Lateral collateral ligament (LCL) tears or sprains – Symptoms, treatment, recovery times

A lateral collateral ligament (LCL) tear is a knee injury that seldom happens in isolation. The force that causes it is usually so big that often something else also gets injured. This article explains how the LCL typically gets injured, what the symptoms are, how the injury is diagnosed and graded, what the treatment options are, and what the recovery times might be under various circumstances. Remember, if you need more help with an injury, you're welcome to consult one of our physios online via video call.

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In this article:

1. Anatomy of the lateral collateral ligament

2. How the LCL gets injured

3. What’s the difference between an LCL sprain and a tear?

4. Lateral collateral ligament tear symptoms

5. Lateral collateral ligament injury tests

6. Grading LCL tears

7. Do you need surgery for an LCL tear?

8. LCL sprain recovery times

9. LCL injury treatment without surgery

10. How we can help

We've alse made a video about this:

Anatomy of the lateral collateral ligament

The lateral collateral ligament of the knee (sometimes called the fibular ligament) runs over the outside of the knee from the lateral epicondyle of the knee to the head of the fibula.

It’s main job is to stop the knee joint from gapping too much to the outside (resisting varus forces) or turning too far out and back. The popliteus tendon, cruciate ligaments, iliotibial band, biceps femoris tendon, and lateral (outer) gastrocnemius tendon all support the lateral collateral ligament in these tasks.

The LCL differs from the medial collateral ligament (located on the inner border of the knee) in that it is more tubular (as opposed to fan-like) and doesn’t attach to the meniscus or the joint capsule.

How the LCL gets injured

LCL tears are usually caused by a strong force from the inner front of the knee, forcing the knee into extreme extension and causing it to gap on the outside. Examples are a rugby player falling on their knee or a tennis player pivoting quickly and forcefully.

It takes a lot of force to injure the LCL, and this type of ligament tear is usually accompanied by injuries to other tendons and ligaments in that area (listed above). You may hear doctors say that someone has an injury to the posterior lateral (back outer) corner (PLC) of the knee – this means that they’ve torn more than one of these structures.

When more than one of these structures are seriously injured, it causes the knee to be unstable and they usually require surgical repair.

Isolated lateral collateral ligament injuries, where only the LCL is torn, are not that common, but when they do occur, they usually recover well without surgery. Tennis and gymnastics are two sports in which isolated LCL tears often occur.

Isolated lateral collateral ligament tears most commonly happen in tennis.

What’s the difference between an LCL sprain and a tear?

Nothing. People often refer to a milder or minor LCL tear as a sprain, but this is not a medical diagnosis. Even the slightest LCL injuries involve a small tear.

You can read more about the grading of LCL injuries below. In this article, we use the term LCL tears and LCL sprains interchangeably.

Lateral collateral ligament tear symptoms

LCL tear symptoms include:

• Sudden, sharp pain during a forceful movement or blow to the knee.

• Pain and mild swelling over the outside of the knee. If you’ve injured something else inside the knee (like a meniscus or cruciate ligament) your knee may be very swollen.

• If the fibular nerve was also injured, you may feel a numbness or weird sensations over the outside of your lower leg or the top of your foot.

• If you have a Grade 3 LCL tear and/or have injured other ligaments around the knee, you knee may feel unstable when you walk and move.

Lateral collateral ligament injury tests

Varus Test for LCL tears

This test is pretty easy to do and the results are used to predict if surgery is needed or not.

1. The patient lies on their back on a bed.

2. Always perform this test on the uninjured side first, so you know how much the patient’s knees normally gap.

3. The examiner places their one hand under the knee so that the heel of that hand can apply force over the inner part of the knee. Their other hand holds the lower leg over the ankle.

4. They then pull the ankle inward while pushing the knee out, trying to gap the outer knee joint. Be gentle - if the ligament is fully torn the knee will gap a lot.

5. The test is first performed with the knee bent to 30 degrees. If the outer part of the injured knee gaps more than that of the uninjured one, the test is a positive indicator for an LCL injury and a potential PLC injury.

6. The test is then repeated with the knee fully straight. If the injured knee gaps less when fully straight, it indicates an isolated LCL injury. If the knee gaps just as much as when it’s bent, it indicates that the LCL as well as other structures that make up the PLC of the knee have been injured.

