[Arthroscopy combined with high tibial osteotomy for the treatment of knee medial compartment osteoarthritis and its influence on cartilage injury].

OBJECTIVE: To investigate the effectiveness of arthroscopy combined with high tibial osteotomy (HTO) in the treatment of knee medial compartment osteoarthritis and its influence on cartilage injury.
METHODS: The clinical data of 57 patients with knee medial compartment osteoarthritis treated with arthroscopy combined with HTO between March 2017 and March 2019 were retrospectively analyzed. There were 27 males and 30 females with an average age of 52.4 years (range, 44-57 years). The disease duration ranged from 3 to 6 years, with an average of 3.6 years. Twenty-one cases were grade Ⅰ and 36 cases were grade Ⅱ according to Kellgren-Lawrence classification. Flexion contracture of knee joint ranged from 0° to 8° with an average of 1.36° and varus deformity ranged from 5° to 10° with an average of 7.60°. Preoperative arthroscopic evaluation showed that there were 11 cases with grade Ⅰ, 42 cases with gradeⅡ, and 4 cases with grade Ⅲ according to the international cartilage repair classification system (ICRS). Lysholm score, American Hospital for Special Surgery (HSS) score, and International Knee Documentation Committee (IKDC) score were used to evaluate knee function before operation, at 3 months, at 1 year after operation, and at last follow-up. Visual analogue scale (VAS) score was used to evaluate pain. The mechanical medial proximal tibial angle (mMPTA) and femoral tibial angle (FTA) were measured before operation and at last follow-up. When the internal fixator was removed, the knee arthroscopy was performed again to explore the cartilage repair condition, and the regeneration level and maturity level were selected for cartilage grading evaluation.
RESULTS: All patients' incisions healed by first intention after operation, and no incision infection or skin necrosis occurred. After operation, the knee joint function of the patients was significantly improved, the pain symptoms were relieved, and the force line measurement reached the target set before operation. The VAS score, Lysholm score, HSS score, and IKDC score were significantly improved at 3 months, 1 year after operation, and at last follow-up when compared with those before operation. They were gradually improved with the time and there were significant differences between time points ( P<0.05). mMPTA and FTA were significantly improved at last follow-up when compared with those before operation ( P<0.05). When the internal fixator was removed, the arthroscopic re-assessment found that the cartilage regeneration was classified into 10 cases of grade Ⅰ and 47 cases of grade Ⅱ; 18 cases of immature cartilage regeneration and 29 cases of mature cartilage regeneration were found in the knee joints of grade Ⅱ cartilage regeneration. There was no significant difference in the cartilage regeneration grade between different ICRS gradings ( H=0.176, P=0.916), and the difference in maturity grading was significant ( H=10.500, P=0.005).
CONCLUSION: Arthroscopy combined with HTO for the treatment of knee medial compartment osteoarthritis can effectively improve the symptoms and function of the knee joint, and can promote the regeneration of articular cartilage.