Predictors of Arthrofibrosis after Pediatric Anterior Cruciate Ligament Reconstruction: What Is the Impact of Quadriceps Autograft?

Background: Recent literature on arthrofibrosis after anterior cruciate ligament reconstruction (ACLR) in children and adolescents is limited, especially with regards to quadriceps tendon (QT) autograft. The purpose of this study was to identify predictors of arthrofibrosis after ACLR, with attention to the impact of graft type. Methods: Patients that underwent primary ACLR at a tertiary children's hospital were reviewed for this retrospective case-control study. Those with multiligament reconstructions, lateral extra-articular tenodesis procedures, allografts, or a modified MacIntosh reconstruction were excluded. Arthrofibrosis was defined as a deficit of 10 degrees of extension and/or 20 degrees of flexion at 3 months after ACLR. Univariate analysis was followed by purposeful entry logistic regression to adjust for confounding factors. Results: A total of 378 patients (mean age 15.9±1.7 y, 49.7% female) were included in the analysis, of which there were 180 patellar tendon (PT), 103 hamstrings tendon (HT), and 95 QT grafts. The rate of arthrofibrosis was 1.9% for HT, 6.3% for QT, and 10.0% for PT (P=0.04). Females developed arthrofibrosis more frequently than males (10.6% vs. 3.2%, P=0.004). Those that ultimately experienced this complication had lower median flexion at 6 weeks after ACLR (88 vs. 110 degrees, P<0.001). In multivariate analysis, PT graft raised the odds of arthrofibrosis 6.2 times compared to HT [95% confidence interval (CI): 1.4-27.6, P=0.02], but there were no significant differences between QT and other grafts. Females were at 4.2 times higher odds than males (95% CI: 1.6-10.8; P=0.003). Patients that were unable to attain 90 degrees of flexion 6 weeks after ACLR had 14.7 times higher odds of eventually developing arthrofibrosis (95% CI: 5.4-39.8; P<0.001). Finally, those with an extension deficit of ≥5 degrees 6 weeks after ACLR had 4.7 times higher odds of experiencing this complication (95% CI: 1.8-12.2, P=0.001). Conclusion: The rate of arthrofibrosis with QT autograft is 6.3% after pediatric ACLR. PT autograft, female sex, and motion deficits at 6 weeks after ACLR were predictive of arthrofibrosis in children and adolescents. Level of Evidence: Level III - prognostic study.