Abstract
Hypothesis
Reverse shoulder arthroplasty has good mid-term results for rotator cuff deficient arthritic conditions.
Methods and Analysis
103 reverse shoulder arthroplasties were performed in 91 patients from January 2003 to September 2009. Twelve patients had bilateral reverse shoulder arthroplasties.
Results
Average clinical follow-up was 13 months (range 3-72 months). There were 38% left and 62% right shoulders. Sixty-eight percent were women and 32% were men. The average age was 72 years (range 47-88 years).
Indications included: rotator cuff arthropathies (79%), failed previous hemiarthroplasties and total shoulder arthroplasties (9%), rheumatoid arthritis (5%). Fractures accounted for 7% of cases, including acute 4-part fractures in the elderly, revision of fractures with deficient cuffs, malunion and nonunion cases with deficient cuffs.
There was a significant improvement in quality of life. The Constant Score increased by an average of 46 points. 62 radiographs were reviewed. 75% of these showed notching of the inferior glenoid, 53% had notching of the posterior glenoid, 10 % had heterotrophic ossification inferior to the glenoid, and 40% had an inferior glenoid spur.
Complications included: 2 dislocations, 1 massive heterotrophic ossification, 3 deep infections, 1 loose glenoid related to a fall, 3 acromial fractures, and 3 scapula spine fractures (all trauma related).
Conclusion
Reverse shoulder arthroplasty is a good salvage procedure for cuff deficient arthritic conditions. Clinical mid-term results are good, but notching inferiorly and posteriorly may lead to deterioration over time. Fractures of the scapula appear to originate from either the superior or posterior screws which act as stress risers and an external rotation force of the greater tuberosity against the spine of the scapula in a fall may contribute to these fractures.