X-ray

X-rays don’t show LCL injuries, but they are useful to rule out other types of injury. Because it takes so much force to tear the LCL, it is quite common to also fracture the head of the fibula, or to pull out a small piece of bone where the LCL attaches to the fibula (an avulsion fracture).

MRI scan

An MRI scan is the best way of fully assessing the LCL and the other ligaments, tendons, and menisci of the knee that may have been injured.

Grading LCL tears

LCL tears can be graded in two ways:

1. According to how much instability or gapping is found when the Varus Test is performed.

2. According to how much of the ligament appears to be torn on an MRI scan.

Grading LCL tears according to the Varus Test

• Grade 1 – Stable: The Varus Test usually produces only pain, without any extra gapping or movement of the joint.

• Grade 2 – Decreased stability: There is usually a bit more movement when the Varus Test is performed on the injured leg vs. the uninjured leg (5 mm to 10 mm), but it is not excessive, and there is still something preventing the movement from going past a certain point.

• Grade 3 – Unstable: There is usually significant gapping of the outer knee joint when doing the Varus Test (more than 10 mm).

Grading LCL tears according to MRI results

• Grade 1 – Minor tear or sprain: Very few fibres of the ligament are injured.

• Grade 2 – Partial tear: A significant portion of the ligament has torn.

• Grade 3 – Complete tear or rupture: The ligament is torn right through.

The results of the Varus Test is used to decide whether an LCL injury requires surgery.

Do you need surgery for an LCL tear?

The results of the Varus Test should be used to decide whether surgery or conservative treatment is the best option.

This means that, even if the LCL looks like it is fully torn on the MRI scan, it can still be treated using only a brace and progressive load bearing and exercise, as long as the Varus Test produces a Grade 1 or 2 result.

Bushnell and colleagues found that NFL athletes who had an isolated Grade 3 lateral collateral ligament tear on an MRI scan recovered more quickly, while achieving an equal likelihood of return to play at the professional level, when they were treated conservatively rather than with surgery.

Even fully torn lateral collateral ligaments can heal without surgery.

There are also several case studies describing the successful treatment of isolated complete LCL ruptures, even with avulsion fractures, using only braces and rehab exercises in various types of athletes, including kids and adults, taking part in ju-jitsu, rock climbing, and soccer.

It is only when you have also torn some of the other ligaments in and around the knee, like the anterior or posterior cruciate ligaments or other structures that make up the posterior lateral corner of the knee, that surgery may be the better treatment option.

LCL sprain recovery times

The current recommendation is that someone should only return to sports when they have full, pain-free knee range of motion, no tenderness on the outside of the knee, and no ligament laxity when the Varus Test is performed.

With conservative treatment, the average recovery times are:

• Grade 1 LCL tear (sprain): Four weeks to slow, controlled types of exercise, and 4 to 6 weeks for sports involving quick changes of direction.

• Grade 2 LCL tear: Eight weeks to get back to easily controlled sports, but usually closer to 12 weeks to get back to sports with quick changes of direction

• Grade 3 LCL tears:

  • About 6 months to get back to full, competitive sport involving twisting, turning, and sudden movements.

  • Can be as soon as 8 weeks for sports that involve only controlled movements, e.g. yoga, as long as only the LCL was injured.

  • If the person also bruised the knee joint’s cartilage or bone (resulting in a very sore and swollen joint), it may take 3 months to get back to controlled activities like yoga.

Recovery times after surgery:

• Isolated LCL reconstruction: Six months to get back to full sport.

• LCL plus other ligament or tendon repair: Six to 9 months to get back to full sport.

LCL injury treatment without surgery

LCL knee braces and weightbearing

If you have a Grade 1 LCL tear or sprain and no laxity in the Varus Test, you likely don’t need a brace, and you can usually walk as soon as it is comfortable.

Grade 2 LCL tears do require a brace for about 6 weeks, but patients are usually allowed to move the knee and place as much weight on the leg as is comfortable from Day 1.

Researchers recommend that Grade 3 LCL tears have to be immobilised in a brace for 2 weeks with the knee fully straight and no weight being placed on the leg. After that, the hinge of the brace is adjusted weekly over a period of 6 weeks with the aim to bend the knee at least 90 degrees before removing the brace. The brace can usually be removed after 8 weeks.

However, research into the best way to treat LCL tears is thin on the ground, and I suspect that these recommendations may change to also allow some early movement and weightbearing, as with MCL tears. But for now, it’s best to stick to what we know works.

