Injuries of the shoulder

Fractures of the clavicle

Fractures of the clavicle account for 2.6% to 5% of all fractures and usually result from a direct blow to the point of the shoulder, but they may also be due to a fall on the outstretched hand. The most common site of fracture is the middle third of the clavicle, which accounts for 69% to 82% of clavicular fractures. Most other clavicular fractures are in the outer third. There are varying degrees of displacement of the fracture ends, with overlapping fragments and shortening being common. Owing to the strategic location of the clavicle, injury to the pleura, axillary vessels and/or brachial plexus is possible, but fortunately these complications are rare. They should be excluded by directed examination.

The clinical signs of clavicular fracture are a patient supporting the weight of the arm at the elbow coupled with local pain and tenderness, often accompanied by deformity.

In non-displaced or minimally displaced fractures, treatment consists of an elbow-supporting sling (e.g. broad arm sling) for 2 to 3 weeks. For comfort, this may be worn under clothing for the first few days. The sling may be discarded when local tenderness has subsided. Note that clinical union usually precedes radiological union by weeks. Early shoulder movement should be encouraged within the limits of pain and immobilization should be discontinued if clinical union has occurred, even if there is not yet radiological union. Non-union is rare.

Midshaft fractures with complete displacement or comminution or fractures in the elderly or women with osteoporosis have a higher rate of non-union and poorer functional outcome. Recent evidence suggests that this group may benefit from surgical stabilization with either plate-and-screw fixation or intramedullary devices.

Fractures of the outer third of the clavicle may involve the coracoclavicular ligaments (CC). These fractures are generally displaced. If so, surgical management should be considered, because these fractures have a high incidence of non-union (30%). Displaced fractures of the medial third of the clavicle are often associated with other serious injuries and warrant further examination. Early orthopaedic consultation is recommended for all (displaced) fractures of the medial and outer third of the clavicle.

Late complications of clavicular fractures include shoulder stiffness and a local lump at the site of fracture healing, which is rarely of cosmetic significance.

Acromioclavicular joint injuries

AC joint injuries usually result from a fall where the patient rolls onto his or her shoulder. The degree of the injury relates to the number of ligaments damaged; about two-thirds of AC injuries are incomplete and involve only part of the AC and CC ligaments (types I and II).

AC dislocations are classified according to the Tossy-Rockwood classification system ( Fig. 4.1.1 ):

• Type I: partial tear of the AC ligament, CC ligament intact. Tenderness over the AC joint, no deformity.

• Type II: complete tear of the AC ligament, partial tear of CC ligament. Radiographs show partial elevation of the distal clavicle.

• Type III: complete tear of the AC and CC ligaments. Radiographs show substantial elevation of the distal clavicle and increased CC distance.

• Type IV: complete tear of the AC and CC ligaments with dislocation of the distal clavicle posteriorly into or through the trapezius muscle.

• Type V: complete tear of the AC and CC ligaments along with disruption of the muscular attachments of the distal clavicle.

• Type VI: complete disruption of the AC and CC ligaments and muscular support. The distal clavicle is forced behind the tendons of the biceps and coracobrachialis.

On clinical examination of the standing patient, the outer end of the affected clavicle may be prominent and there will be local tenderness over the AC joint. The degree of damage can be ascertained by taking standing x-rays of both shoulders with the patient holding weights in both hands (stress x-rays) and by ultrasound. Stress x-rays may be normal in mild strains, but dynamic ultrasonographic techniques may better define the injury.

Treatment is with a broad arm sling. For minor injuries (Rockwood type I–II) 1 to 2 weeks is usually sufficient. For type II injuries, heavy lifting and contact sports should be avoided for 4 to 6 weeks to avoid conversion to a type III injury. The treatment of type III injuries is controversial, with some authors recommending conservative treatment and others surgery. Type IV to VI injuries are usually treated surgically.

Sternoclavicular subluxation and dislocation

Sternoclavicular dislocations are uncommon and usually due to a direct, high-velocity blow to the medial clavicle or to medial compression of the shoulder girdle. Subluxation is more common than dislocation, with the affected medial end of the clavicle displaced forwards and downwards. Dislocations may be anterior or, rarely, posterior. In the latter case, the great vessels or trachea may be damaged.

Clinical features include local tenderness and asymmetry of the medial ends of the clavicles. The diagnosis is essentially clinical. X-rays are difficult to interpret and are not necessary for subluxations. For dislocations, contrast enhanced computed tomography (CT) scanning should be obtained.

Subluxations should be treated in a broad arm sling for 2 to 3 weeks. Anterior sternoclavicular joint instability should also be treated conservatively; however, there is a significant risk of ongoing instability; this is usually well tolerated and of little if any functional consequence. For patients with posterior dislocations, expeditious diagnosis and treatment are important. Closed reduction performed under general anaesthesia is usually stable, and the joint can then be managed in a brace or sling for 4 to 6 weeks. Operative stabilization is required if closed reduction is unsuccessful or there is persistent instability.

Fractures of the scapula

Fractures of the scapula are uncommon, accounting for less than 1% of all fractures. They typically occur after high-energy trauma. Up to 90% of patients have other associated injuries.

Fractures of the blade of the scapula are most common and are usually due to direct violence. Clinical features are local tenderness, sometimes with marked swelling. Healing is usually rapid, even in the presence of comminution and displacement, with an excellent functional outcome. Treatment is usually non-operative, with a broad arm sling and early mobilization. There is growing acceptance of surgical treatment for highly displaced fractures. However, there is no evidence comparing outcome for surgical versus non-surgical treatment.

Fractures of the scapular neck are often comminuted and may involve the glenoid. Swelling and bruising of the shoulder may be marked. Clinical examination and x-rays should ensure that the humeral head is enlocated. CT scans may be useful in defining the anatomy and the degree of involvement of the glenoid, including any steps in the articular surface. Surgery is often indicated for fractures involving the scapular neck or glenoid.

The ‘floating shoulder’ is an uncommon injury pattern. Although it is usually defined as an ipsilateral fracture of the clavicle and scapular neck, recent studies suggest that ligamentous disruption associated with a scapular neck fracture can give the functional equivalent of this injury pattern, with or without an associated clavicle fracture. Because the degree of ligament disruption is difficult to assess, indications for non-surgical versus surgical management are not well defined. Minimally displaced fractures typically do well with conservative management. The degree of fracture displacement and ligament disruption that results in poor outcome with conservative management is not well defined and the indications for surgery are controversial, as is choice of surgical technique. Options include fixation of the clavicular fracture, which often indirectly reduces the scapular fracture, or fixation of both fractures.