Multiligament Knee Injuries

What is a multiligament knee injury?

A multiligament knee injury occurs when two or more of the major stabilising ligaments of the knee are torn. These are serious injuries that can significantly affect the stability and function of the knee.

The key ligaments of the knee each play an important role:

• Anterior cruciate ligament (ACL): Controls forward movement and rotation of the tibia. Injury often leads to instability with twisting or pivoting.
• Posterior cruciate ligament (PCL): Prevents the tibia from moving backwards. Important for stability when walking downhill or descending stairs.
• Medial collateral ligament (MCL): Provides stability to the inner side of the knee. Often injured in valgus (inward) stress injuries.
• Lateral collateral ligament (LCL) and posterolateral corner (PLC): Stabilise the outer side of the knee and control rotational stability. These are critical for overall knee function and are often involved in more complex injuries.

These injuries often occur following:

• High-energy trauma (e.g. road traffic accidents)
• Sporting injuries (particularly contact or twisting injuries)
• Knee dislocation (which may spontaneously reduce before assessment)

Symptoms

Patients with multiligament injuries may experience:

• Severe pain at the time of injury
• Significant swelling
• A feeling that the knee is unstable or “giving way”
• Difficulty weight bearing
• Reduced range of movement

Because of the severity of these injuries, there may also be associated nerve or blood vessel injury, which requires urgent assessment.

Assessment and diagnosis

A thorough assessment is essential and includes:

• Detailed clinical examination
• MRI scan to assess ligament damage and associated injuries (meniscus, cartilage)
• X-rays or CT scans in some cases

In acute injuries, careful evaluation of the blood supply (vascular status) and nerve function is critical.

Do all multiligament injuries need surgery?

Not all cases require surgery, but many do.

Treatment depends on:

• Which ligaments are injured
• Severity of instability
• Patient activity level and goals
• Associated injuries

Some lower-grade injuries or patients with lower functional demands may be managed with:

• Bracing
• Physiotherapy

However, surgical reconstruction is often recommended in active individuals or where the knee remains unstable.

Surgical treatment

Surgery aims to restore stability to the knee by reconstructing the injured ligaments.

This may involve:

• Reconstruction of two or more ligaments (e.g. ACL + PCL, or ACL + PLC)
• A combination of arthroscopic (keyhole) and open surgical techniques
• Careful sequencing of ligament reconstruction to restore normal knee biomechanics

Graft choice

In multiligament reconstruction, it is common to use a combination of autograft (your own tissue) and allograft (donor tissue).

This approach is used because:

• Multiple ligaments often need to be reconstructed
• Using only autograft may not provide enough suitable tissue
• It helps reduce surgical time and donor site morbidity

Autograft options may include:

• Hamstring tendons
• Quadriceps tendon

Allograft tissue is frequently used for:

• PCL reconstruction
• Posterolateral corner (PLC) reconstruction
• Additional ligament reconstructions where required

The exact graft choice is tailored to the individual injury pattern and patient factors.

Timing of surgery

Surgery may be performed:

• Early (acute setting) in selected cases
• Delayed, once swelling has settled and range of movement has improved
• As a staged procedure, particularly in complex injuries

The timing is carefully planned to optimise outcomes and reduce complications such as stiffness.

Recovery and rehabilitation

Recovery from multiligament knee surgery is longer and more structured than single ligament injuries.

Typical rehabilitation includes:

• Early protected movement
• Use of a knee brace
• Gradual progression of weight bearing
• Physiotherapy focusing on strength, control and stability

Return to activities:

• Daily activities: 3–4 months
• Higher level activity: 9–12 months
• Return to sport: around 12 months once clinically cleared

Outcomes

With appropriate treatment and rehabilitation:

• Most patients achieve a stable, functional knee
• Many return to an active lifestyle

However, recovery can be demanding, and outcomes depend on:

• Severity of injury
• Associated damage (cartilage, meniscus, nerves)
• Adherence to rehabilitation

Some patients may experience:

• Residual stiffness
• Reduced high-level sporting ability
• Risk of longer-term osteoarthritis

Why choose specialist care?

Multiligament knee injuries are complex and relatively uncommon, and optimal outcomes depend on specialist management.

Care includes:

• Accurate diagnosis and surgical planning
• Expertise in complex ligament reconstruction
• Appropriate graft selection
• Structured, closely supervised rehabilitation

Summary

• Multiligament knee injuries involve damage to two or more knee ligaments
• Each ligament plays a distinct role in knee stability
• Surgery is commonly required and often involves multiple reconstructions
• A combination of autograft and allograft is frequently used
• Recovery takes time, but good outcomes are achievable with specialist care