Outcomes of total knee arthroplasty, with revision surgery as an endpoint, following previous periarticular osteotomy or unicompartmental knee arthroplasty

Abstract

Aims This study evaluates the risk of revision of total knee arthroplasty (TKA) in patients with a history of previous periarticular osteotomy compared with those with a history of unicompartmental knee arthroplasty (UKA). Understanding the differences in TKA outcome following these procedures is important for informed decision-making and patient counselling when considering osteotomy or UKA in the management of single-compartment osteoarthritis in young, high-demand patients. Methods We conducted a retrospective analysis using data from the New Zealand Joint Registry, identifying 1,895 TKAs performed after prior osteotomy and 1,391 after previous UKA. We compared TKA revision rates and patient-reported outcome using the Oxford Knee Score (OKS), between the two groups at six months. Adjusted hazard ratios (HRs) were calculated to account for differences in demographic details. Results The revision rate for TKA following osteotomy was significantly lower than TKA following UKA with rates of 0.88 per 100 component years (95% CI 0.74 to 1.03) versus 1.38 per 100 component years (95% CI 1.15 to 1.19), respectively. Adjusted HR calculations indicated that previous UKA more than doubled the risk of revision of TKA compared with previous osteotomy (HR 2.29, 95% CI 1.66 to 3.17; p < 0.001). In patients aged under 55 years, the risk of revision for TKA was nearly 2.5-fold for those with previous UKA compared with those with previous osteotomy (1.32, 95% CI 1.01 to 1.71 vs 3.25, 95% CI 2.01 to 4.97; p < 0.001). The mean-adjusted OKS scores at six months demonstrated a significant difference between the two groups, with improved OKS in the previous osteotomy group (34.85 (SD 0.36) vs 36.64 (SD 0.48); p < 0.001). However, this did not reach the minimal important clinical level of difference for the OKS. Conclusion Patients undergoing TKA after periarticular osteotomy exhibit a lower risk of revision compared to those with previous UKA, particularly in younger patients. Our study enhances the understanding of the risk of revision of a TKA following previous procedures, and confirms that TKA after osteotomy performs significantly better compared with previous unicompartmental arthroplasty.