By Dr. Chris Milne, Sports Physician

1. What is it?

It is a disruption of the posterior cruciate ligament. This one of the main supporting and stabilising ligaments of the knee joint.

2. What causes it?

It is usually caused by a hyperextension or forced flexion injury to the knee.

3. Symptoms – what you notice

• Pain – in the middle or back of the knee which is worse with running.
• Inability to accelerate rapidly.
• Instability – if there is damage to the posterolateral complex, you may also experience instability.
• Such an injury is rare on the football field, but may occur in motocross or other high speed accidents.

4. Signs – what the doctor finds

• A positive posterior sag test – this test is performed with both knees flexed to 90°.
• A positive posterior drawer test – this test is performed by pushing the tibia (shin bone) backwards and is positive is there is pain or increased movement compared with the other knee.

5. Investigations

• X-rays are important to exclude any bony problem in the knee. It is often necessary to perform an
• MRI scan to assess any damage to other structures that may be injured in association with the posterior cruciate ligament.

6. Treatment

• First aid – an ice pack applied to the back of the knee may be helpful. Take Panadol or anti-inflammatory tablets.
• This injury is difficult to diagnose and it is often necessary to get specialist review to be sure of the nature of the problem.
• Most posterior cruciate injuries can be managed via a standard rehabilitation programme (see below).
• If there is evidence of associated damage to the posterolateral complex, surgical reconstruction should be considered.

7. Recovery time

Average recovery time is 4-12 weeks. It is about 6 months if surgical reconstruction is undertaken.

8. Recovery sequence

• Step 1 Ice packs, pain relief.
• Step 2 Regain full extension in the knee.
• Step 3 Physiotherapy supervised rehabilitation to build up quadriceps and hamstring function. This
• includes daily exercise such as stair climbing.
• Step 4 Cycling and swimming.
• Step 5 Restart gentle running and progress to stop-start then multidirectional activity.
• Step 7 Team training and skill sessions.
• Step 8 Resume playing, half game at first.