[Short-term effectiveness of high tibial osteotomy combined with arthroscopic surgery for knee varus arthritis and the results of secondary arthroscopic exploration].

Objective: To investigate the effectiveness of high tibial osteotomy (HTO) combined with arthroscopic surgery to treat medial compartment knee osteoarthritis (KOA) and secondary arthroscopic exploration to evaluate the outcome of cartilage and meniscus.
Methods: A clinical data of 57 patients with medial compartment KOA with varus deformity of lower extremities admitted between August 2014 and October 2018 were retrospectively analyzed. There were 23 males and 34 females with an average age of 51.2 years (range, 41-63 years). The disease duration ranged from 2 to 8 years, with an average of 4.7 years. The preoperative femorotibial angle was (179.86±4.69)°, the relative position of the lower limb mechanical axis passing through the tibial plateau was 24.21%±6.98%, and the posterior slope of the tibial plateau was (5.23±1.45)°. The Kellgren-Lawrence grade of knee joint was grade Ⅱ in 22 cases and grade Ⅲ in 35 cases. The preoperative Hospital for Special Surgery (HSS) score, Lysholm score, and visual analogue scale (VAS) score were 59.1±7.3, 48.8±7.6, and 6.2±1.1, respectively. Arthroscopic exploration was performed during the operation to record the articular cartilage degeneration in the weight-bearing area of the medial compartment (Outerbridge grade Ⅰ in 18 cases, grade Ⅱ in 30 cases, and grade Ⅲ in 9 cases) and the condition of the medial meniscus injury, and the corresponding treatment was performed. The coronal force line was adjusted according to the preoperative Kellgren-Lawrence grade of the knee joint during the operation. After operation, the relative position of the lower limb mechanical axis passing through the tibial plateau, the femorotibial angle, and the posterior slope of the tibial plateau were measured; the Kellgren-Lawrence grade of the knee joint was recorded; the Outerbridge grade of articular cartilage degeneration and the meniscus outcome were evaluated by combining with the MRI of the knee joint at 1 year after operation and the second arthroscopic exploration when the internal fixator was removed. The function and pain of the knee were evaluated by Lysholm score, HSS score, and VAS score.
Results: All the 57 patients were followed up 36-58 months with an average of 42.1 months. Incisions healed by first intention, and no neurovascular injury, intraarticular or hinge fractures occurred during operation, and no postoperative complications such as deep vein thrombosis of lower limbs and internal fixation failure occurred. All the osteotomy sites healed at 3 months after operation. At 1 year after operation, the internal fixator was removed, and the second arthroscopic exploration showed that there were 15 cases of Outerbridge grade Ⅰ, 31 cases of grade Ⅱ, and 11 cases of grade Ⅲ in the weight-bearing area of the medial compartment, and there was no significant difference when compared with preoperative grade ( Z=31.992, P=0.997); there was no cartilage degeneration in other compartments. Meniscus healing was seen in the injured meniscus, and no injury was seen in the normal meniscus. At last follow-up, there were 19 cases of Kellgren-Lawrence grade Ⅱ and 38 cases of grade Ⅲ, and there was no significant difference when compared with preoperative grade ( Z=49.049, P=0.764). The relative position of the lower limb mechanical axis passing through the tibial plateau was 59.16%±2.87%, and the femorotibial angle was (171.54±3.39)°, which significantly improved when compared with those before operation ( P<0.001). The posterior slope of the tibial plateau was (5.65±1.22)°, which was not significantly different from that before operation ( t=-1.673, P=0.096). The HSS score, Lysholm score, and VAS score were 82.3±7.7, 83.4±6.4, and 1.6±1.1 respectively, which were significantly different from those before operation ( P<0.001).
Conclusion: HTO combined with arthroscopic surgery for medial compartment KOA with varus deformity of lower extremities can effectively improve the force line of lower extremities, relieve pain symptoms, and improve joint function, with satisfactory short-term effectiveness, and without significant progress in articular cartilage or meniscus injury after operation.