MCP) joint, it bifurcates, with the FDP passing through the bifurcation. Just proximal to the bifurcation lies the entrance of the digital flexor sheath. It is within the tendinous sheath that one can find the annular and cruciate pulleys. These pulleys provide both a mechanical advantage and flexibility to the tendons they support. Whereas annular pulley A1 is the strongest, A2 and A4 are the most important pulleys to provide the mechanical advantage of the tendons. Unlike the extensor compartment, there are many etiologies of flexor tendon hand pain, which include tenosynovitis and avulsion and complications from their subsequent treatment.
FlexorTenosynovitis (Trigger Finger, TriggerThumb) Flexor tendon tenosynovitis is a very common diagnosis characterized by pain in the area of the A1 pulley. Triggering digits are more common in women than in men. Triggering will be more common early in the day and becomes less bothersome with increased use of the fingers and hand. Patients often report a palpable nodule located in the same area, although this is not necessary for the diagnosis. The affected digit is typically ‘‘stuck’’ or locked in flexion after forceful flexion and may require use of the opposite hand to bring the digit back into extension. As the nodule passes under the pulley during extension, the finger will suddenly fully extend. For mildly symptomatic patients, NSAIDs and nighttime extension splinting may be done. Clinicians may also elect to place a corticosteroid injection into the tendon sheath. This may be repeated a few times if symptoms return. Refractory flexor tenosynovitis may require surgical release of the A1 pulley, with care taken not to disrupt the A2 pulley. This is a minor procedure with excellent results.
Wrist FlexorTenosynovitis Acute flexor carpi radialis tendinitis may be precipitated by acute use of the wrist. It presents with pain and tenderness ulnar to the scaphoid tuberosity. Longitudinal swelling may exist along this tendon. This may be confirmed with MRI and responds to bracing or steroid injection. Calcific tendinitis may also be seen at the wrist but is more common on the ulnar side.
Avulsion Injuries The most common etiology of an avulsion comes from a forced extension in an already actively flexed digit. In the case of an FDP
Complications of Treatment Adhesions are by far the most common complication of flexor tendon surgery, regardless of the appropriateness of therapy. In the case of active flexion restriction, tenolysis is the appropriate treatment of adhesions when active motion is poor and tendons are well healed. Tendon repair rupture is the second most common complication of surgical tendon repair. It may also occur after tenolysis. If the diagnosis is made acutely, the tendons may be repaired back together without resection of their ends. If the diagnosis is made at a later date, tendon resection and graft or staged repair is often the treatment of choice. Bowstringing is another complication of surgical therapy, particularly in flexor tenosynovitis. If the A2 and/or A4 pulleys are disrupted, the tendons will consequently lose their mechanical advantage, and therefore, active flexion strength will be diminished.
DEGENERATIVE JOINT DISEASE OF THE WRISTAND HAND The wrist functions as a connection between the distal radius and ulna and the metacarpal bones of the hand. It is a complex structure made of eight carpal bones, which precisely articulate with one another to increase the motion and strength of the hand in space (Fig. 21–4). Pain in the wrist is often difficult to localize because the sensory innervations are relatively nonspecific. X-rays are also challenging to critically evaluate because many of the bones overlap. When evaluating radiography, it is important to realize that the wrist is dynamic with multiple bones that change their individual positions depending on hand position. An initial approach to wrist pain should always begin with a thorough history and physical examination. The patient should be asked about a history of recent trauma, the duration and location on the pain, and any movement that makes the pain worse or better. Also important is whether the pain is worse during the day or night, if it is localized or if it radiates, and if sensory or motor symptoms are present. One method when obtaining a history is to organize the history by system (e.g., nervous, tendinous, bony). A physical examination should compare the painful side with the normal side when possible. Range of motion of the wrist should include flexion, extension, ulnar deviation, radial deviation, supination, and pronation. The hand should be examined for asymmetry such as swelling or eccymosis and whether any muscular atrophy is present, which would be suggestive of disuse or denervation. Tendon function can be systematically checked with resistance against active motion to elicit pain. All joints should also be palpated to localize the pain. It is often helpful to get comparison x-rays of the other side to detect subtle differences in the symptomatic limb.
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Arthritis of the wrist can be due to a number of causes including inflammatory disease and trauma. Rheumatoid arthritis is an inflammatory synovitis that classically affects the proximal interphalangeal (PIP) and MCP joints. With an advanced disease process, the fingers usually deviate ulnarly as the wrist goes radially (Fig. 21–5). The synovitis also affects the wrist, causing capsular laxity and volar and ulnar instability. This is most common with extensor tendinitis lasting greater than 6 months. It can also lead to tendon ruptures. Patients may present with an atraumatic inability to extend a finger. The EDM is the most common
tendon ruptured, followed by the EDC of the ring and small finger, finally followed by the EPL. New pharmacologic therapies for the inflammatory arthridites have reduced these debilitating conditions and are reviewed extensively in Section V, Chapter 33, Rheumatoid Arthritis. Post-traumatic arthritis of the wrist may also present as pain due to altered biomechanics of the hand and forearm. The distal radius normally absorbs approximately 80% of the load of the hand and wrist, with the ulna responsible for 20%. If the radius is shortened by 2.5 mm, the load approaches 50% for both bones. This abnormal loading of the ulnar side of the wrist may lead to what is known as ‘‘abutment, or impaction, syndrome.’’ This causes a breakdown of the TFCC. Damage here can cause pain with ulnar deviation of the wrist or with pronation and supination. This is common with distal radius malunions and may result in early arthritis of the wrist. Classic osteoarthritis of the hand and wrist affects the DIP and PIP joints. Signs of osteoarthritis on x-ray include joint space narrowing, sclerosis, osteophytes, and subchondral cysts. Fusion of the finger joints is the most common treatment for advanced disease. PIP joint replacement may be done in the middle, ring, and little fingers but has a limited life expectancy. Excellent hand function may be expected if the PIP and DIP joints are fused in positions of function. Many techniques have been described for IP fusion. Compression screws and tension band wiring techniques are most common (Fig. 21–6). The most common painful joint in the hand is the thumb carpometacarpal (CMC) joint. CMC arthritis (which is largely osteoarthritis) causes pain with thumb motion. As with other arthridites of the hand and wrist, conservative therapy with NSAIDs, steroid injections, ice, heat, rest, and splinting should be attempted. Surgery is the last alternative. Fusion of the CMC joint at the base of the thumb is a surgical option for pain relief that is typically reserved for heavy laborers. It severely limits dexterity. Good pain relief, preservation of length, and stability are usually achieved with a CMC fusion; however, motion is limited.
Figure 21^5. X-ray of a rheumatoid hand.
Figure 21^6. Tension band fusion technique.
Capitate
Trapezoid Trapezium
Hamate Scaphoid Pisiform Triquetrum
Lunate
Figure 21^4. Carpal bones.
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The articulation of the trapezium with the thumb metacarpal has classically been described as a ‘‘saddle joint’’ because of its shape. Several operations have been described to reduce pain and maintain motion. CMC arthritis is a relatively common problem attributed to the large amount of motion and force that cross this small surface area. The most common arthroplasty procedure for first CMC arthritis is ligament reconstruction and tendon interposition (LRTI). The trapezium is removed and the space is filled with a tendon graft. Numerous tendons have been used, but the flexor carpi radialis has the advantage of being already attached to the second metacarpal base and can be used to stabilize the first metacarpal base along with filling the void. LRTI has been shown to be as effective in eliminating the pain of CMC arthritis as synthetic implants and does not have the long-term failure rates. The LRTI has a greater than 95% satisfaction rate. Stability is not as good as with the fusion; however, motion is better preserved and the little shortening that can result does not compromise patient satisfaction.
*
FRACTURES OF THE WRISTAND HAND Fractures of the Carpal Bones The diagnosis of fractures of the carpal bones requires a careful physical examination including palpation of the individual carpal bones. Any area of tenderness should be imaged with anteroposterior (AP), lateral, and oblique images. Computed tomography (CT), MRI, and bone scan are often useful if the x-rays are difficult to interpret and injury is suspected. The most common fractured carpal bone is the scaphoid (70%–80%) followed by the triquetrum (7%–20%) and trapezium (5%). Scaphoid fractures pose one of the greatest challenges to orthopedic surgeons owing to both the difficulty in diagnosis and the tenuous blood supply to this bone. Much like the odontoid process of the second cervical vertebrae, the scaphoid possesses a watershed region in its vascular supply. The primary blood supply arises from a branch of the radial artery that enters the scaphoid at the dorsal aspect of its waist. A separate, more distal branch is also typically present and supplies the distal pole of the scaphoid; therefore, fractures at the waist of the scaphoid leave the proximal fragment prone to nonunion as well as avascular necrosis (AVN). Scaphoid fractures should be suspected in any patient with wrist pain. A classically described presentation is pain with palpation of the anatomic snuffbox, or radial fossa. The anatomic snuffbox is a triangular deepening on the radial dorsal aspect of the hand (Fig. 21–7). The snuffbox is bordered above by the tendon of the EPL and below by a pair of parallel and intimate tendons (the extensor pollicis brevis [EPB] and the abductor pollicis longus [APL]). Fractures of the scaphoid that are nondisplaced may be treated with cast immobilization. This is usually a long arm thumb spica cast to control rotation of the forearm and possible displacement of the fracture. Displaced fractures should be treated with surgery to prevent AVN and restore alignment. Surgery is also an option in nondisplaced fractures to reduce the period of cast immobilization for the athlete or laborer. Fractures with any degree of displacement are best treated surgically with open reduction and internal fixation (Fig. 21–8). In patients with an injury and positive examination findings but normal x-rays, immobilize the patient’s painful limb in a thumb spica splint or cast for 10 to 14 days. Repeat the x-rays if the patient is still symptomatic. If pain is still present but x-ray continues to be normal; consider MRI or a bone scan. The hamate is also susceptible to fracture at the volar process (‘‘hook of the hamate’’) due to a fall on an outstretched hand or classically participation in racquet sports (Fig. 21–9). Hamate hook fractures were also discussed in the section ‘‘Guyon’s Canal or Ulnar
Figure 21^7. Snuffbox tenderness.
