(Anatomical Museum, University of Edinburgh.)
The treatment is influenced by the nature of the original lesion, the variety of the ankylosis, and the attitude of the joint. When there is restriction of movement due to fibrous adhesions, these may be elongated or ruptured. Elongation of the adhesions may be effected by manipulations, exercises, and the use of special forms of apparatus—such as the application of weights to the limb. It may be necessary to administer an anæsthetic before rupturing strong fibrous adhesions, and this procedure must be carried out with caution, in view of such risks as fracture of the bone—which is often rarefied—or separation of an epiphysis. There is also the risk of fat embolism, and of re-starting the original disease. The giving way of adhesions may be attended with an audible crack; and the procedure is often followed by considerable pain and effusion into the joint, which necessitate rest for some days before exercises and manipulations can be resumed.
Operative treatment may be called for in cases in which the bones are closely bound to one another by fibrous or by osseous tissue.
Arthrolysis, which consists in opening the joint and dividing the fibrous adhesions, is almost inevitably followed by their reunion.
Arthroplasty.—Murphy of Chicago devised this operation for restoring movement to an ankylosed joint. It consists in transplanting between the bones a flap of fat-bearing tissue, from which a bursal cavity lined with endothelium and containing a fluid rich in mucin is ultimately formed.
Arthroplasty is most successful in ankylosis following upon injury; when the ankylosis results from some infective condition such as tuberculosis or gonorrhœa, it is liable to result in failure either because of a fresh outbreak of the infection or because the ankylosis recurs.
When arthroplasty is impracticable, and a movable joint is desired—for example at the elbow—a considerable amount of bone, and it may be also of periosteum and capsular ligament, is resected to allow of the formation of a false joint.
When bony ankylosis has occurred with the joint in an undesirable attitude—for example flexion at the hip or knee—it can sometimes be remedied by osteotomy or by a wedge-shaped resection of the bone, with or without such additional division of the contracted soft parts as will permit of the limb being placed in the attitude desired.
Bony ankylosis of the joints of a finger, whether the result of injury or disease, is difficult to remedy by any operative procedure, for while it is possible to restore mobility, the new joint is apt to be flail-like.
Locking.—A joint is said to lock when its movements are abruptly arrested by the coming together of bony outgrowths around the joint. It is best illustrated in arthritis deformans of the hip in which new bone formed round the rim of the acetabulum mechanically arrests the excursions of the head of the femur. The new bone, which limits the movements, is readily demonstrated in skiagrams; it may be removed by operative means. Locking of joints is more often met with as a result of injuries, especially in fractures occurring in the region of the elbow. In certain injuries of the semilunar menisci of the knee, also, the joint is liable to a variety of locking, which differs, however, in many respects from that described above.