High tibial osteotomy for medial meniscus posterior root tears in knees with moderate varus alignment can achieve favorable clinical outcomes

PURPOSE: Favorable clinical results have been reported following high tibial osteotomy (HTO) for medial meniscus posterior root tear (MMPRT) in knees with varus alignment. However, the effect on the preoperative neutral alignment of the knee is not known. This study sought to evaluate the clinical outcomes of medial open-wedge HTO for MMPRT with neutral alignment. METHODS: We retrospectively reviewed 119 medial open-wedge HTOs and analyzed 22 knees with MMPRT. The knees were divided according to the preoperative hip-knee-ankle angle into a moderate varus alignment group (≤4° of varus alignment) and a varus alignment group (> 4° of varus alignment). The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Forgotten Joint Score-12 (FJS-12) values were evaluated preoperatively and at the latest follow-up. The healing status of MMPRT at the time of second-look arthroscopy, performed at a mean of 15.4 ± 4.2 months, was compared with that after the primary HTO. RESULTS: There were 11 knees in the moderate varus alignment group and 11 in the varus alignment group. In terms of perioperative patient-reported outcome measures, there was no significant difference in the preoperative or postoperative KOOS subscale score or FJS-12 score between the moderate varus and varus alignment groups. The healing rate was significantly higher in the moderate varus alignment group. CONCLUSION: Favorable clinical results were obtained by medial open-wedge HTO in knees with MMPRT and moderate varus alignment in the short term. Surgeons should consider the indications for medial open-wedge HTO, even with moderate varus alignment, when planning treatment for MMPRT with persistent knee pain. LEVEL OF EVIDENCE: IV SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40634-022-00504-9.