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Elbow Arthroscopy: Set Up, Portals, and Tools for Success
Elbow Arthroscopy: Set Up, Portals, and Tools for Success Matthew D. Budge, MD, and April D. Armstrong, BSc(PT), MSc, MD, FRCSC Elbow arthroscopy is a safe and effective tool for the diagnosis and treatment of multiple intra and extra-articular elbow pathologies. However, the elbow’s small size, complex three-dimensional anatomy, and proximity to neurovascular structures can make arthroscopic visualization and treatment technically demanding. Complications are uncommon, but include injury to superficial and deep nervous structures, infection, portal site drainage, and compartment syndrome. The safe performance of elbow arthroscopy requires not only an in-depth knowledge of superficial and intra-articular anatomy, but also proper technique. Attention to key set-up components, including, patient positioning, operative and nonoperative arm positioning, arthroscopic instrumentation, arthroscopic pump pressure, and portal placement can facilitate ease of visualization and allow for the prevention of iatrogenic complications. With the appropriate planning, foundation of knowledge, and meticulous surgical technique, elbow arthroscopy can be performed safely and efficiently for a wide range of elbow disorders. Oper Tech Orthop 19:209-219 © 2009 Elsevier Inc. All rights reserved. KEYWORDS elbow, arthroscopy, portals
T
he elbow joint was initially described as “unsuitable for examination” because of small volume and proximity to neurovascular structures by Burman1 in his classic 1931 article on arthroscopy. Routinely performed, arthroscopic visualization of the elbow joint has indeed proved to be a challenging task. The unique combination of complex threedimensional anatomy, small working space, and the proximity of vital neurovascular structures limited the progression of elbow arthroscopy for almost 50 years after its initial description.2 Fortunately, advances in arthroscopic techniques, coupled with an increased knowledge of local anatomy revitalized elbow arthroscopy as a viable treatment option in the early 1980s.2,3 During its infancy, indications for elbow arthroscopy were narrow and described only for select intraarticular pathologies, including pain with normal radiographic and physical examination findings, loose bodies, synovectomy/synovial biopsy, lysis of adhesions, and osteochondritis dissecans lesions.2-4 As elbow arthroscopy has evolved, these initial indications have been expanded to in-
Department of Orthopaedic Surgery and Rehabilitation, Penn State Milton S. Hershey Medical Center, Hershey, PA. Address reprint requests to April D. Armstrong, BSc(PT), MSc, MD, FRCSC, Department of Orthopaedic Surgery and Rehabilitation, Milton S. Hershey Medical Center, Bone and Joint Institute, 30 Hope Dr, Building A, EC 089, Hershey, PA 17033. E-mail: [email protected]
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clude complex intra-articular problems, such as elbow arthritis and contracture; extra-articular pathology, such as biceps tendon disorders and lateral epicondylitis; and fracture management.4-7 Although increasing experience and refinements in technique have simplified the performance of elbow arthroscopy, it remains a challenging procedure with a steep learning curve.6 Special attention to elbow arthroscopic technique is required to avoid complications and improve results. The surgeon need not only a detailed knowledge of the working anatomy of the elbow, but should also strive for surgical efficiency as the constraints of tourniquet time and pericapsular edema can prove overwhelming in an already difficult to visualize joint. Safe and efficient elbow arthroscopy requires particular attention to patient positioning, as well as meticulous placement of arthroscopic portals. When elbow arthroscopy is performed in a systematic, meticulous fashion it can be a very effective tool for diagnosing and treating elbow pathology.
Anesthesia A general anesthetic has been the preferred choice for many elbow arthroscopists as it allows for total muscle relaxation, variability in positioning, and protection of the patients airway. However, regional blocks have often been used in elbow 209
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Figure 1 2.9 and 4.0-mm arthroscopes as well as 30 and 70 degree angled arthroscopes.
arthroscopy to alleviate post operative pain, decrease the need for inhaled anesthetics, and facilitate post operative range of motion.8 Choices for a regional anesthesia, with or without intravenous sedation, include interscalene, Bier, and axillary blocks. The choice between general and regional anesthesia can be influenced by several variables, including patient comorbidities, availability of regional anesthesia, postoperative rehabilitation protocol, and surgeon preference. The most frequently mentioned disadvantage of a regional anesthesia for elbow arthroscopy is the inability to obtain an accurate postoperative neurologic examination after the procedure.9 Although nerve palsy or nerve transection after arthroscopy of the elbow is rare,10 it can be catastrophic11 and early identification could influence patient care and expectations.10,11 Recently, the use of regional blocks with indwelling catheterization has become a possibility to specifically address the earlier mentioned concern. With this technique, the patient has a catheter placed preoperatively and is dosed with a short-acting anesthetic before and during the procedure. In the postoperative holding area the infusion can be halted to obtain a detailed neurologic examination and then restarted to obtain pain control. The patient can either go home with a removable-catheter or have a long acting anesthetic injected before the catheter is removed in the postoperative area. This allows for the benefits of regional anesthesia and the surgeon an adequate postoperative examination.
Instrumentation Arthroscope Although the size and volume of the elbow is considerably smaller than that of other commonly visualized joints, the same basic instrumentation is used. A standard 4.0-mm arthroscope with a 30 degree angled lens routinely allows for
full visualization of the joint. The surgeon should also have a 2.9-mm arthroscope as well as a 70 degree angled arthroscope in the event patient anatomy compromises visualization. It is common to switch to a smaller arthroscope when working in the posterolateral compartment (ie, posterior radiocapitellar space). Whether alternative size arthroscopes are used, it is important to use an interchangeable cannula system that allows passage of both the 2.9 and 4.0-mm scope through the same cannula. This will minimize the number of capsulotomies and facilitate passage of cameras between portals, decreasing the chance of iatrogenic neurovascular injury, and reducing the amount of fluid extravasation into the pericapsular soft tissue (Fig. 1). Cannula/Trochar Several features of the cannula system are important in elbow arthroscopy. Due to the small working space of the elbow, an unfenestrated cannula system should always be used to provide inflow into the joint, as the side portal of a fenestrated system has the possibility of being subcutaneous, whereas the primary inflow portal is intra-articular. If this occurs, then the side portal will extravasate fluid directly into the subcutaneous tissue, increasing pericapsular edema and the risk of compartment syndrome.12 Also, the chosen trochar system should be conical and blunt ended as this poses lower risk to the neurovascular structures than sharp tipped trochars, whereas providing similar ease of entry into the joint thus decreasing the risk of articular cartilage damage in an already small working space (Fig. 2). Pump System The intracapsular pressure tolerated by the elbow joint before rupture can be as low as 30 mm Hg in compliant elbows13 and may be significantly altered in stiff elbows.14 To maintain distention of the joint, but minimize fluid extravasation, either a low-pressure pump system (⬍30 mm Hg) or gravity
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Figure 2 Sharp and blunt trocars as well as fenestrated and unfenestrated cannulas.
pressure flow from a hanging bag should be used. Intraarticular capsule retractors have also been recommended to increase visualization and decrease the need for high-pressure systems.10,15
Other Instrumentation Depending on the procedure to be performed, a variety of instruments should be available to the arthroscopist, including (Fig. 3A): 1. 2. 3. 4. 5. 6.