Tunnel Syndrome,’’ earlier. Pain is often localized to the volar and ulnar palm, however, many times it will present with dorsal pain over the hamate. Ulnar nerve symptoms may be present. This fracture is best diagnosed by CT scan. If conservative measures such as immobilization or steroid injection fail, excision of the fragment will usually result in pain relief. Fractures of the remaining carpal bone fractures are rare. The fracture type, age of the patient, handedness, activity level, and employment are just a few of the considerations that must be taken into account when discussing treatment with the patient. Carpal fractures are usually cared for when possible by either an orthopedic surgeon or a hand surgery subspecialist owing to the complex anatomy and interrelationships of the carpus.
Fractures of the Metacarpal Bones Metacarpal fractures are relatively common fractures of the hand. They can be fractured at the base, shaft, neck, or head and may be the result of axial loading, a direct blow, or torsional loading. Fractures of the fifth metacarpal neck are among the most common fractures in the hand. The ‘‘boxer’s fracture’’ most often refers to a fracture at the neck of the fifth metacarpal bone just proximal to the MCP joint. It is usually the result of a person punching a hard object with poor skill. Metacarpal neck fractures rarely require surgery. As much as 408 to 508 of angulation deformity may be tolerated for a boxer’s fractures because the fifth metacarpal is a border digit and will usually result in no functional deficit. Patients are typically treated by some form of cast or splint immobilization, with the most common complaint being cosmetic because the knuckle of the hand with a clenched fist is often less prominent. Surgery is rarely indicated. The fourth metacarpal neck is also at risk as the result of the same mechanism as the fifth metacarpal. As the digits become more central, deformity is not as well tolerated. Only small amounts of deformity, typically less than 108, are acceptable for shaft fractures of the second and third metacarpals. Shaft fractures of the fourth and fifth metacarpals may accept angulations of
164 Chapter 21 HAND PAIN 208 618 and 308, respectively. The index finger through little finger metacarpal neck and shaft fractures are usually treated conservatively with splinting unless the fractures are irreducible or unstable. Rotational alignment is the most important factor in the assessment of fracture reduction. Malrotation will lead to finger overlap and an abnormal arch of finger motion if not addressed. Intraarticular fractures of the head of the metacarpals should be addressed similar to other joint fractures. If the articular surface is displaced, reduction and K-wire fixation should be attempted to restore joint congruity. Stiffness of the MCP joints should be avoided with initiation of range of motion exercises as soon as possible. Motion of the PIP joints should begin immediately to avoid permanent stiffness. Any laceration over the MCP joints
should be considered potentially open and treated as a human bite unless proved otherwise. The first metacarpal is unique because it is much more mobile to allow for the oppositional function of the thumb. Approximately 25% of all metacarpal fractures occur in the thumb metacarpal, with 80% of those occurring at the base. The ligamentous structures at the first CMC joint are very important to thumb stability. Bennett and Rolondo fractures are the two main variants of thumb metacarpal base fractures. Extra-articular or minimally displaced fractures of thumb metacarpal base can be treated with a thumb spica cast; however, displaced fractures into the CMC joint need to be surgically reduced and internally fixed using plates and screws or K-wire fixation.
A
B Figure 21^8. A, Scaphoid fracture. B,Open reduction and internal fixation of a scaphoid fracture.
V CHRONIC PAIN: NONCANCER PAIN 165
Figure 21^9. Computed tomography (CT) of a fracture of the hook of the hamate.
Fractures of the Phalanges Fractures of the middle and proximal phalanges are usually buddytaped to the adjacent digit, which acts a protective splint. This obviates the need for a bulky accessory splint that can interfere with hand function and necessary joint motion. Compression fractures, vertical shear fractures, and unstable or displaced/irreducible fractures should be treated surgically with closed reduction and pinning or open reduction and internal fixation. Displaced intraarticular fractures should also be surgically reduced and stabilized to restore articular congruity. Care must be taken during surgical exposure to prevent injury to the complex extensor and flexor mechanisms in addition to the digital artery and nerve, which travel on either side of the fingers. Of paramount importance is early motion to prevent joint stiffness. Distal phalynx fractures rarely require opened reduction. The nail should be carefully examined with distal finger trauma, and the patient should be educated on the possibility of abnormal nail growth or nail loss depending on the severity of the injury.
Fractures of the Distal Radius Fractures of the distal radius were first described in the literature by an Irish surgeon and anatomist, Abraham Colles in 1814. The Colles’ fracture typically occurs in patients over 60 years old due to osteoporosis. As a fracture of fragility, relatively minor trauma such as a fall from a standing position causes the fracture. As a sign of osteoporosis, either medical management or referral for an osteoporosis evaluation is warranted. The most common demographic is an older postmenopausal woman. Women who sustain this injury outnumber men by ratio of 4:1. The position (alignment) of the fracture and the extent of articular involvement dictate fracture management. For most distal radius fractures, a splint is usually used for the first few days to allow for swelling. For extra-articular fractures with little dorsal comminution, immobilization may be all that is needed to achieve a good result. The splint can be replaced by a cast a few days to a week later, after the swelling goes down. X-rays are taken at regular weekly intervals for 3 weeks and then at 6 weeks. The cast is typically removed at about 6 weeks. Protective bracing is then applied. Physical therapy is often started to help improve motion and function of the injured wrist if needed. If at 2 weeks the patient does not have full digital motion in the cast, therapy should begin in order to avoid permanent stiffness and the risk of complex regional pain syndrome type I [CRPS I] (formerly known as reflex sympathetic dystrophy).
Figure 21^10. Fracture with dorsal angulation and
comminution.
If the fracture is intra-articular or unable to be kept corrected in a cast, surgery is often indicated. This is especially the case with dorsal comminution because this pattern is classically unstable (Fig. 21–10). Measurements are often made on a reduction x-ray to determine whether length, volar tilt, and radial inclination are acceptable (Fig. 21–11). Near-anatomic alignment is preferred in the younger, more active patient to avoid future arthritis and pain. For articular fractures, the treatment goal is reconstruction of an anatomic joint surface.
Ligament Injuries After a fall, if pain persists and radiographs remain normal, one should suspect ligament injuries. The most common devastating ligament injury is a torn scapholunate ligament. Initial radiographs may be normal, but over time, these carpal bones begin to shift apart and the scaphoid rotates. This will lead to very early arthritis. It is similar to a tire being way out of alignment and causing excessive wear. Early diagnosis with MRI and acute surgical treatment give the best prognosis.
Carpal Avascular Necrosis The lunate has an unusual blood supply and may be prone to avascular necrosis if the ulna is shorter than the radius. It presents with dorsal pain in the central aspect of the wrist with swelling from synovitis. This may be associated with repetitive trauma to the wrist. Diagnosis in the earliest stage via MRI will have the best prognosis with the most treatment options. Casting, radial shortening, and bone graft revascularization are all viable options. Late diagnosis with fragmentation and associated arthritis has the worst prognosis, often requiring carpal wrist fusion.
PAINFUL HAND TUMORS Benign Hand Tumors Ganglions are the most common of all hand tumors. They are commonly found on the volar radial side of the wrist and cause
166 Chapter 21 HAND PAIN
25 deg.
A
10 deg
10 mm
C
B
Figure 21^11. Normal measurements for a distal radius.
A, Radial inclination (208 ^308).B, Radial length (8 ^18 mm).C, Radial tilt (08 ^288).
pain when they are under pressure or compress tendons or nerves. Dorsal ganglions, which are very visible, do not always produce pain unless they are entrapped during wrist extension. Smaller ganglions are not always seen clinically but are a common cause of dorsal pain, often picked up on an MRI. These can be removed arthroscopically or via an open procedure. Volar flexion sheath tumors of the digits, also called retinacular cysts, are commonly found near the A1 and A2 pulleys. They produce pain during grasping activities as they become compressed. Such activities include lifting weights and using the steering wheel of a vehicle. Vascular tumors can be extremely painful. Glomus tumors, which arise from the thermoregulatory system near the finger tips, are often difficult to diagnose. They are very well localized and may be seen under the nail bed. On the pulp side of the digit, they are often not seen but localized to a specific spot of tenderness. Bone scan or MRI may or may not identify them. Exploration and excision may be required to diagnose and alleviate the symptoms. Patients may see several physicians who may not be knowledgeable about glomus tumors before someone familiar with these tumors surgically explores the area. Glomus tumors should be suspected with extreme localized pain and temperature sensitivity. Terminal neuromas secondary to trauma may also cause severe local pain and hypersensitivity with distal loss of sensation. A localized Tinel test over the nerve is often seen. Excision and/or mobilization to a less exposed or traumatized area may be a solution. There are numerous other benign tumors that cause pain such as an inclusion cyst in the finger tip pulp, giant cell tumor, which may compress nerves, or schwannomas, which may cause neurogenic symptoms.
