Osteoarthritis

Primary shoulder osteoarthritis (OA) is much less common than that of the major joints of the lower limb. It results in a global reduction in range of movement of the gleno-humeral joint, but most particularly external rotation. Secondary OA may follow a major tear of the rotator cuff tendons (see below). Radiographs confirm loss of joint space and osteosclerosis. Rheumatoid arthritis (RA) frequently affects the shoulder joint and causes destruction of humeral head, glenoid and rotator cuff. In the presence of reasonable bone stock and an intact cuff, a total shoulder replacement can be performed. Where the glenoid cavity or rotator cuff is deficient, however, it may be best simply to undertake a hemi-arthroplasty in which the humeral head alone is replaced. This acts as a ‘spacer’ and abolishes pain, although movement is very restricted.

The sterno-clavicular joints can become arthritic. This may be difficult to discriminate from a medial end of clavicle swelling, which is usually due to an osteitis and is rarely neoplastic. Sterno-clavicular arthropathy is most commonly part of an inflammatory process. A steroid injection may help in speeding resolution. At the other end, the acromio-clavicular joint may be arthritic. Steroid injection is rarely longlasting, and surgical treatment is excision of the distal 1 cm of clavicle.

Biceps tendon rupture

The biceps tendon has a long-head origin from the superior margin of the glenoid and its insertion is the bicipital eminence of the radius. Both tendons can be avulsed, resulting in a ‘Popeye’ bunching-up appearance to the biceps belly when contracted. It is possible to repair the long head only when the injury is very acute. Repair of the insertion is achieved by drilling a new insertion into the radius.

Impingement syndrome and rotator cuff disease

Movement of the shoulder in rotation and initiation of abduction is produced by action of the rotator cuff – a conjoined tendon that is also a roof to the gleno-humeral joint capsule described in Chapter 1. When the shoulder abducts, the tendon has to be accommodated underneath the acromion. This may result in impingement between the acromion and the cuff where it inserts into the greater tuberosity. Usually the subacromial bursa will act as a buffer to prevent a frictional reaction, but in middle age there is a tendency for inflammation to occur within the bursa after shoulder exercise. If only the bursa and cuff are inflamed, this is known as (subacromial) impingement syndrome. It is painful to elevate and abduct the arm through an arc of movement of about 45–120° (Fig. 21.1). There may be only slight tenderness just lateral to the acromion, but special tests for impingement are usually positive (Jobe’s test puts the greater tuberosity under the acromion in shoulder abduction and internal rotation; forced abduction against resistance now provokes pain). Resolution may be expected, but can be speeded by steroid injection into the subacromial bursa. Plain radiographs may reveal acute calcification (calcific tendonitis) within the supraspinatus tendon; if acute, then chalky material may be aspirated, providing instant relief. Where plain radiographs show osteophytic ‘beaking’ of the lateral edge of the acromion or a reduced distance between the humerus and the acromion, steroid injection may help but will not provide a cure. Arthroscopic subacromial decompression of the bony spur and debridement of inflammatory soft tissue may give relief. A tear of the rotator cuff may be partial or complete. A tear of any size may inhibit abduction through pain, so a diagnostic local anaesthetic injection into the subacromial bursa, followed by assessment of active movement, may be diagnostic of the extent of a tear. Ultrasonography or magnetic resonance imaging (MRI) can define its extent further. A small tear can be managed as impingement syndrome. A medium-sized tear can be repaired by open or arthroscopic surgery. A chronic massive tear in the elderly is rarely repairable; over time it will result in abnormal forces applied across the gleno-humeral joint and secondary osteoarthritis (cuff arthropathy) will result.

FIGURE 21.1 Painful arc syndrome – diagram showing range of painful movement between 45° and 120° of abduction. The scapula is stabilized by the examiner’s hand and the patient asked to abduct the arm. The examiner observes the presence or absence of discomfort as the arm abducts