Lateral Collateral Ligament
Its description, causes, symptoms, diagnosis and treatment (operative and non-operative)
The lateral collateral ligament (LCL) is the main stabilizing ligament on the outer aspect of the knee. Its main function is to prevent the knee from giving way outward (varus motion). Tears/ruptures of the ligament results in knee instability.
What are the causes?
Isolated LCL tears are uncommon. They typically occur from trauma. A direct force to the inside of the knee stresses the ligament. This typically occurs in collision sports like football. LCL tears are also seen in high-energy trauma like motor vehicle accidents and are accompanied by tears in the other ligaments and tendons on the outside of the knee (aka – posterolateral corner injury and knee dislocation).
What are the symptoms?
LCL tears cause immediate pain and often swelling. You may feel something “pop” on the outer aspect of the knee. Pain is centralized over the ligament (outside aspect of the knee). Walking after the injury may be possible but the knee may feel like it’s going to “give out” depending on the severity of the tear.
How is it diagnosed?
Your surgeon will perform a thorough history and physical exam with X-rays. On exam, swelling and loss of motion and strength is present. Your surgeon will perform maneuvers to check stability of all the knee ligaments and the meniscus. An MRI is helpful to confirm the diagnosis, showing the LCL tear. The type of tear (partial, complete, avulsion from either the tibia or femur) can be defined, which may assist in treatment planning. The MRI may also show bone bruising secondary to the injury.
How is it treated?
Non-operative - Almost all minor LCL tears can be treated non-operatively. Non-operative treatment consisting of bracing, anti-inflammatory medication, physical therapy, cryotherapy and activity modification may be prescribed to decrease the swelling, regain motion and strength. Most patients may be able to return to normal activity without surgery depending on the type and severity of the tear. A brace may be prescribed to return to sports activities. If symptoms persist (pain, instability), reconstruction surgery may be recommended by your surgeon. If other structures are damaged (i.e.- Posterolateral Corner), surgery is recommended to reconstruct the knee.
Operative - Operative management of LCL tears depends on the type of tear. LCL repair may be indicated in patients where the LCL is clearly torn off the wall of the femur (thigh bone) or tibia (shin bone. LCL repair is accomplished through a series of small incisions and sewed back into place and fixed with screws or buttons. The repair may also be supplemented with high-strength suture.
If formal reconstruction is required, a new LCL graft will be fixed in place of the original ligament. A technique for graft placement and graft choice is a shared decision between you and your surgeon. Most techniques are performed through a minimally-invasive incision. The graft can be taken from around your knee or from a donor. Postoperative rehabilitation, return to daily activities and return to sport depends on the technique and graft chosen, and is at your surgeon’s discretion.