Malignant Hand Tumors Although they are very rare in the hand, malignant tumors can cause cortical erosions and subsequent fracture and pain. Because of the relatively minimal overlying soft tissue in the hand, these tumors can be picked up when they are small. The most common
malignant tumor of the hand is a squamous cell carcinoma, which rarely causes pain.
Ischemia of the Hand Small or large vessel occlusion may produce hand pain. Scleroderma, a connective tissue disorder, often causes painful nonhealing ulcerations. These patients frequently have Raynaud’s phenomenon with cold-induced vasospasm. Sympathetic blockade may be helpful as well as vasodilators. Digital artery sympathectomy may improve microarterial flow. Amputation may also be offered as a last resort to alleviate symptoms.
CONCLUSION The hand and wrist are complex structures that can cause pain, severely limiting a person’s quality of life. A careful history and physical examination should be combined with imaging studies to elucidate the patient’s pathology. Treatment usually begins with conservative measures; however, with problems such as scaphoid fractures and FDP avulsions, surgical treatment may be the first line of therapy. Comparison to the unaffected extremity when possible is a useful tool to help make an accurate diagnosis and guide treatment.
REFERENCES 1. Zanette G, Marani S, Tamburin S. Proximal pain in patients with carpal tunnel syndrome: a clinical-neurophysicological study. J Peripher Nerv Syst 2007;12:91–97. 2. Naeser MA. Photobiomodulation of pain in carpal tunnel syndrome: review of seven laser therapy studies. Photomed Laser Surg 2006;24:101–110. 3. Naeser MA, Hahn KA, Lieberman BE, et al. Carpal tunnel syndrome pain treated with low-level laser and microamperes transcutaneous electric nerve stimulation: A controlled study. Arch Phys Med Rehabil 2002;83:978–988.
V CHRONIC PAIN: NONCANCER PAIN 167 4. Elwakil TF, Elazzazi A, Shokeir H. Treatment of carpal tunnel syndrome by low-level laser versus carpal tunnel release. Lasers Med Sci 2007 (in press). 5. Irvine J, Chong SL, Amirjani N, et al. Double-blind randomized controlled trial of low-level laser therapy in carpal tunnel syndrome. Muscle Nerve 2004;30:182–187. 6. Nalamachu S, Crockett RS, Gammaitoni AR, et al. A comparison of the lidocaine patch 5% vs naproxen 500 mg twice daily for the relief of pain associated with carpal tunnel syndrome: a 6-week, randomized, parallel-group study. Med Gen Med 2006b;9:33. 7. Nalamachu S, Crockett RS, Mathur D. Lidocaine patch 5 for carpal tunnel syndrome: how it compares with injections: a pilot study. J Fam Pract 2006a;55:209–214.
Chapter 22
BACK PAIN William F. Lavelle, Allen L. Carl, Elizabeth Demers Lavelle, and Aimee Furdyna
INTRODUCTION The majority of patients will experience spine-related pain at some time in their lives. Low back pain, in particular, is most common in patients between the ages of 35 and 55 years. Fortunately, the majority of acute back pain is self-limited, with over 90% of patients recovering within 6 weeks. Back pain has a high recurrence rate, with symptoms returning within the year in two thirds of patients. The majority of sciatic pain is also self-limiting. Certain aspects of lifestyle, such as a lack of physical activity, obesity, and smoking, predispose patients to recurrent episodes of back pain and sciatica.
LUMBAR SPINE ANATOMY The spine is composed of three anatomic sections, the cervical, lumbar, and thoracic spine. The pain conditions discussed within this chapter involve primarily the lumbar spine. The five lumbar vertebrae are characterized by their relatively large size compared with the cervical and thoracic vertebrae. This increased size is necessary to support the patient’s body weight from successive vertebral levels. The outer portion of each vertebra is composed of dense cortical bone. The cortical bone is narrower in the center of the vertebra and flares at the superior and inferior ends in an hourglass pattern. On the dorsal side of the vertebral body are the laminae, two short, broad plates of bone that cover and protect the dural sac. These plates join medially at the spinous processes (Fig. 22–1). The pedicles are also found on the posterior side of the vertebral body and act to join the posterior bony structures to the anterior vertebral body (Fig. 22–2). From the confluence of the laminae and the pedicles protrudes the articular processes that form the facet joints. This particular confluence of bone is referred to as the pars interarticularis. The transverse processes, which extend laterally, also protrude from this junction. Together, the pedicles and processes form the vertebral arch. Muscles and ligaments connect to the
8. Rinker B, Effron CR, Beaslet RW. Proximal radial compression neuropathy. Ann Plast Surg 2004;52:174–180. 9. Lister GD, Belsole RB, Kleinert HE. The radial tunnel syndrome. J Hand Surg 1979;4:52–59. 10. Lee YK, Kim YI, Choy WS. Radial nerve compression between the brachialis and brachioradialis muscles in a manual worker: a case report. J Hand Surg 2006;31:744–746. 11. Adolfsson LE, Nettleblad H. Radial nerve entrapment in the upper arm as a cause of lateral arm pain: a report of four cases. Scand J Plast Reconstr Surg Hand Surg 2001;35:217–220.
vertebrae at the spinous and transverse processes, which arise from the dorsal aspect of the vertebra.
MOTION SEGMENTS The vertebrae link together through facet joints on the posterior side of the spinal column. The facet joints are formed between the superior articular processes of one vertebra and the inferior articular processes of the vertebra directly above. Between each of the lumbar vertebrae is a thick, spongy disk made up of various types of cartilage. The three major constituents of the disk are water, fibrillar collagens, and aggrecan (a large aggregating proteoglycan [PG]) with highly sulfated glycosaminoglycan (GAG) chains that attract and hold water. The annulus fibrosus is the outer ring that forms the border of the disk. It is composed of 15 to 25 distinct layers of concentric collagenous lamellae (made of bundles of collagen fibers running obliquely from one vertebrae to the next, thereby anchoring the disk to bone or cartilaginous endplate, highest in the outer annulus fibrosus and lowest in the inner annulus fibrosus). With aging and/or degeneration of the disk, the relative content of collagen increases owing to a loss of water and aggrecan. At a pressure of 0.25 megapascals (Mpa; 36 pounds/inch2 [psi]) a 37-year-old disk is hydrated with approximately 4 g water per gram of dry weight, whereas a 91-year-old disk is hydrated to about 1.8 g water per gram of dry weight with four- to fivefold less aggrecan. This may be due in part to actions of matrix metalloproteinases (MMP; collagenases from connective tissue cells [MMP-1] and from polymorphonuclear leukocyte [MMP-8], and stromelysin [MMP-3]). Stromelysin may degrade multiple connective tissue matrix components (including aggrecan and type IX collagen activating procollagenase; also referred to as aggrecanase). The nucleus pulposus forms the center of the disk and functions to resist compressive loads. The nucleus pulposus largely consists of PGs, water, collagen, and cells. PGs have gained the most attention with respect to nerve irritation secondary to herniated nucleus pulposus material; however, cells may produce MMPs, cytokines (interleukin [IL]-6), and prostaglandin E2. Each disk is approximately 1=4 to 3=4 inch thick. Furthermore, the cartilaginous endplate separates the nucleus from the adjacent vertebral bone. Together, these layers form a strong disk, capable of absorbing the shock produced from the movement of the spine. When weight is put on the spine, the disks compress; when the weight is lifted, the disks return to their original shape and size. The loads on an L3 disk in a 70-kg person are approximately: lying prone 0.10 Mpa (14 psi), lying lateral 0.12 Mpa (17 psi), free sitting 0.3 Mpa (43 psi), sitting unsupported 0.46 Mpa (67 psi), relaxed standing 0.5 Mpa (72 psi), lifting a 20-kg weight close to the body
Chapter 21
HAND PAIN Joseph M. Bellapianta, William F. Lavelle, Elizabeth Demers Lavelle, Ike Onyedika, Demetri Economedes, and Richard Whipple
INTRODUCTION The hand is a complex anatomic structure that has been in part credited with the development of modern people. Tendons, nerves, blood vessels, and small bones allow for the seemingly fluid function of the hand, yet all of these structures may fall victim to pathology and become sources of hand pain. The diagnosis of hand pain requires a working knowledge of functional hand anatomy and an understanding of the processes that may lead to pain. Hand pain may be primary or referred from other areas.
