Multi-ligament knee injuries

What is a multi-ligament knee injury?

Four main ligaments hold the knee steady. The ACL and PCL cross inside the joint and control forward and backward motion. The MCL runs along the inner side. The LCL runs along the outer side. The LCL is part of a wider group of structures at the back outer corner of the knee, called the posterolateral corner, which helps control twisting.

A multi-ligament injury usually means two or more of these are torn. Some of these knees fully dislocate at the time of injury, and others do not. Causes range from car crashes and falls from a height to tackles and twists in sport.

If your ACL is torn along with other ligaments, the plan looks different from a standard ACL reconstruction. The order of repairs, the timing, and the rehabilitation all change.

Why are nerves and blood vessels checked first?

The nerve and the main artery behind the knee are close to the ligaments, so they can be hurt in the same injury. This matters even if the knee went back into place by itself.

Go to an emergency room right away if your foot is cold, pale, or numb, if you cannot lift your foot or toes, or if your knee looked out of place. A blood vessel injury is an emergency.

A review of 45 studies and 3,391 patients found nerve injury in 19.2%, involving the peroneal nerve, which lifts the foot. Vascular injury was found in 18.4% (Kim, 2021).

An international panel of 39 experts agreed on a low threshold for CT angiography, a scan of the arteries. They applied this to high-energy injuries and to certain patterns, such as both the ACL and PCL being torn, or a posterolateral corner injury (Murray, 2024).

What else can be damaged?

The same review found medial meniscus tears in 30.4%, lateral meniscus tears in 27.5%, and cartilage injuries in 27.5% (Kim, 2021). A meniscus tear or cartilage damage can change what surgery involves.

X-rays and an MRI map the injury. Stress X-rays, which show how far the bones shift under gentle force, can add useful detail (Murray, 2024).

Will I need surgery?

Many people do. The expert panel agreed that the research generally favors surgery, particularly for young patients (Murray, 2024). Surgery may mean repairing a torn ligament, reconstructing it with a tendon graft, or both.

Surgery is not the right plan for everyone. Other injuries, your health, and your goals all count. If you were hurt in a major accident, the rest of your body comes first.

When should surgery happen?

Nobody has settled this. A review of 31 studies and 2,594 injuries could not tell whether early or delayed surgery gave better results. Few of those studies were high quality, and the authors called for better trials (Marder, 2021).

In practice, timing depends on the blood supply, the skin and swelling, your other injuries, and which ligaments are torn. Some patterns may be easier to treat early.

Should surgery be done in one stage or two?

In single-stage surgery, all the ligaments are treated in one operation. In staged surgery, some are treated first and the rest are treated later.

Experts on the panel agreed that single-stage surgery should be done whenever possible (Murray, 2024). Other data point the other way. A review of 2,086 patients found less stiffness scarring, called arthrofibrosis, after staged surgery: 1.95% versus 7.29%. Function scores and return to sport were also higher with staging. However, only 186 of those patients had staged surgery, and the authors supported a plan built around each person (Jaibaji, 2025).

So this is a decision to talk through, based on your injury pattern, the state of your knee, and your goals.

What are the risks of surgery?

Risks include stiffness, ongoing looseness, graft failure, infection, blood clots, nerve problems, ongoing pain, and later arthritis. Arthrofibrosis was found in 11.2% in one review (Kim, 2021). Results vary from person to person, and no surgeon can promise a certain outcome.

Should I get a second opinion?

It can help, especially if you were told different things about timing or staging, or if an earlier surgery did not hold. Here’s how a second opinion works.

Where can I see Dr. Pareek?

Dr. Pareek sees patients with knee ligament injuries at HSS in New York and at HSS in New Jersey. Bring any X-rays, MRI images, and reports you already have.

What does recovery look like?

These are typical ranges. Your surgeon’s plan comes first, and recovery varies from person to person.

• Weeks 0-2: Protect the repairMany people use crutches and a locked or hinged brace. The focus is on swelling, wound care, and waking up the thigh muscle. Limits on weight depend on which ligaments were treated.
• Weeks 2-6: Start motionPhysical therapy works on bending the knee within safe limits, because stiffness is a real risk after this surgery. Your brace and weight limits usually stay in place.
• Weeks 6-12: Come off crutchesMany people build up to full weight and start to walk without crutches, often still in a brace. Therapy adds gentle strength work.
• Months 3-6: Build strengthTherapy moves on to harder leg strength, balance, and a normal walking pattern. The timing depends on which ligaments were reconstructed.
• Months 6-12: Sport-specific workRunning and agility work start only when strength and testing allow. Many people need longer than they would after a single ligament surgery.
• Months 12 and beyond: Return to full activitySome people return to cutting and pivoting sports, and others change their activity level. These are typical ranges, and your surgeon's plan governs.

Sources

1. Murray IR, et al. Multiligament knee injury (MLKI): an expert consensus statement on nomenclature, diagnosis, treatment and rehabilitation. Br J Sports Med 2024;58:1385-1400.
2. Kim SH, et al. Incidence of associated lesions of multiligament knee injuries: a systematic review and meta-analysis. Orthop J Sports Med 2021;9:23259671211010409.
3. Marder RS, et al. Acute versus delayed surgical intervention in multiligament knee injuries: a systematic review. Orthop J Sports Med 2021;9:23259671211027855.
4. Jaibaji M, et al. Single-stage vs. multi-stage reconstruction in multi-ligament knee injuries: a systematic review and meta-analysis of outcomes and complications. J Clin Med 2025;14:6897.