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Clinical disorders of the acromioclavicular andsternoclavicular joints
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Clinical disorders of the acromioclavicular and sternoclavicular joints C H R I S T O P H E R R. CONSTANT
The clavicle is an important connecting bone between the trunk and the arm and forms a main anterior strut, on which muscles insert and from which other muscles originate. It maintains the distance between the acromion and the sternum, thus ensuring effective muscle tension in the deltotrapezius unit. Its 'S' shape, combined with the multi-axial hinged movement at its medial end, makes it a most effective 'crank'. Minimal displacement at the medial end is allied to considerable displacement in motion at the outer end. This mechanism, in turn, allows free mobility of the outer end of the shoulder girdle (the acromion). The anatomical and biomechanical considerations of the joints at either end of the clavicle, which are discussed in Chapter ], are important in understanding and appreciating the clinical problems affecting the acromioclavicular and sternoclavicular joints.
ACROMIOCLAVICULAR JOINT The main clinical entities affecting the acromioclavicular joint are osteoarthrosis and trauma. Instability of the acromioclavicular joint may be associated with either condition. Osteoarthrosis De Palma (1957) describes studies which indicate an increased incidence of osteoarthrosis in type 1 vertical joints. It is also the author's opinion that type 1 joints are more prone to develop osteoarthrosis. Osteoarthrosis of the acromioclavicular joint is frequently not recognized as a cause of major symptoms. The author feels that the condition is much more common than reported and is a cause of significant and remediable shoulder symptoms. Trauma is an important predisposing factor to osteoarthrosis in this joint. Clinical picture
The clinical picture of osteoarthrosis of the acromioclavicular joint is Bailli&e's ClinicalRheurnatology~Vol. 3, No. 3, December t989
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frequently characteristic. The patient presents with pain, often localized to the region of the acromioclavicular joint, which frequently radiates to the region of the deltotrapezius unit. The radiating ache is often relieved by supporting the arm in a sling. The pain is worse on activities above the horizontal level. Pain at night is caused by lying on the affected side. Turning over on to the affected side during the night usually wakes the patient with pain. Shoulder abduction power may be weak as a result of either pain or damage to the deltotrapezius muscle unit. R e m e m b e r that there may be an associated rotator cuff tear which will also cause weakness of abduction.
Examination findings In examining the acromioclavicular joint, it is important to note its contour, which will frequently indicate the joint pathology as well as indicating whether previous trauma has occurred. It is usually possible to see or feel upward-facing osteophytes i~(Figure 1). In pure acromioclavicular joint
Figure 1. Upward facing osteophytes in acromioclavicularosteoarthrosis. disease there is locaIized tenderness at the acromioclavicular joint and any manoeuvre which increases the pressure across the joint surfaces reproduces the pain. Particular manoeuvres which usually result in pain are adduction of the arm across the trunk in the horizontally placed position, elevation above 90~ abduction or forward flexion with firm pressure held on the outer end of the clavicle. Extension of the arm in the 90 ~ abducted position frequently does not cause pain, but extension of the adducted arm does. In the absence of secondary rotator cuff problems, shoulder power may or may not be normal. An important cause of strain to, and ultimately osteoarthrosis in, the acromioclavicular joint, is the repeated 'hiking up' of the shoulder girdle in patients in whom scapulothoracic rhythm is abnormal. This usually occurs in patients who have poor rotator cuff function or severe long-standing adhesive capsulitis. Elevation of the arm in many of these individuals is accompanied by a 'hiking up' of the affected shoulder, which in turn puts an
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excessive strain across the acromioclavicular joint. In a series at present being studied, the author has noted a late occurrence of symptoms related to acromioclavicular joint problems in patients in whom an unsatisfactory rotator cuff repair had been undertaken. Similar features also occurred in patients in whom conservative therapy had resulted in poor rotator cuff function. The development of such osteoarthrosis and pain usually begins 12-18 months after the abnormal shoulder hiking rhythm began.
Clinical sequelae There are three important sequelae of osteoarlhrosis of the acromioclavicular joint: (1) rotator cuff tear, (2) instability of the acromioclavicular joint, and (3) deltotrapezius incompetence, with or without perforation by osteophytes.
Rotator cuff tear. Downward facing osteophytes at the outer end of the clavicle (Figure 2) or on the acromial side of the acromioclavicular joint (Figure 3) frequently result in a secondary rotator cuff tear. The patient will often give a typical history of acromioclavicular joint pain and subsequent sudden onset of arm weakness, associated with further pain, often in the form of a painful arc. An arthrogram usually confirms the tear and may show evidence of a Geiser sign (FigUre 4), where contrast injected into the shoulder joint passes freely into the subacromial space, enters the acromioclavicular joint and travels upwards to the area of the deltotrapezius fascia.
Figure 2. Osteophytesat the outer end of the clavicle.
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Operative findings in these cases usually demonstrate a tendinous substance tear at the site where impingement with the osteophyte occurs. Excellent results are obtained by treatment with early excision acromioclavicular joint arthroplasty and simultaneous rotator cuff repair. In trying to distinguish between primary osteoarthrosis of the acromioclavicular joint and secondary rotator cuff tear, on the one hand, and primary rotator cuff
Figure 3. Acromial osteophytes.
Figure 4. Geiser sign on shoulder arthrogram.
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incompetence with associated secondary acromioclavicular joint arthrosis on the other, it is usual to see downward-facing osteophytes in the primary osteoarthrosis, while secondary osteoarthrosis does not demonstrate this feature. Secondary osteoarthrosis is frequently associated with radiological cysts and sclerosis in the outer end of the clavicle.
Joint instability. In the presence of osteoarthrosis of the acromioclavicular joint, mild anteroposterior and superoinferior instability occurs, usually as a result of deltotrapezius damage from osteophytic lipping of the outer end of the clavicle or acromion. It is frequently missed and should be checked for during the examination. Posterior subluxation of the clavicle in relation to the acromion is sometimes seen on axial radiographs and should be noted (Figure 5). An important part of an excision acromioclavicular joint arthroplasty is the stabilization procedure, which ensures both anteroposterior and superoinferior stability following the operation. Continuing instability after surgery was a common problem after excision of the outer end of the clavicle in bygone days, when the importance of deltotrapezius reconstruction was not understood. Instability, either as part of the arthritic process or as a postoperative problem after acromioclavicular joint excision arthroplasty, is a disabling problem and usually results in continuing pain and inability to use the arm above the horizontal level. During surgery to excise the acromioclavicular joint, it is important that the bony surfaces left behind are smoothed, so that sharp edges of bone do not tear through the reconstructed deltotrapezius
Figure 5. Posterior subluxationof the clavicle.