Probe Grasper Forceps Pituitary rongeur Switching sticks (retractors) Osteotomes
7. Motorized shaver 8. Motorized burr 9. Small biting instruments
Patient Positioning The ideal position for elbow arthroscopy is ultimately determined by the experience and comfort level of the surgeon; however, several general principals apply to all positions. The patient’s bony prominences should be well padded and the antecubital space of the operative arm should remain free of constriction to allow for distention of the anterior capsule. The elbow should be positioned in 70-80 degrees flexion that allows for maximal distention of the elbow.13 The distal forearm should be wrapped to prevent leakage of irrigation fluid
Figure 3 (A, B) Arthroscopic instrumentation and bent rod elbow positioned.
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Figure 4 Elbow in the lateral position showing the proper amount of flexion.
into the subcutaneous tissues that could lead to compartment syndrome. Finally, a tourniquet should be placed proximal sufficient on the arm to prevent constriction of the antecubital space, yet allow for hemostasis and visualization of the joint.
Supine The supine position for elbow arthroscopy was first described by Andrews and Carson in 1985.2 The patient lies in the supine position with the operative arm abducted 90 degrees at the shoulder with the elbow flexed to 90 degrees. The arm is held suspended by the hand with either a traction gauntlet or with a commercial arm-holding device allowing the elbow to hang free.9 There are several advantages to the supine position. With the arm flexed, the neurovascular structures of the antecubital fossa are in a relaxed position that can aid in preventing iatrogenic injury. Also, in this position the elbow maintains its normal anatomic relationship to the arthroscopist, facilitating easier navigation. From an anesthesia standpoint, the position is beneficial as the airway is easily accessible in the event of obstruction or compromise. The disadvantages of this position include instability of the arm in a hanging position, often mandating an additional assistant to stabilize the arm, and more difficult access to the posterior compartment of the elbow. When visualizing the posterior elbow from this position, the surgeon is also forced to operate in an “uphill” fashion that can be difficult both technically and perceptually. Recent modifications to the supine technique have addressed these concerns.9 Using a static arm positioning device, the arm can be positioned with the shoulder in 90 degrees of flexion and the arm draped over the chest. This removes the need for an additional assistant to control the arm and prevents the surgeon from working “uphill.”
Prone Due to the difficulty encountered in obtaining a complete view of the elbow joint in supine position, Poehling et al3 described the prone position for elbow arthroscopy in 1989. In their description, the patient is placed prone on chest rolls with the affected shoulder abducted 90 degrees and the humerus draped over an arm board or arthroscopic arm holder. The antecubital fossa is kept free of contact and the forearm is allowed to hang in 90 degrees of flexion. There are multiple advantages of this position. Stability of the elbow is improved over the supine position by the placement of the bolster under the arm. Also, there is improved access to the posterior compartment and elimination of the need to operate in an upside-down manner. Similarly, the prone position is easily converted to an open approach as most approaches to the elbow can be performed from this position. The primary disadvantages of this position are the difficulties with access to the airway and patient tolerance when undergoing regional anesthesia alone.
Lateral The lateral position was originally described by O’Driscoll and Morrey in 19924 and has similar advantages to the prone position without the concern of access to the patient’s airway. It is, likewise, well tolerated by patients undergoing regional anesthesia with sedation. The patient is placed in the lateral decubitus position using a bean bag, Wixson hip positioner, peg board, or other restraint to control the trunk and pelvis. An axillary roll is placed, and the patient is secured to the table with a restraining belt or tape strips. The operative shoulder is then flexed forward to 90 degrees, internally rotated 90 degrees, and suspended over a padded bolster with the forearm allowed to hang free (Fig. 4). Care should be taken to specifically avoid any pressure or constriction of the antecubital fossa as this will compress the neurovascular structures to the anterior capsule and can lead to iatrogenic
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Figure 5 Lateral and medial portal superficial landmarks. (Reprinted with permission.24)
neurovascular injury during arthroscopy. The nonoperative arm is positioned to allow free movement of the operative elbow during surgery. The shoulder and elbow of the contralateral arm should both be flexed so they do not impede elbow flexion of the operative arm that can compromise access to structures in the anterior compartment, such as the coronoid (Fig. 4). A particular arm positioner, with a bent rod to allow ease of elbow flexion, can be helpful (Fig. 3B). When properly positioned there is stable, unrestricted access to the medial, lateral, and posterior aspects of the elbow. The main disadvantage to this position is that the patient may need to be repositioned whether additional open procedure is necessary that requires the supine position.
Portal Placement The bony and ligamentous anatomy of the elbow joint serve to divide it into 3 major arthroscopic compartments: anterior, posterior, and posterolateral. Arthroscopic visualization of the anterior compartment allows viewing of the anterior ulnohumeral, radio-capitellar, and proximal radioulnar articulations, as well as evaluation of the coronoid process, anterior trochlea, radial head, capitellum, and the medial and lateral condyles. Visualization of the posterior compartment allows viewing of the posterior ulnohumeral articulation and evaluation of the olecranon tip, the olecranon fossa, posterior trochlea, and medial and lateral gutters. Visualization of the posterolateral compartment allows posterior viewing of the radio-capitellar articulation and evaluation of the radial head, olecranon, lateral gutter, and capitellum.
Surface Anatomy Anatomical understanding of the elbow begins with identifying the superficial landmarks. To avoid distortion, normal
landmarks should be palpated and marked with a surgical marker before joint distention. The most readily palpable structures are the olecranon and medial and lateral epicondyles. These should be marked and served as a reference for additional landmarks. The medial intramuscular septum, lateral supracondylar ridge can then be easily appreciated and marked, as well as the radial head/capitellum articulation that can be found by supinating and pronating the forearm. Attention is then turned to the neurovascular structures. The ulnar nerve should be palpated by flexing and extending the arm to determine whether there is subluxation or dislocation during this motion. Whether instability of the ulnar nerve is found, the nerve should be specifically protected during portal placement or a mini open approach to the medial portal should be undertaken. After the course of the ulnar nerve is marked, the paths of the radial and median nerves, as well as the brachial artery, may also be diagrammed to further prevent neurovascular injury during portal placement (Fig. 5).
