Closed wedge high tibial osteotomy can reduce medial meniscus extrusion in comparison with open wedge high tibial osteotomy.

Abstract

Most patients indicated for high tibial osteotomy (HTO) often have medial meniscus extrusion (MME), which is associated with the progression of knee osteoarthritis. However, limited research has discussed the changes in MME before and after HTO. This study aimed to compare preoperative and postoperative MME, assess the amount of change in MME (ΔMME), and identify factors influencing MME and ΔMME in open wedge (OW) and closed wedge (CW) HTO. This retrospective study analyzed 82 knees that underwent HTO between 2018 and 2022. Among them, 50 knees were treated with OWHTO and 32 knees were treated with CWHTO. Computed tomography was used to evaluate preoperative and postoperative MME. Radiographic parameters included the hip-knee-ankle (HKA) angle, femorotibial angle (FTA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTSA), joint line convergence angle (JLCA), and joint space height (JSH). Joint laxity was calculated as the difference between supine and standing JLCA. Preoperative MME, postoperative MME and ΔMME were compared between the OWHTO (O group) and CWHTO (C group). ΔMME and its associations with perioperative variables were assessed using univariate and multivariate analyses. The mean postoperative MME (5.71 ± 1.63 mm) was significantly larger than the mean preoperative MME (5.16 ± 1.84 mm) in the O group (P = 0.002), while there was no significant difference between preoperative MME (5.71 ± 2.02 mm) and postoperative MME (5.32 ± 1.86 mm) in the C group (P = 0.239). ΔMME in the C group was significantly smaller than that in the O group (P < 0.001). In the O group,ΔMME negatively correlated with age (R = -0.377, P = 0.007) and positively with joint laxity (R = 0.309, P = 0.029). No factors correlated with ΔMME in the C group. MME increased after OWHTO but was maintained or reduced after CWHTO. From the perspective of MME, CWHTO might be preferable to OWHTO. III (Retrospective cohort study).