2024, Vol. 28 ›› Issue (24): 3903-3909

Predictors of a forgotten joint after medial open wedge high tibial osteotomy

Huang Yiwei1, Peng Bo1, Zhang Chen1, Ge Hao1, Li Jiahao1, Li Yijin1, Chen Jinlun2, Feng Wenjun2, Zeng Yirong2   

Abstract: BACKGROUND: Medial open wedge high tibial osteotomy is an effective procedure for preserving the knee joint in patients with medial compartmental osteoarthritis. Previous studies have demonstrated that the forgotten joint score provides a lower ceiling effect and consistency of medial open wedge high tibial osteotomy outcomes compared to traditional assessment tools.
OBJECTIVE: To identify predictive factors associated with the occurrence of a forgotten joint after medial open wedge high tibial osteotomy.
METHODS: 117 patients with medial open wedge high tibial osteotomy who were treated at First Affiliated Hospital of Guangzhou University of Chinese Medicine were selected, including 35 males and 82 females, with an average age of 61 years. They were followed up for at least 2 years. Patients were divided into a forgotten joint group (n=28) and a non-forgotten joint group (n=89) by evaluating whether they achieved forgotten joint after surgery. Univariate and multivariate logistic regression analyses were performed with preoperative patient characteristics and surgery-related factors as potential predictors.
RESULTS AND CONCLUSION: (1) There were significant differences in the proximal medial tibial angle between the two groups before surgery (P < 0.05). There were significant differences in the forgotten joint score, Knee Injury and Osteoarthritis Outcome Score, knee society knee score, function score, and patients joint perception between the two groups after surgery (P < 0.05). There was a significant difference between the hip-knee-ankle angle and the medial proximal tibial angle after operation (P < 0.05). (2) Univariate Logistic regression analysis showed that the medial proximal tibial angle had a significant influence on the forgotten joint before operation [OR=0.755, 95%CI(0.635-0.897), P < 0.001]. There were significant effects on the forgotten joint of hip-knee-ankle angle and medial proximal tibial angle [OR=1.546, 95%CI(1.242-1.924), P < 0.001; OR=0.815, 95%CI(0.713-0.931), P=0.003]. (3) Multivariate logistic regression analysis showed that preoperative K-L grade 1 was a favorable factor for obtaining forgotten joints. Preoperative medial proximal tibial angle and postoperative hip-knee-ankle angle were independent predictors of forgetting joints, and they had a curvilinear relationship with the probability of achieving forgetting joints. When preoperative medial proximal tibial angle increased by 1°, the probability of achieving a forgotten joint decreased by 27.7% [OR=0.723, 95%CI(0.593-0.882), P < 0.001]. Conversely, when postoperative hip-knee-ankle angle increased by 1°, the probability of achieving a forgotten joint increased by 46.4% [OR=1.464, 95%CI(1.153-1.860), P=0.002]. (4) The results showed that patients with preoperative knee osteoarthritis K-L grade 1, small medial proximal tibial angle (< 85.5°), and large postoperative hip-knee-ankle angle (> 176.0°) were predictors of forgotten joint.

Key words: medial open wedge high tibial osteotomy, forgotten joint score, medial compartmental osteoarthritis, predictor, forgotten joint