Numerous types of injuries can cause lateral knee pain. According to the Mayo Clinic website, almost 33 percent of Americans over the age of 45 have some type of knee pain, including lateral knee pain or pain on the outside aspect of the knee. Lateral knee pain can be caused by any type of tissue that composes the knee, including muscle, tendon, ligament, bone and cartilage. Most lateral knee pain responds well to conservative care methods.
Iliotibial Band Syndrome
Iliotibial band syndrome can cause lateral knee pain. According to the Nicholas Institute of Sports Medicine and Athletic Trauma--the first hospital-based facility in the United States dedicated to the study of sports medicine--iliotibial band syndrome occurs when pain manifests over the lateral femoral condyle during vigorous physical activity, especially walking and running. The lateral femoral condyle is a bony prominence on the outside aspect of the knee. The iliotibial band is a long, fibrous band of tissue that runs down the lateral thigh and over the lateral femoral condyle to eventually insert onto the lateral condyle of the tibia or shin bone. NISMAT states that shortening of the iliotibial band due to overuse, along with repetitive knee flexion and extension, can produce inflammation and pain in the area of the lateral femoral condyle. Iliotibial band syndrome usually responds well to manual therapies and physical therapy.
Lateral Collateral Ligament Sprain
A lateral collateral ligament sprain can cause lateral knee pain. The National Institutes of Health states that a lateral collateral ligament sprain is an injury--a stretch, partial tear or complete tear--of the lateral collateral ligament, which is on the outside aspect of the knee. The lateral collateral ligament is responsible for stabilizing the outside portion of the knee or the portion of the knee that faces away from the body. According to the NIH, the most common cause of a lateral collateral ligament sprain is pressure, often from blunt-force trauma, to the medial or inside aspect of the knee. Force applied to the medial knee stretches and stresses tissues and structures on the outside part of the knee, including the lateral collateral ligament. Common signs and symptoms associated with a lateral collateral ligament sprain include the following: the sensation of knee instability, lateral knee pain, tenderness on the outside of the knee and knee swelling.
Proximal Fibula Fractures
A fibular head fracture can cause lateral knee pain. According to orthopaedia.com, proximal fibula fractures or fractures of the upper aspect of the smaller of the two shin bones usually involves damage to other tissues or structures in the lateral knee and lower leg. Ligament, nerve and blood vessel injuries near the fracture site may occur in conjunction with the proximal fibula fracture. The signs and symptoms of a proximal fibula fracture depend on the location and the amount of force delivered to the upper shin, although possible signs and symptoms include the following: lateral knee and lateral shin swelling, tenderness with palpation or compression of the affected area, blood in the knee joint, an inability to bear weight or ambulate and an observable deformity in the involved area. Possible complications of proximal fibula fractures include injury to the peroneal nerve and popliteal artery--structures that lie in proximity to the fibular head--and compartment syndrome or increased swelling in the muscles that can lead to tissue death.