NERVE ETIOLOGIES OF HAND PAIN Carpal Tunnel Syndrome Carpal tunnel syndrome (CTS) is the most common compression neuropathy of the upper extremity. It is caused by compression of the median nerve at the wrist through the carpal tunnel. It may be acute or chronic in nature. Any space-occupying lesion in the carpal tunnel or a reduction of the space inside the tunnel from external compression will result in reduced space for the median nerve. Pressure on the nerve may result from swelling of the lining of the flexor tendons, joint dislocations, fractures, and inflammatory arthritis (Box 21–1). The root cause of the compression is often unknown. Occupational hazards such as keeping the wrist bent for long periods of time have also been speculated to cause CTS. Wrist and distal radius fractures can often produce acute CTS because of swelling or immobilization of the wrist in a flexed position. Repetitive flexion/extension of the wrist, repetitive motion of the fingers, the repetitive and forceful squeezing and releasing of a tool, and vibration exposure have all been implicated. Patients will often complain of symptoms when driving a car or reading a newspaper. Swelling and symptoms can also develop from pregnancy, thyroid disorder, and diabetes. CTS may present with paresthesia, hypothesia, anesthesia, or pain on the surfaces of the hand innervated by the median nerve, which includes the palmar and the dorsal distal phalangeal aspects of the lateral three and a half digits (Fig. 21–1). With prolonged median nerve compression, weakness and atrophy will be seen in the thenar muscles as a result of denervation. The pain, paresthesia, hypothesia, and anesthesia associated with CTS tend to be more severe at night and often interrupt sleep. This is due to elevated carpal tunnel pressures and lower systemic blood pressures causing acute ischemia. Patients will often awake with pain and dangle or shake out the hand to increase blood flow. Patients with CTS usually complain of pain and paresthesia in the hand or wrist, but pain
proximal to the wrist (radiating toward the shoulder) has been frequently reported as well.1 The presence of proximal pain may represent a clinical marker of mild median nerve damage and appears to be related to ‘‘extramedian spread of symptoms in the hand, from peripheral or central nervous system mechanisms.’’1 A careful history and physical examination should be performed with the addition of certain specific tests to reveal median nerve neuropathy (Box 21–2). Electromyography/nerve conduction velocity studies can be helpful in confounding cases in which other causes for symptoms need to be ruled out, such as compression at a higher level. In some cases of CTS, the only complaints are deep hand pain and aching, but no numbness. Treatment for CTS should always begin with conservative measures. Conservative therapy includes splinting the wrist in a neutral position, oral anti-inflammatory drugs to reduce synovitis, diuretics to reduce edema, and treatment of any underlying medical condition. Corticosteroid injections can also be tried; however, only a small percentage of patients will be symptom-free 12 months later. Noninvasive treatment approaches for mild to moderate CTS with median motor nerve distal latencies of more than 4.2 msec but less than 7.0 msec have been advocated with mixed results. The use of laser therapy for mild to moderate CTS may be beneficial2–4 or without dramatic success.5 Differences in treatment technique may be at least partly responsible for varied results. Another noninvasive treatment strategy for CTS that may be beneficial is the use of the lidocaine 5% patch.6,7 Injections can also be used for diagnostic purposes to predict surgeon outcome. Patients with typical symptoms but normal nerve tests, who improve with injections, may be candidates for surgical release. Injections may also be used for atypical patients with only hand pain but no numbness. Injections can help to distinguish fixed neuropathy versus compressive neuropathy. The steroid, if placed in the carpal tunnel, will shrink the synovium and lower the carpal tunnel pressure. If noninvasive measures fail, surgical release of the transverse carpal ligament is generally recommended. Sectioning of the transverse carpal ligament decompresses the median nerve, thus relieving the symptoms. The point of compression on the median nerve can often be seen with a hyperemic epineurium and changing nerve diameter in the carpal tunnel. This procedure can be done open or endoscopically with similar long-term results.
Guyon’s Canal or UlnarTunnel Syndrome In the palm, the ulnar nerve passes under the pisohamate ligament, which is a fascial band between the pisiform and the hamate. This tunnel is called Guyon’s canal. Guyon’s canal contains the ulnar artery and vein and the ulnar nerve. Patients with ulnar tunnel syndrome complain of paresthesias and decreased sensation in the little finger and half of the ring finger. Unlike CTS, it is not caused directly by tendinitis because no tendons run through the tunnel. Compression may be induced by activities such as using the palm of the hand as a hammer or with repetitive use of tools such as a screwdriver or pliers. Ulnar tunnel syndrome is also more common in long-distance cyclers. The compression may be the result of a cyst in the canal, swelling of the ulnar artery, or a fracture of the hook of the hamate. Hamate fractures are seen in golfers as the result of hitting the firm ground instead of the golf ball while swinging. These are also seen in racquet sports. Treatment options for ulnar neuropathy at the wrist include avoiding provocative activities, splinting, anti-inflammatory medication, steroid injections, and occupational therapy. If these are
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Box 21^1 CAUSES OF CARPAL TUNNEL SYNDROME Anatomic Causes Due to Decreased Size Carpal bone abnormalities Thickened transverse carpal ligaments Anatomic Causes Due to Increased Contents of Canal Neuroma, lipoma, myeloma, persistent median artery, anomalous muscles in the tunnel Hypertrophic synovium, distal radial fractures, post-traumatic osteophyte, hematoma Neuropathic Causes Diabetes, alcoholism, proximal lesion of median nerve
Median nerve
Inflammatory Causes Tenosynovitis, rheumatoid arthritis, infection, gout
Ulnar nerve
Alteration of Fluid Balance Pregnancy, eclampsia, myxedma, long-term hemodialysis, horizontal position and muscle relaxation, Raynaud’s disease, obesity Congenital Mucopolysaccharidosis, mucolipidosis, Down’s syndrome, achondroplasia
unsuccessful, surgery to decompress the nerve may be needed. The tunnel may be directly decompressed for isolated ulnar nerve symptoms or in combination with a release of the carpal tunnel.
Cubital Tunnel Syndrome Cubital tunnel syndrome is the most common site of ulnar nerve entrapment and the second most common peripheral compression neuropathy. Cubital tunnel syndrome affects men more often than women. The ulnar nerve enters the cubital tunnel by passing deep to the arcuate ligament (Osborne’s ligament), which connects the ulnar and the humeral heads of the flexor carpi ulnaris (FCU) muscle. The nerve then passes between the two heads of the FCU before heading deep to the flexor pronator aponeurosis. Compression or injury may develop because of repetitive elbow motion, prolonged elbow flexion, direct compression, or childhood elbow fractures with subsequent abnormal growth and alignment (tardy ulnar nerve palsy) (Box 21–3). Patients with this condition commonly exhibit symptoms of intermittent pain on the medial side of the elbow and paresthesias of the fourth and fifth digits. An associated aching discomfort along the inner forearm or elbow may be present. If nerve damage persists, there is loss of sensation in the fourth and fifth digits. Eventually, there is loss of pinch and grip strength owing to atrophy of the muscle of the hand because the ulnar nerve is responsible for innervation of most of the intrinsic hand muscles. The major diagnostic tests for cubital tunnel syndrome include an elbow flexion test, Tinel’s test, and the pressure provocative test. In the elbow flexion test, patients are positioned with their arms at their side, and elbows flexed approximately 1208. The patient maintains that position for 3 minutes in an attempt to reproduce the symptoms. In Tinel’s test, the groove between the olecranon process and the medial epicondyle through which the ulnar nerve passes is palpated and tapped. Similarly to a Tinel test at the carpal tunnel, a positive test is characterized by a tingling sensation in the ulnar distribution of the forearm and hand distal to the tapping point (see Fig. 21–2). The pressure provocative test for cubital tunnel syndrome involves applying pressure proximal to the cubital tunnel, with the elbow flexed 208 and the forearm in a supine position. Anterior subluxation of the ulnar nerve should also be identified by direct palpation with flexion of the elbow. Nonoperative treatment of cubital tunnel syndrome includes immobilization with long arm splints to prevent elbow flexion at night, a padded elbow brace during the day, and avoidance of
Transverse carpal ligament
A Median nerve
Radial nerve
Ulnar nerve
B Figure 21^1. A, Nerves of the palm of the hand. B, Nerves of
the dorsal hand.
activities with repetitive elbow movements. The use of nonsteroidal anti-inflammatory drugs may be beneficial. Steroid injections are rarely used. If nonoperative treatments are ineffective, surgical procedures may be entertained. The goal of surgery is to relieve compression of the ulnar nerve. The methods used to decompress the ulnar nerve
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Box 21^2 TESTS USED TO CONFIRM THE DIAGNOSIS OF CARPAL TUNNEL SYNDROME *Phalen’s test: Patient places elbow on table, forearm vertical, wrists flexed. The test is positive when paresthesias develop on the radial side digits within 60 sec (Fig. 21^2). Reverse Phalen’s with wrist extended can also be done. *Tinel’s test: Examiner lightly taps along median nerve at the wrist, proximal to distal. Positive if tingling develops in fingers at site of compression. *Carpal tunnel compression test: Examiner compresses median nerve. If paresthesias develop within 30 sec, test is positive. Hand diagram: Patient marks signs of pain or paresthesias on diagram of hand. Hand-volume stress test: Measure hand volume by water displacement, repeat after stress test and10 min rest. Measurement of carpal tunnel pressure: Measure carpal tunnel pressure via infusion catheter. Positive if pressure reaches 25 mm Hg or more. Static two-point discrimination: Determine minimum separation of two points on the palmer aspect of the hand. Test is positive if one fails to discriminate points more than 6 mm apart. Moving two-point discrimination: Similar to static two-point discrimination. Positive if patient fails to discriminate points more than 5 mm apart. Vibrometry: Head of vibrometer is placed on palmar side of the digit. An amplitude of 120 Hz is increased to threshold of perception. It is then compared with the median and ulnar nerves in both hands. Test is positive if there is asymmetry with contralateral hand or between radial and ulnar digits. Semmes-Weinstein monofilament test: Monofilaments of increasing lengths are touched to the palmar side of digit until patient can tell which digit is touched. Positive if value is greater than 2.83 in radial digit. *Electromyogaphy: Needle electrodes placed in muscle.Fibrillation potentials, sharp waves, increased insertional activity. Nerve conduction velocities can also be useful. *Commonly used tests.