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fascial layer. Should any sharp bone be left behind, further perforation of the deltotrapezius layer may occur, with postoperative instability and problems related to deltotrapezius incompetence. Following surgery for acromioclavicular joint excision arthroplasty, an X-ray taken with the arm at rest (Figure 6) should show no evidence of upward dislocation of the outer end of the clavicle in relation to the acromion. Traction views should similarly show no evidence of upward displacement of the remaining outer end of clavicle. X-rays will, of course, show the increased space between the clavicle and acromion as a result of the excision.
Figure 6. Claviclestabilityfollowingexcision acromioclavicularjoint arthroplasty.
Deltotrapeziusincompetence. The problems of deltotrapezius incompetence and perforation have already been mentioned. The importance of deltotrapezius reconstruction following acromioclavicular joint surgery cannot be overemphasized. Pain in the region of the acromioclavicular joint is an important inhibitor of deltotrapezius function, and a localized, painful acromioclavicular joint can result in deltotrapezial incompetence and dropping of the shoulder. In this situation it is important to take a careful history and to distinguish the primary problem of osteoarthrosis of the acromioclavicular joint, with pain in that area, from the radiating pain described in the region of the deltotrapezius muscles due to secondary deltotrapezius irritation. A trial with local anaesthetic injection into the acromioclavicular joint usually relieves the symptoms of both the acromioclavicular joint pain and the radiating ache in the region of the deltotrapezius muscles. The use of a sling support may well relieve the deltotrapezius ache without significantly relieving the localized acromioclavicular joint pain. Awareness of acromioclavicular joint problems and the use of these two simple manoeuvres can usually allow a clear diagnosis to be made.
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Management In making a diagnosis of osteoarthrosis of the acromioclavicular joint, it is important to establish, before surgery, whether or not there is an associated rotator cuff tear. In the presence of maintainable normal shoulder power, it is unlikely that a significant rotator cuff tear will be present. However, it is the author's strong belief that a preoperative arthrogram should be obtained in all cases, as a rotator cuff tear may be present and may be difficult to identify at surgery. While it is true that many patients with a small rotator cuff tear in association with arthrosis of the acromioclavicular joint may well heal the tear following satisfactory surgery for the acromioclavicular joint, the author does not believe that this is a satisfactory course of management, and feels that an accompanying rotator cuff tear should be dealt with at the time of any surgery to the acromioclavicular joint. Surgery for osteoarthrosis of the acromioclavicular joint usually consists of an excision arthroplasty of the joint, with careful reconstruction of the deltotrapezius fascia in order to restore proper stability. Careful surgical technique is required to ensure that a reasonable layer of deltotrapezius fascia can be reconstituted at the end of the operative procedure. Regardless of whether pain, instability, deltotrapezius incompetence, with or without perforation, or a combination of any or all of these are the primary presenting symptoms, excision acromioclavicular joint arthroplasty with deltotrapezius reconstruction gives satisfactory results. Following such a procedure, in the absence of the need to repair a rotator cuff tear, surgery can be expected to give near normal function some 4-6 months postoperatively. In cases where a rotator cuff repair has also been undertaken, the recovery from the point of view of the acromioclavicular joint is usually satisfactory; however, overall shoulder functional recovery may take a great deal longer to achieve.
Trauma
In considering trauma to the acromioclavicular joint region, there are two groups of injuries to be discussed: (1) fractures of the outer end of the clavicle, and (2) acromioclavicular joint sprains, subluxations and dislocations.
Fractures Neer (1963, 1968) classified these fractures into three types. Type 1 consists of undisplaced fractures of the outer end of the clavicle in which no instability or deformity of the acromioclavicular joint occurs. Type 2 is a fracture of the outer end of the clavicle, effectively resulting in an upward dislocation of the outer end together with the acromioclavicular joint. These fractures frequently heal with deformity, resulting in a late occurrence of secondary osteoarthrosis of the acromioclavicular joint. Treatment of the acromioclavicular joint problem is as already discussed for osteoarthrosis. T y p e 3 fractures are those of the outer end of the clavicle which are comminuted and involve the articular surface of the acromioclavicular joint.
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These fractures are associated with late, stable osteoarthrosis of the acromioclavicular joint; their treatment is along the lines already discussed. Sprains, subluxations and dislocations The second major group of injuries to the acromioclavicular joint are the sprains, subluxations and dislocations. Traditionally, textbooks describe three grades of injury to the acromioclavicular joint; however, more recently it has been recognized that six grades can be identified. Grade 1. This is a sprain of the soft tissue ligament structures around the acromioclavicular joint, without resultant instability. The patient complains of pain following an injury; clinical examination reveals no deformity but there is tenderness in the region of the joint. X-rays show no evidence of fracture and no instability on traction. Symptomatic treatment with a sling results in satisfactory recovery from pain over a period of 4-6 weeks and full recovery of function by 3 months following the injury. Occasionally symptoms persist and further investigations reveal an osteochondral defect in the articular surface of the clavicle. In this situation, d6bridement of the acromioclavicular joint and minimal excision arthroplasty frequently relieve the problem. Grade 2. This is a subluxation of the acromioclavicular joint, with the acromion going downwards and the lateral end of the clavicle travelling upwards. The deltotrapezius unit is not ruptured in this injury, but stretching of the inferior acromioclavicular ligaments occurs, and there is also stretching and partial tear of the vertical coracoclavicular ligaments. Examination reveals a 'bump' in the region of the outer end of the clavicle, which is painful, tender and radiologically stable on traction views. In the majority of cases, treatment should be conservative. The bump may remain, or improve with the passage of time, and pain relief is usually complete within 6-8 weeks. Functional mobility of the shoulder also returns in that time with the appropriate use of painless, graded exercises. A late consequence of this injury is osteoarthrosis of the acromioclavicular joint with deformity, but without instability, and treatment along the lines mentioned for primary osteoarthrosis should be undertaken. It is most unusual for an associated rotator cuff injury to occur in association with the late occurrence of osteoarthrosis following this injury. Grade 3. This is a dislocation of the acromioclavicular joint with preservation of the deltotrapezius unit and complete rupture of the vertical coracoclavicular ligaments. This injury results in a significant bump in the region of the outer end of the clavicle, a definite instability on traction, and a permanent, unsightly bump which varies in size with the position of the arm. In this injury it is important to note that the deltotrapezius fascial layer is stretched, but intact, and it is therefore possible to reduce this dislocation clinically by downward pressure on the clavicle and upward pressure on the elbow, displacing the acromion upwards. Should reduction in this way not be possible, then the injury is more severe than grade 3. Treatment for grade 3
