LCL Injuries
An LCL injury is a tear or sprain of the lateral collateral ligament, a band of tissue on the outer side of your knee that connects your thighbone to your lower leg bones. This ligament normally prevents your knee from bending outward abnormally. The LCL can tear from a direct blow to the inside of your knee, a varus force (when your knee bends outward), or hyperextension. Unlike medial collateral ligament (MCL) injuries on the inner knee, LCL injuries are less common but more likely to involve the posterolateral corner, or PLC, a complex group of ligaments and structures at the back and outside of your knee.
LCL injuries can affect anyone, though they are more common in athletes in sports like football, soccer, skiing, and basketball. In my practice, I see LCL injuries ranging from mild sprains to severe tears, and often they come with injury to other structures like the posterior cruciate ligament or anterior cruciate ligament. The key to good outcomes is accurate diagnosis and prompt treatment tailored to the severity and extent of the injury.
Treatment depends on the grade of injury. Grade I and II injuries often heal well with conservative care. But Grade III injuries and those involving the posterolateral corner structures rarely heal on their own without surgery. Early specialist evaluation helps me determine the right path forward and, if surgery is needed, prevents long-term instability and damage to your knee.
Treatment Options
For Grade I and Grade II LCL injuries, the goal is to allow the ligament to heal naturally. Treatment includes a hinged knee brace to stabilize the knee, ice and elevation to reduce swelling, and physical therapy starting within a few weeks. Most patients return to their activities within six to eight weeks with this conservative approach.
Grade III LCL injuries and posterolateral corner injuries are a different story. These severe tears rarely heal without surgery, and delaying treatment often leads to chronic instability, further cartilage damage, and a much harder recovery later. In my practice, I recommend surgery for isolated Grade III LCL injuries to restore normal knee function and prevent long-term problems.
My surgical approach depends on the anatomy of the tear. For fresh injuries where the ligament is still in good condition, I may perform an LCL repair. More commonly, Grade III injuries need an LCL reconstruction, where I replace the torn ligament with a tissue graft. If the posterolateral corner is involved, I reconstruct multiple structures to restore full stability. When there are combined injuries, such as LCL plus ACL or LCL plus PCL, I plan either a staged approach or combined reconstruction based on what your knee needs. The goal is always to restore normal knee mechanics and get you back to the activities you enjoy.
Recovery Timeline
Non-surgical recovery for Grade I and II injuries is relatively quick. Most patients wear a brace for three to six weeks while doing guided physical therapy. Pain and swelling typically resolve within one to six weeks, and you can gradually return to normal activities.
Surgical recovery is longer and more demanding. After LCL or posterolateral corner reconstruction, you will use crutches for six weeks and wear a protective brace for six to twelve weeks. Physical therapy starts 5 to 7 days after surgery, 2 times a week. Bending is limited to 90° for the first 6 weeks. Most patients are walking without crutches by 10 to 12 weeks. Running usually starts around 4 to 5 months, and return to cutting and contact sports takes six to nine months, longer with a posterolateral corner reconstruction.
The timeline varies based on how many ligaments were injured and your commitment to rehabilitation.
The good news is that outcomes after surgery are generally very good. In my patients, LCL reconstructions have low failure rates, and those who complete their rehabilitation program regain good knee function and stability. Posterolateral corner reconstructions using modern anatomic techniques also have strong outcomes, though they require patience and dedication during the recovery phase. Physical therapy, progressive weight-bearing, and a gradual return to strength and sport-specific training are critical to your success.
LCL Reconstruction Recovery Timeline
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Surgery & Physical Therapy Resources
Discover detailed instructions and protocols to guide patients through Pre-Op, Post-Op and Physical Therapy from Dr. Merritt.
Common LCL Injury Questions
Injury Information
A: Modern anatomic LCL and posterolateral corner reconstructions have low failure rates, typically in the range of four to twelve percent depending on the technique and whether other ligaments are also injured. Failure usually means the knee remains unstable or becomes unstable again over time. The best outcomes occur when surgery is done promptly, the technique is anatomically sound, and the patient completes rehabilitation. In my practice, emphasizing both technical excellence and patient compliance has resulted in very good long-term outcomes.
A: An LCL repair is performed when the ligament is torn but the tissue is still in good condition and is recent. I use sutures and anchors to reattach the ligament to the bone. Reconstruction is used when the ligament is too damaged to repair or when the injury is older and the tissue has degraded. In reconstruction, I replace the torn ligament with a tissue graft from your own tendon (autograft) or from donated tissue (allograft). Most Grade III injuries need reconstruction because the ligament tissue is too damaged to reliably heal after repair alone.
