Anatomy of the Knee

The large bone of the thigh, known as the femur meets the tibia to form the knee joint. The patella protects the joint in front. The ends of the bones are covered with a layer of surface cartilage to provide a smooth friction-less surface for motion to take place. The hyalin or surface cartilage is frequently the problem in arthritis and tracking problems. (see chondromalacia) This cartilage is to be distinguished from the meniscal cartilage. The menisci are triangular, semi-lunar shaped structures that fit in each side of the joint. They provide a cushion, stabilize, and distribute the weight-bearing surface over a larger area. The menisci can be torn and lead to catching, local pain and locking episodes. Many of these tears can be repaired or removed by a simple surgical procedure called arthroscopy. Ligaments hold the bones in relationship to each other. The side ligaments are called collateral ligaments, and are frequently injured in collision sports.

The Cruciate ligaments are deep within the knee, and frequently injured in skiing and often even in non-contact situations. The hallmarks of an ACL tear are an audible "pop" and immediate onset of swelling. (see ACL reconstruction)

Not all knee pain is from something wrong inside the knee. There are numerous tendons that also cross the knee joint and act as secondary stabilizers of the joint. These structures, such as the iliotibial band, patellar tendon, popliteus tendon, and hamstring tendons can often become inflamed in overuse injuries. They can then be confused with ligament and meniscal injuries, and be difficult to sort out. If any of the above situations sound familiar to you, contact the Mapleton Hill Orthopaedics for a referral or appointment.