Box 21^3 CAUSES OF CUBITAL TUNNEL SYNDROME Compression of the ulnar nerve Entrapment in distal humeral fracture or elbow dislocation Cubitus valgus, cubitus varus, malunion, nonunion Aberrant or abnormal musculature of forearm musculature Osteoarthritis Inflammatory arthritis Synovial chondromatosis Bands, vascular and fascial, musculotendinous variations around the medial epicondyle, aberrant muscle anomalies. The ulnar nerve may be compressed at different levels including the medial intermuscular septum or posterior compartment of the arm (e.g., arcade [or ligament] of Struthers) and soft tissue of bony abnormalities of the cubital tunnel (e.g., epitrochleoanconeus muscle [anconeus epitrochlearis muscle], thick arcuate ligament of Osbourne [‘‘Osborne’s band’’]). Space-occupying lesions, e.g., tumors
include in situ decompression, in situ decompression with medial epicondylectomy, and anterior transposition. Transpositions may be completed in a subcutaneous or submuscular fashion. Decompression of the nerve usually leads to symptom resolution.
Radial Tunnel Syndrome Proximal radial compression neuropathy occurs infrequently and is diagnosed correctly even less frequently (Rinker, 2004). The radial nerve emerges from the intermuscular septum on the lateral arm and descends distally along the border of the brachialis muscle (Rinker, 2004). Roughly 2 cm distal to the elbow, the radial nerve divides into the posterior interosseous nerve (PIN) and the superficial sensory divisions.8 The PIN courses under the fibrous proximal margin of the supinator muscle, known as the arcade of Frohse, and bifurcates to innervate the extensor carpi ulnaris muscle and the digital extensor muscles.8
Figure 21^2. Tinel’s test.
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Table 21^1. Dorsal Compartment Tendons Compartment
Tendons
I
II
III
1. Extensor pollicis 1. Extensor carpi radialis brevis longus (EPL) (ECRB) 2. Abductor pollicis brevis 2. Extensor carpi radialis longus (APB) (ECRL)
IV
Extensor pollicis longus (EPL)
In 1979, Lister and colleagues9 suggested four possible sites of radial nerve compression: (1) the fibrous bands anterior to the radial head; (2) the ‘‘radial recurrent fan’’ of vessels described by Henry; (3) the tendinous margin of the extensor carpi radialis brevis (ECRB); and (4) the arcade of Frohse.8,9 Symptoms and signs depend on the site of compression, however; the most common symptoms were deep aching pain in the lateral forearm (from compression of the PIN), pain radiation to the neck and shoulder, and a ‘‘heavy’’ sensation of the affected arm.8 The most common physical findings were tenderness over the radial nerve at the supinator muscle level, pain on resisted supination, and the presence of Tinel’s sign over the radial forearm.8 Furthermore, the radial nerve may be compressed between the brachialis and the brachioradialis muscles (e.g., in a manual worker)10; may mimic epicondylitis lateralis humeri (‘‘tennis elbow’’); or present with lateral upper arm pain, local tenderness, and tingling sensations at the distal end of the upper arm when the radial nerve is percussed in the mid third of the upper arm (Tinel’s sign), without clinical muscular weakness.11 Surgical decompression in cases refractory to conservative therapy may yield good results.8
REFERRED HAND PAIN
V
Extensor digiti 1. Extensor minimi (EDM) digitorum communis (EDC) 2. Extensor indicis proprius (EIP)
VI
Extensor carpi ulnaris (ECU)
Scalenotomy or first rib resections may be done to relieve symptoms, although the prognosis is guarded.
Double Crush Carpal tunnel and cervical root compression may coexist, causing what is frequently called the double crush. CTS may cause pain above the hand but never numbness above the carpal tunnel. If the work-up reveals a double crush, injections of the carpal tunnel may help to determine the more primary lesion. Generally speaking, the carpal tunnel is released prior to a cervical procedure because the risk of disability is much less.
Cardiac Disease Do not forget that acute and chronic cardiac disease may present with hand and arm pain. The patient may describe tingling in the hand with activity. Do not be misled. Family history and risk factors should always be assessed.
TENDON DISORDERS OF THE HAND
Cervical Entrapment More proximal nerve compression may produce hand pain. Cervical disk disease or stenosis may produce pain radiating down the arm into the hand. Numbness and pain typically follow a radicular pattern based on the root that is compressed. Reflexes may be diminished along with proximal strength. Diagnosis is confirmed with magnetic resonance imaging (MRI). Conservative treatment with traction therapy, steroids, and pain management injections may help initially. Decompression with fusion may be indicated for intractable pain or progressive weakness. Symptoms may be relieved by placing the hand above the head.
Thoracic Outlet Syndrome Thoracic outlet syndrome may produce arm pain and numbness, especially on the ulnar side of the hand. Symptoms are exacerbated by overhead activity. Diagnosis may be difficult because nerve testing may be inconclusive. Pancoast’s tumors of the lung should be ruled out because they can mimic thoracic outlet syndrome.
Diagnosing and treating tendon related disorders of the hand require an understanding of the anatomy, course, and function of both the volar and the dorsal tendons of the hand. The dorsal aspect of the hand has six compartments as described in Table 21–1. A helpful memory aide is ‘‘2-2-1-2-1-1.’’ The volar, or flexor, aspect of the hand is not as neatly compartmentalized; however, zones of injury are often discussed to describe injuries and develop a treatment plan. Anatomic landmarks divide the zones from distal to proximal. Table 21–2 describes the flexor zones and their boundaries. Of highest regards is zone 2, which is often referred to as ‘‘No man’s land.’’ This name developed owing to the difficulties encountered by the pioneers of hand surgery. Surgical interventions within the fibro-osseus sheath of the palm resulted in large numbers of postsurgical complications, particularly adhesions. Through improved surgical techniques and postoperative hand therapy protocols, hand surgeons have realized better functional outcomes after zone 2 injuries. Zone 2 injuries present this management difficulty because both the flexor digitorum superficialis (FDS) and the flexor digitorum profundus (FDP) tendons enter the fibro-osseous tunnel at the midpalm level, making repair difficult. The primary
Table 21^2. Flexor Zones of the Hand and Their Respective Landmarks Zone
Landmarks
1
Flexor digitorum superficialis insertion to tip of finger
2
3
4
5
Distal palmar crease to insertion of flexor digitorum superficialis
Distal edge of transverse carpal ligament to distal palmar crease
Carpal tunnel (transverse carpal ligament)
Proximal to carpal tunnel
160 Chapter 21 HAND PAIN postoperative complication of repair is formation of adhesions to the flexor tendon sheaths. Physicians managing hand pain after an operative repair should emphasize aggressive occupational therapy with passive range of motion. A balance between therapies that protect the repaired tendons from the forces of active flexion yet allow for excursion of the tendon in the fibro-osseous sheath is necessary.
Extensor Compartment Hand PainçExtensor Tenosynovitis Compartment1 The most common etiology of pain within this compartment is due to DeQuervain’s tenosynovitis. This is caused by inflammation and stenosis of the synovial sheath surrounding the extensor pollicis longus (EPL) and abductor pollicis brevis (APB) tendons. Patients may experience an acute exacerbation, but symptoms are far more commonly chronic in nature and caused by repetitive motion. The Finklestein test is used for confirmation of diagnosis (Fig. 21–3). In this test, the patient flexes the thumb of the affected hand while making a fist around ther thumb. The patient then ulnarly deviates the hand. A positive test elicits increased pain over this compartment. Local injection of corticosteroids into this compartment may confirm the diagnosis. Rest and nonsteroidal anti-inflammatory drugs (NSAIDs) are a first line of treatment. Immobilization techniques include thumb spica casting or bracing for up to 1 month; however, shorter durations of immobilization are more common. Surgical decompression of the first dorsal compartment is reserved for recalcitrant pain but has an excellent prognosis. Persistent pain after surgery may be due to inadequate release, subluxation of the tendons, or radial nerve injury.
Compartment 2 Far less common than pain within the first dorsal compartment is pain within the second. If the patient is experiencing pain within this compartment, however, intersection or cross-over syndrome
must be considered. This is a syndrome by which the tendons of the first dorsal compartment cross over the tendons of the second, causing a site of irritation proximal to the extensor retinaculum. This occurs proximal to the wrist in the distal forearm. This condition commonly affects patients who do repeated wrist actions such as shoveling or raking. Conservative management is again first-line treatment. Hand surgeons will typically recommend activities that emphasize neutral wrist alignment. Corticosteroid injection within the second dorsal compartment at the intersection point may be offered. Surgery is rarely necessary to treat intersection syndrome. In extremely difficult cases, a hand surgeon may remove some of the thickened tenosynovium around the irritated tendons.
