The shoulder capsule is the deepest soft-tissue layer in the shoulder and represents the ligaments between the humeral head (ball) and glenoid (socket) of the shoulder joint that gets tight at the extreme ends of shoulder motion to keep the shoulder stable. The capsule ligaments can be torn during glenohumeral dislocation. Additional repetitive activity (throwing, swimming, etc.) can injure or stretch the capsule ligaments resulting in instability. When the capsule ligaments are torn, this often results in uncontrolled shoulder instability (slipping out of place).
Conservative treatment including rest from aggravating activities and physical therapy to restore the stabilizing function of the rotator cuff muscles of the shoulder can be successful; however, many patients continue to have symptoms and require an arthroscopic capsular plication (tightening). This is an arthroscopic surgery performed through limited small incisions where the torn edges of the capsule are sewn back together. Some patients have a chronically torn or absent capsule and ligaments that requires reconstruction, making a new capsule with a tendon graft from either another location like the iliotibial band or an allograft from a cadaver. After surgery, patients are immobilized in a sling for six weeks followed by physical therapy for four to six months.