Sports medicine developed in the 1970s as an orthopedic specialty focusing on competitive athletes. Today, sports medicine includes the overall care of athletes from many skill levels. Increasingly, care of recreational athletes has risen to that common for professional athletes. In addition to the musculoskeletal system, care includes the cardiovascular and pulmonary systems and also focuses on training techniques, nutrition, and women's athletics. This wide range of care requires a multidisciplinary team of medical personnel, including athletic trainers, physical therapists, cardiologists, pulmonologists, orthopedic surgeons, and general practitioners.
The bones of the knee are the distal femur, the proximal tibia, and the patella. These bones depend on supporting ligaments, the joint capsule, and the menisci to provide stability for the joint.
Menisci and Joint Capsule
The menisci, or semilunar cartilages, are C-shaped fibrocartilaginous disks in the knee that provide shock absorption, allow for increased congruency between joint surfaces, enhance joint stability, and aid in distribution of synovial fluid.
The medial and lateral menisci provide a concave surface with which the convex femoral condyles can articulate. If the menisci are not present, the convex femoral condyles articulate with the relatively flat tibial plateaus, and the joint surfaces are not congruent. This decreases the surface area of contact and increases the pressure on the articular cartilage of the tibia and femur, which may lead to rapid deterioration of the joint surface. The medial meniscus is firmly attached to the joint capsule along its entire peripheral edge. The lateral meniscus is attached to the anterior and posterior capsule, but there is a region posterolaterally where it is not firmly attached (Figure 3–1). Therefore, the medial meniscus has less mobility than the lateral meniscus and is more susceptible to tearing when trapped between the femoral condyle and tibial plateau. The lateral meniscus is larger than the medial meniscus and carries a greater share of the lateral compartment pressure than the medial meniscus carries for the medial compartment.
The medial and lateral menisci with their associated intermeniscal ligaments. Note: The lateral meniscus is not attached in the region of the popliteus tendon. (Reproduced, with permission, from Scott WN: Ligament and Extensor Mechanism Injuries of the Knee: Diagnosis and Treatment. New York: Mosby-Year Book; 1991.)
Within the knee, the anterior cruciate ligament (ACL) travels from the medial border of the lateral femoral condyle to its insertion site anterolateral to the medial tibial spine. This ligament prevents anterior translation and rotation of the tibia on the femur (Figure 3–2). The posterior cruciate ligament (PCL) prevents posterior subluxation of the tibia on the femur. It runs from the lateral aspect of the medial femoral condyle to the posterior aspect of the tibia, just below the joint line (...