Instability of the shoulder joint

Introduction
The classic presentation of shoulder instability is the dislocation of the shoulder joint caused by an accident (=traumatic dislocation). There are however, all possible variations from  a dislocation exclusively caused by an accident, to congenital or, more precisely, constitutional shoulder instability. While constitutional shoulder instability can often be improved by an exercise programme designed to strengthen the shoulder muscles, traumatic dislocation is successfully managed surgically. Because the statistical probability of a second dislocation among 20-year-old patients reaches approximately 80 %, it is advisable to recommend the operation to younger patients after the first shoulder dislocation. Among patients over 30 years of age, the frequency of a repetition after a single dislocation is clearly lower, so in this case surgery can often be postponed.

Another reason for operating earlier these days is the development of less damaging arthroscopic surgical techniques for shoulder stabilisation. It is clear that these operations are more successful the less the anatomy of the joint is damaged by frequent dislocations. In addition to actual complete dislocations, there are also patients with partial dislocations, which express themselves as a painful snapping sensation (subluxations). Finally, one type of instability arises from tears to the long biceps tendon at the supraglenoid tubercule. These present themselves as socalled SLAP-lesions (Superior Labral tear from Anterior to Posterior) among participants in throwing sports and can likewise be elegantly repaired by arthroscopy.

Surgical procedure
To start with, the procedure is the same as described in chapter 3. Arthroscopy again allows the precise anatomical changes to be established and a definitive plan for the most favourable surgical procedure to be set up. A large proportion of unstable shoulders can be stabilised arthroscopically. The installation of bone anchors loaded with threads on the front edge of the socket has been proved valuable. These sutures reattach and gather up the torn and stretched joint capsule together with its ligaments (Bankart-repair).

If the long biceps tendon is torn at its origin suture anchors can be used as well (SLAP-repair). An overstrained joint capsule can additionally be gathered up with sutures (Capsular shift).

If the anatomical conditions differ greatly from the norm, i.e. in the presence of relevant bony defects, open surgery for shoulder stabilisation is preferred (although I only perform this in exceptional circumstances). Only in rare cases do we revert to the former standard procedure for shoulder stabilisation by using bone grafts.

Follow-up
Follow-up is dependent on the surgical procedure and is indicated in the surgical report. I will be pleased to provide you with a copy of the report if desired. In the case of arthroscopic shoulder stabilisation, the shoulder is partially immobilized for 6 weeks. However, the shoulder may, and indeed should be moved to the described extent, and muscle-strengthening exercises are desirable from the start.

From the 7th week onwards, the range of motion can be steadily increased. If a stretched capsule was found to be involved, the shoulder needs to be immobilized longer, otherwise the capsule could stretch again. Please adhere to the instruction sheets indicating the follow-up schemes according to the type of operation.

Prognosis
Arthroscopic shoulder stabilisation remains controversial as certain authors claim that it has an increased recurrence rate. However, on the basis of my own experience, I feel that, when a correct surgical technique appropriate to the individual patient, is used together with the correct follow-up, good results can be achieved with a recurrence rate of no more than 5 %.

The arthroscopic procedure is less damaging to the patient, not only because of reduced scarring, but also because something approaching normal anatomy can be reconstructed in the joint. In comparison, the open surgical procedure, causes distinct scarring and changes to the structure of the joint, which, eventually, may only become noticeable years later.