Analysis of the Efficacy of High Tibial Osteotomy in Treating Knee Osteoarthritis at Different Levels of Weight Bearing Line Correction

Objective investigating the efficacy of medial open wedge high tibial osteotomy (MOWHTO) in treating medial compartment osteoarthritis of the knee under different levels of postoperative Weight bearing line (WBL) correction to identify the optimal lower limb alignment zone. Methods A retrospective analysis was conducted on the clinical data of 180 patients with medial compartment knee osteoarthritis treated by MOWHTO at our institution from April 2016 to November 2024. The degree of postoperative correction of the WBL was calculated using full-length radiographs of both lower limbs. Patients were categorized into three groups based on the degree of postoperative WBL correction: Group A (50–55%), Group B (55–60%), and Group C (60–65%). Measurements of hip-knee-ankle (HKA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and posterior tibial slope angle (PTSA) were taken at preoperative and final postoperative follow-up.Data on knee range of motion (ROM), pain visual analogue scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lysholm scores were collected at preoperative and final postoperative follow-up to evaluate clinical outcomes before and after the surgery and compare clinical results among the three patient groups. Results The average follow-up duration for the three groups was approximately 39 months, with no statistically significant differences (P > 0.05). The postoperative HKA and MPTA in the three groups were significantly higher than preoperative levels (P < 0.001). PTSA and JLCA showed no significant difference compared to preoperative measurements (P > 0.05).At the final postoperative follow-up, ROM, VAS, WOMAC scores, and Lysholm scores were all significantly improved compared to preoperative levels (P < 0.001). Comparing the three groups, patients in Group B demonstrated the most favourable outcomes in ROM (P = 0.013), VAS (P = 0.010), WOMAC score (P < 0.001), and Lysholm score (P = 0.004), while patients in Group C had the worst outcomes for these parameters. These differences were statistically significant. There were no statistically significant differences in the postoperative thrombosis incidence or wound complication rates among the three groups (P > 0.05). Conclusion Correcting the WBL to within the 50–65% range can effectively improve knee function by optimizing the distribution of lower limb alignment. The procedure is considered safe. Among the three groups, Correcting the WBL to 55–60% yielded the most significant improvement in knee function, while the range of 50–55% produced the weakest effect.