General Techniques for Portal Placement Before trochar placement, a key facet of portal creation is distention of the joint with normal saline. This serves to increase the maximum distance from the articular surface to the neurovascular structures and, hence, decreases the risk of iatrogenic injury.16 However it is important to realize that distention of the joint does not change the relationship of the nerves to the capsule itself. Rather, it simply increases the distance of the capsule and nerves from the articular surface allowing for ease in placing the arthroscopic trochar (Fig. 6). This relationship is particularly important to understand when performing any type of arthroscopic capsular release. Along with joint distention, having the elbow in a flexed position during trochar placement has been shown to decrease the chances of neurovascular injury to anterior struc-
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Figure 6 The relationship between the capsule and neurovascular structures in an undistended and distended joint. (Reprinted with permission.24)
tures when establishing portals.16 The combination of these 2 techniques helps reduce the risk of portal-based injury. It is important to note, however that when working with a stiff elbow the capsular compliance may be only 15% of the normal joint,14 preventing significant influx of fluid and joint distention. A greater risk of neurovascular injury can be expected in this situation and special care must be taken with trochar placement. To distend the joint, sterile normal saline is injected into the lateral “soft spot”, located at the center of a triangle between the lateral epicondyle, subcutaneous olecranon tip, and the radial head (Fig. 7). The needle is directed medially from the soft spot and 20-30 cc. of fluid may be injected with the elbow in the flexed position. The correct location is confirmed by noting a visual joint effusion, a flashback of yellow
tinged synovial fluid, and slight joint extension as increasing fluid is injected into the joint. Care must be taken not to overdistend the joint that can lead to capsular rupture and an inability to maintain capsular pressure during arthroscopy. Once the joint is distended, trochar placement may commence. When making the incision for the portals only the skin should be incised. The subcutaneous tissues should be bluntly dissected using a hemostat or blunt-tipped trochar to protect the superficial nervous structures. The joint itself should be entered with a single puncture, rather than multiple passes, to help diminish joint fluid extravasation. Proper placement of the arthroscopic trochar is confirmed by fluid return from the portal once the inner sleeve is removed. There is continued debate over the proper starting portal for elbow arthroscopy with anatomic dissection studies pro-
Figure 7 The lateral soft spot superficial landmarks and underlying anatomy. (Reprinted with permission.24)
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Figure 8 Anterolateral portal sites and underlying anatomy. (Reprinted with permission.24)
viding evidence for the risks and benefits of both medial and lateral starting points.17,18 Today there is no consensus of the superiority of 1 approach over another, and the choice is ultimately according to surgeon comfort and experience.
Anterior Portal Anatomy and Placement Anterolateral Portals There are 3 described portals for access to the anterolateral aspect of the elbow joint during arthroscopy. The classic anterolateral portal, as described by Andrews and Carson in 1985,2 is located the most distally on the lateral aspect of the arm. It lies in the sulcus just anterior to the radial head approximately 3 cm distal and 1 cm anterior to the lateral epicondyle. This can be readily found by pronating and supinating the forearm (Fig. 8). In this approach, the trochar passes through the extensor carpi radialis brevis and supinator16,19 and runs posterolateral to the radial nerve. The nerves most at risk are the posterior antebrachial cutaneous nerve (PABCN) and radial nerve. Cadaveric studies have shown that the PACBN averages approximately 2-7 mm from the portal site, and the radial nerve distance averages 3-4 mm.16,18,19,20 The position of the forearm has also been noted to be a factor in determining the distance from the portal site to the nerves, with pronation increasing the distance.21 As demonstrated on cadaveric dissection, the anterolateral portal has fallen out of favor due to the proximity of the peripheral nerves. The mid-anterolateral portal is another option for lateral entry into the joint. The portal lies more proximal than the anterolateral portal, and is located 2 cm anterior to the lateral epicondyle directly in line with the joint. The trochar directly penetrates the extensor carpi radialis longus,20 and is located within 5-10 mm of the radial nerve.20
The proximal anterolateral portal is the most proximal of the anterolateral portals and is located 2 cm proximal and 1 cm anterior to the lateral epicondyle. The trochar directly penetrates the origin of the extensor carpi radialis longus and, occasionally, the brachioradialis and is located approximately 5-8 mm from the radial nerve,20,22 and 0-14 mm from the PACBN.22 The mentioned advantages of this portal are the increased distances from the radial nerve and PACBN, as well as the ease of entry into the capsule and relative increased ability to visualize the anterior joint. Several classic studies, including Field et al20 and Stothers et al,22 have compared the various anterolateral portals and confirmed that the proximal anterolateral portal provides a larger soft tissue margin from the radial nerve and PACBN and implied that visualization of the anterior joint is superior. For these reasons the proximal anterolateral portal is used routinely for arthroscopic visualization of the anterior elbow joint. Whichever lateral portal is chosen to access the anterior aspect of the joint, the predominant anatomic structures available for viewing are the coronoid process and the trochlea. As these structures articulate, flexion and extension of the elbow can help better identify the coronoid and allows you to position it optimally for intra-articular work. Also, well-visualized from the lateral portal is the coronoid fossa, which accepts the coronoid process at extreme flexion, and is a common location for loose bodies (Fig. 9). Moving more distally in the joint one can visualize the brachialis insertion on the coronoid process, which is covered by a synovial sheath. Moving the arthroscope medially, the medial capsule as well as the anterior bundle of the medial collateral ligament can occasionally be appreciated. Moving more laterally, closer to the portal, one can visualize the radiocapitellar joint
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M.D. Budge and A.D. Armstrong the anterior aspect of the joint acts as a cushion to protect the median nerve and brachial artery. Once the joint had been entered medially, the radial head serves as a landmark, and can be identified as it rotates during forearm pronation and supination (Fig. 12). Proximal to the radial head is the anterosuperior portion of the capitellum and the bare radial fossa. On occasion, a synovial fold exists between the radial head and capitellum, which seems as a thin meniscus. Fibers of the annular ligament may be visible over the radial head. Sequlae of lateral epicondylitis may also be noted and occasionally you will observe a rent in the lateral capsule. Moving more medially, the coronoid, coronoid fossa, trochlea, and capsule may be visualized (Fig. 13).
Posterior Portal Anatomy and Placement Figure 9 Coronoid and trochlea as viewed from the anterolateral portal. (Reprinted with permission.24)
and above this the radial fossa (Fig. 10). There is typically a distinct ridge on the anterior humerus delineating the divide between the coronoid and radial fossa, and this ridge is often accentuated in arthritis of the elbow. Antero-Medial Portals The first portal described for medial entry into the elbow joint was the direct antero-medial portal.2,16 It is located 2 cm anterior and 2 cm distal to the medial epicondyle, and transverses the common flexor origin between the flexor carpi radialis and flexor digitorum superficialis before penetrating the pronator teres16 (Fig. 11). Because of its distal location in the forearm, the placement of this portal into the joint can only be made by directing the trochar laterally in the direction of the neurovascular structures.18 Cadaveric studies have shown that the median nerve is located close to the arthroscopic tract, with an average of 4-14 mm of clearance.16,19,21 The medial antebrachial cutaneous nerve is also at risk with an average of 1-4 mm of clearance from the portal entry site.16,19 Further away, but still of concern, are the brachial artery and ulnar nerve that have an average soft tissue clearance of 20-25 mm.16,19 Due to concerns over the proximity of the neurovascular structures, the more commonly used portal for medial entry into the joint is the proximal antero-medial portal. Located 1-2 cm proximal to the medial epicondyle and anterior to the intramuscular septum, this portal has the advantages of increased average distance from the median nerve of approximately 20 mm,18 although still providing full visualization of the joint.17-19 To place this portal, the elbow should be maintained at 90 degrees of flexion and the trochar should be directed toward the center of the joint anterior to the intramuscular septum. Care should be taken to ensure that the ulnar nerve does not subluxate anterior to the medial epicondyle with flexion of the elbow or it will be at risk for injury during placement of the antero-medial portals. Staying anterior to the medial intermuscular septum, which is easily palpable, will protect the ulnar nerve. The brachialis muscle on
Direct Posterior Portal The direct posterior or posterocentral portal is used for visualization of the tip of the olecranon, olecranon fossa, and the medial/lateral gutters of the posterior compartment of the elbow. It is placed in the midline of the posterior elbow approximately 3 cm proximal to the olecranon tip (Fig. 14). The portal tract directly pierces the triceps at the musculotendonous junction, and should be established with the elbow in 20-30 degrees of flexion to permit relaxation of the triceps. Although a safe portal compared with the anterior portals, there is still the risk of injury to the ulnar nerve and PABCN that lie approximately 25 mm away from the portal site in full extension.19 Establishment of this portal allows for removal of loose bodies from the posterior compartment as well as resection of osteophytes from the olecranon and olecranon fossa. Careful attention to the medial gutter and the proximity of the ulnar nerve is essential to prevent injury to the nerve. The posterolateral portals are the accessory portals for working within the posterior aspect of the elbow joint. They can be envisioned as beginning 2-3 cm proximal to the tip of
Figure 10 Radial head and capitellum as viewed from the anterolateral portal on the lateral side of the joint. (Reprinted with permission.24)
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Figure 11 Medial portal sites and underlying anatomy. (Reprinted with permission.24)
the olecranon along the lateral border of the triceps tendon (proximal posterolateral portal) and continuing distally in a straight-line until reaching the direct lateral portal at the “soft spot.” As with the direct posterior portal, the portal is established with the elbow in 20-30 degrees of flexion with the cannula inserted toward the olecranon fossa. The main dangers are the ulnar nerve and the PABCN,19 which should be safe from injury as long as the cannulas are kept lateral to the midline of the elbow. The main anatomic landmark of the posterior compartment is the tip of the olecranon that can be seen seating in the olecranon fossa with flexion and extension of the elbow (Fig. 15). The olecranon fossa itself is triangular or oval and frequently has significant osteophytes and loose bodies. The
postero-medial and posterolateral gutters are best seen in this compartment and can be visualized by directing the camera medially or laterally, respectively. The posterior capsule is also well seen in this compartment. More medially, the postero-medial aspect of the joint shows the vertically oriented fibers of the posterior band of the ulnar collateral ligament. Approximately fifty percent of the ligament can be visualized and, just superficial to this, lies the ulnar nerve23 (Fig. 16). Great care should be taken when working in this area. More laterally, the posterior radiocapitellar joint may be visualized.
