Do Pediatric Patients With Anterior Cruciate Ligament Tears Have a Higher Rate of Familial Anterior Cruciate Ligament Injury?

Background: Several studies have examined the anterior cruciate ligament (ACL) injury history among relatives of patients undergoing ACL reconstruction (ACLR), but they have primarily analyzed adults with variable results. Hypothesis: We hypothesized that he rate of familial ACL injuries among pediatric patients with ACL tears would be greater than that among pediatric patients with uninjured knees. Study Design: Cohort study; Level of evidence, 3. Methods: Pediatric patients (≤18 years of age) who underwent ACLR between January 2009 and May 2016 were contacted to complete a questionnaire on subsequent complications and family history of ACL tears. A control cohort was recruited from children with uninjured knees seen in the concussion clinic of our institution. Binary logistic regression was used to determine the factors predictive of having a familial ACL tear history or complications. Results: Overall, 450 pediatric patients with primary ACL tears were included. Age at the time of surgery was 14.9 ± 2.2 years with a follow-up of 4.3 ± 2.1 years. When compared with 267 control patients, those with an ACL tear reported a higher rate of first-degree relatives with an ACL injury history (25.1% vs 12.0%; P <.001). In multivariate analysis, children with ACL injury had nearly 3 times (odds ratio [OR], 2.7) higher odds of having a first-degree relative with an ACL tear (95% CI, 1.7-4.2; P <.001). Patients were stratified by the number of first-degree relatives with ACL tears: no relatives, 1 relative, or ≥2 relatives. Children with ≥2 first-degree relatives were more likely to sustain a postoperative graft failure (OR, 5.1; 95% CI 1.7-15.2; P =.003) or a complication requiring surgical intervention (OR, 7.5; 95% CI, 2.6-22.0; P <.001). Conclusion: A family history of ACL injury is more likely in pediatric patients with ACL tears than in uninjured children. Further, patients undergoing primary ACLR as well as a strong family history of ACL tears are more likely to sustain a postoperative graft rupture or complication requiring surgery.