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The following is a summary of “Change of leg length after closed wedge high tibial osteotomy and associated factors,” published in the February 2025 issue of the Journal of Orthopaedic Surgery and Research by Sakurai et al.

The objective of this study was to evaluate the distribution of leg length (LL) changes following closed wedge high tibial osteotomy (CWHTO) and to identify factors influencing the magnitude of these postoperative variations. A retrospective analysis was conducted on 70 knees from 58 patients diagnosed with knee osteoarthritis who underwent CWHTO. Radiographic assessments included measurements of LL, hip–knee–ankle angle (HKAA), mechanical axis deviation (MAD), joint line convergence angle (JLCA), mechanical medial proximal tibial angle (mMPTA), and mechanical lateral distal femoral angle (mLDFA) using anteroposterior whole-leg radiographs. 

Additionally, posterior tibial slope (PTS) and flexion contracture (FC) were assessed through lateral knee radiographs. Changes in each parameter from preoperative to postoperative assessments were denoted as Δ. The mean correction angle was 18.3 ± 6.6°, with an average ΔLL of -0.8 ± 10.2 mm, exhibiting substantial variability ranging from -22 mm to 24 mm. Statistically significant differences were observed between preoperative and postoperative values for HKAA, MAD, JLCA, mMPTA, and FC; however, no significant changes were found in LL, mLDFA, or PTS. A significant correlation was identified between ΔLL and postoperative FC (ρ=-0.28, P=0.03), while moderate correlations were found between postoperative FC and preoperative FC (ρ=0.61, P<0.01) or postoperative PTS (ρ=0.44, P<0.01). Furthermore, ΔFC exhibited moderate correlations with postoperative FC (ρ=0.54, P<0.01), postoperative PTS (ρ=0.60, P<0.01), and ΔPTS (ρ=0.55, P<0.01). 

The findings indicate that while the mean LL change after CWHTO was minimal (-0.8 mm), the wide range of variation underscores the importance of surgical precision in addressing factors contributing to LL changes. Specifically, FC and PTS were identified as key variables influencing LL variation, highlighting the need for careful intraoperative management of PTS and postoperative monitoring of FC to minimize unintended LL discrepancies. Despite these insights, the study acknowledges limitations in assessing LL and FC, necessitating further research to refine measurement techniques and improve predictive models for postoperative outcomes.

Source: josr-online.biomedcentral.com/articles/10.1186/s13018-025-05582-w