Figure 12 Radial head and capitellum as viewed from the anteromedial portal. (Reprinted with permission.24)
Figure 13 Coronoid and coronoid fossa as viewed from the anteromedial portal. (Reprinted with permission.24)
Posterior Lateral Portal The posterolateral compartment of the elbow is often visualized through the direct lateral portal site, or the “soft
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Figure 14 Posterior portal sites and underlying anatomy. (Reprinted with permission.24)
spot,” as described by Poehling et al.3 The portal start site is located at the center of the triangle formed by the lateral epicondyle, olecranon process, and radial head and is most often used for visualization of the inferior-posterior aspect of the capitellum and the radioulnar articulation. Upon entering this compartment, the capitellum is the most obvious structure, as well as the radial head, as the scope is brought anteriorly. The radial head should be slightly concave on its most proximal surface, whereas the capitellum should be gently convex (Fig. 17). The scope can be redirected posteriorly and medially between the olecranon and trochlea. By looking down on the olecranon articular surface, a roughened area that lacks articular car-
tilage can commonly be observed, which denotes the apophyseal scar or bare area of the olecranon. By turning the scope anteriorly, the underside of the trochlea can be visualized. A distal posterolateral portal can be created along the posterolateral gutter and used as a viewing portal to facilitate arthroscopic work through the direct lateral portal. One may also appreciate a lateral plica, and it is not uncommon to find loose bodies within the posterolateral joint. A diagnostic arthroscopy of the elbow joint is not complete without looking in the posterolateral compartment. It can sometimes be useful to switch to a 2.9-mm arthroscope to allow more working room.
Figure 15 Olecranon tip and fossa as viewed from the posterior portal. (Reprinted with permission.24)
Figure 16 Medial gutter and ulnar nerve as viewed from the posterior portal. (Reprinted with permission.24)
Elbow arthroscopy
Figure 17 Radial head and capitellum as viewed from the posterior lateral portal. (Reprinted with permission.24)
Conclusions Elbow arthroscopy is an effective procedure for the diagnosis and treatment of a multitude of elbow pathologies. It is, however, a technically challenging procedure due to the small working space, proximity of neurovascular structures, and complex anatomy. A systematic approach to positioning, set up, and portal placement as well as a comprehensive knowledge of superficial and deep elbow anatomy can prevent complications and allow the safe performance of elbow arthroscopy.
References 1. Burman MS: Arthroscopy or the direct visualization of joints: An experimental cadaver study. J Bone Joint Surg Am 13:669-695, 1931 2. Andrews JR, Carson WG: Arthroscopy of the elbow. Arthroscopy 1:97107, 1985 3. Poehling CG, Whipple TL, Sisco L, et al: Elbow arthroscopy: A new technique. Arthroscopy 5:222-224, 1989 4. O’Driscoll SW, Morrey BF: Arthroscopy of the elbow: Diagnostic and therapeutic benefits and hazards. J Bone Joint Surg Am 74:84-94, 1992
219 5. Eames MHA, Bain GI: Distal biceps tendon endoscopy and anterior elbow arthroscopy portal. Tech Shoulder Elbow Surg 7:139-142, 2006 6. Savoie FH: Guidelines to becoming an expert elbow Arthroscopist. Arthroscopy 23:1237-1240, 2007 7. Baker CL Jr, Baker CL III: Long-term Follow-up of arthroscopic treatment of lateral epicondylitis. Am J Sports Med 36:254-260, 2008 8. Baker CL, Jones GL: Arthroscopy of the elbow. Am J Sports Med 27: 251-264, 1999 9. Dodson DC, Altchek DW, Williams RJ, et al: Elbow arthroscopy. J Am Acad Orthop Surg 16:574-585, 2008 10. Kelly EW, Morrey BF, O’Driscoll SW: Complications of elbow arthroscopy. J Bone Joint Surg Am 83-A:25-34, 2001 11. Haapaniemi T, Berggren M, Adolfsson L: Complete transaction of the median and radial nerves during arthroscopic release of post-traumatic elbow contracture. Arthroscopy 15:784-787, 1999 12. Angelo RL: Advances in elbow arthroscopy. Orthopedics 16:10371046, 1993 13. O’Driscoll SW, Morrey BP, An KN: Intra-articular pressure and capacity of the elbow. Arthroscopy 6:100-103, 1990 14. Gallay SH, Richards RR, O’Driscoll SW: Intraarticular capacity and compliance of stiff and normal elbows. Arthroscopy 9:9-13, 1993 15. Steinmann SP: Elbow Arthroscopy. J Hand Surg 3:199-207, 2003 16. Lynch GJ, Meyers JF, Whipple TL, et al: Neurovascular anatomy and elbow arthroscopy: Inherent risks. Arthroscopy 2:190-197, 1986 17. Verhaar J, VanMameraen H, Brandsma A: Risks of neurovascular injury in elbow arthroscopy: Starting anteromedially or Anterolaterally. Arthroscopy 7:287-290, 1991 18. Lindenfeld TN: Medial approach in elbow arthroscopy. Am J Sports Med 18:413-417, 1990 19. Adolfsson L: Arthroscopy of the elbow joint: A cadaveric study of portal placement. J Shoulder Elbow Surg 3:53-61, 1994 20. Field LD, Altchek DW, Warren RF, et al: Arthroscopic anatomy of the lateral elbow: A comparison of three portals. Arthroscopy 10:602-607, 1994 21. Marshall PD, Fairclough JA, Johnson SR, et al: Avoiding nerve damage during elbow arthroscopy. J Bone Joint Surg Br 75B:129-131, 1993 22. Stothers K, Day B, Regan WR: Arthroscopy of the elbow: Anatomy, portal sites, and a description of the proximal lateral portal. Arthroscopy 11:449-457, 1995 23. Andrews JR, Baumgarten TE: Arthroscopic anatomy of the elbow. Orthop Clin North Am 26:671-677, 1995 24. Strigenz TJ, Armstrong AD: Elbow arthroscopy: Set-up, anatomy, and portal placement, in Levine WN, Blaine TA, Ahmad CS (eds): Minimally Invasive Shoulder and Elbow Surgery. New York, NY, Taylor and Francis, 2007, pp 301-312
T
he elbow joint was initially described as “unsuitable for examination” because of small volume and proximity to neurovascular structures by Burman1 in his classic 1931 article on arthroscopy. Routinely performed, arthroscopic visualization of the elbow joint has indeed proved to be a challenging task. The unique combination of complex threedimensional anatomy, small working space, and the proximity of vital neurovascular structures limited the progression of elbow arthroscopy for almost 50 years after its initial description.2 Fortunately, advances in arthroscopic techniques, coupled with an increased knowledge of local anatomy revitalized elbow arthroscopy as a viable treatment option in the early 1980s.2,3 During its infancy, indications for elbow arthroscopy were narrow and described only for select intraarticular pathologies, including pain with normal radiographic and physical examination findings, loose bodies, synovectomy/synovial biopsy, lysis of adhesions, and osteochondritis dissecans lesions.2-4 As elbow arthroscopy has evolved, these initial indications have been expanded to in-