Compartments 3 to 6 The EPL tendon is alone in the third extensor compartment. It deviates sharply around Lister’s tubercle to provide extension of the thumb. Lister’s tubercle is a palpable bony landmark on the dorsal radius. It acts as a fulcrum to prevent radial subluxation of the EPL tendon. Tendinitis can occur in this compartment and is usually treated without surgery. Rupture of the EPL can also occur and is discussed further in the section ‘‘Degenerative Joint Disease of the Wrist and Hand,’’ later. The fourth compartment has the extensor digitorum communis (EDC) and extensor indicis proprius (EIP) tendons. It is a broad compartment that is often violated during dorsal approaches to the wrist. Distally, the EDC can be avulsed off of the distal phalynx, which is called ‘‘mallet finger.’’ This injury to the distal extensor tendon insertion is usually treated with immobilization of the distal interphalangeal (DIP) joint in extension for approximately 8 weeks. Compartment 5 has the extensor digiti minimi (EDM) tendon, which provides independent fifth finger extension. Compartment 6 contains the extensor carpi ulnaris (ECU) tendon, which is closely associated with the triangular fibrocartilage complex (TFCC) of the ulnar wrist. The ECU tendon can sublux with wrist motion, leading to tendinitis and ulnar wrist pain. Treatment is initially conservative with rest and anti-inflammatory medication.
Figure 21^3. Finklestein’s test.
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Tendon Lacerations
Table 21^3. Classification of Flexor Digitorum Profundus Avulsion Injuries
Lacerations to the extensor tendons that are less than 50% of the tendon substance generally do not have to be repaired, and early gentle motion can be started. Tendon lacerations that are greater than 50% are usually repaired. There are a variety of suture techniques for tendon repair. Of the utmost importance, however, is the number of strands of suture that cross the repair site, with increasing number of sutures providing a stronger repair. Tendon repair has been proved to be strongest when four to six sutures cross the repair site. Protected gentle active motion may be started with multisuture repairs, which lessen adhesions and increase mobility.
Proximal Location of Palm interphalangeal retracted joint tendon Timing of Within 7–10 4 wk repair days
FLEXOR ASPECT HAND PAIN
Type 1
Type 2
Type 3
Distal interphalangeal joint 4 wk
avulsion, classically known as ‘‘Jersey finger,’’ injuries are classified based on the location of tendon retraction, as illustrated in Table 21–3. This is most common in the ring finger and is diagnosed by lack of flexion at the DIP joint.
Anatomy The two extrinsic flexors of the fingers are the FDS and the FDP. As the FDS approaches the metacarpophalangeal (MCP) joint, it bifurcates, with the FDP passing through the bifurcation. Just proximal to the bifurcation lies the entrance of the digital flexor sheath. It is within the tendinous sheath that one can find the annular and cruciate pulleys. These pulleys provide both a mechanical advantage and flexibility to the tendons they support. Whereas annular pulley A1 is the strongest, A2 and A4 are the most important pulleys to provide the mechanical advantage of the tendons. Unlike the extensor compartment, there are many etiologies of flexor tendon hand pain, which include tenosynovitis and avulsion and complications from their subsequent treatment.
FlexorTenosynovitis (Trigger Finger, TriggerThumb) Flexor tendon tenosynovitis is a very common diagnosis characterized by pain in the area of the A1 pulley. Triggering digits are more common in women than in men. Triggering will be more common early in the day and becomes less bothersome with increased use of the fingers and hand. Patients often report a palpable nodule located in the same area, although this is not necessary for the diagnosis. The affected digit is typically ‘‘stuck’’ or locked in flexion after forceful flexion and may require use of the opposite hand to bring the digit back into extension. As the nodule passes under the pulley during extension, the finger will suddenly fully extend. For mildly symptomatic patients, NSAIDs and nighttime extension splinting may be done. Clinicians may also elect to place a corticosteroid injection into the tendon sheath. This may be repeated a few times if symptoms return. Refractory flexor tenosynovitis may require surgical release of the A1 pulley, with care taken not to disrupt the A2 pulley. This is a minor procedure with excellent results.
Wrist FlexorTenosynovitis Acute flexor carpi radialis tendinitis may be precipitated by acute use of the wrist. It presents with pain and tenderness ulnar to the scaphoid tuberosity. Longitudinal swelling may exist along this tendon. This may be confirmed with MRI and responds to bracing or steroid injection. Calcific tendinitis may also be seen at the wrist but is more common on the ulnar side.
Avulsion Injuries The most common etiology of an avulsion comes from a forced extension in an already actively flexed digit. In the case of an FDP
Complications of Treatment Adhesions are by far the most common complication of flexor tendon surgery, regardless of the appropriateness of therapy. In the case of active flexion restriction, tenolysis is the appropriate treatment of adhesions when active motion is poor and tendons are well healed. Tendon repair rupture is the second most common complication of surgical tendon repair. It may also occur after tenolysis. If the diagnosis is made acutely, the tendons may be repaired back together without resection of their ends. If the diagnosis is made at a later date, tendon resection and graft or staged repair is often the treatment of choice. Bowstringing is another complication of surgical therapy, particularly in flexor tenosynovitis. If the A2 and/or A4 pulleys are disrupted, the tendons will consequently lose their mechanical advantage, and therefore, active flexion strength will be diminished.
DEGENERATIVE JOINT DISEASE OF THE WRISTAND HAND The wrist functions as a connection between the distal radius and ulna and the metacarpal bones of the hand. It is a complex structure made of eight carpal bones, which precisely articulate with one another to increase the motion and strength of the hand in space (Fig. 21–4). Pain in the wrist is often difficult to localize because the sensory innervations are relatively nonspecific. X-rays are also challenging to critically evaluate because many of the bones overlap. When evaluating radiography, it is important to realize that the wrist is dynamic with multiple bones that change their individual positions depending on hand position. An initial approach to wrist pain should always begin with a thorough history and physical examination. The patient should be asked about a history of recent trauma, the duration and location on the pain, and any movement that makes the pain worse or better. Also important is whether the pain is worse during the day or night, if it is localized or if it radiates, and if sensory or motor symptoms are present. One method when obtaining a history is to organize the history by system (e.g., nervous, tendinous, bony). A physical examination should compare the painful side with the normal side when possible. Range of motion of the wrist should include flexion, extension, ulnar deviation, radial deviation, supination, and pronation. The hand should be examined for asymmetry such as swelling or eccymosis and whether any muscular atrophy is present, which would be suggestive of disuse or denervation. Tendon function can be systematically checked with resistance against active motion to elicit pain. All joints should also be palpated to localize the pain. It is often helpful to get comparison x-rays of the other side to detect subtle differences in the symptomatic limb.
162 Chapter 21 HAND PAIN
Arthritis of the wrist can be due to a number of causes including inflammatory disease and trauma. Rheumatoid arthritis is an inflammatory synovitis that classically affects the proximal interphalangeal (PIP) and MCP joints. With an advanced disease process, the fingers usually deviate ulnarly as the wrist goes radially (Fig. 21–5). The synovitis also affects the wrist, causing capsular laxity and volar and ulnar instability. This is most common with extensor tendinitis lasting greater than 6 months. It can also lead to tendon ruptures. Patients may present with an atraumatic inability to extend a finger. The EDM is the most common
tendon ruptured, followed by the EDC of the ring and small finger, finally followed by the EPL. New pharmacologic therapies for the inflammatory arthridites have reduced these debilitating conditions and are reviewed extensively in Section V, Chapter 33, Rheumatoid Arthritis. Post-traumatic arthritis of the wrist may also present as pain due to altered biomechanics of the hand and forearm. The distal radius normally absorbs approximately 80% of the load of the hand and wrist, with the ulna responsible for 20%. If the radius is shortened by 2.5 mm, the load approaches 50% for both bones. This abnormal loading of the ulnar side of the wrist may lead to what is known as ‘‘abutment, or impaction, syndrome.’’ This causes a breakdown of the TFCC. Damage here can cause pain with ulnar deviation of the wrist or with pronation and supination. This is common with distal radius malunions and may result in early arthritis of the wrist. Classic osteoarthritis of the hand and wrist affects the DIP and PIP joints. Signs of osteoarthritis on x-ray include joint space narrowing, sclerosis, osteophytes, and subchondral cysts. Fusion of the finger joints is the most common treatment for advanced disease. PIP joint replacement may be done in the middle, ring, and little fingers but has a limited life expectancy. Excellent hand function may be expected if the PIP and DIP joints are fused in positions of function. Many techniques have been described for IP fusion. Compression screws and tension band wiring techniques are most common (Fig. 21–6). The most common painful joint in the hand is the thumb carpometacarpal (CMC) joint. CMC arthritis (which is largely osteoarthritis) causes pain with thumb motion. As with other arthridites of the hand and wrist, conservative therapy with NSAIDs, steroid injections, ice, heat, rest, and splinting should be attempted. Surgery is the last alternative. Fusion of the CMC joint at the base of the thumb is a surgical option for pain relief that is typically reserved for heavy laborers. It severely limits dexterity. Good pain relief, preservation of length, and stability are usually achieved with a CMC fusion; however, motion is limited.
Figure 21^5. X-ray of a rheumatoid hand.
Figure 21^6. Tension band fusion technique.
Capitate
Trapezoid Trapezium
Hamate Scaphoid Pisiform Triquetrum
Lunate
Figure 21^4. Carpal bones.
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The articulation of the trapezium with the thumb metacarpal has classically been described as a ‘‘saddle joint’’ because of its shape. Several operations have been described to reduce pain and maintain motion. CMC arthritis is a relatively common problem attributed to the large amount of motion and force that cross this small surface area. The most common arthroplasty procedure for first CMC arthritis is ligament reconstruction and tendon interposition (LRTI). The trapezium is removed and the space is filled with a tendon graft. Numerous tendons have been used, but the flexor carpi radialis has the advantage of being already attached to the second metacarpal base and can be used to stabilize the first metacarpal base along with filling the void. LRTI has been shown to be as effective in eliminating the pain of CMC arthritis as synthetic implants and does not have the long-term failure rates. The LRTI has a greater than 95% satisfaction rate. Stability is not as good as with the fusion; however, motion is better preserved and the little shortening that can result does not compromise patient satisfaction.
