Second-look arthroscopic findings after medial open-wedge high tibial osteotomy combined with all-inside repair of medial meniscus posterior root tears

Purpose: To examine the results of medial open-wedge high tibial osteotomy (MOWHTO) combined with all-inside repair focusing on medial meniscus posterior root tears (MMPRT) by second-look arthroscopy and determine the clinical relevance of the findings. Methods: From June 2015 to June 2017, 27 consecutive patients underwent MOWHTO and meniscal treatment for MMPRT using all-inside repair. All were available for second-look arthroscopy evaluation at the time of plate removal. Cartilage regeneration in the medial condyles and healing status of the MMPRT were assessed at the time of second-look arthroscopy. Clinical outcomes were evaluated by the Hospital for Special Surgery (HSS) scores and the Lysholm score scale. The potential factors affecting the healing of MMPRT, including age, body mass index (BMI), weight-bearing line rate (WBLR) and femorotibial angle (FTA) were discussed. Results: There were 11 (41%) cases with complete healing (group A) and 16 (59%) cases with lax healing (group B). A complete cartilage coverage of chondral lesions was observed at second-look arthroscopy. Improvements of HSS in both groups were 41.25 +/- 6.18 and 38.82 +/- 5.43, while improvements in Lysholm score seen in both groups were 30.40 +/- 4.84 and 32.65 +/- 4.11. There was no significant difference in the postoperative clinical results between the two groups. In group A, the age (months), BMI, WBLR, and FTA are 54.61 +/- 2.53, 23.58 +/- 2.39, 66.10 +/- 2.86% and 169.00 +/- 2.62 degrees, respectively, while in group B, they are 55.16 +/- 4.92, 29.58 +/- 3.91, 57.51 +/- 5.49% and 175.21 +/- 2.87 degrees, respectively. A significant difference has been identified between two groups except for age. Conclusion: As seen in this retrospective study, a higher healing rate of MMPRT using all-inside repair and regeneration of degenerated articular cartilage in the medial condyles after MOWHTO can be expected. Healing of the MMPRT was not related to a better clinical outcome. Moreover, it can be inferred that BMI, WBLR and FTA may affect the healing status of MMPRT.