Multiligament Knee Injuries

Figure 1. The four main ligaments of the knee.

Figure 3. Mr Damasena is part of the VOTOR study group on multiligament knee injuries. You may be asked to participate in studies currently underway.

Figure 4.4. *These rehabilitation guidelines were developed collaboratively by UW Health Sports Rehabilitation and the UW Health Sports Medicine Physician group.

What is a multiligament knee injury?

A multiligament knee injury is when two or more of the ligaments of the knee have been injured. These types of injuries are often severe and usually result from a high energy injury such as in motor vehicle accident, a fall from a height or a significant sporting field injury. In some cases the knee can be completely dislocated (figure 2). The injury may involve two or more of the ACL, PCL, MCL and LCL.

In addition, the posterolateral corner, common peroneal nerve, and popliteal artery can also be injured at the time of the traumatic event (Figure 3).

Injury to Neurovascular structures
(Popliteal artery, Common peroneal nerve)

Due to the violent nature of these injuries, the large blood vessel at the back of the knee may be injured. This is a surgical emergency and requires immediate specialist intervention to repair or bypass the torn structure. This is usually done by a vascular surgeon. Without treatment the blood supply to the leg is compromised and may result in permanent damage and loss of limb.

The nerve (common peroneal nerve) on the outside of the knee joint can get stretched during the injury. This may cause weakness in the foot (foot drop) and altered sensation in the affected leg. Often this recovers after some time but in certain circumstances it may be permanently injured and require

How is a multiligament knee injury usually treated?

A multiligament knee injury is a complex problem that requires treatment by a knee specialist. The first priority is to ensure that the knee joint is back in position (enlocated) and that the blood supply is not compromised.

Sometimes, if the knee joint is highly unstable due to multiple ligament ruptures, an external frame may be used to hold the knee joint in its normal position. This needs to be done in the operating theatre.

If there are any concerns about the blood supply to the leg, a vascular surgeon will assess you and may either request a CT scan of the blood vessels or will perform an angiogram (an injection of dye into the blood vessels followed by an X-ray). If necessary, they will advise you about further procedures to restore the blood supply to the leg.

Once the knee is in position and the blood supply is not compromised, an MRI scan of the knee will be conducted to assess the extent of the damage. Depending on the scan, a repair and/or reconstruction of the affected ligaments will ideally take place within 3 weeks of the injury. Partially torn ligaments may be allowed to heal on their own, or with the assistance of a brace and a rehabilitation programme. Mr Damasena will advise you of the most appropriate treatment.

Sometimes, the operation is performed in a single sitting, and other times the operation is staged (i.e., 2 sittings).

What does surgery for a multiligament knee injury involve?

Most patients will require several days in hospital. Depending on which ones and the number of ligaments torn Mr Damasena will advise you on which ligaments will be ammenable to reconstruction (replaced using donor tissue) or repair using the torn ligament.

Sometimes the MRI scan may not reveal the true nature of the injury, and you may need a general anaesthetic so your knee can be examined for the degree and direction of instability.

The operation itself is usually done using keyhole surgery in addition to open incisions. This is to reduce bleeding, swelling and scarring. The operation may take several hours and differs depending on which ligaments are being reconstructed or repaired.

How long is recovery after a multiligament knee injury?

A multiligament knee injury is a serious injury with long-term consequences. Patients can experience arthritis, stiffness, pain, ongoing instability, and inability to return to a preinjury level.

A combination of good operative planning and execution with appropriate rehabilitation can still allow a significant proportion of patients to resume sporting activities. Figure 4 provides a guideline for you and your physiotherapist. Certain parts of the guideline may not specifically relate to you and Mr Damasena will outline this in your post operative instructions.

In general, the recovery time is 9-12 months before returning to full and unrestricted activities.