The lateral collateral ligament (LCL) is a band of tissue located on the outer side of the knee. It connects the femur (thigh bone) to the fibula (the smaller bone in the lower leg), providing stability to the knee joint during movement. The LCL helps prevent excessive side-to-side motion, which can lead to injuries. Injuries to the LCL can occur due to trauma, such as a fall or a direct blow to the knee. Symptoms may include pain, swelling, and instability in the knee. Treatment often involves rest, ice, compression, and physical therapy to restore strength and mobility.