Shoulder instability represents a spectrum from micro-instability through subluxation (partial dislocation) to frank dislocation and may occur as a result of different underlying pathologies. Anterior shoulder instability occurs when the humeral head moves out of its shallow joint socket in forward direction, usually following an injury such as a fall on the outstretched hand. Dislocation occurs when the head of the humerus moves completely out of the socket. As it does so, various ligaments around the joint may be torn and the bone of the humeral head or of the socket may be damaged. Recurrent episodes of dislocation are common unless complete healing of the damaged structures occurs. A 'Bankart lesion' is a type of tear involving the lining of the socket part of the shoulder joint. Such a tear predisposes the shoulder dislocate easily and in a recurrent manner. If recurrent episodes are troublesome, surgical repair using an open or minimally invasive (keyhole) technique may be advised and this principally involves the repair of 'Bankart lesion'.
This systematic review compared different techniques of surgical repair for anterior shoulder instability. Only three randomised controlled trials, involving a total of 184 people with anterior shoulder instability that usually followed a traumatic event, are included in the review. All three trials compared arthroscopic (key hole) surgery with open surgery, generally involving the repair of Bankart lesions. All three trials were inadequately reported but appeared well-conducted with minimum follow-ups of two years.
The limited data available showed no statistically significant differences between the two groups in recurrent instability or re-injury, in subsequent instability-related surgery or surgery for all reasons. Data for other outcomes, including shoulder function, also showed no significance differences between the two groups. In all the available evidence was insufficient to draw conclusions and further well designed randomised controlled trials are required.