What is a knee ligament injury? 

Ligaments connect one bone to another and are important stabilisers of joints. The knee joint has four main ligaments. Two are located inside the knee joint (the anterior and posterior cruciate ligaments); the others are located outside the joint (the medial and lateral collateral ligaments). There are different grades of severity of a ligament injury:

  • Grade I – mild ligament tear
  • Grade II – moderate ligament tear
  • Grade III – complete ligament tear

Signs and Symptoms of a knee ligament injury? 

Symptoms will vary depending on the knee ligament that is injured and the severity of the ligament injury.

The ACL is the most common ligament in the knee to be sprained. Signs and symptoms for ACL injuries include:

  • A feeling of a pop or crack at the time of injury
  • The amount of pain and swelling will vary depending on the severity of the sprain
  • Feeling of instability or complaint that the knee feels ‘wobbly’ to walk on
  • The mechanism of injury will likely be a quick change in direction
  • The swelling that occurs in the joint will make a feeling of stiffness when full bending and straightening the knee

Another common ligament in the knee that is sprained is the MCL. MCL injury signs and symptoms will vary from ACL such as:

  • Pain and tenderness on the inner aspect of the knee
  • Less swelling and restriction of movement – complaints will vary depending on the severity of sprain

Your physiotherapist, GP or surgeon can examine your knee to determine which ligament or combination of ligaments are injured and the severity of the injury and refer you for imaging if required.

What causes a knee ligament injury? 

The most common and serious knee ligament injuries include those to the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL). Causes of these ligament injuries include:

  • Cutting or twisting movements
  • Sudden stopping
  • Direct trauma
  • Incorrect landing from a jump or awkwardly landing.

These movements most commonly occur in sports such as netball, football, basketball, soccer and gymnastics. Less frequently, the ACL and MCL can be injured during a tackle or collision with another player (contact ACL injury) or an awkward fall while skiing.

Young females and people with a family history of ACL injures are statistically at a higher risk of an ACL injury.

 Treatment of a knee ligament injury?

Common to all knee ligament injuries, you will need to regain your knee movement, reduce any swelling, strengthen the muscles that support your knee and regain your normal walking pattern.

A complete rupture of the ACL does not heal, so treatment involves reconstructing the damaged ligament, usually with the person’s own hamstring or knee-cap tendon. If you require surgery you will still need to prehab you knee injury to ensure best surgical outcomes. The rehabilitation program after surgical reconstruction will be a long process as there are many phases to your rehabilitation. The general phases that will be similar across different surgeons protocols include:

  • Phase 1: will focus on reducing swelling, controlling pain, improving quadriceps control and improving range. Modalities used in physiotherapy will include:
    • use rest, ice, compression and elevation to assist with swelling and pain
    • The game ready system can be used to provide intermittent compression with circumferential cold therapy
    • effusion and soft tissue massage
    • home exercise prescription
  • Phase 2: will focus on gait re-education and improving strength
    • after surgery you may be discharge with crutches and possibly with a brace. The physiotherapist will be able to wean you off the crutches as appropriate
    • strengthening exercises will be progressed to weight bearing and will incorporate neuromuscular control exercises
  • Phase 3: as you progress through your program and goals of full range of motion, good knee control and adequate strength equal to the opposite side you will be progressed towards return to sport specific exercises. These may include running and jumping drills.
    • one point health offers alterG Anti-Gravity treadmill training which can assist with improving running tolerance

For MCL injuries your physiotherapist may fit you with a brace, depending on the severity and grade of the MCL ligament injury, to protect the ligament while it is healing. Gentle pain-free knee movement exercises will help you regain your knee motion, and strengthening exercises for the quadriceps, hamstrings and hip muscles will help to support the knee. Taping to support the MCL will often be applied on return to sport, which varies from 2–6 weeks, post-injury, depending on the severity.