Abstract
Introduction
The use of reverse total shoulder arthroplasty (RSA) is becoming increasingly common in the treatment of rotator cuff arthropathy. Standard RSA technique involves medialising the centre of rotation (COR) maximising the deltoid lever arm and compensating for rotator cuff deficiency. However reported complications include scapular notching, prosthetic loosening and loss of shoulder contour. As a result the use of Bony Increased Offset Reverse Shoulder Arthroplasty (BIO-RSA) has been gaining in popularity. The BIO-RSA is reported to avoid these complications by lateralising the COR using a modified base plate, longer central post and augmentation with cancellous bone graft harvested from the patients humeral head.
Objectives
This study aims to compare the outcome in terms of analgesic effect, function and satisfaction, in patients treated with standard RSA and BIO-RSA.
Methods
All cases were performed in a single centre by one of two upper limb consultant orthopaedic surgeons over a consecutive 2-year period. At time of listing for operation, the decision as to whether to undertake a bony-increased offset reverse total shoulder was made.
Standard deltopectoral approach was performed. Standard and Bony increased offset Tournier reverse was the implant of choice (BIO-RSA). All patients underwent a standardised rehabilitation programme. Standard follow up was clinical review with radiographs at 2 weeks, 6weeks and 3months.
Retrospective data was collected using case notes on patient reported stausfaction and oxford shoulder score, analgesia requirement at final follow up, and final range of movement.
Results
A total of 60 patients (65 shoulders) were treated with reverse total shoulder replacements (RSA) within a 2-year period in a single centre for chronic complex shoulder conditions.
Mean age at time of intervention was 74.1years (49.3 – 88.7). Mean follow up was 7.1 months (3.4 – 24). Average time to discharge 16.1 months (3.4 – 37.4). 43 patients currently under review.
Of the 65 shoulders, 40 underwent BIO-RSA procedures. Indications for surgery were predominantly rotator cuff arthropathy (N=36). Other indications included severe osteoarthritis (N=1) and complex proximal humeral fracture (N=3). The remaining 25 patients treated with standard RSA were similar in terms of indication and basic demographics.
In terms of range of movement, outcomes between the two groups were broadly similar. Patients receiving BIO-RSA demonstrated mean active forward flexion of 92.2° (70–120°) and abduction 93.3° (80–120°). The RSA group had mean forward flexion 90.5° (50–130°) and mean abduction 88.6° (40–160°).
Both groups had excellent analgesic effect with 92% in each either being completely pain free or requiring only occasional analgesia. The majority of patients were either very satisfied or satisfied with the outcome of the surgery.
Mean Oxford shoulder score for the BIO-RSA group was 4.9 (0–13) preoperatively and 43.7 (36–48) postoperatively. The mean RSA pre-operative score was 7.9 (0–19) and postoperatively 40.2(32–48).
In total three patients experienced complications; 1 haematoma (BIO-RSA), 1 brachial plexus contusion (BIO-RSA) and 1 deep infection (RSA).
Conclusion
If grafting is necessary, the use of BIO-RSA within this centre seems to have comparable results to those undergoing standard RSA. Early results also suggest the Bio-RSA allows earlier improvement and conserves a larger bone stock. These early result are encouraging however a further study with longer follow-up is required.