A: No, not reliably. Grade III LCL injuries are complete tears, and in my experience and in published studies, they do not heal well with conservative care alone. Without surgery, most patients develop chronic knee instability, pain with activity, and an increased risk of further damage to the cartilage inside the knee. That is why I recommend surgery for Grade III injuries, especially if you want to return to sports or remain active. Waiting only makes the problem worse.
A: Grading is based on how much the ligament is damaged. Grade I is a mild stretch or partial tear with little instability. Grade II is a moderate partial tear with some instability when we test the knee in the office. Grade III is a complete tear with significant instability. I use physical examination, stress testing, MRI, and sometimes ultrasound to grade the injury accurately and see if other structures are also torn.
A: The posterolateral corner is a complex group of ligaments and soft tissue structures at the back and outside of your knee. It includes the LCL, popliteus muscle and tendon, popliteofibular ligament, and biceps femoris tendon. Together, these structures control rotation and prevent the knee from bending backward or outward. When you injure the LCL, the PLC structures are often injured too. That is why I always evaluate the entire posterolateral corner, not just the LCL alone.
Surgery Information
A: An LCL reconstruction typically takes one to two hours, depending on how many ligaments need to be addressed. If we are also reconstructing the posterolateral corner or treating combined injuries, the surgery may take longer. I perform these surgeries at Proliance Surgery Center at Valley, which allows most patients to go home the same day after surgery.
A: Yes. An MRI is essential to see the exact anatomy of your tear, confirm that the LCL is torn, check for injuries to other ligaments like the PCL or ACL, and assess the posterolateral corner. MRI helps me plan the surgery and set realistic expectations. In some cases, ultrasound or CT imaging may also be helpful. A thorough imaging workup before surgery leads to better surgical planning and outcomes.
Post-Op Recovery
A: Most patients can return to the same sport, but it depends on the demands of that sport and your knee’s recovery. High-impact, cutting sports like basketball or soccer require excellent strength, stability, and confidence. Low-impact activities like swimming or cycling may be possible sooner. I assess each patient’s progress and use functional testing to determine readiness. With commitment to rehabilitation, the vast majority of my patients who want to return to their sport are able to do so safely.
A: Yes, initially. Most patients wear a protective knee brace for six to twelve weeks after LCL or PLC reconstruction. After that, some patients continue to wear a brace during sports or high-impact activities, while others do not. It depends on your knee’s stability, your activity level, and your comfort. Many of my patients find that a brace gives them confidence and prevents re-injury during the return to sport.
A: Full return to cutting and contact sports typically takes six to nine months after surgery for LCL and longer for posterolateral corner reconstruction. This timeline is longer than you might hope, but it is necessary to restore strength, proprioception, and confidence in your knee. I use objective testing, including strength measurements and functional tests, to determine when you are truly ready. Returning too early is the number-one reason patients have setbacks, so patience is essential.
A: That depends on your job. If you have a desk job, you may return within a few weeks, though you need to keep your leg elevated and avoid standing for long periods. If your job requires standing, walking, or physical activity, recovery will take longer, typically eight weeks or more. I work with each patient to develop a realistic work return plan that does not compromise healing.
A: You cannot drive while on crutches or strong pain medication. If your right knee was operated on, you can drive once you are off crutches, out of the brace, off narcotic pain medication, and able to brake hard, usually 10 weeks or later. If your left knee was operated on and you drive an automatic car, most patients can drive around 2 to 4 weeks, once off narcotic pain medication.
A: Physical therapy starts 5 to 7 days after surgery, 2 times a week, in a protected way. Early therapy focuses on gentle motion, swelling control, and quad sets (gentle muscle contractions). You will progress to weight-bearing, range-of-motion exercises, and strength training as your knee heals. The exact timeline depends on the type of reconstruction and how your knee responds. Your surgeon and therapist will guide you through each phase.
A: You will have pain and swelling, which is normal. You will be on crutches and may have a brace on your knee. Pain medication and ice will help manage your symptoms. Your first follow-up is a visit with my PA at 2 weeks to check the incision and your progress. Physical therapy starts 5 to 7 days after surgery. Only a toe-touch on the leg, about 10 to 15 pounds, for balance, for the first 6 weeks. Swelling and bruising can last several weeks, but they gradually improve with elevation and ice.
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