We've written a detailed article about the type of knee brace needed for lateral collateral ligament injuries – here are some examples on Amazon.

Crutches

If you have a Grade 3 tear and been told that you aren’t allowed to place any weight through your leg, you will have to use crutches.

Crutches are optional for other cases. They can be useful to help you move and recover better if your knee is quite painful to stand or walk on. It is always good to try and mimic your normal gait pattern when you use crutches, but this will only be possible once your brace allows your knee to bend.

Rehab exercises for LCL strains and tears

These exercises are only appropriate for cases that are managed conservatively. If you’ve had surgery for your LCL tear, you have to follow you surgeon’s suggestions, because the healing process is different.

General guidelines

• Early movement within the pain-free range is good – never push through pain.

• If you have been told to wear a brace, you have to wear it whenever you do your exercises, stand, or walk. Find more detailed advice about braces for LCL tears here.

Exercises for early LCL rehab

These exercises activate and work the quads and hamstrings without placing strain on the LCL. Limit how far you move your leg to what you can do pain-free or to the restriction of your brace.

Examples include:

1. Knee flexion and extension: This gets the knee moving, helping with circulation and stiffness.

2. Active straight leg raises: Tensing your quads and lifting your straight leg.

3. Prone or standing leg curls: Start with no weight/resistance, and gradually add some.

Exercises for mid-stage LCL rehab

These exercises help you to regain your knee’s full range of motion and strength in controlled positions. Some examples include:

1. Continue flexion and extension until full range

2. Squats

3. Balancing

4. Bridges

Exercises for later-stage LCL rehab

It is now time to introduce more dynamic movements that load the knee and the LCL more forcefully.

Your sport will guide the choice of exercises here – the final rehab for someone who just enjoys walking will be very different from that of someone who wants to run. Similarly, the rehab plan for a runner will look very different from that of a footballer. If you’re looking to get back to a sport like football, which requires quick changing of direction, your rehab will have to build up to this over time.

Examples include:

1. Lunges

2. Single-leg squats

3. Single-leg deadlifts

4. Hopping and jumping exercises, if your sport requires it

5. Easing into running – first in straight lines and then adding in changes of direction (if needed), also starting slow and building the speed over several weeks.

LCL exercises to avoid

Avoid doing exercises like side-leg lifts during early rehab – the weight your leg as you lift it can cause a strain on the LCL. You can usually start them once you’re allowed to remove your brace.

Side planks, where you carry your full weight through the side of your leg and trunk, place a very large force through he LCL and should be avoided until much later in your rehab.

Avoid doing exercise that load the LCL directly during the early stages of rehab. Examples are side-leg lifts and side planks.

Medication

You may benefit from pain medication if your knee is very painful. However, pain medication doesn’t speed up the healing, so only use it if it is really necessary.

In most cases, it’s best to avoid anti-inflammatory medication, because it may interfere with healing. However, there are some instances where this medication is needed and beneficial, so speak to your doctor before you start or stop taking any medication.

How we can help

Need more help with your injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.

We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine or at least 10 years' experience in the field. But at Sports Injury Physio we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.

About the Author

Maryke Louw is a chartered physiotherapist with more than 20 years' experience and a Master’s Degree in Sports Injury Management. Follow her on LinkedIn and ResearchGate.

References

1. Bushnell, B. D., et al. (2010). "Treatment of magnetic resonance imaging-documented isolated grade III lateral collateral ligament injuries in National Football League athletes." The American Journal of Sports Medicine 38(1): 86-91.

2. Davenport, D., et al. (2018). "Non-operative management of an isolated lateral collateral ligament injury in an adolescent patient and review of the literature." BMJ Case Reports 2018: bcr-2017-223478.

3. Petrillo, S., et al. (2017). "Management of combined injuries of the posterior cruciate ligament and posterolateral corner of the knee: a systematic review." British Medical Bulletin 123(1): 47-57.

4. Ramos, L. A., et al. (2019). "Treatment and outcomes of lateral collateral ligament injury associated with anterior and posterior cruciate ligament injury at 2-year follow-up." Journal of Orthopaedics 16(6): 489-492.

5. Sikka, R. S., et al. (2015). "Isolated fibular collateral ligament injuries in athletes." Sports Medicine and Arthroscopy Review 23(1): 17-21.

6. Yaras, R. J., et al. (2022). "Lateral collateral ligament knee injuries.” StatPearls Publishing.