Factors affecting return to sports after eccentric rotational acetabular osteotomy

Abstract

Background: Although eccentric acetabular rotation osteotomy (ERAO) is an effective treatment for developmental dysplasia of the hip (DDH), there is little information about return to sports after ERAO. This study aimed to investigate 1) the patient factors that influence the return to sports after ERAO, 2) whether postoperative sports participation will affect future osteoarthritis progression.

Hypothesis: Some factors affect the return to sports after ERAO.

Patients and methods: Of 503 patients who underwent ERAO from 1990 to 2010, 124 who had been continuously participating in sports preoperatively (average 13.2 years after surgery) were included. Patient demographics of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative Kellgren-Lawrence (KL) grade, center edge angle, joint congruency, Harris hip score, complications and the survival rate were compared between the S group (patients who participated in the same sports preoperatively) and N group (patients who could not participate in sports postoperatively).

Results: Seventy-two (58%) and 52 patients (42%) in the S and N groups, respectively, had an overall return to sports rate of 64% (79 patients). The most common sports that patients participated in were swimming (30 patients [24%]), jogging (12 [10%]), and golf (10 [8%]) preoperatively, and swimming (14 patients [11%]), golf (8 [6%]), and jogging (8 [6%]) postoperatively. There were no significant differences between both groups in terms of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative KL grade, and joint congruency. There was a significant difference in patient factors between the S (11 joints [14%]) and N (20 joints [38%]) groups only when the preoperative center edge angle was <0°. There was no significant difference in the preoperative Harris hip score and the final survey between the S (73.2±4.6 and 93.4±7.2) and N (72.5±4.8 and 92.1±7.4) groups. Complications showed no significant differences between the five patients (7%) in the S group and six patients (13%) in the N group. The KL grade progressed in 10 cases (grade II to III in 2 cases and grade III to IV in 8) in the S group and 8 cases (grade II to III in 1 case and grade III to IV in 7 cases) in the N group. The 10-year and 20-year joint survival rates with THA conversion as the endpoint were 98.1% (95% CI: 87.4%-99.7%) and 83.7% (95% CI: 62.6%-93.4%) in the S group and 100% (95% CI: 70.7%-99.3%) and 95.2% (95% CI: 12.6%-92.6%) in the N group, respectively. In the evaluation of factors affecting sports return by logistic regression analysis, only one significant factor (odds ratio 3.42, 95% confidence interval: 1.58-7.42, p<0.01) was the preoperative center edge angle <0°.

Discussion: The chief factor affecting the return to sports after surgery was a preoperative center edge angle <0°; moreover, the continuation of sports did not affect the subsequent progression of osteoarthritis or THA conversion.

Level of evidence: level III, cohort study.

Keywords: Eccentric acetabular rotation osteotomy; Osteoarthritis progression; Return to sports; Risk factor; Sports activity.