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injuries depends on the particular activities of the patient. The majority of patients will do perfectly well on conservative treatment. If the unsightly bump is not a problem, restoration of painless motion and function occurs within a period of 2-3 months following injury. People in whom surgery may have to be considered to stabilize the joint include hod carriers and others whose occupation involves placement of objects directly upon their shoulders; overarm sporting enthusiasts and gymnasts. Surgery in such cases should consist of examination of the articular surfaces of the joint and the disc in between. Reconstitution of the acromioclavicular joint anatomy by reduction of the clavicle into its normal position, with or without minimal excision of the outer end of the clavicle if damage is present, and careful reconstitution of the deltotrapezius fascia overlying the joint is undertaken. The use of a vertical retaining screw, or horizontally placed screws or threaded wires, as an adjunct for maintaining stability for a temporary period while the repair is healing, may or may not be considered necessary. It is the author's practice not to use such devices unless there is good reason to do so. It is important that any hardware used to fix the acromioclavicular joint should be removed prior to any attempt at elevation above the horizontal level. Remember that wires can migrate, with disastrous consequences. The results of surgical treatment for the grade 3 acromioclavicular joint injury are very satisfactory and full functional recovery can be expected to occur over a period of 3 months. Grade 4. The specific feature of a grade 4 injury is perforation or rupture of the deltotrapezius fascial layer overlying the acromioclavicular joint. This results in a palpable subcutaneous outer tip of the clavicle which is irreducible. A physical sign, frequently seen, is a dimple overlying the outer end of the clavicle, which increases on attempts to reduce the clavicle downwards into its normal position. Treatment for this injury is always surgical, aiming to reduce the dislocation and stabilize the acromioclavicular joint, with or without outer clavicular excision. If properly done, the results of surgery are excellent. The importance of the deltotrapezius damage cannot be stressed sufficiently; it is not infrequent for this injury to be classified as a grade 3 and treated conservatively with poor functional results. Grade 5. This is a severe injury where deltotrapezius damage is so extensive as to allow multidirectional instability of the outer end of the clavicle. There is frequently a significant posterior dislocation of the clavicle into the supraspinous fossa. Treatment for this uncommon degree of injury is always surgical. Grade 6. The grade 6 injury is a catastrophic subcoracoid dislocation of the clavicle, usually associated with major neurovascular disruption and generally occurring as a result of extreme combined hyperextension and downward force on to the clavicle. In those patients who survive this injury, surgery to relieve the dislocation must be an urgent consideration. Appropriate treatment for the commonly occurring accompanying vascular injuries should also be undertaken.
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Late consequences of trauma
It is apparent from the above that osteoarthrosis, long-term deformity, and, in some instances, persistent instability are consequences of acromioclavicular joint trauma. Excision arthroplasty, trimming of the bump, as described by Rowe (1962), and deltotrapezius stabilization give good results in post-traumatic late osteoarthrosis of the acromioclavicular joint. It is the author's view that the acromioclavicular joint is frequently wrongly dismissed as a cause of shoulder symptoms, that disorders affecting the acromioclavicular joint are not uncommon and that, with judicious use of the procedures described in this chapter, a significant improvement in overall shoulder function can be achieved. The author stresses the importance of meticulous attention to the deltotrapezius unit in all acromioclavicular joint surgery.
THE STERNOCLAVICULAR JOINT It is noted that the clavicle is the first bone to show ossification centres and the last in which the epiphyses finally close. The sternoclavicular joint is a small but very strong joint and, together with the scapulothoracic joint, forms the main junction between the trunk and the upper limb girdle. Anatomy Anatomically, the joint is a non-congruous synovial joint with an intraarticular disc. Multi-axial movements occur with elevation and rotation of the shoulder but the overall excursion of movements within the sternoclavicular joint is small. The most noteworthy anatomical feature of the joint, when one considers the incongruous nature of the joint surfaces, is its immense stability. This stability is achieved by a strong costoclavicular ligament, a large triangular anterior ligament, and a very strong interclavicular ligament running from the medial end of one clavicle, across the sternoclavicular joint, across the upper end of the manubrium, across the opposite sternoclavicular joint and on to the opposite clavicle. The interclavicular ligament maintains clavicular poise (Beam, 1967) and is effectively a superior thickening of the capsule of both sternoclavicular joints. Conditions affecting the sternoclavicular joint The three conditions affecting the sternoclavicular joint are: (1) osteoarthrosis with osteophyte formation, (2) pain and swelling, which is often non-specific or may prove to be the first manifestation of subsequent rheumatoid disease, and (3) instability, which may be either due to a congenital laxity, in which case it often involves both joints and may be voluntary in nature, or is traumatic.
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Osteoarthrosis with osteophyte formation (Figure 7) Inferior osteophyte formation is a not uncommon finding in patients with a painful sternoclavicular joint. It usually occurs in the sixth decade onwards, may be asymptomatic and discovered only on routine X-rays, or may present with significant pain on movements of the shoulder. Instability is not a specific feature of osteoarthrosis of the sternoclavicular joint and will be dealt with as a separate entity.
Figure 7. Osteophyte formation at the medial end of the clavicle.
The treatment of asymptomatic osteophyte formation or osteoarthrosis of the sternoclavicular joint is masterly inactivity. The condition frequently remains asymptomatic indefinitely. Should symptoms become apparent, then conservative treatment with analgesics, non-steroidal anti-inflammatories and a course of perhaps three steroid injections, frequently reduces symptoms to a tolerable level. Should symptoms persist after a reasonable period of conservative management, then surgery to excise the osteophyte and ddbride the joint frequently gives good relief. In occasional cases an excision of the medial end.of the clavicle is necessary. Should such a procedure be undertaken, it is of great importance that the muscle layers overlying the clavicle (platysma, sternomastoid and pectoralis major) be carefully reconstructed after excision in order to avoid instability of the remaining medial end of the clavicle. Such instability is a disabling condition, and can be avoided by careful reconstruction of the aforementioned muscle layers.