Department of Orthopaedic Surgery and Rehabilitation, Penn State Milton S. Hershey Medical Center, Hershey, PA. Address reprint requests to April D. Armstrong, BSc(PT), MSc, MD, FRCSC, Department of Orthopaedic Surgery and Rehabilitation, Milton S. Hershey Medical Center, Bone and Joint Institute, 30 Hope Dr, Building A, EC 089, Hershey, PA 17033. E-mail: [email protected]
1048-6666/09/$-see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1053/j.oto.2009.09.003
clude complex intra-articular problems, such as elbow arthritis and contracture; extra-articular pathology, such as biceps tendon disorders and lateral epicondylitis; and fracture management.4-7 Although increasing experience and refinements in technique have simplified the performance of elbow arthroscopy, it remains a challenging procedure with a steep learning curve.6 Special attention to elbow arthroscopic technique is required to avoid complications and improve results. The surgeon need not only a detailed knowledge of the working anatomy of the elbow, but should also strive for surgical efficiency as the constraints of tourniquet time and pericapsular edema can prove overwhelming in an already difficult to visualize joint. Safe and efficient elbow arthroscopy requires particular attention to patient positioning, as well as meticulous placement of arthroscopic portals. When elbow arthroscopy is performed in a systematic, meticulous fashion it can be a very effective tool for diagnosing and treating elbow pathology.
Anesthesia A general anesthetic has been the preferred choice for many elbow arthroscopists as it allows for total muscle relaxation, variability in positioning, and protection of the patients airway. However, regional blocks have often been used in elbow 209
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Figure 1 2.9 and 4.0-mm arthroscopes as well as 30 and 70 degree angled arthroscopes.
arthroscopy to alleviate post operative pain, decrease the need for inhaled anesthetics, and facilitate post operative range of motion.8 Choices for a regional anesthesia, with or without intravenous sedation, include interscalene, Bier, and axillary blocks. The choice between general and regional anesthesia can be influenced by several variables, including patient comorbidities, availability of regional anesthesia, postoperative rehabilitation protocol, and surgeon preference. The most frequently mentioned disadvantage of a regional anesthesia for elbow arthroscopy is the inability to obtain an accurate postoperative neurologic examination after the procedure.9 Although nerve palsy or nerve transection after arthroscopy of the elbow is rare,10 it can be catastrophic11 and early identification could influence patient care and expectations.10,11 Recently, the use of regional blocks with indwelling catheterization has become a possibility to specifically address the earlier mentioned concern. With this technique, the patient has a catheter placed preoperatively and is dosed with a short-acting anesthetic before and during the procedure. In the postoperative holding area the infusion can be halted to obtain a detailed neurologic examination and then restarted to obtain pain control. The patient can either go home with a removable-catheter or have a long acting anesthetic injected before the catheter is removed in the postoperative area. This allows for the benefits of regional anesthesia and the surgeon an adequate postoperative examination.
Instrumentation Arthroscope Although the size and volume of the elbow is considerably smaller than that of other commonly visualized joints, the same basic instrumentation is used. A standard 4.0-mm arthroscope with a 30 degree angled lens routinely allows for
full visualization of the joint. The surgeon should also have a 2.9-mm arthroscope as well as a 70 degree angled arthroscope in the event patient anatomy compromises visualization. It is common to switch to a smaller arthroscope when working in the posterolateral compartment (ie, posterior radiocapitellar space). Whether alternative size arthroscopes are used, it is important to use an interchangeable cannula system that allows passage of both the 2.9 and 4.0-mm scope through the same cannula. This will minimize the number of capsulotomies and facilitate passage of cameras between portals, decreasing the chance of iatrogenic neurovascular injury, and reducing the amount of fluid extravasation into the pericapsular soft tissue (Fig. 1). Cannula/Trochar Several features of the cannula system are important in elbow arthroscopy. Due to the small working space of the elbow, an unfenestrated cannula system should always be used to provide inflow into the joint, as the side portal of a fenestrated system has the possibility of being subcutaneous, whereas the primary inflow portal is intra-articular. If this occurs, then the side portal will extravasate fluid directly into the subcutaneous tissue, increasing pericapsular edema and the risk of compartment syndrome.12 Also, the chosen trochar system should be conical and blunt ended as this poses lower risk to the neurovascular structures than sharp tipped trochars, whereas providing similar ease of entry into the joint thus decreasing the risk of articular cartilage damage in an already small working space (Fig. 2). Pump System The intracapsular pressure tolerated by the elbow joint before rupture can be as low as 30 mm Hg in compliant elbows13 and may be significantly altered in stiff elbows.14 To maintain distention of the joint, but minimize fluid extravasation, either a low-pressure pump system (⬍30 mm Hg) or gravity
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Figure 2 Sharp and blunt trocars as well as fenestrated and unfenestrated cannulas.
pressure flow from a hanging bag should be used. Intraarticular capsule retractors have also been recommended to increase visualization and decrease the need for high-pressure systems.10,15
Other Instrumentation Depending on the procedure to be performed, a variety of instruments should be available to the arthroscopist, including (Fig. 3A): 1. 2. 3. 4. 5. 6.
Probe Grasper Forceps Pituitary rongeur Switching sticks (retractors) Osteotomes
7. Motorized shaver 8. Motorized burr 9. Small biting instruments
Patient Positioning The ideal position for elbow arthroscopy is ultimately determined by the experience and comfort level of the surgeon; however, several general principals apply to all positions. The patient’s bony prominences should be well padded and the antecubital space of the operative arm should remain free of constriction to allow for distention of the anterior capsule. The elbow should be positioned in 70-80 degrees flexion that allows for maximal distention of the elbow.13 The distal forearm should be wrapped to prevent leakage of irrigation fluid
Figure 3 (A, B) Arthroscopic instrumentation and bent rod elbow positioned.
