The risk of revision is higher following shoulder hemiarthro-plasty compared with total shoulder arthroplasty for osteo-arthritis: a matched cohort study of 11,556 patients from the National Joint Registry, UK

Background and purpose - Total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) are used in the management of osteoarthritis of the glenohumeral joint. We aimed to determine whether TSA or HA resulted in a lower risk of adverse outcomes in patients of all ages with osteoarthritis and an intact rotator cuff and in a subgroup of patients aged 60 years or younger. Patients and methods - Shoulder arthroplasties recorded in the National Joint Registry, UK, between April 1, 2012 and June 30, 2021, were linked to Hospital Episode Statistics in England. Elective TSAs and HAs were matched on propensity scores based on 11 variables. The primary outcome was all -cause revision. Secondary outcomes were combined revision/non-revision reoperations, 30 -day inpatient complications, 1 -year mortality, and length of stay. 95% confidence intervals (CI) were reported. Results - 11,556 shoulder arthroplasties were included: 7,641 TSAs, 3,915 HAs. At 8 years 95% (CI 94-96) of TSAs and 91% (CI 90-92) of HAs remained unrevised. The hazard ratio (HR) varied across follow-up: 4 -year HR 2.7 (CI 1.9- 3.5), 8 -year HR 2.0 (CI 0.5-3.5). Rotator cuff insufficiency was the most common revision indication. In patients aged 60 years or younger prosthesis survival at 8 years was 92% (CI 89-94) following TSA and 84% (CI 80-87) following HA. Conclusion - The risk of revision was higher following HA in patients with osteoarthritis and an intact rotator cuff. Patients aged 60 years and younger had a higher risk of revision following HA.