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Pain and swelling Pain and swelling in the region of the medial end of the clavicle is a condition frequently seen in people in both their third and fourth decades, as well as in later life. It affects both men and women, and is occasionally a forerunner of frank rheumatoid disease. Frequently, however, it is a non-specific condition for which no apparent cause is ultimately detected. Management consists primarily in the exclusion of serious problems, and many cases settle spontaneously. The patient frequently presents with a painful swelling in the region of the sternoclavicular joint without a history of previous injury or joint problems. The onset is usually insidious and symptoms may be quite severe. It is frequently temporarily relieved by aspirin and other antiinflammatory agents. Clinical examination reveals diffuse swelling of the medial end of the clavicle and sternoclavicular joint, without an effusion in the sternoclavicular joint being apparent. Manoeuvring the upper limb so as to stress the sternoclavicular joint into horizontal compression frequently aggravates symptoms so that the patient finds it difficult to lie on the shoulder of the affected side. As mentioned, the diagnosis includes exclusion of a serious pathology. It is sometimes difficult to be sure that a fracture or dislocation is not present. Investigations should therefore include plain X-rays as well as routine tomograms, with computerized tomographic scanning if the tomograms do not clarify the position. Routine haematological investigations should include erythrocyte sedimentation rate, rheumatoid factor and serum uric acid. Treatment of this condition is primarily symptomatic and should consist of analgesics, anti-inflammatories and supportive therapy, with advice to sleep on the opposite side, avoiding activities which cause pain, and awaiting spontaneous resolution. The majority of cases spontaneously resolve after a course of intermittent symptoms over a lengthy period of time. It is frequently 2 years or more before symptoms completely settle. Permanent, slight thickening in the region is frequently present, but in the absence of symptoms should not give cause for concern. If symptoms persist after a reasonable and extended course of conservative therapy, then excision arthroplasty with removal of the medial end of the clavicle can usually resolve them. It must be stressed, however, that the swelling is frequently not helped by this procedure and, indeed, an unsightly scar frequently follows surgery in this area.
Instability Two types of instability in the sternoclavicular joint are described: spontaneous and traumatic.
Spontaneous instability. Spontaneous, habitual or, indeed, voluntary dislocation of the sternoclavicutar joints frequently dates back to teenage years, is more frequent in girls than boys, is usually asymptomatic, and is demonstrated by the patient as a voluntary ability to dislocate both sterno-
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clavicular joints anteriorly or superiorly with minimal effort. It can sometimes be present as an entirely involuntary symptom, without the patient's own voluntary effort to produce the dislocations. In treating spontaneous or voluntary instability, the patient should be strongly advised to avoid such dislocations. Surgical treatment should be reserved for those in whom serious attempts to avoid dislocation on a voluntary basis have proved unsuccessful, and in whom symptoms are disabling. In the rare situation where treatment for such spontaneous dislocation is required, one of the procedures described below may be appropriate. It should be remembered that the results of surgical treatment for symptomatic spontaneous recurrent instability of the sternoclavicular joint depend entirely on the patient's own motivation to avoid further dislocations in the future. A determined voluntary attempt at sternoclavicular dislocation will always disrupt a surgical reconstruction. Traumatic dislocation. The sternoclavicular joint accounts for 1% of all dislocations of the shoulder girdle. Traumatic posterior dislocation of the sternoclavicular joint is common in major chest injuries and in 'roll over' and 'crush' injuries. The direction of dislocations may be anterior, superior or posterior. Traditionally, the posterior dislocation occurs as mentioned in the 'roll over' or 'crush' injuries, and in major chest injuries, while the anterior dislocation occurs in forced hyperextension of both shoulders and is classically seen in the cyclist or motorcyclist whose shoulder fails to clear a vertical object, such as a lamp post. Superior dislocation results from a variety of injuries in which either a direct downward force to the outer end of the clavicle, or a direct upward force to the inner half of the clavicle, is applied. The anterior and superior dislocations can usually be easily diagnosed by the obvious deformity and visible dislocation of the joint. Posterior dislocation may not be obvious clinically, and may present with airway obstruction, major vessel obstruction in the thoracic inlet, rapid loss of consciousness, and death. While reduction of the anterior and superior dislocation can be delayed without significant ill effect, delay in reduction of a posterior dislocation of the ste.rnoclavicular joint may well prove fatal. It is, therefore, essential that a rapid reduction is performed. Diagnosis of the posterior dislocation is based on clinical grounds. It is sometimes possible to demonstrate the problem on X-ray, using 40 ~ angulation skyline views, which are frequently unhelpful, and tomograms, which will usually confirm the diagnosis. Treatment of the posterior dislocation is usually a matter of extreme urgency. Reduction is usually achieved by placing a sandbag between the shoulder blades, traction is applied to the arms, and the clavicle is pulled forward at the same time. Such anterior traction may be achieved by thumb ' and forefinger grasping the medial end of the clavicle; in some instances the use of a large towel clip may be necessary. Although painful, this is an extremely effective way of reducing the dislocation and saving life. The anterior and superior dislocations can generally be reduced by pressure but usually continue to be unstable, and recurrent dislocation is
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frequent. Conversely, the posterior dislocation, once reduced, is usually stable and no further treatment is necessary. If recurrent superior or anterior dislocation of the sternoclavicular joint becomes a symptomatic problem, then operative stabilization may be undertaken. Over the years, a variety of methods have been described by numerous authors, including the use of fascia lata by B a t e m a n (1978) and the subclavius tendon by Burrows (1951). Other methods of stabilization include excision of the medial end of the clavicle, arthrodesis of the sternoclavicular joint, the use of Steinmann pin fixation and the use of clavicular osteotomy, none of which are regularly used nowadays. T h e author's preference is for direct repair of the anterior ligament in cases where such a ligament is present, thickened and stretched. The author now has a series of six such cases, where long-term stability with follow-up of over 4 years has been recorded. In the absence of sufficient tissue to obtain such a repair, the Burrows subclavian tendon transfer is a useful technique and provides good long-term results. In the young, sportsminded individual, the author prefers the use of fascia lata from the thigh, looped around the clavicle and either through or under the first rib, using a further length of fascia lata to reinforce the anterior ligament. Results in three such cases have proved successful, with the patient returning to a preinjury level of sporting activity without problems.
CONCLUSION The acromioclavicular and sternoclavicular joints are small but important joints among the complex joints of the shoulder girdle. Problems affecting these joints can be functionally disabling. Effective treatment is possible for m a n y of the c o m m o n afflictions affecting these joints.
REFERENCES Bateman JE (1978) The Shoulder and Neck, 2nd edn, p 546. Philadelphia: WB Saunders. Bearn JG (1967) Direct observations on the function of the capsule of the sternoclavicularjoint in clavicular support. Journal of Anatomy 101: 159-179. Burrows HJ (1951) Tenodesis of subclavius in the treatment of recurrent dislocation of the sternoclavicular joint. Journal of Bone and Joint Surgery 33B: 240. De Palma AF (1957) Degenerative changes in sternoclavicular and acromioclavicularjoints in various decades, p 118. Springfield IL: CC Thomas. Neer CS I! (1963) Fracture of the distal clavicle with detachment of the coracoclavicular ligaments in adults. Journal of Trauma 3: 99-110. Neer CS II (1968) Fractures of the distal third of the clavicle. Clinical Orthopaedics 58: 43-50. Rowe CR (1962) Symposium on surgical lesions of the shoulder: acute and recurrent dislocations of the shoulder. Journal of Bone and Joint Surgery 44A: 997-1012.
