Anterior Cruciate Ligament Rupture

The number of anterior cruciate ligament (ACL) injuries among young athletes has increased over the past 2 decades. It is currently estimated that 47 per 100,000 boys aged 10 to 19 years will require surgery for an ACL injury each year. Apart from the immediate debilitating effects, there are serious long-term consequences of ACL injuries, including chronic knee instability, cartilage damage, and osteoarthritis—all leading to decreased activity levels. On average, 50% of individuals will develop radiographic signs of osteoarthritis, which is associated with pain and functional impairment, 10 to 20 years after diagnosis. Thus, it is imperative to identify young athletes that may be susceptible to ACL injuries and implement preventative training measures in these individuals. The incidence rate of ACL injuries among young, male, American football players has been reported to be 0.58 ACL injuries per 10,000 athlete-exposures, with an athlete-exposure being defined as 1 athlete participating in either 1 game or 1 practice. We report a case study of 4 consecutive brothers all requiring surgical treatment for football-related ACL injuries before the age of 22 years. The probability of such injuries occurring to the first 4 brothers in any given family by chance would be approximately 1 in 36 million given the reported incidence rate and an estimated 100 exposures per year for competitive players and 10 exposures per year for players playing leisurely. Given the uniqueness of such a case, we evaluated the brothers and the specifics to their injuries. We hypothesize that these brothers may have familial risk factors such as an increased posterior tibial slope, a narrow intercondylar notch width, or a high body mass index (BMI) underlying this apparent predisposition to ACL injury.