Clinical and Radiological Outcomes of Medial Opening-Wedge Monoplanar and Biplanar High Tibial Osteotomy Using a Triangular Allograft Impaction Technique: A Retrospective Single Centre Study

Purpose: The aim of the study was to research the clinical and radiological outcomes between monoplanar and biplanar medial opening-wedge high tibial osteotomy. We hypothesized that there would be no differences between both techniques when using a triangular allograft impaction technique.<br><br>Methods: A single-centre, observational, retrospective study was conducted on 103 opening-wedge high tibial osteotomy patients. Data collection, NRS and KOOS-PS, was performed preoperatively, 3 months and 12 months postoperatively. Radiological assessment (Kellgren-Lawrence, mFTA, pTSA, LPT, ISI, BP, and CD) was performed on radiographs taken preoperatively, 3 and 12 months postoperatively.<br><br>Results: In total 32 patients were included in the biplanar group and 71 patients in the monoplanar group. NRS and KOOS-PS scores improved significantly (p&lt;0.001) in time for both groups from baseline to 3m PO and further to 1 year postoperatively. Our results showed no differences in radiological outcomes such as patellar height, LPT and posterior tibial slope angle. The monoplanar group did have more Takeuchi I and III fractures and a higher mFTA angle without clinical repercussion.<br><br>Conclusions: Our results show that using a triangular allograft impaction technique for monoplanar and biplanar medial opening-wedge high tibial osteotomy gives no differences in clinical (NRS and KOOS) and radiological outcomes. Although a difference in Takeuchi fractures was found for monoplanar patients, no additional fixation was necessary, nor did clinical complications occur. We can conclude that triangular allograft impaction technique creates a stable construct and standardizes the healing procedure postoperatively for both monoplanar and biplanar medial opening-wedge high tibial osteotomy.