Clinical disorders of the acromioclavicular and sternoclavicular joints C H R I S T O P H E R R. CONSTANT
The clavicle is an important connecting bone between the trunk and the arm and forms a main anterior strut, on which muscles insert and from which other muscles originate. It maintains the distance between the acromion and the sternum, thus ensuring effective muscle tension in the deltotrapezius unit. Its 'S' shape, combined with the multi-axial hinged movement at its medial end, makes it a most effective 'crank'. Minimal displacement at the medial end is allied to considerable displacement in motion at the outer end. This mechanism, in turn, allows free mobility of the outer end of the shoulder girdle (the acromion). The anatomical and biomechanical considerations of the joints at either end of the clavicle, which are discussed in Chapter ], are important in understanding and appreciating the clinical problems affecting the acromioclavicular and sternoclavicular joints.
ACROMIOCLAVICULAR JOINT The main clinical entities affecting the acromioclavicular joint are osteoarthrosis and trauma. Instability of the acromioclavicular joint may be associated with either condition. Osteoarthrosis De Palma (1957) describes studies which indicate an increased incidence of osteoarthrosis in type 1 vertical joints. It is also the author's opinion that type 1 joints are more prone to develop osteoarthrosis. Osteoarthrosis of the acromioclavicular joint is frequently not recognized as a cause of major symptoms. The author feels that the condition is much more common than reported and is a cause of significant and remediable shoulder symptoms. Trauma is an important predisposing factor to osteoarthrosis in this joint. Clinical picture
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frequently characteristic. The patient presents with pain, often localized to the region of the acromioclavicular joint, which frequently radiates to the region of the deltotrapezius unit. The radiating ache is often relieved by supporting the arm in a sling. The pain is worse on activities above the horizontal level. Pain at night is caused by lying on the affected side. Turning over on to the affected side during the night usually wakes the patient with pain. Shoulder abduction power may be weak as a result of either pain or damage to the deltotrapezius muscle unit. R e m e m b e r that there may be an associated rotator cuff tear which will also cause weakness of abduction.
Examination findings In examining the acromioclavicular joint, it is important to note its contour, which will frequently indicate the joint pathology as well as indicating whether previous trauma has occurred. It is usually possible to see or feel upward-facing osteophytes i~(Figure 1). In pure acromioclavicular joint
Figure 1. Upward facing osteophytes in acromioclavicularosteoarthrosis. disease there is locaIized tenderness at the acromioclavicular joint and any manoeuvre which increases the pressure across the joint surfaces reproduces the pain. Particular manoeuvres which usually result in pain are adduction of the arm across the trunk in the horizontally placed position, elevation above 90~ abduction or forward flexion with firm pressure held on the outer end of the clavicle. Extension of the arm in the 90 ~ abducted position frequently does not cause pain, but extension of the adducted arm does. In the absence of secondary rotator cuff problems, shoulder power may or may not be normal. An important cause of strain to, and ultimately osteoarthrosis in, the acromioclavicular joint, is the repeated 'hiking up' of the shoulder girdle in patients in whom scapulothoracic rhythm is abnormal. This usually occurs in patients who have poor rotator cuff function or severe long-standing adhesive capsulitis. Elevation of the arm in many of these individuals is accompanied by a 'hiking up' of the affected shoulder, which in turn puts an
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excessive strain across the acromioclavicular joint. In a series at present being studied, the author has noted a late occurrence of symptoms related to acromioclavicular joint problems in patients in whom an unsatisfactory rotator cuff repair had been undertaken. Similar features also occurred in patients in whom conservative therapy had resulted in poor rotator cuff function. The development of such osteoarthrosis and pain usually begins 12-18 months after the abnormal shoulder hiking rhythm began.
Clinical sequelae There are three important sequelae of osteoarlhrosis of the acromioclavicular joint: (1) rotator cuff tear, (2) instability of the acromioclavicular joint, and (3) deltotrapezius incompetence, with or without perforation by osteophytes.
Rotator cuff tear. Downward facing osteophytes at the outer end of the clavicle (Figure 2) or on the acromial side of the acromioclavicular joint (Figure 3) frequently result in a secondary rotator cuff tear. The patient will often give a typical history of acromioclavicular joint pain and subsequent sudden onset of arm weakness, associated with further pain, often in the form of a painful arc. An arthrogram usually confirms the tear and may show evidence of a Geiser sign (FigUre 4), where contrast injected into the shoulder joint passes freely into the subacromial space, enters the acromioclavicular joint and travels upwards to the area of the deltotrapezius fascia.
Figure 2. Osteophytesat the outer end of the clavicle.
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Operative findings in these cases usually demonstrate a tendinous substance tear at the site where impingement with the osteophyte occurs. Excellent results are obtained by treatment with early excision acromioclavicular joint arthroplasty and simultaneous rotator cuff repair. In trying to distinguish between primary osteoarthrosis of the acromioclavicular joint and secondary rotator cuff tear, on the one hand, and primary rotator cuff
Figure 3. Acromial osteophytes.
Figure 4. Geiser sign on shoulder arthrogram.
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incompetence with associated secondary acromioclavicular joint arthrosis on the other, it is usual to see downward-facing osteophytes in the primary osteoarthrosis, while secondary osteoarthrosis does not demonstrate this feature. Secondary osteoarthrosis is frequently associated with radiological cysts and sclerosis in the outer end of the clavicle.
Joint instability. In the presence of osteoarthrosis of the acromioclavicular joint, mild anteroposterior and superoinferior instability occurs, usually as a result of deltotrapezius damage from osteophytic lipping of the outer end of the clavicle or acromion. It is frequently missed and should be checked for during the examination. Posterior subluxation of the clavicle in relation to the acromion is sometimes seen on axial radiographs and should be noted (Figure 5). An important part of an excision acromioclavicular joint arthroplasty is the stabilization procedure, which ensures both anteroposterior and superoinferior stability following the operation. Continuing instability after surgery was a common problem after excision of the outer end of the clavicle in bygone days, when the importance of deltotrapezius reconstruction was not understood. Instability, either as part of the arthritic process or as a postoperative problem after acromioclavicular joint excision arthroplasty, is a disabling problem and usually results in continuing pain and inability to use the arm above the horizontal level. During surgery to excise the acromioclavicular joint, it is important that the bony surfaces left behind are smoothed, so that sharp edges of bone do not tear through the reconstructed deltotrapezius
Figure 5. Posterior subluxationof the clavicle.
