The Osteotomy Gap Filling Rate of Multiple Time Points After Medial Opening Wedge High Tibial Osteotomy Without Bone Graft

Abstract

BackgroundThe purpose of the present study was to analyze osteotomy gap filling of multiple time points until 2 years post-medial opening wedge high tibial osteotomy (MOWHTO). The absolute value of gap filling and postoperative changes relative to the preoperative void osteotomy gap were evaluated using computed tomography (CT) at each time point. MethodsData of 30 patients who underwent MOWHTO between September 2019 and July 2021 were retrospectively analyzed. Surgical procedures without bone grafts were performed; a standardized rehabilitation protocol was implemented. The osteotomy gap filling rate was measured using computed tomography scans at the immediate postoperative period and at 6, 12, and 24 months after surgery. Statistical analyses were performed to assess changes over time. ResultsThe osteotomy gap filling rate showed a significant continuous increase after MOWHTO, reaching 45.2% at 6 months and 66.7 and 84.4% at 1 and 2 years, postoperatively, respectively. The most substantial increase occurred within the initial 6 months, thus indicating a critical period for bone healing. ConclusionsThe osteotomy gap filling rate showed a significant and gradual increase from immediately after surgery to 2 years after MOWHTO without bone grafting, the greatest of which was achieved in the initial 6-month period. Therefore, this study may be helpful for planning postoperative rehabilitation, including the extent of weight-bearing load and the period of crutch use. Study designCase series; Level of Evidence IV.