Comparison of the effect of medial open wedge high tibial osteotomy for moderate and severe knee osteoarthritis / 中华骨科杂志

ABSTRACT

Objective:To investigate the effect of medial open wedge high tibial osteotomy (HTO) on moderate and severe medial compartmental knee osteoarthritis.Methods:This study retrospectively reviewed patients treated with medial open wedge HTO between January 2017 and January 2019. All cases were followed up for more than 2 years. There were 28 patients with severe osteoarthritis, including 11 males and 17 females, aged 56.36±5.06 years. There were 32 patients with moderate osteoarthritis, including 12 males and 20 females, aged 54.16±6.3 years. Kellgren-Lawrence (K-L) grading, hip-knee-ankle angle (HKA), weight bearing line (WBL) ratio, joint line convergence angle (JLCA), medial joint space (MJS), posterior tibial slope (PTS), medial meniscus extrusion (MME) and medial meniscus extrusion ratio (MMER) were evaluated on radiographs before and 2 years after surgery. The International Cartilage Repair Society (ICRS) of the cartilage of medial femoral condyle (MFC) and medial tibial condyle (MTC) were evaluated under arthroscopy. The clinical outcomes were assessed by the Western Ontario and McMaster University (WOMAC) score, visual analogue scale (VAS) and the degree of medial collateral ligament (MCL) pseudo-relaxation. Predictors of MCL pseudo-relaxation were screened by binary logistic regression analysis.Results:K-L grading, HKA, WBL ratio and MJS improved in both groups after surgery, with no statistical significance between groups ( P>0.05). The postoperative JLCA was improved, whereas MME and MMER were not. And the severe group was higher than the moderate group before and after surgery ( P<0.05). Cartilage of MFC in the severe group, 2 cases of ICRS 3 grade, 26 of 4 grade improved to 11 of 2 grade, 12 of 3 grade, 5 of 4 grade; in the moderate group, 12 cases of ICRS 2 grade, 18 of 3 grade, 2 of 4 grade improved to 30 of 2 grade, 2 of 3 grade. Cartilage of MTC in the severe group, 2 cases of ICRS 3 grade, 26 of 4 grade improved to 17 of 2 grade, 8 of 3 grade, 3 of 4 grade; in the moderate group, 11 of 2 grade, 8 of 3 grade, 3 of 4 grade improved to 27 of 2 grade, 5 of 3 grade. The postoperative WOMAC score of the severe group improved from 50.71±8.07 to 3.86±1.84, while in the moderate group it improved from 44.09±6.63 to 3.34±2.24. The postoperative VAS score of the severe group decreased from 7.14±1.21 to 3.34±2.24, whereas it decreased from 6.38±1.24 to 0.44±0.62 in the moderate group ( P<0.05). There was no significant difference between the postoperative groups ( P>0.05). In the severe group, the degree of pseudo-relaxation of the MCL improved from preoperative 25 of I degree, 3 of II degree to postoperative 28 of 0 degree at the 0° position, and from 25 of I degree, 3 of II degree to 24 of 0 degree, 4 of I degree at 30° position ( P<0.05). In the moderate group, the degree of pseudo-relaxation of the MCL improved from preoperative 31 of 0 degree, 1 of I degree to postoperative 32 of 0 degree at the 0° position, and from 28 of 0 degree, 4 of I degree to 32 of 0 degree at the 30° position ( P<0.05). JLCA ( OR=0.08, 95% CI 0.007, 0.948, P=0.045), MME ( OR=0.11, 95% CI 0.100, 1.32, P=0.082) and MMER ( OR=0.66, 95% CI 0.422, 1.030, P=0.067) were independent predictors of MCL pseudo-relaxation (the difference was statistically significant at P<0.10). Conclusion:Medial open wedge HTO has significant short-term clinical effect on the treatment of moderate and severe medial compartmental knee osteoarthritis, which can effectively relieve pain symptoms, improve joint function, and restore medial knee stability. Preoperative large JLCA, MME and MMER indicate pseudo-relaxation of the MCL.