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fascial layer. Should any sharp bone be left behind, further perforation of the deltotrapezius layer may occur, with postoperative instability and problems related to deltotrapezius incompetence. Following surgery for acromioclavicular joint excision arthroplasty, an X-ray taken with the arm at rest (Figure 6) should show no evidence of upward dislocation of the outer end of the clavicle in relation to the acromion. Traction views should similarly show no evidence of upward displacement of the remaining outer end of clavicle. X-rays will, of course, show the increased space between the clavicle and acromion as a result of the excision.
Figure 6. Claviclestabilityfollowingexcision acromioclavicularjoint arthroplasty.
Deltotrapeziusincompetence. The problems of deltotrapezius incompetence and perforation have already been mentioned. The importance of deltotrapezius reconstruction following acromioclavicular joint surgery cannot be overemphasized. Pain in the region of the acromioclavicular joint is an important inhibitor of deltotrapezius function, and a localized, painful acromioclavicular joint can result in deltotrapezial incompetence and dropping of the shoulder. In this situation it is important to take a careful history and to distinguish the primary problem of osteoarthrosis of the acromioclavicular joint, with pain in that area, from the radiating pain described in the region of the deltotrapezius muscles due to secondary deltotrapezius irritation. A trial with local anaesthetic injection into the acromioclavicular joint usually relieves the symptoms of both the acromioclavicular joint pain and the radiating ache in the region of the deltotrapezius muscles. The use of a sling support may well relieve the deltotrapezius ache without significantly relieving the localized acromioclavicular joint pain. Awareness of acromioclavicular joint problems and the use of these two simple manoeuvres can usually allow a clear diagnosis to be made.
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Management In making a diagnosis of osteoarthrosis of the acromioclavicular joint, it is important to establish, before surgery, whether or not there is an associated rotator cuff tear. In the presence of maintainable normal shoulder power, it is unlikely that a significant rotator cuff tear will be present. However, it is the author's strong belief that a preoperative arthrogram should be obtained in all cases, as a rotator cuff tear may be present and may be difficult to identify at surgery. While it is true that many patients with a small rotator cuff tear in association with arthrosis of the acromioclavicular joint may well heal the tear following satisfactory surgery for the acromioclavicular joint, the author does not believe that this is a satisfactory course of management, and feels that an accompanying rotator cuff tear should be dealt with at the time of any surgery to the acromioclavicular joint. Surgery for osteoarthrosis of the acromioclavicular joint usually consists of an excision arthroplasty of the joint, with careful reconstruction of the deltotrapezius fascia in order to restore proper stability. Careful surgical technique is required to ensure that a reasonable layer of deltotrapezius fascia can be reconstituted at the end of the operative procedure. Regardless of whether pain, instability, deltotrapezius incompetence, with or without perforation, or a combination of any or all of these are the primary presenting symptoms, excision acromioclavicular joint arthroplasty with deltotrapezius reconstruction gives satisfactory results. Following such a procedure, in the absence of the need to repair a rotator cuff tear, surgery can be expected to give near normal function some 4-6 months postoperatively. In cases where a rotator cuff repair has also been undertaken, the recovery from the point of view of the acromioclavicular joint is usually satisfactory; however, overall shoulder functional recovery may take a great deal longer to achieve.
Trauma
In considering trauma to the acromioclavicular joint region, there are two groups of injuries to be discussed: (1) fractures of the outer end of the clavicle, and (2) acromioclavicular joint sprains, subluxations and dislocations.
Fractures Neer (1963, 1968) classified these fractures into three types. Type 1 consists of undisplaced fractures of the outer end of the clavicle in which no instability or deformity of the acromioclavicular joint occurs. Type 2 is a fracture of the outer end of the clavicle, effectively resulting in an upward dislocation of the outer end together with the acromioclavicular joint. These fractures frequently heal with deformity, resulting in a late occurrence of secondary osteoarthrosis of the acromioclavicular joint. Treatment of the acromioclavicular joint problem is as already discussed for osteoarthrosis. T y p e 3 fractures are those of the outer end of the clavicle which are comminuted and involve the articular surface of the acromioclavicular joint.
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These fractures are associated with late, stable osteoarthrosis of the acromioclavicular joint; their treatment is along the lines already discussed. Sprains, subluxations and dislocations The second major group of injuries to the acromioclavicular joint are the sprains, subluxations and dislocations. Traditionally, textbooks describe three grades of injury to the acromioclavicular joint; however, more recently it has been recognized that six grades can be identified. Grade 1. This is a sprain of the soft tissue ligament structures around the acromioclavicular joint, without resultant instability. The patient complains of pain following an injury; clinical examination reveals no deformity but there is tenderness in the region of the joint. X-rays show no evidence of fracture and no instability on traction. Symptomatic treatment with a sling results in satisfactory recovery from pain over a period of 4-6 weeks and full recovery of function by 3 months following the injury. Occasionally symptoms persist and further investigations reveal an osteochondral defect in the articular surface of the clavicle. In this situation, d6bridement of the acromioclavicular joint and minimal excision arthroplasty frequently relieve the problem. Grade 2. This is a subluxation of the acromioclavicular joint, with the acromion going downwards and the lateral end of the clavicle travelling upwards. The deltotrapezius unit is not ruptured in this injury, but stretching of the inferior acromioclavicular ligaments occurs, and there is also stretching and partial tear of the vertical coracoclavicular ligaments. Examination reveals a 'bump' in the region of the outer end of the clavicle, which is painful, tender and radiologically stable on traction views. In the majority of cases, treatment should be conservative. The bump may remain, or improve with the passage of time, and pain relief is usually complete within 6-8 weeks. Functional mobility of the shoulder also returns in that time with the appropriate use of painless, graded exercises. A late consequence of this injury is osteoarthrosis of the acromioclavicular joint with deformity, but without instability, and treatment along the lines mentioned for primary osteoarthrosis should be undertaken. It is most unusual for an associated rotator cuff injury to occur in association with the late occurrence of osteoarthrosis following this injury. Grade 3. This is a dislocation of the acromioclavicular joint with preservation of the deltotrapezius unit and complete rupture of the vertical coracoclavicular ligaments. This injury results in a significant bump in the region of the outer end of the clavicle, a definite instability on traction, and a permanent, unsightly bump which varies in size with the position of the arm. In this injury it is important to note that the deltotrapezius fascial layer is stretched, but intact, and it is therefore possible to reduce this dislocation clinically by downward pressure on the clavicle and upward pressure on the elbow, displacing the acromion upwards. Should reduction in this way not be possible, then the injury is more severe than grade 3. Treatment for grade 3
