THE PAINFUL SHOULDER Review of One Hundred Personal Cases with Remarks on the Pathology

In considering the well-defined group of conditions in which there is limitation or alteration in the range of movement of the shoulder joint, pain on attempted movement, and sometimes muscle wasting, with no radiographic evidence of abnormality, certain anatomical features must be recalled. In the adult the capsule is fused with the overlying short rotator muscles ; whereas in infants the capsule is separated from the deep muscles of the shoulder by areolar tissue, the tendons being short and the muscle fibres extending to within a few millimetres of their humeral attachment. With increasing age the tendons become longer and in old age the supraspinatus tendon may extend as far proximally as the suprascapular notch. The degree of adhesion of the tendons to the capsule increases with age, and in older subjects the fusion is complete. The changes are more marked in the upper part of the capsule so that in adult life the entire breadth of the supraspinatus tendon, and the upper parts of the infraspinatus and subscapularis tendons, are intimately fused with the shoulder capsule. The frequency with which rupture of the supraspinatus tendon is found at post-mortem examination was emphasized by Codman (1931) and Codman and Akerson (1931). Grant and Smith (1948) demonstrated that degenerative changes in the capsule, especially in its upper part, increased in arithmetical progression as age advanced. In ninety-five dissectingroom specimens they found degenerative changes causing complete or incomplete rupture of the capsule in no case of a subject aged 17 to 40 years; in 25 per cent. of subjects aged 40 to 56 years ; in 39 per cent. of subjects aged 56 to 76 years ; and in 50 per cent. of subjects aged 76 to 86 years. It must also be recognised that falls on the shoulder are more likely to cause injury to the upper part of the capsule than to its anterior or posterior aspects. For these three reasons-fusion of the supraspinatus with the capsule, increasing degeneration of this fused part as years advance, and liability to direct injury from falls-it is evident that most cases of ‘ ‘ painful shoulder ‘ ‘ are due to pathological changes in the upper part of the capsule. In this review, a series of one hundred patients have been re-examined at intervals ranging from one to three years after cessation of treatment. The series includes only patients in whom there was no radiographic evidence of abnormality ; examples of calcareous deposit in the tendons round the joint have been excluded. The average age was fifty-two years. There were fifty-two men and forty-eight women. The right shoulder was affected in fifty-seven and the left in forty-three patients. There was a definite history of injury in 60 per cent . Three clinical groups were differentiated : 1 ) rupture of the supraspinatus; 2) supraspinatus tendinitis ; 3) capsulitis of the shoulder. Rupture of the supraspinatus-After a fall on the shoulder there was diffuse pain over the shoulder and sometimes pain referred to the insertion of the deltoid muscle, with inability to elevate the limb, and inability to support it in the elevated position after it had been so placed, but with a normal range of passive movement. In this group the disability was due to loss of the power of fixation of the humeral head to the glenoid by the spinati; the deltoid was thereby put at such a disadvantage that although it was able to contract, as could be felt by the examining hand, it was unable to sustain true shoulder movement. In cases of recent rupture this loss of fixator function may be no more than a reflex phenomenon