DOES THE PRE-OPERATIVE RANGE OF ACTIVE ANTERIOR ELEVATION ALTER THE OUTCOME OF REVERSE SHOULDER PROSTHESIS? A REVIEW OF 96 CASES

Abstract

Does the pre-operative range of active anterior elevation alter the outcome of reverse shoulder prosthesis? A review of 96 cases.

Aims: The aim of this retrospective study was to analyse the results of reverse shoulder prosthesis in massive, irreparable rotator cuff tears in terms of the preoperative active anterior elevation (AAE).

Materials and Methods: This was a retrospective study of 96 reverse shoulder prostheses in patients with a mean age of 74 years, and with an average follow-up of 30 months. We divided the patients into three groups for the purposes of the study. Group 1 had an AAE less than 60° (n=51); group 2 had an AAE between 60 and 120° (n=39); group 3 had an AAE above 120° (n=6). The majority had off-centre arthritis with a Fukuda Hamada classification of IV or V (n=77); only 19 fell within classes I, II or III. We excluded patients who had previously had a failed anterior cuff repair or arthroplasty and those with a diagnosis of rheumatoid arthritis.

Results: There was no significant difference in constant score between the three groups based on preoperative AAE: group 1: 63.50; group 2: 65.05; group 3: 65.16. Analysis of the 96 reverse prostheses in relation to the Fukuda Hamada classification also showed no difference: types I, II and III had a constant score of 64.37; types IV and V a score of 63.68. However, the improvement in AAE (I), rotation (RE1 and RI) and in power was significantly greater in shoulders with pseudoparalysis (p< 0.001): group 1: I = 71.43%; group 2: I = 33.48%; group 3: I = 3.03%. The degree of improvement of the pseudoparalytic shoulders (group 1) was influenced by the Fukuda Hamada classification (p< 0.01): 77.78% for stages I, II and III compared with 69% for stages IV and V.

Discusssion and conclusion: This retrospective study confirms that the reverse shoulder prosthesis is a beneficial treatment for massive, irreparable cuff tears in older patients with shoulder psuedoparalysis. Its use is debatable if the preoperative AAE is over 120°, in which case hemiarthroplasty may be a better option. The benefit of the reverse prosthesis is greatest in the shoulder with pseudoparalysis, no glenohumeral arthritis (Fukuda I, II or III), and no previous surgical intervention.