Opening-wedge high tibial osteotomy with a secure bone allograft (Osteopure™) and locked plate fixation: Retrospective clinical and radiological evaluation of 69 knees after 7.5 years follow-up

BackgroundMedial opening-wedge high tibial osteotomy (OWHTO) provides reliable and long-lasting benefits, despite the wide range of wedge-filling and internal-fixation techniques used. The purpose of this work was to assess the clinical and radiological outcomes in a case-series of OWHTO performed using a secure bone allograft and locked plate fixation.HypothesisThe clinical and radiological outcomes of OWHTO with a high-safety bone allograft and locked plate fixation are similar to those reported in previous case-series studies.Materials and methodsA single-centre retrospective design was used to study 69 knees in 64 patients with a mean age of 51.8 years (31–53 years) and a preoperative hip-knee-ankle (HKA) angle of 173° (165°–180°). The wedge was filled with secure Osteopure™ bone allograft and fixation was achieved using an Integra Surfix® locked plate. Mean follow-up was 7.5 years (5–9.3 years). Clinical and functional outcomes were assessed by determining the IKS and KOOS-PS scores and recording complications related or unrelated to the allograft. The main criterion for assessing OWHTO survival was the time to revision surgery for symptom recurrence. Radiological assessment criteria were the HKA angle, tibial slope, patellar height, and osteoarthritis grade. GESTO criteria were used to evaluate the behaviour of the allograft.ResultsOf the 69 knees, 64 (92.8%) were re-evaluated. The survival rate after 9.3 years was 95% ± 2.7% (3 failures managed with arthroplasty). The functional IKS score improved significantly, by 20 points (P < 0.001). Mean increases of 7.8° for the HKA angle and 3.5° for tibial slope were recorded. Bone healing without radiological abnormalities was consistently achieved within 6 months. There were no complications related to the allograft (infections, allergies; local or systemic toxicity).DiscussionThe clinical, radiological, and safety outcomes documented in our study were similar to those reported in earlier work.Level of evidenceIV, retrospective case-series study.