What Is The Lateral Collateral Ligament?
The lateral collateral ligament is one of four major ligaments that help to stabilise the knee joint. Also know as the lateral ligament or the LCL for short is a cord-like ligament on the outside (lateral side) of the knee. The ligament connects from the lateral femoral epicondyle to the head of the fibula (joining the lateral hamstring tendon before attaching to the top of the fibula bone in the lower leg). Its function is to provide stability to the outside of the knee.
A sprain is the most common form of lateral collateral ligament injury. These sprains are relatively uncommon when compared to injuries occurring to the MCL or ACL ligaments of the knee. Most lateral ligaments injuries will occur in combination with, injury to other structures such as the ACL or PCL and not in isolation.
Causes Of A Lateral Collateral Ligament Sprain
Injury to the lateral ligament is injured when the force is too great for the ligament to withstand and the LCL is overstretched. Such stress can occur with a twisting movement of the knee whilst the foot is fixed, a sharp change in direction, awkward landing from a jump. Most commonly the LCL is injured in sports through direct impact to the inner surface of the knee, such as during a high speed football or rugby tackle. This force puts pressure on the outside of the knee, where the lateral collateral ligament is causing it to stretch or tear. Lateral ligament sprains are far less prevalent than medial ligament sprains which commonly occur due to trauma applied to the outside of the knee.
Grading Lateral Collateral Ligament Sprain Severity
Lateral ligament sprains are graded from Grade 1-3 with Grade 1 being the most mild injury and Grade 3 being the most severe.
- In a mild Grade 1 LCL sprain, usually there will be little or no swelling and there is pain on stress testing the ligament but no instability of the knee.
- With a Grade 2 LCL sprain the ligament partially tears. In this situation some swelling is common and there may be feelings on instability and the knee giving way with certain movements. As well as feelings of instability the knee joint may feel painful and there is often difficulty moving the knee through its full range of motion.
- A Grade 3 sprain is where the ligament completely tears. This injury is normally associated with swelling and the joint will feel unstable. Weight bearing early on can be difficult however the pain can vary (with a complete tear the pain may be actually less than a Grade 2 LCL sprain). On stress testing the knee there is significant joint laxity and there will be feelings of giving way when mobilising on the knee.
Disclaimer: Sydney Physio Clinic provides this information as an educational service and is not intended to serve as medical advice. Anyone seeking specific advice or assistance on Lateral Collateral Ligament Of The Knee Injury should consult his or her general practitioner, sports medicine specialist, orthopedic surgeon, physiotherapist or otherwise appropriately skilled practitioner.