Knee Anatomy

The knee is more likely to be damaged than most other joints because it is subject to tremendous forces during vigorous activity. The knee is the joint where the femur (thighbone) meets the tibia (lower leg bone). The knee moves like a hinge, but it can also rotate and move from side to side.

The patella (kneecap) is a small, flat, triangular bone in front of the joint. It is not directly connected with any other bone. Muscle and ligaments hold it in place.

The femur and tibia are connected in three ways: by ligaments (strong cord-like tissues), by muscles, and by a capsule. The capsule surrounds the joint (thighbone) and the tibia (large bone of the lower leg) are connected in three ways: by ligaments (strong, cordlike tissues); by muscles; and by a synovial capsule. The synovial capsule surrounds the joint.

The synovial capsule secretes a liquid called synovial fluid, which resembles raw egg white. The synovial fluid nourishes the joint surfaces and reduces friction between them. If the synovial capsule is injured, it may produce too much fluid. The knee ligaments are the strongest connections between the femur and the tibia. Ligaments keep the bones from moving out of position. One group of muscles bends the knee and another group straightens it.

Smooth tissue called cartilage covers the ends of the femur and the tibia. This tissue helps the bones slide easily over each other and is a tissue that is attacked in arthritis.

Common Causes of Knee Pain Treated at GSOS

Patients with knee pain typically experience swelling, stiffness, weakness or instability in the joint. They may also experience crunching or popping noises or the inability to fully straighten the knee.

Knee pain is most commonly caused by injuries during activities like recreational sports or tasks at work or home. Injuries to the knee may be sudden, such as during a fall, a direct blow to the knee, or abnormally twisting or bending the knee.

The following are some common causes of knee pain

• Arthritis
• Knee (prepatellar) bursitis
• Bone chips
• Cartilage wear and tear
• Chronic knee pain
• Knee fracture
• Iliotibial (IT) band syndrome
• Meniscus tears
• Osgood-Schlatter disease
• Osteochondritis dissecans
• Runner’s knee
• Infected knee replacement
• Failed knee replacement
• Sprains & strains
• Subluxation or dislocation
• Tendonitis
• Anterior cruciate ligament (ACL) tears, ruptures & sprains

Knee pain can also be caused by overuse of the joint, due to repetitive motions. This is often associated with activities such as climbing stairs, running, jumping, or bicycle riding.