Does the stemless reverse arthroplasty compare to a conventional stemmed implant? Clinical and radiographic evaluation at 2 years’ minimum follow-up

Abstract

AimReverse shoulder arthroplasty (RSA) is a well recognized treatment for many shoulder conditions, including rotator cuff arthropathy, primary glenohumeral joint arthritis, rheumatoid arthritis and can be utilized in both trauma and revision settings. Over the past 10 years its popularity in New Zealand has been increasing, with a 6-7% annual growth during this period. The proposed advantages of a stemless (sRSA) design are to preserve humeral bone stock, limit periprosthetic fractures and can be indicated in patients with abnormal diaphyseal humeral anatomy. To date there is only one study evaluating the outcomes of Lima stemless SMR implant. We present our data with an aim to report how the stemless reverse arthroplasty compares to a conventional stemmed implant. MethodsA retrospective review was performed of a consecutive series from a single institution between 2015 to 2020. Endpoints were defined as final follow-up at a minimum of 2 years. Patients were excluded from final analysis if they had a revision. Thirty-three patients were identified as having had sRSA. Thirty patients had PROMS and radiographs at minimum 2 years follow-up. Three patients were revised within 2 years. The same sample size (n=33) of stemmed RSA was selected for comparison ResultsA total of 60 patients were included in the final analysis, of which 30 were stemless and 30 stemmed. The demographic characteristics of the two groups were comparable except age at operation which was statistically significant (P=0.001), 77 years (stemmed) vs 65 years (stemless). The mean OSS score in the stemless group was 40.1 versus 40 in the stemmed group. The ASES was 72.9 in the stemless group and 79 in the stemmed group. The patient reported outcome measures, pain scores or satisfaction were not statistically significant between the two groups. In terms of radiographic data, subsidence of two sRSA was observed but the patients had no clinical symptoms. Also in the sRSA group one patient had an acromial stress fracture, and one patient had a superficial wound infection successfully treated with oral antibiotics. In terms of revisions in the sRSA group, one patient was revised due to chronic infection, one revised as a result of a periprosthetic fracture following a fall and one revised for gross instability. ConclusionsEarly results of sRSA are promising and show similar outcomes to a conventional stemmed implant.