Manipulation Under Anesthesia is Safe and Effective for Management of Early Postoperative Knee Arthrofibrosis in Adolescent Patients

Background: Management of postoperative knee arthrofibrosis can be challenging and the preferred time for intervention remains controversial. The purpose of this study is to evaluate the safety and efficacy of early (<3 mo postoperatively) manipulation under anesthesia (MUA) for the treatment of knee arthrofibrosis in adolescent patients. We hypothesized that early MUA could restore normal knee motion with a low complication rate and without the need for more invasive intervention.Methods: In a retrospective review, 57 patients who underwent MUA for postoperative knee arthrofibrosis were identified. The time between the index surgery and MUA as well as changes in range of motion (ROM) before and after MUA were analyzed. Descriptive statistics with median and interquartile range were used to analyze this non-parametric study cohort. Repeated measures ANOVA was performed to assess improvement in ROM over time. A P value <0.05 denoted statistical significance.Results: The median age of the cohort at time of MUA was 14.5 years [interquartile range (IQR) 12.9 to 17.6)]. 54.4% were male. Median time to MUA was 64 days (IQR 52 to 79) after index surgery. ROM before MUA was 90.0 degrees (IQR 75 to 100), which improved to 130 degrees (120 to 135) after MUA. At final median follow-up of 8.9 months (IQR 5.1 to 16.1), mean ROM was 133 degrees (130 to 140). There were no iatrogenic fractures or physeal separations associated with MUA. 12.3% (n=7/57) failed MUA either due to the need for subsequent repeat MUA (n=2), need for lysis of adhesions (n=3) or need for surgery after MUA (n=2). Those who failed early MUA and required subsequent procedures had ROM >120 degrees at final follow-up.Conclusions: Postoperative knee arthrofibrosis can be safely and effectively treated with early (<3 mo postoperative) MUA. There were no iatrogenic fractures or physeal separations during MUA. Patients who had recurrence of motion deficits after early MUA and required further intervention, regained satisfactory knee motion at final follow-up. Although further research is warranted to better characterize risk factors for knee arthrofibrosis in adolescent patients, early recognition and MUA is a safe and effective treatment for arthrofibrosis to help patients regain full ROM without invasive intervention.Level of Evidence: Therapeutic Study - Level IV.