Although the least frequent of all knee injuries, Lateral Collateral Ligament (LCL) injuries are at high suspicion on many knee exams. The most common way to injure your LCL is via a high-energy blow to the anteromedial aspect of your knee. This makes those participating in contact sports and high velocity sports most prone to LCL and posterolateral corner (PLC) related injuries. If you believe you may have a LCL injury, you may require reconstructive surgery to regain functioning of the ligament prior to returning to physical and/or daily activities. Although, there are non-surgical treatments available that may help alleviate pain.
The LCL serves as a key stabilizer in the knee joint. This ligament originates on the lateral epicondyle of the femur, and inserts directly on to the fibular head. The primary function of the LCL is to prevent both excess varus stress (knees caving outward) and posterior-lateral rotation of the knee.
When the LCL is injured, orthopaedic surgeons will classify the injury and grade it depending on the severity. As physical examination may not always provide adequate information to determine the severity of the injury, additional imaging such as X-Ray or MRI may be required to more confidently illustrate degree of the injury.
As a part of posterolateral corner (PLC), it is not uncommon to see other damaged structures during an LCL injury. This includes structures such as the popliteus tendon and popliteofibular ligament. In extreme cases where all three of these structures are damaged, complete reconstruction of the PLC may be advised.
If you have a LCL injury, you may experience one or several of the following symptoms:
- Knee pain, soreness, tenderness and/or stiffness originating along outer edge
- Unstable knee when walking or standing
- Knee locks or “catches” in place during walking
- Atypical range of motion of the knee
- Foot numbness
- Bruising on or around the knee joint
Determination of treatment is extremely dependent on the severity of the LCL injury and if other injuries are present and associated (for example, a complete PLC tear vs. a grade I LCL sprain). Acutely, many LCL injuries can be treated with rest, ice, compression, NSAIDs (aspirin, ibuprofen, etc.).
In many cases regarding grade I and grade II LCL injuries, surgical treatment may not needed and restoration of the LCL may occur with a therapeutic approach. In addition to physical therapy, patients can expect to be non-weightbearing for a period of time in order to control for pain. Following this, a patient may expect to be placed in a hinged-knee brace to stabilize the knee joint while performing functional rehabilitation.
With a complete tear (grade III) of the LCL, surgical intervention will be needed in order to restore anatomy and biomechanics of the knee. With these severe injuries, studies have illustrated not only that pain reduction was highest in patients who underwent surgery, but range of motion increased significantly as well. Isolated LCL reconstruction surgery is typically performed using a semitendinosus graft. In the case of grade III PLC injuries, multiple grafts may need to be utilized to restore anatomical functioning of the knee.
In any case of treatment, rehabilitation and physical therapy play a critical role in helping you return to your daily activities. Physical therapy programs help restore knee strength and motion. In the case of LCL reconstruction, physical therapy focuses on returning movement to the surrounding muscles and knee, which is followed by a strengthening treatment to maintain and protect the new ligament. Finally, in the last step of rehabilitation the methods are customized for a safe return to the athlete’s sport.