The annual prevalence of knee injuries was found to be 54% among athletes who attended the annual NFL Combine. The prevalence of full-thickness articular cartilage defects of the knee identified by magnetic resonance imaging (MRI) was found to be 20%. 8% of NFL Combine attendees had multiple cartilage lesions in the knee, 4% had isolated lateral femoral condyle lesions, 5% had isolated patellofemoral chondral damage, and 3% had isolated medial femoral condyle lesions. Risk factors for cartilage injuries are having a body mass index (BMI) greater than 30.5, weight greater than 222.5 lbs, and playing the linebacker position.
Source: Arthroscopy, 2010