The Familial Predisposition Toward Tearing the Anterior Cruciate Ligament: a Case Control Study

Purpose: A study of 171 surgical cases and 171 matched controls was conducted to investigate whether a familial predisposition toward tearing the anterior cruciate ligament of the knee exists.

Study Design: Case control study; Level of evidence, 3.

Methods: Patients who were diagnosed with an anterior cruciate ligament tear were matched by age (within 5 years), gender, and primary sport to subjects without an anterior cruciate ligament tear. All 342 subjects completed a questionnaire detailing their family history of anterior cruciate ligament tears.

Results: When controlling for subject age and number of relatives, participants with an anterior cruciate ligament tear were twice as likely to have a relative (first, second, or third degree) with an anterior cruciate ligament tear compared to participants without an anterior cruciate ligament tear (adjusted odds ratio = 2.00; 95% confidence interval, 1.19-3.33). When the analysis was limited to include only first-degree relatives, participants with an anterior cruciate ligament tear were slightly greater than twice as likely to have a first-degree relative with an anterior cruciate ligament tear compared to participants without an anterior cruciate ligament tear (adjusted odds ratio = 2.24; 95% confidence interval, 1.24-4.00).

Conclusions: Findings are consistent with a familial predisposition toward tearing the anterior cruciate ligament.

Clinical Relevance: Future research should concentrate on identifying the potentially modifiable risk factors that may be passed through families and developing strategies for the prevention of anterior cruciate ligament injuries.