*
FRACTURES OF THE WRISTAND HAND Fractures of the Carpal Bones The diagnosis of fractures of the carpal bones requires a careful physical examination including palpation of the individual carpal bones. Any area of tenderness should be imaged with anteroposterior (AP), lateral, and oblique images. Computed tomography (CT), MRI, and bone scan are often useful if the x-rays are difficult to interpret and injury is suspected. The most common fractured carpal bone is the scaphoid (70%–80%) followed by the triquetrum (7%–20%) and trapezium (5%). Scaphoid fractures pose one of the greatest challenges to orthopedic surgeons owing to both the difficulty in diagnosis and the tenuous blood supply to this bone. Much like the odontoid process of the second cervical vertebrae, the scaphoid possesses a watershed region in its vascular supply. The primary blood supply arises from a branch of the radial artery that enters the scaphoid at the dorsal aspect of its waist. A separate, more distal branch is also typically present and supplies the distal pole of the scaphoid; therefore, fractures at the waist of the scaphoid leave the proximal fragment prone to nonunion as well as avascular necrosis (AVN). Scaphoid fractures should be suspected in any patient with wrist pain. A classically described presentation is pain with palpation of the anatomic snuffbox, or radial fossa. The anatomic snuffbox is a triangular deepening on the radial dorsal aspect of the hand (Fig. 21–7). The snuffbox is bordered above by the tendon of the EPL and below by a pair of parallel and intimate tendons (the extensor pollicis brevis [EPB] and the abductor pollicis longus [APL]). Fractures of the scaphoid that are nondisplaced may be treated with cast immobilization. This is usually a long arm thumb spica cast to control rotation of the forearm and possible displacement of the fracture. Displaced fractures should be treated with surgery to prevent AVN and restore alignment. Surgery is also an option in nondisplaced fractures to reduce the period of cast immobilization for the athlete or laborer. Fractures with any degree of displacement are best treated surgically with open reduction and internal fixation (Fig. 21–8). In patients with an injury and positive examination findings but normal x-rays, immobilize the patient’s painful limb in a thumb spica splint or cast for 10 to 14 days. Repeat the x-rays if the patient is still symptomatic. If pain is still present but x-ray continues to be normal; consider MRI or a bone scan. The hamate is also susceptible to fracture at the volar process (‘‘hook of the hamate’’) due to a fall on an outstretched hand or classically participation in racquet sports (Fig. 21–9). Hamate hook fractures were also discussed in the section ‘‘Guyon’s Canal or Ulnar
Figure 21^7. Snuffbox tenderness.
Tunnel Syndrome,’’ earlier. Pain is often localized to the volar and ulnar palm, however, many times it will present with dorsal pain over the hamate. Ulnar nerve symptoms may be present. This fracture is best diagnosed by CT scan. If conservative measures such as immobilization or steroid injection fail, excision of the fragment will usually result in pain relief. Fractures of the remaining carpal bone fractures are rare. The fracture type, age of the patient, handedness, activity level, and employment are just a few of the considerations that must be taken into account when discussing treatment with the patient. Carpal fractures are usually cared for when possible by either an orthopedic surgeon or a hand surgery subspecialist owing to the complex anatomy and interrelationships of the carpus.
Fractures of the Metacarpal Bones Metacarpal fractures are relatively common fractures of the hand. They can be fractured at the base, shaft, neck, or head and may be the result of axial loading, a direct blow, or torsional loading. Fractures of the fifth metacarpal neck are among the most common fractures in the hand. The ‘‘boxer’s fracture’’ most often refers to a fracture at the neck of the fifth metacarpal bone just proximal to the MCP joint. It is usually the result of a person punching a hard object with poor skill. Metacarpal neck fractures rarely require surgery. As much as 408 to 508 of angulation deformity may be tolerated for a boxer’s fractures because the fifth metacarpal is a border digit and will usually result in no functional deficit. Patients are typically treated by some form of cast or splint immobilization, with the most common complaint being cosmetic because the knuckle of the hand with a clenched fist is often less prominent. Surgery is rarely indicated. The fourth metacarpal neck is also at risk as the result of the same mechanism as the fifth metacarpal. As the digits become more central, deformity is not as well tolerated. Only small amounts of deformity, typically less than 108, are acceptable for shaft fractures of the second and third metacarpals. Shaft fractures of the fourth and fifth metacarpals may accept angulations of
164 Chapter 21 HAND PAIN 208 618 and 308, respectively. The index finger through little finger metacarpal neck and shaft fractures are usually treated conservatively with splinting unless the fractures are irreducible or unstable. Rotational alignment is the most important factor in the assessment of fracture reduction. Malrotation will lead to finger overlap and an abnormal arch of finger motion if not addressed. Intraarticular fractures of the head of the metacarpals should be addressed similar to other joint fractures. If the articular surface is displaced, reduction and K-wire fixation should be attempted to restore joint congruity. Stiffness of the MCP joints should be avoided with initiation of range of motion exercises as soon as possible. Motion of the PIP joints should begin immediately to avoid permanent stiffness. Any laceration over the MCP joints
should be considered potentially open and treated as a human bite unless proved otherwise. The first metacarpal is unique because it is much more mobile to allow for the oppositional function of the thumb. Approximately 25% of all metacarpal fractures occur in the thumb metacarpal, with 80% of those occurring at the base. The ligamentous structures at the first CMC joint are very important to thumb stability. Bennett and Rolondo fractures are the two main variants of thumb metacarpal base fractures. Extra-articular or minimally displaced fractures of thumb metacarpal base can be treated with a thumb spica cast; however, displaced fractures into the CMC joint need to be surgically reduced and internally fixed using plates and screws or K-wire fixation.
A
B Figure 21^8. A, Scaphoid fracture. B,Open reduction and internal fixation of a scaphoid fracture.
V CHRONIC PAIN: NONCANCER PAIN 165
Figure 21^9. Computed tomography (CT) of a fracture of the hook of the hamate.
Fractures of the Phalanges Fractures of the middle and proximal phalanges are usually buddytaped to the adjacent digit, which acts a protective splint. This obviates the need for a bulky accessory splint that can interfere with hand function and necessary joint motion. Compression fractures, vertical shear fractures, and unstable or displaced/irreducible fractures should be treated surgically with closed reduction and pinning or open reduction and internal fixation. Displaced intraarticular fractures should also be surgically reduced and stabilized to restore articular congruity. Care must be taken during surgical exposure to prevent injury to the complex extensor and flexor mechanisms in addition to the digital artery and nerve, which travel on either side of the fingers. Of paramount importance is early motion to prevent joint stiffness. Distal phalynx fractures rarely require opened reduction. The nail should be carefully examined with distal finger trauma, and the patient should be educated on the possibility of abnormal nail growth or nail loss depending on the severity of the injury.
Fractures of the Distal Radius Fractures of the distal radius were first described in the literature by an Irish surgeon and anatomist, Abraham Colles in 1814. The Colles’ fracture typically occurs in patients over 60 years old due to osteoporosis. As a fracture of fragility, relatively minor trauma such as a fall from a standing position causes the fracture. As a sign of osteoporosis, either medical management or referral for an osteoporosis evaluation is warranted. The most common demographic is an older postmenopausal woman. Women who sustain this injury outnumber men by ratio of 4:1. The position (alignment) of the fracture and the extent of articular involvement dictate fracture management. For most distal radius fractures, a splint is usually used for the first few days to allow for swelling. For extra-articular fractures with little dorsal comminution, immobilization may be all that is needed to achieve a good result. The splint can be replaced by a cast a few days to a week later, after the swelling goes down. X-rays are taken at regular weekly intervals for 3 weeks and then at 6 weeks. The cast is typically removed at about 6 weeks. Protective bracing is then applied. Physical therapy is often started to help improve motion and function of the injured wrist if needed. If at 2 weeks the patient does not have full digital motion in the cast, therapy should begin in order to avoid permanent stiffness and the risk of complex regional pain syndrome type I [CRPS I] (formerly known as reflex sympathetic dystrophy).
Figure 21^10. Fracture with dorsal angulation and
comminution.
If the fracture is intra-articular or unable to be kept corrected in a cast, surgery is often indicated. This is especially the case with dorsal comminution because this pattern is classically unstable (Fig. 21–10). Measurements are often made on a reduction x-ray to determine whether length, volar tilt, and radial inclination are acceptable (Fig. 21–11). Near-anatomic alignment is preferred in the younger, more active patient to avoid future arthritis and pain. For articular fractures, the treatment goal is reconstruction of an anatomic joint surface.
Ligament Injuries After a fall, if pain persists and radiographs remain normal, one should suspect ligament injuries. The most common devastating ligament injury is a torn scapholunate ligament. Initial radiographs may be normal, but over time, these carpal bones begin to shift apart and the scaphoid rotates. This will lead to very early arthritis. It is similar to a tire being way out of alignment and causing excessive wear. Early diagnosis with MRI and acute surgical treatment give the best prognosis.
