Analysis of Factors Affecting Early Functional Recovery of Bernese Periacetabular Osteotomy

Objectives To explore factors affecting the efficacy of Bernese periacetabular osteotomy for the treatment of hip dysplasia. Methods A retrospective study was conducted on 44 patients with hip dysplasia who underwent Bernese periacetabular osteotomy with a modified Smith-Peterson approach between January 2017 and November 2019. Among them, 40 were women and four were men. The average age was 31.2 +/- 9.4. Preoperative and postoperative imaging parameters were measured. The acetabular top tilt angle, lateral central edge angle, acetabular abduction angle, femoral head extrusion index, sphericity index of femoral head, Shenton line, Tonnis grade of osteoarthritis, joint congruency, p/a ratio, acetabular anteversion angle, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale scores, and modified Harris hip score (MHHS) were observed. MHHS were divided into three clinically relevant categories: poor (<70 points), good (70-85 points), and excellent (86-91 points). Patient demographic data, as well as preoperative and postoperative radiographic parameters, were subjected to univariate logistic regression analysis. Multiple regression analysis was used to determine factors influencing postoperative MHHS. Results The follow-up time was 1.0-3.9 years after surgery, with an average of 1.6 years. By the last follow-up, MHHS increased from 70 points before surgery to 91 points after surgery (P < 0.001), WOMAC pain score decreased from 4 points before surgery to 0 points after surgery (P < 0.001). WOMAC functional score decreased (Preoperative: 18.0 [4.0]; Postoperative: 4.0 [0], P = 0.004). Six patients had sensory disturbance of the lateral femoral cutaneous nerve, four of which recovered completely during follow-up. No other complications related to surgical approach, osteotomy, acetabular displacement, acetabular fixation, and postoperative stage were found. There was no significant vascular, nerve, or visceral injuries in any of the patients. On multiple regression analysis, the probability of the postoperative modified Harris hip score of a hip joint with a preoperative lateral center edge angle >= 4.5 degrees being classified as excellent was six times that of angles <4.5 degrees (Exp[beta]: 6.249, 95% CI: 1.03-37.85, P = 0.046). Regression analysis of other factors found no significant correlation with postoperative functional scores. Conclusion Overall functional scores post-PAO significantly improved, and pain symptoms were significantly reduced. Patients with a preoperative lateral center edge angle >= 4.5 degrees had better joint function after surgery.