The shoulder joint has only one small bony entry. Its stability is due to the perfect interplay of tendons, capsule, and musculature. If these important building blocks are not functioning perfectly, shoulder instability may result. We distinguish between congenital instabilities and those due to accidents.
Arbitrary shoulder luxations that may be triggered without being caused by the application of force are based on a general looseness of tissue. This involves a congenital weakness in the supporting tissue, which leads to increased play of the joint. Other joints are also frequently affected (e.g., the knee disk). One can protect against this ailment profile by conservative forms of treatment, including an intensive program of physical therapy exercise and training. Operations are performed only in exceptional cases.
This involves patients in whom the first luxation is caused by an accident (e.g., in playing sports). This initial accident leads to damage to the joint capsule, the tendons, and the fibrous cartilage ring (labrum). Bony damage to the glenoid cavity and to the bone head is also frequently found. In younger patients in particular more luxations follow without an actual accident.
To stabilize unstable shoulders, until recently extensive "open" operations were necessary. In recent years operations performed by arthroscopy have become very common. The principle of the operation is to shorten the joint capsule including the tendons running within it, which have been excessively stretched or torn by the frequent luxations. The detached fibrous ring is then reattached to the capsule at the joint socket. In this operation the labrum capsule complex is attached to the bony edge of the socket with bone anchors. In most cases, reliable stability of the shoulder can be achieved with this technique. There is little pain that occurs after the operation. The use of resorbable material does away with the need for removing any metal.
An operation that opens the body is unavoidable in certain exceptional cases (e.g., damage to the bony joint socket). Here the damaged structures are revealed by an incision in the skin on the front side of the shoulder. The joint capsule is tightened together with the tendon apparatus; it is shortened, and reattached to the edge of the socket (what is called a capsule shift). Any damage to the rotator cuff that occurs during the operation is sutured.
The arm that is operated on is protected by a shoulder bandage for 3-4 weeks. However, physical therapy exercises begin early on. Only good cooperation among the operating doctor, the physical therapist, and the patient will allow a good result from the operation. Sports that require lifting the arms over the head may be begun only after 6 months. The prognosis after an operation to stabilize the shoulder is very good.