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Figure 4 Elbow in the lateral position showing the proper amount of flexion.
into the subcutaneous tissues that could lead to compartment syndrome. Finally, a tourniquet should be placed proximal sufficient on the arm to prevent constriction of the antecubital space, yet allow for hemostasis and visualization of the joint.
Supine The supine position for elbow arthroscopy was first described by Andrews and Carson in 1985.2 The patient lies in the supine position with the operative arm abducted 90 degrees at the shoulder with the elbow flexed to 90 degrees. The arm is held suspended by the hand with either a traction gauntlet or with a commercial arm-holding device allowing the elbow to hang free.9 There are several advantages to the supine position. With the arm flexed, the neurovascular structures of the antecubital fossa are in a relaxed position that can aid in preventing iatrogenic injury. Also, in this position the elbow maintains its normal anatomic relationship to the arthroscopist, facilitating easier navigation. From an anesthesia standpoint, the position is beneficial as the airway is easily accessible in the event of obstruction or compromise. The disadvantages of this position include instability of the arm in a hanging position, often mandating an additional assistant to stabilize the arm, and more difficult access to the posterior compartment of the elbow. When visualizing the posterior elbow from this position, the surgeon is also forced to operate in an “uphill” fashion that can be difficult both technically and perceptually. Recent modifications to the supine technique have addressed these concerns.9 Using a static arm positioning device, the arm can be positioned with the shoulder in 90 degrees of flexion and the arm draped over the chest. This removes the need for an additional assistant to control the arm and prevents the surgeon from working “uphill.”
Prone Due to the difficulty encountered in obtaining a complete view of the elbow joint in supine position, Poehling et al3 described the prone position for elbow arthroscopy in 1989. In their description, the patient is placed prone on chest rolls with the affected shoulder abducted 90 degrees and the humerus draped over an arm board or arthroscopic arm holder. The antecubital fossa is kept free of contact and the forearm is allowed to hang in 90 degrees of flexion. There are multiple advantages of this position. Stability of the elbow is improved over the supine position by the placement of the bolster under the arm. Also, there is improved access to the posterior compartment and elimination of the need to operate in an upside-down manner. Similarly, the prone position is easily converted to an open approach as most approaches to the elbow can be performed from this position. The primary disadvantages of this position are the difficulties with access to the airway and patient tolerance when undergoing regional anesthesia alone.
Lateral The lateral position was originally described by O’Driscoll and Morrey in 19924 and has similar advantages to the prone position without the concern of access to the patient’s airway. It is, likewise, well tolerated by patients undergoing regional anesthesia with sedation. The patient is placed in the lateral decubitus position using a bean bag, Wixson hip positioner, peg board, or other restraint to control the trunk and pelvis. An axillary roll is placed, and the patient is secured to the table with a restraining belt or tape strips. The operative shoulder is then flexed forward to 90 degrees, internally rotated 90 degrees, and suspended over a padded bolster with the forearm allowed to hang free (Fig. 4). Care should be taken to specifically avoid any pressure or constriction of the antecubital fossa as this will compress the neurovascular structures to the anterior capsule and can lead to iatrogenic
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Figure 5 Lateral and medial portal superficial landmarks. (Reprinted with permission.24)
neurovascular injury during arthroscopy. The nonoperative arm is positioned to allow free movement of the operative elbow during surgery. The shoulder and elbow of the contralateral arm should both be flexed so they do not impede elbow flexion of the operative arm that can compromise access to structures in the anterior compartment, such as the coronoid (Fig. 4). A particular arm positioner, with a bent rod to allow ease of elbow flexion, can be helpful (Fig. 3B). When properly positioned there is stable, unrestricted access to the medial, lateral, and posterior aspects of the elbow. The main disadvantage to this position is that the patient may need to be repositioned whether additional open procedure is necessary that requires the supine position.
Portal Placement The bony and ligamentous anatomy of the elbow joint serve to divide it into 3 major arthroscopic compartments: anterior, posterior, and posterolateral. Arthroscopic visualization of the anterior compartment allows viewing of the anterior ulnohumeral, radio-capitellar, and proximal radioulnar articulations, as well as evaluation of the coronoid process, anterior trochlea, radial head, capitellum, and the medial and lateral condyles. Visualization of the posterior compartment allows viewing of the posterior ulnohumeral articulation and evaluation of the olecranon tip, the olecranon fossa, posterior trochlea, and medial and lateral gutters. Visualization of the posterolateral compartment allows posterior viewing of the radio-capitellar articulation and evaluation of the radial head, olecranon, lateral gutter, and capitellum.
Surface Anatomy Anatomical understanding of the elbow begins with identifying the superficial landmarks. To avoid distortion, normal
landmarks should be palpated and marked with a surgical marker before joint distention. The most readily palpable structures are the olecranon and medial and lateral epicondyles. These should be marked and served as a reference for additional landmarks. The medial intramuscular septum, lateral supracondylar ridge can then be easily appreciated and marked, as well as the radial head/capitellum articulation that can be found by supinating and pronating the forearm. Attention is then turned to the neurovascular structures. The ulnar nerve should be palpated by flexing and extending the arm to determine whether there is subluxation or dislocation during this motion. Whether instability of the ulnar nerve is found, the nerve should be specifically protected during portal placement or a mini open approach to the medial portal should be undertaken. After the course of the ulnar nerve is marked, the paths of the radial and median nerves, as well as the brachial artery, may also be diagrammed to further prevent neurovascular injury during portal placement (Fig. 5).
General Techniques for Portal Placement Before trochar placement, a key facet of portal creation is distention of the joint with normal saline. This serves to increase the maximum distance from the articular surface to the neurovascular structures and, hence, decreases the risk of iatrogenic injury.16 However it is important to realize that distention of the joint does not change the relationship of the nerves to the capsule itself. Rather, it simply increases the distance of the capsule and nerves from the articular surface allowing for ease in placing the arthroscopic trochar (Fig. 6). This relationship is particularly important to understand when performing any type of arthroscopic capsular release. Along with joint distention, having the elbow in a flexed position during trochar placement has been shown to decrease the chances of neurovascular injury to anterior struc-
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Figure 6 The relationship between the capsule and neurovascular structures in an undistended and distended joint. (Reprinted with permission.24)
tures when establishing portals.16 The combination of these 2 techniques helps reduce the risk of portal-based injury. It is important to note, however that when working with a stiff elbow the capsular compliance may be only 15% of the normal joint,14 preventing significant influx of fluid and joint distention. A greater risk of neurovascular injury can be expected in this situation and special care must be taken with trochar placement. To distend the joint, sterile normal saline is injected into the lateral “soft spot”, located at the center of a triangle between the lateral epicondyle, subcutaneous olecranon tip, and the radial head (Fig. 7). The needle is directed medially from the soft spot and 20-30 cc. of fluid may be injected with the elbow in the flexed position. The correct location is confirmed by noting a visual joint effusion, a flashback of yellow
tinged synovial fluid, and slight joint extension as increasing fluid is injected into the joint. Care must be taken not to overdistend the joint that can lead to capsular rupture and an inability to maintain capsular pressure during arthroscopy. Once the joint is distended, trochar placement may commence. When making the incision for the portals only the skin should be incised. The subcutaneous tissues should be bluntly dissected using a hemostat or blunt-tipped trochar to protect the superficial nervous structures. The joint itself should be entered with a single puncture, rather than multiple passes, to help diminish joint fluid extravasation. Proper placement of the arthroscopic trochar is confirmed by fluid return from the portal once the inner sleeve is removed. There is continued debate over the proper starting portal for elbow arthroscopy with anatomic dissection studies pro-
Figure 7 The lateral soft spot superficial landmarks and underlying anatomy. (Reprinted with permission.24)
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Figure 8 Anterolateral portal sites and underlying anatomy. (Reprinted with permission.24)
viding evidence for the risks and benefits of both medial and lateral starting points.17,18 Today there is no consensus of the superiority of 1 approach over another, and the choice is ultimately according to surgeon comfort and experience.