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injuries depends on the particular activities of the patient. The majority of patients will do perfectly well on conservative treatment. If the unsightly bump is not a problem, restoration of painless motion and function occurs within a period of 2-3 months following injury. People in whom surgery may have to be considered to stabilize the joint include hod carriers and others whose occupation involves placement of objects directly upon their shoulders; overarm sporting enthusiasts and gymnasts. Surgery in such cases should consist of examination of the articular surfaces of the joint and the disc in between. Reconstitution of the acromioclavicular joint anatomy by reduction of the clavicle into its normal position, with or without minimal excision of the outer end of the clavicle if damage is present, and careful reconstitution of the deltotrapezius fascia overlying the joint is undertaken. The use of a vertical retaining screw, or horizontally placed screws or threaded wires, as an adjunct for maintaining stability for a temporary period while the repair is healing, may or may not be considered necessary. It is the author's practice not to use such devices unless there is good reason to do so. It is important that any hardware used to fix the acromioclavicular joint should be removed prior to any attempt at elevation above the horizontal level. Remember that wires can migrate, with disastrous consequences. The results of surgical treatment for the grade 3 acromioclavicular joint injury are very satisfactory and full functional recovery can be expected to occur over a period of 3 months. Grade 4. The specific feature of a grade 4 injury is perforation or rupture of the deltotrapezius fascial layer overlying the acromioclavicular joint. This results in a palpable subcutaneous outer tip of the clavicle which is irreducible. A physical sign, frequently seen, is a dimple overlying the outer end of the clavicle, which increases on attempts to reduce the clavicle downwards into its normal position. Treatment for this injury is always surgical, aiming to reduce the dislocation and stabilize the acromioclavicular joint, with or without outer clavicular excision. If properly done, the results of surgery are excellent. The importance of the deltotrapezius damage cannot be stressed sufficiently; it is not infrequent for this injury to be classified as a grade 3 and treated conservatively with poor functional results. Grade 5. This is a severe injury where deltotrapezius damage is so extensive as to allow multidirectional instability of the outer end of the clavicle. There is frequently a significant posterior dislocation of the clavicle into the supraspinous fossa. Treatment for this uncommon degree of injury is always surgical. Grade 6. The grade 6 injury is a catastrophic subcoracoid dislocation of the clavicle, usually associated with major neurovascular disruption and generally occurring as a result of extreme combined hyperextension and downward force on to the clavicle. In those patients who survive this injury, surgery to relieve the dislocation must be an urgent consideration. Appropriate treatment for the commonly occurring accompanying vascular injuries should also be undertaken.
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Late consequences of trauma
It is apparent from the above that osteoarthrosis, long-term deformity, and, in some instances, persistent instability are consequences of acromioclavicular joint trauma. Excision arthroplasty, trimming of the bump, as described by Rowe (1962), and deltotrapezius stabilization give good results in post-traumatic late osteoarthrosis of the acromioclavicular joint. It is the author's view that the acromioclavicular joint is frequently wrongly dismissed as a cause of shoulder symptoms, that disorders affecting the acromioclavicular joint are not uncommon and that, with judicious use of the procedures described in this chapter, a significant improvement in overall shoulder function can be achieved. The author stresses the importance of meticulous attention to the deltotrapezius unit in all acromioclavicular joint surgery.
THE STERNOCLAVICULAR JOINT It is noted that the clavicle is the first bone to show ossification centres and the last in which the epiphyses finally close. The sternoclavicular joint is a small but very strong joint and, together with the scapulothoracic joint, forms the main junction between the trunk and the upper limb girdle. Anatomy Anatomically, the joint is a non-congruous synovial joint with an intraarticular disc. Multi-axial movements occur with elevation and rotation of the shoulder but the overall excursion of movements within the sternoclavicular joint is small. The most noteworthy anatomical feature of the joint, when one considers the incongruous nature of the joint surfaces, is its immense stability. This stability is achieved by a strong costoclavicular ligament, a large triangular anterior ligament, and a very strong interclavicular ligament running from the medial end of one clavicle, across the sternoclavicular joint, across the upper end of the manubrium, across the opposite sternoclavicular joint and on to the opposite clavicle. The interclavicular ligament maintains clavicular poise (Beam, 1967) and is effectively a superior thickening of the capsule of both sternoclavicular joints. Conditions affecting the sternoclavicular joint The three conditions affecting the sternoclavicular joint are: (1) osteoarthrosis with osteophyte formation, (2) pain and swelling, which is often non-specific or may prove to be the first manifestation of subsequent rheumatoid disease, and (3) instability, which may be either due to a congenital laxity, in which case it often involves both joints and may be voluntary in nature, or is traumatic.
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Osteoarthrosis with osteophyte formation (Figure 7) Inferior osteophyte formation is a not uncommon finding in patients with a painful sternoclavicular joint. It usually occurs in the sixth decade onwards, may be asymptomatic and discovered only on routine X-rays, or may present with significant pain on movements of the shoulder. Instability is not a specific feature of osteoarthrosis of the sternoclavicular joint and will be dealt with as a separate entity.
Figure 7. Osteophyte formation at the medial end of the clavicle.
The treatment of asymptomatic osteophyte formation or osteoarthrosis of the sternoclavicular joint is masterly inactivity. The condition frequently remains asymptomatic indefinitely. Should symptoms become apparent, then conservative treatment with analgesics, non-steroidal anti-inflammatories and a course of perhaps three steroid injections, frequently reduces symptoms to a tolerable level. Should symptoms persist after a reasonable period of conservative management, then surgery to excise the osteophyte and ddbride the joint frequently gives good relief. In occasional cases an excision of the medial end.of the clavicle is necessary. Should such a procedure be undertaken, it is of great importance that the muscle layers overlying the clavicle (platysma, sternomastoid and pectoralis major) be carefully reconstructed after excision in order to avoid instability of the remaining medial end of the clavicle. Such instability is a disabling condition, and can be avoided by careful reconstruction of the aforementioned muscle layers.