Carpal Avascular Necrosis The lunate has an unusual blood supply and may be prone to avascular necrosis if the ulna is shorter than the radius. It presents with dorsal pain in the central aspect of the wrist with swelling from synovitis. This may be associated with repetitive trauma to the wrist. Diagnosis in the earliest stage via MRI will have the best prognosis with the most treatment options. Casting, radial shortening, and bone graft revascularization are all viable options. Late diagnosis with fragmentation and associated arthritis has the worst prognosis, often requiring carpal wrist fusion.
PAINFUL HAND TUMORS Benign Hand Tumors Ganglions are the most common of all hand tumors. They are commonly found on the volar radial side of the wrist and cause
166 Chapter 21 HAND PAIN
25 deg.
A
10 deg
10 mm
C
B
Figure 21^11. Normal measurements for a distal radius.
A, Radial inclination (208 ^308).B, Radial length (8 ^18 mm).C, Radial tilt (08 ^288).
pain when they are under pressure or compress tendons or nerves. Dorsal ganglions, which are very visible, do not always produce pain unless they are entrapped during wrist extension. Smaller ganglions are not always seen clinically but are a common cause of dorsal pain, often picked up on an MRI. These can be removed arthroscopically or via an open procedure. Volar flexion sheath tumors of the digits, also called retinacular cysts, are commonly found near the A1 and A2 pulleys. They produce pain during grasping activities as they become compressed. Such activities include lifting weights and using the steering wheel of a vehicle. Vascular tumors can be extremely painful. Glomus tumors, which arise from the thermoregulatory system near the finger tips, are often difficult to diagnose. They are very well localized and may be seen under the nail bed. On the pulp side of the digit, they are often not seen but localized to a specific spot of tenderness. Bone scan or MRI may or may not identify them. Exploration and excision may be required to diagnose and alleviate the symptoms. Patients may see several physicians who may not be knowledgeable about glomus tumors before someone familiar with these tumors surgically explores the area. Glomus tumors should be suspected with extreme localized pain and temperature sensitivity. Terminal neuromas secondary to trauma may also cause severe local pain and hypersensitivity with distal loss of sensation. A localized Tinel test over the nerve is often seen. Excision and/or mobilization to a less exposed or traumatized area may be a solution. There are numerous other benign tumors that cause pain such as an inclusion cyst in the finger tip pulp, giant cell tumor, which may compress nerves, or schwannomas, which may cause neurogenic symptoms.
Malignant Hand Tumors Although they are very rare in the hand, malignant tumors can cause cortical erosions and subsequent fracture and pain. Because of the relatively minimal overlying soft tissue in the hand, these tumors can be picked up when they are small. The most common
malignant tumor of the hand is a squamous cell carcinoma, which rarely causes pain.
Ischemia of the Hand Small or large vessel occlusion may produce hand pain. Scleroderma, a connective tissue disorder, often causes painful nonhealing ulcerations. These patients frequently have Raynaud’s phenomenon with cold-induced vasospasm. Sympathetic blockade may be helpful as well as vasodilators. Digital artery sympathectomy may improve microarterial flow. Amputation may also be offered as a last resort to alleviate symptoms.
CONCLUSION The hand and wrist are complex structures that can cause pain, severely limiting a person’s quality of life. A careful history and physical examination should be combined with imaging studies to elucidate the patient’s pathology. Treatment usually begins with conservative measures; however, with problems such as scaphoid fractures and FDP avulsions, surgical treatment may be the first line of therapy. Comparison to the unaffected extremity when possible is a useful tool to help make an accurate diagnosis and guide treatment.
REFERENCES 1. Zanette G, Marani S, Tamburin S. Proximal pain in patients with carpal tunnel syndrome: a clinical-neurophysicological study. J Peripher Nerv Syst 2007;12:91–97. 2. Naeser MA. Photobiomodulation of pain in carpal tunnel syndrome: review of seven laser therapy studies. Photomed Laser Surg 2006;24:101–110. 3. Naeser MA, Hahn KA, Lieberman BE, et al. Carpal tunnel syndrome pain treated with low-level laser and microamperes transcutaneous electric nerve stimulation: A controlled study. Arch Phys Med Rehabil 2002;83:978–988.
V CHRONIC PAIN: NONCANCER PAIN 167 4. Elwakil TF, Elazzazi A, Shokeir H. Treatment of carpal tunnel syndrome by low-level laser versus carpal tunnel release. Lasers Med Sci 2007 (in press). 5. Irvine J, Chong SL, Amirjani N, et al. Double-blind randomized controlled trial of low-level laser therapy in carpal tunnel syndrome. Muscle Nerve 2004;30:182–187. 6. Nalamachu S, Crockett RS, Gammaitoni AR, et al. A comparison of the lidocaine patch 5% vs naproxen 500 mg twice daily for the relief of pain associated with carpal tunnel syndrome: a 6-week, randomized, parallel-group study. Med Gen Med 2006b;9:33. 7. Nalamachu S, Crockett RS, Mathur D. Lidocaine patch 5 for carpal tunnel syndrome: how it compares with injections: a pilot study. J Fam Pract 2006a;55:209–214.
Chapter 22
BACK PAIN William F. Lavelle, Allen L. Carl, Elizabeth Demers Lavelle, and Aimee Furdyna
INTRODUCTION The majority of patients will experience spine-related pain at some time in their lives. Low back pain, in particular, is most common in patients between the ages of 35 and 55 years. Fortunately, the majority of acute back pain is self-limited, with over 90% of patients recovering within 6 weeks. Back pain has a high recurrence rate, with symptoms returning within the year in two thirds of patients. The majority of sciatic pain is also self-limiting. Certain aspects of lifestyle, such as a lack of physical activity, obesity, and smoking, predispose patients to recurrent episodes of back pain and sciatica.
LUMBAR SPINE ANATOMY The spine is composed of three anatomic sections, the cervical, lumbar, and thoracic spine. The pain conditions discussed within this chapter involve primarily the lumbar spine. The five lumbar vertebrae are characterized by their relatively large size compared with the cervical and thoracic vertebrae. This increased size is necessary to support the patient’s body weight from successive vertebral levels. The outer portion of each vertebra is composed of dense cortical bone. The cortical bone is narrower in the center of the vertebra and flares at the superior and inferior ends in an hourglass pattern. On the dorsal side of the vertebral body are the laminae, two short, broad plates of bone that cover and protect the dural sac. These plates join medially at the spinous processes (Fig. 22–1). The pedicles are also found on the posterior side of the vertebral body and act to join the posterior bony structures to the anterior vertebral body (Fig. 22–2). From the confluence of the laminae and the pedicles protrudes the articular processes that form the facet joints. This particular confluence of bone is referred to as the pars interarticularis. The transverse processes, which extend laterally, also protrude from this junction. Together, the pedicles and processes form the vertebral arch. Muscles and ligaments connect to the
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vertebrae at the spinous and transverse processes, which arise from the dorsal aspect of the vertebra.
MOTION SEGMENTS The vertebrae link together through facet joints on the posterior side of the spinal column. The facet joints are formed between the superior articular processes of one vertebra and the inferior articular processes of the vertebra directly above. Between each of the lumbar vertebrae is a thick, spongy disk made up of various types of cartilage. The three major constituents of the disk are water, fibrillar collagens, and aggrecan (a large aggregating proteoglycan [PG]) with highly sulfated glycosaminoglycan (GAG) chains that attract and hold water. The annulus fibrosus is the outer ring that forms the border of the disk. It is composed of 15 to 25 distinct layers of concentric collagenous lamellae (made of bundles of collagen fibers running obliquely from one vertebrae to the next, thereby anchoring the disk to bone or cartilaginous endplate, highest in the outer annulus fibrosus and lowest in the inner annulus fibrosus). With aging and/or degeneration of the disk, the relative content of collagen increases owing to a loss of water and aggrecan. At a pressure of 0.25 megapascals (Mpa; 36 pounds/inch2 [psi]) a 37-year-old disk is hydrated with approximately 4 g water per gram of dry weight, whereas a 91-year-old disk is hydrated to about 1.8 g water per gram of dry weight with four- to fivefold less aggrecan. This may be due in part to actions of matrix metalloproteinases (MMP; collagenases from connective tissue cells [MMP-1] and from polymorphonuclear leukocyte [MMP-8], and stromelysin [MMP-3]). Stromelysin may degrade multiple connective tissue matrix components (including aggrecan and type IX collagen activating procollagenase; also referred to as aggrecanase). The nucleus pulposus forms the center of the disk and functions to resist compressive loads. The nucleus pulposus largely consists of PGs, water, collagen, and cells. PGs have gained the most attention with respect to nerve irritation secondary to herniated nucleus pulposus material; however, cells may produce MMPs, cytokines (interleukin [IL]-6), and prostaglandin E2. Each disk is approximately 1=4 to 3=4 inch thick. Furthermore, the cartilaginous endplate separates the nucleus from the adjacent vertebral bone. Together, these layers form a strong disk, capable of absorbing the shock produced from the movement of the spine. When weight is put on the spine, the disks compress; when the weight is lifted, the disks return to their original shape and size. The loads on an L3 disk in a 70-kg person are approximately: lying prone 0.10 Mpa (14 psi), lying lateral 0.12 Mpa (17 psi), free sitting 0.3 Mpa (43 psi), sitting unsupported 0.46 Mpa (67 psi), relaxed standing 0.5 Mpa (72 psi), lifting a 20-kg weight close to the body