ABSTRACT
PURPOSE: This study investigated whether inducing valgus alignment and shifting the load laterally through high tibial osteotomy (HTO) alone decreases the extent of medial meniscus extrusion (MME) in the setting of medial meniscus posterior root tear(MMPRT) using ultrasound evaluation. METHODS: Eight fresh-frozen human cadaveric knee specimens were tested using a six-degree-of-freedom robotic testing system and ultrasound. Each specimen was tested in five conditions: (1) intact, (2) MMPRT, (3) medial meniscus repair (MMR), (4) combined medial open-wedge HTO + MMR, and (5) HTO + MMPRT. Measurements were obtained over the medial collateral ligament (MCL, central image) and posterior to the MCL (posterior image) with a 250 N axial load at 0°, 30°, and 90° of knee flexion. Statistical analysis was performed using a two-factor repeated-measures ANOVA. RESULTS: MME was significantly greater in HTO + MMPRT(0°: 2.44 ± 0.41mm, 30°: 2.47 ± 0.37mm, 90°: 2.41 ± 0.28mm) than HTO + MMR in central images (mean difference +0.83 mm, p < .001). No significant difference was found between HTO + MMPRT and MMPRT in MME . MMR had significantly less MME than MMPRT (mean difference -0.58mm, p < .001, posterior image at 0°and central image at 90°, p=.002). HTO + MMR showed significantly less MME than MMR alone at 30° and 90° knee flexion in central image (30°: -0.38 ± 0.05mm, 90°: -0.45 ± 0.06mm, p < .001) and 90° knee flexion in posterior image (-0.38 ± 0.08mm, p = .004). CONCLUSION: HTO alone did not decrease MME in the setting of MMPRT, while MMR alone decrease MME after MMPRT. Additionally, HTO + MMR decreases MME aftrer MMPRT compared to MMR alone, although the clinical significance was uncertain. CLINICAL RELEVANCE: The findings of this study provide clinicians with valuable insights for improving MME. HTO alone does not decrease MME in cases of MMPRT.
ABSTRACT
INTRODUCTION: This study evaluated the correlation between postoperative knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures excluding excessively overcorrected knees. This study further identified preoperative radiological factors related to the increased postoperative knee joint line obliquity. MATERIALS AND METHODS: We retrospectively evaluated patients who underwent medial open-wedge high tibial osteotomy between March 2013 and March 2021. Postoperative excessively overcorrected knees with hip-knee-ankle angle > 7° were excluded. We investigated radiological parameters and patient-reported outcome measures preoperatively and at the last follow-up. The following radiologic parameters were measured: hip-knee-ankle angle, weight-bearing line ratio, mechanical medial proximal tibial angle, mechanical lateral distal femoral angle, lateral distal tibial angle, joint line convergent angle, knee joint line obliquity, ankle joint line obliquity, hip abduction angle, tibial posterior slope, Carton-Deschamps index, and patella tilting angle. Clinical outcomes were evaluated using Japanese knee outcome measures. This assessment criterion is based on the Western Ontario McMaster Universities Arthritis Index and MOS Short Form 36. Multiple regression analysis was performed to evaluate the association between postoperative knee joint line obliquity and patient-reported outcome measures or preoperative radiological factors (P < .05). RESULTS: A total of 52 knees were included. The mean age at the time of the surgery was 61.6 ± 9.0 years and the mean follow-up period was 30.6 ± 10.1 months. Increased postoperative knee joint line obliquity was associated with lower Japanese knee outcome measures. The preoperative hip-knee-ankle angle was significantly associated with postoperative knee joint line obliquity. CONCLUSIONS: Increased knee joint line obliquity after medial open-wedge high tibial osteotomy is associated with inferior clinical outcomes. Care should be given to the center of the rotational angulation in around-knee osteotomy to avoid postoperative increased knee joint line obliquity. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.