Anterior Portal Anatomy and Placement Anterolateral Portals There are 3 described portals for access to the anterolateral aspect of the elbow joint during arthroscopy. The classic anterolateral portal, as described by Andrews and Carson in 1985,2 is located the most distally on the lateral aspect of the arm. It lies in the sulcus just anterior to the radial head approximately 3 cm distal and 1 cm anterior to the lateral epicondyle. This can be readily found by pronating and supinating the forearm (Fig. 8). In this approach, the trochar passes through the extensor carpi radialis brevis and supinator16,19 and runs posterolateral to the radial nerve. The nerves most at risk are the posterior antebrachial cutaneous nerve (PABCN) and radial nerve. Cadaveric studies have shown that the PACBN averages approximately 2-7 mm from the portal site, and the radial nerve distance averages 3-4 mm.16,18,19,20 The position of the forearm has also been noted to be a factor in determining the distance from the portal site to the nerves, with pronation increasing the distance.21 As demonstrated on cadaveric dissection, the anterolateral portal has fallen out of favor due to the proximity of the peripheral nerves. The mid-anterolateral portal is another option for lateral entry into the joint. The portal lies more proximal than the anterolateral portal, and is located 2 cm anterior to the lateral epicondyle directly in line with the joint. The trochar directly penetrates the extensor carpi radialis longus,20 and is located within 5-10 mm of the radial nerve.20
The proximal anterolateral portal is the most proximal of the anterolateral portals and is located 2 cm proximal and 1 cm anterior to the lateral epicondyle. The trochar directly penetrates the origin of the extensor carpi radialis longus and, occasionally, the brachioradialis and is located approximately 5-8 mm from the radial nerve,20,22 and 0-14 mm from the PACBN.22 The mentioned advantages of this portal are the increased distances from the radial nerve and PACBN, as well as the ease of entry into the capsule and relative increased ability to visualize the anterior joint. Several classic studies, including Field et al20 and Stothers et al,22 have compared the various anterolateral portals and confirmed that the proximal anterolateral portal provides a larger soft tissue margin from the radial nerve and PACBN and implied that visualization of the anterior joint is superior. For these reasons the proximal anterolateral portal is used routinely for arthroscopic visualization of the anterior elbow joint. Whichever lateral portal is chosen to access the anterior aspect of the joint, the predominant anatomic structures available for viewing are the coronoid process and the trochlea. As these structures articulate, flexion and extension of the elbow can help better identify the coronoid and allows you to position it optimally for intra-articular work. Also, well-visualized from the lateral portal is the coronoid fossa, which accepts the coronoid process at extreme flexion, and is a common location for loose bodies (Fig. 9). Moving more distally in the joint one can visualize the brachialis insertion on the coronoid process, which is covered by a synovial sheath. Moving the arthroscope medially, the medial capsule as well as the anterior bundle of the medial collateral ligament can occasionally be appreciated. Moving more laterally, closer to the portal, one can visualize the radiocapitellar joint
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M.D. Budge and A.D. Armstrong the anterior aspect of the joint acts as a cushion to protect the median nerve and brachial artery. Once the joint had been entered medially, the radial head serves as a landmark, and can be identified as it rotates during forearm pronation and supination (Fig. 12). Proximal to the radial head is the anterosuperior portion of the capitellum and the bare radial fossa. On occasion, a synovial fold exists between the radial head and capitellum, which seems as a thin meniscus. Fibers of the annular ligament may be visible over the radial head. Sequlae of lateral epicondylitis may also be noted and occasionally you will observe a rent in the lateral capsule. Moving more medially, the coronoid, coronoid fossa, trochlea, and capsule may be visualized (Fig. 13).
Posterior Portal Anatomy and Placement Figure 9 Coronoid and trochlea as viewed from the anterolateral portal. (Reprinted with permission.24)
and above this the radial fossa (Fig. 10). There is typically a distinct ridge on the anterior humerus delineating the divide between the coronoid and radial fossa, and this ridge is often accentuated in arthritis of the elbow. Antero-Medial Portals The first portal described for medial entry into the elbow joint was the direct antero-medial portal.2,16 It is located 2 cm anterior and 2 cm distal to the medial epicondyle, and transverses the common flexor origin between the flexor carpi radialis and flexor digitorum superficialis before penetrating the pronator teres16 (Fig. 11). Because of its distal location in the forearm, the placement of this portal into the joint can only be made by directing the trochar laterally in the direction of the neurovascular structures.18 Cadaveric studies have shown that the median nerve is located close to the arthroscopic tract, with an average of 4-14 mm of clearance.16,19,21 The medial antebrachial cutaneous nerve is also at risk with an average of 1-4 mm of clearance from the portal entry site.16,19 Further away, but still of concern, are the brachial artery and ulnar nerve that have an average soft tissue clearance of 20-25 mm.16,19 Due to concerns over the proximity of the neurovascular structures, the more commonly used portal for medial entry into the joint is the proximal antero-medial portal. Located 1-2 cm proximal to the medial epicondyle and anterior to the intramuscular septum, this portal has the advantages of increased average distance from the median nerve of approximately 20 mm,18 although still providing full visualization of the joint.17-19 To place this portal, the elbow should be maintained at 90 degrees of flexion and the trochar should be directed toward the center of the joint anterior to the intramuscular septum. Care should be taken to ensure that the ulnar nerve does not subluxate anterior to the medial epicondyle with flexion of the elbow or it will be at risk for injury during placement of the antero-medial portals. Staying anterior to the medial intermuscular septum, which is easily palpable, will protect the ulnar nerve. The brachialis muscle on
Direct Posterior Portal The direct posterior or posterocentral portal is used for visualization of the tip of the olecranon, olecranon fossa, and the medial/lateral gutters of the posterior compartment of the elbow. It is placed in the midline of the posterior elbow approximately 3 cm proximal to the olecranon tip (Fig. 14). The portal tract directly pierces the triceps at the musculotendonous junction, and should be established with the elbow in 20-30 degrees of flexion to permit relaxation of the triceps. Although a safe portal compared with the anterior portals, there is still the risk of injury to the ulnar nerve and PABCN that lie approximately 25 mm away from the portal site in full extension.19 Establishment of this portal allows for removal of loose bodies from the posterior compartment as well as resection of osteophytes from the olecranon and olecranon fossa. Careful attention to the medial gutter and the proximity of the ulnar nerve is essential to prevent injury to the nerve. The posterolateral portals are the accessory portals for working within the posterior aspect of the elbow joint. They can be envisioned as beginning 2-3 cm proximal to the tip of
Figure 10 Radial head and capitellum as viewed from the anterolateral portal on the lateral side of the joint. (Reprinted with permission.24)
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Figure 11 Medial portal sites and underlying anatomy. (Reprinted with permission.24)
the olecranon along the lateral border of the triceps tendon (proximal posterolateral portal) and continuing distally in a straight-line until reaching the direct lateral portal at the “soft spot.” As with the direct posterior portal, the portal is established with the elbow in 20-30 degrees of flexion with the cannula inserted toward the olecranon fossa. The main dangers are the ulnar nerve and the PABCN,19 which should be safe from injury as long as the cannulas are kept lateral to the midline of the elbow. The main anatomic landmark of the posterior compartment is the tip of the olecranon that can be seen seating in the olecranon fossa with flexion and extension of the elbow (Fig. 15). The olecranon fossa itself is triangular or oval and frequently has significant osteophytes and loose bodies. The
postero-medial and posterolateral gutters are best seen in this compartment and can be visualized by directing the camera medially or laterally, respectively. The posterior capsule is also well seen in this compartment. More medially, the postero-medial aspect of the joint shows the vertically oriented fibers of the posterior band of the ulnar collateral ligament. Approximately fifty percent of the ligament can be visualized and, just superficial to this, lies the ulnar nerve23 (Fig. 16). Great care should be taken when working in this area. More laterally, the posterior radiocapitellar joint may be visualized.