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Pain and swelling Pain and swelling in the region of the medial end of the clavicle is a condition frequently seen in people in both their third and fourth decades, as well as in later life. It affects both men and women, and is occasionally a forerunner of frank rheumatoid disease. Frequently, however, it is a non-specific condition for which no apparent cause is ultimately detected. Management consists primarily in the exclusion of serious problems, and many cases settle spontaneously. The patient frequently presents with a painful swelling in the region of the sternoclavicular joint without a history of previous injury or joint problems. The onset is usually insidious and symptoms may be quite severe. It is frequently temporarily relieved by aspirin and other antiinflammatory agents. Clinical examination reveals diffuse swelling of the medial end of the clavicle and sternoclavicular joint, without an effusion in the sternoclavicular joint being apparent. Manoeuvring the upper limb so as to stress the sternoclavicular joint into horizontal compression frequently aggravates symptoms so that the patient finds it difficult to lie on the shoulder of the affected side. As mentioned, the diagnosis includes exclusion of a serious pathology. It is sometimes difficult to be sure that a fracture or dislocation is not present. Investigations should therefore include plain X-rays as well as routine tomograms, with computerized tomographic scanning if the tomograms do not clarify the position. Routine haematological investigations should include erythrocyte sedimentation rate, rheumatoid factor and serum uric acid. Treatment of this condition is primarily symptomatic and should consist of analgesics, anti-inflammatories and supportive therapy, with advice to sleep on the opposite side, avoiding activities which cause pain, and awaiting spontaneous resolution. The majority of cases spontaneously resolve after a course of intermittent symptoms over a lengthy period of time. It is frequently 2 years or more before symptoms completely settle. Permanent, slight thickening in the region is frequently present, but in the absence of symptoms should not give cause for concern. If symptoms persist after a reasonable and extended course of conservative therapy, then excision arthroplasty with removal of the medial end of the clavicle can usually resolve them. It must be stressed, however, that the swelling is frequently not helped by this procedure and, indeed, an unsightly scar frequently follows surgery in this area.
Instability Two types of instability in the sternoclavicular joint are described: spontaneous and traumatic.
Spontaneous instability. Spontaneous, habitual or, indeed, voluntary dislocation of the sternoclavicutar joints frequently dates back to teenage years, is more frequent in girls than boys, is usually asymptomatic, and is demonstrated by the patient as a voluntary ability to dislocate both sterno-
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clavicular joints anteriorly or superiorly with minimal effort. It can sometimes be present as an entirely involuntary symptom, without the patient's own voluntary effort to produce the dislocations. In treating spontaneous or voluntary instability, the patient should be strongly advised to avoid such dislocations. Surgical treatment should be reserved for those in whom serious attempts to avoid dislocation on a voluntary basis have proved unsuccessful, and in whom symptoms are disabling. In the rare situation where treatment for such spontaneous dislocation is required, one of the procedures described below may be appropriate. It should be remembered that the results of surgical treatment for symptomatic spontaneous recurrent instability of the sternoclavicular joint depend entirely on the patient's own motivation to avoid further dislocations in the future. A determined voluntary attempt at sternoclavicular dislocation will always disrupt a surgical reconstruction. Traumatic dislocation. The sternoclavicular joint accounts for 1% of all dislocations of the shoulder girdle. Traumatic posterior dislocation of the sternoclavicular joint is common in major chest injuries and in 'roll over' and 'crush' injuries. The direction of dislocations may be anterior, superior or posterior. Traditionally, the posterior dislocation occurs as mentioned in the 'roll over' or 'crush' injuries, and in major chest injuries, while the anterior dislocation occurs in forced hyperextension of both shoulders and is classically seen in the cyclist or motorcyclist whose shoulder fails to clear a vertical object, such as a lamp post. Superior dislocation results from a variety of injuries in which either a direct downward force to the outer end of the clavicle, or a direct upward force to the inner half of the clavicle, is applied. The anterior and superior dislocations can usually be easily diagnosed by the obvious deformity and visible dislocation of the joint. Posterior dislocation may not be obvious clinically, and may present with airway obstruction, major vessel obstruction in the thoracic inlet, rapid loss of consciousness, and death. While reduction of the anterior and superior dislocation can be delayed without significant ill effect, delay in reduction of a posterior dislocation of the ste.rnoclavicular joint may well prove fatal. It is, therefore, essential that a rapid reduction is performed. Diagnosis of the posterior dislocation is based on clinical grounds. It is sometimes possible to demonstrate the problem on X-ray, using 40 ~ angulation skyline views, which are frequently unhelpful, and tomograms, which will usually confirm the diagnosis. Treatment of the posterior dislocation is usually a matter of extreme urgency. Reduction is usually achieved by placing a sandbag between the shoulder blades, traction is applied to the arms, and the clavicle is pulled forward at the same time. Such anterior traction may be achieved by thumb ' and forefinger grasping the medial end of the clavicle; in some instances the use of a large towel clip may be necessary. Although painful, this is an extremely effective way of reducing the dislocation and saving life. The anterior and superior dislocations can generally be reduced by pressure but usually continue to be unstable, and recurrent dislocation is
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frequent. Conversely, the posterior dislocation, once reduced, is usually stable and no further treatment is necessary. If recurrent superior or anterior dislocation of the sternoclavicular joint becomes a symptomatic problem, then operative stabilization may be undertaken. Over the years, a variety of methods have been described by numerous authors, including the use of fascia lata by B a t e m a n (1978) and the subclavius tendon by Burrows (1951). Other methods of stabilization include excision of the medial end of the clavicle, arthrodesis of the sternoclavicular joint, the use of Steinmann pin fixation and the use of clavicular osteotomy, none of which are regularly used nowadays. T h e author's preference is for direct repair of the anterior ligament in cases where such a ligament is present, thickened and stretched. The author now has a series of six such cases, where long-term stability with follow-up of over 4 years has been recorded. In the absence of sufficient tissue to obtain such a repair, the Burrows subclavian tendon transfer is a useful technique and provides good long-term results. In the young, sportsminded individual, the author prefers the use of fascia lata from the thigh, looped around the clavicle and either through or under the first rib, using a further length of fascia lata to reinforce the anterior ligament. Results in three such cases have proved successful, with the patient returning to a preinjury level of sporting activity without problems.
CONCLUSION The acromioclavicular and sternoclavicular joints are small but important joints among the complex joints of the shoulder girdle. Problems affecting these joints can be functionally disabling. Effective treatment is possible for m a n y of the c o m m o n afflictions affecting these joints.
REFERENCES Bateman JE (1978) The Shoulder and Neck, 2nd edn, p 546. Philadelphia: WB Saunders. Bearn JG (1967) Direct observations on the function of the capsule of the sternoclavicularjoint in clavicular support. Journal of Anatomy 101: 159-179. Burrows HJ (1951) Tenodesis of subclavius in the treatment of recurrent dislocation of the sternoclavicular joint. Journal of Bone and Joint Surgery 33B: 240. De Palma AF (1957) Degenerative changes in sternoclavicular and acromioclavicularjoints in various decades, p 118. Springfield IL: CC Thomas. Neer CS I! (1963) Fracture of the distal clavicle with detachment of the coracoclavicular ligaments in adults. Journal of Trauma 3: 99-110. Neer CS II (1968) Fractures of the distal third of the clavicle. Clinical Orthopaedics 58: 43-50. Rowe CR (1962) Symposium on surgical lesions of the shoulder: acute and recurrent dislocations of the shoulder. Journal of Bone and Joint Surgery 44A: 997-1012.