Instability after arthroplasty of the shoulder is difficult to correct surgically. Soft-tissue procedures and revision surgery using unconstrained anatomical components are associated with a high rate of failure. The purpose of this study was to determine the results of revision of an unstable anatomical shoulder arthroplasty to a reverse design prosthesis. Between 2004 and 2007, 33 unstable anatomical shoulder arthroplasties were revised to a reverse design. The mean age of the patients was 71 years (53 to 86) and their mean follow-up was 42 months (25 to 71). The mean time to revision was 26 months (4 to 164). Pain scores improved significantly (pre-operative visual analogue scale (VAS) of 7.2 (sd 1.6); most recent VAS 2.2 (sd 1.9); p = 0.001). There was a statistically significant increase in mean active forward elevation from 40.2° (sd 27.3) to 97.0° (sd 36.2) (p = 0.001). There was no significant difference in internal (p = 0.93) or external rotation (p = 0.40). Radiological findings included notching in five shoulders (15%) and heterotopic ossification of the inferior capsular region in three (9%). At the last follow-up 31 shoulders (94%) were stable. The remaining two shoulders dislocated at 2.5 weeks and three months post-operatively, respectively. According to the Neer rating system, there were 13 excellent (40%), ten satisfactory (30%) and ten unsatisfactory results (30%). Revision of hemiarthroplasty or anatomical total shoulder replacement for instability using a reverse design prosthesis gives good short-term results.

Cite this article: Bone Joint J 2013;95-B:668–72.

We present the long-term outcome, at a median of 18 years (12.8 to 23.5) of open posterior bone block stabilisation for recurrent posterior instability of the shoulder in a heterogenous group of 11 patients previously reported on in 2001 at a median follow-up of six years.

We found that five (45%) would not have chosen the operation again, and that four (36%) had further posterior dislocation. Clinical outcome was significantly worse after 18 years than after six years of follow-up (median Rowe score of 60 versus 90 (p = 0.027)). The median Western Ontario Shoulder Index was 60% (37% to 100%) at 18 years’ follow-up, which is a moderate score. At the time of surgery four (36%) had glenohumeral radiological osteoarthritis, which was present in all after 18 years.

This study showed poor long-term results of the posterior bone block procedure for posterior instability and a high rate of glenohumeral osteoarthritis although three patients with post-traumatic instability were pleased with the result of their operations.

Between March 1994 and June 2003, 80 patients with brachial plexus palsy underwent a trapezius transfer. There were 11 women and 69 men with a mean age of 31 years (18 to 69). Before operation a full evaluation of muscle function in the affected arm was carried out. A completely flail arm was found in 37 patients (46%). Some peripheral function in the elbow and hand was seen in 43 (54%). No patient had full active movement of the elbow in combination with adequate function of the hand. Patients were followed up for a mean of 2.4 years (0.8 to 8). We performed the operations according to Saha’s technique, with a modification in the last 22 cases. We demonstrated a difference in the results according to the pre-operative status of the muscles and the operative technique. The transfer resulted in an increase of function in all patients and in 74 (95%) a decrease in multidirectional instability of the shoulder. The mean increase in active abduction was from 6° (0 to 45) to 34° (5 to 90) at the last review. The mean forward flexion increased from 12° (0 to 85) to 30° (5 to 90). Abduction (41°) and especially forward flexion (43°) were greater when some residual function of the pectoralis major remained (n = 32). The best results were achieved in those patients with most pre-operative power of the biceps, coracobrachialis and triceps muscles (n = 7), with a mean of 42° of abduction and 56° of forward flexion. Active abduction (28°) and forward flexion (19°) were much less in completely flail shoulders (n = 34). Comparison of the 19 patients with the Saha technique and the 15 with the modified procedure, all with complete paralysis, showed the latter operation to be superior in improving shoulder stability. In all cases a decrease in instability was achieved and inferior subluxation was abolished. The results after trapezius transfer depend on the pre-operative pattern of paralysis and the operative technique. Better results can be achieved in patients who have some function of the biceps, coracobrachialis, pectoralis major and triceps muscles compared with those who have a complete palsy. A simple modification of the operation ensures a decrease in joint instability and an increase in function