Double-level osteotomy (DLO) for varus deformity results in over a decade of mean survival without compromising subsequent total knee arthroplasty function at a mean 26-year follow-up

Abstract

Purpose: Double-level osteotomies (DLOs) have shown promising results for knee joint preservation, however, most ultimately progress in terms of degenerative disease resulting in conversion to total knee arthroplasty (TKA). Therefore, the purpose of this study was to examine the time to TKA conversion, long-term clinical outcomes and revision rates of patients who have undergone TKA after prior ipsilateral DLO. Methods: Patients who underwent simultaneous or staged DLO and subsequently underwent conversion to TKA at a single academic institution from 1997 to 2022 were evaluated. The type of osteotomy performed (opening- vs. closing-wedge), osteotomy hardware fixation, when and if osteotomy hardware was removed, implanted TKA components and revision rates were recorded. Postoperative outcomes, including Forgotten Joint Score-12 (FJS-12), Tegner Activity Scale score and subjective knee preference were also obtained. Results: A total of 22 patients (24 knees) underwent TKA following DLO and were followed for an average of 26.1 ± 7.7 years. The average time from DLO to TKA conversion was 14.1 ± 6.5 years, with 70.8% of knees converting to TKA more than 10 years after DLO. The mean follow-up after conversion to TKA was 12.0 ± 7.7 years. Only 12.5% of patients received a varus-valgus or hinged-constrained TKA. At the final follow-up, the mean FJS-12 was 75.8 ± 23.1, while the mean Tegner Activity Scale score was 2.5 ± 1.1. Seventy-seven percent of patients had no subjective knee preference or preferred their DLO-TKA knee. Only two knees (7.4%) underwent subsequent revision after index arthroplasty at a mean of 9.3 years postoperatively. Conclusions: A majority of DLOs (70.8%) converted to TKA after more than a decade. Subsequent TKA function was favorable as most patients had either no subjective knee preference or preferred their DLO-TKA knee. This study demonstrates both long-term joint preservation and uncompromised TKA function after prior DLO. Level of Evidence: Level IV.