Figure 12 Radial head and capitellum as viewed from the anteromedial portal. (Reprinted with permission.24)
Figure 13 Coronoid and coronoid fossa as viewed from the anteromedial portal. (Reprinted with permission.24)
Posterior Lateral Portal The posterolateral compartment of the elbow is often visualized through the direct lateral portal site, or the “soft
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Figure 14 Posterior portal sites and underlying anatomy. (Reprinted with permission.24)
spot,” as described by Poehling et al.3 The portal start site is located at the center of the triangle formed by the lateral epicondyle, olecranon process, and radial head and is most often used for visualization of the inferior-posterior aspect of the capitellum and the radioulnar articulation. Upon entering this compartment, the capitellum is the most obvious structure, as well as the radial head, as the scope is brought anteriorly. The radial head should be slightly concave on its most proximal surface, whereas the capitellum should be gently convex (Fig. 17). The scope can be redirected posteriorly and medially between the olecranon and trochlea. By looking down on the olecranon articular surface, a roughened area that lacks articular car-
tilage can commonly be observed, which denotes the apophyseal scar or bare area of the olecranon. By turning the scope anteriorly, the underside of the trochlea can be visualized. A distal posterolateral portal can be created along the posterolateral gutter and used as a viewing portal to facilitate arthroscopic work through the direct lateral portal. One may also appreciate a lateral plica, and it is not uncommon to find loose bodies within the posterolateral joint. A diagnostic arthroscopy of the elbow joint is not complete without looking in the posterolateral compartment. It can sometimes be useful to switch to a 2.9-mm arthroscope to allow more working room.
Figure 15 Olecranon tip and fossa as viewed from the posterior portal. (Reprinted with permission.24)
Figure 16 Medial gutter and ulnar nerve as viewed from the posterior portal. (Reprinted with permission.24)
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Figure 17 Radial head and capitellum as viewed from the posterior lateral portal. (Reprinted with permission.24)
Conclusions Elbow arthroscopy is an effective procedure for the diagnosis and treatment of a multitude of elbow pathologies. It is, however, a technically challenging procedure due to the small working space, proximity of neurovascular structures, and complex anatomy. A systematic approach to positioning, set up, and portal placement as well as a comprehensive knowledge of superficial and deep elbow anatomy can prevent complications and allow the safe performance of elbow arthroscopy.
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219 5. Eames MHA, Bain GI: Distal biceps tendon endoscopy and anterior elbow arthroscopy portal. Tech Shoulder Elbow Surg 7:139-142, 2006 6. Savoie FH: Guidelines to becoming an expert elbow Arthroscopist. Arthroscopy 23:1237-1240, 2007 7. Baker CL Jr, Baker CL III: Long-term Follow-up of arthroscopic treatment of lateral epicondylitis. Am J Sports Med 36:254-260, 2008 8. Baker CL, Jones GL: Arthroscopy of the elbow. Am J Sports Med 27: 251-264, 1999 9. Dodson DC, Altchek DW, Williams RJ, et al: Elbow arthroscopy. J Am Acad Orthop Surg 16:574-585, 2008 10. Kelly EW, Morrey BF, O’Driscoll SW: Complications of elbow arthroscopy. J Bone Joint Surg Am 83-A:25-34, 2001 11. Haapaniemi T, Berggren M, Adolfsson L: Complete transaction of the median and radial nerves during arthroscopic release of post-traumatic elbow contracture. Arthroscopy 15:784-787, 1999 12. Angelo RL: Advances in elbow arthroscopy. Orthopedics 16:10371046, 1993 13. O’Driscoll SW, Morrey BP, An KN: Intra-articular pressure and capacity of the elbow. Arthroscopy 6:100-103, 1990 14. Gallay SH, Richards RR, O’Driscoll SW: Intraarticular capacity and compliance of stiff and normal elbows. Arthroscopy 9:9-13, 1993 15. Steinmann SP: Elbow Arthroscopy. J Hand Surg 3:199-207, 2003 16. Lynch GJ, Meyers JF, Whipple TL, et al: Neurovascular anatomy and elbow arthroscopy: Inherent risks. Arthroscopy 2:190-197, 1986 17. Verhaar J, VanMameraen H, Brandsma A: Risks of neurovascular injury in elbow arthroscopy: Starting anteromedially or Anterolaterally. Arthroscopy 7:287-290, 1991 18. Lindenfeld TN: Medial approach in elbow arthroscopy. Am J Sports Med 18:413-417, 1990 19. Adolfsson L: Arthroscopy of the elbow joint: A cadaveric study of portal placement. J Shoulder Elbow Surg 3:53-61, 1994 20. Field LD, Altchek DW, Warren RF, et al: Arthroscopic anatomy of the lateral elbow: A comparison of three portals. Arthroscopy 10:602-607, 1994 21. Marshall PD, Fairclough JA, Johnson SR, et al: Avoiding nerve damage during elbow arthroscopy. J Bone Joint Surg Br 75B:129-131, 1993 22. Stothers K, Day B, Regan WR: Arthroscopy of the elbow: Anatomy, portal sites, and a description of the proximal lateral portal. Arthroscopy 11:449-457, 1995 23. Andrews JR, Baumgarten TE: Arthroscopic anatomy of the elbow. Orthop Clin North Am 26:671-677, 1995 24. Strigenz TJ, Armstrong AD: Elbow arthroscopy: Set-up, anatomy, and portal placement, in Levine WN, Blaine TA, Ahmad CS (eds): Minimally Invasive Shoulder and Elbow Surgery. New York, NY, Taylor and Francis, 2007, pp 301-312