When is PCL reconstruction needed

The posterior cruciate ligament is the stronger of the two cruciates and is injured far less often. It is also treated differently, and a good proportion of PCL injuries do not need reconstructing at all.

How it usually happens

• A direct blow to the front of the bent knee. Dashboard injuries in road traffic accidents are the classic mechanism, and falls onto a bent knee are common in sport.
• Because the mechanism is often high energy, other structures around the knee are frequently involved.

Why many are managed without surgery

• An isolated PCL injury with mild laxity often does well with a structured programme focused on the quadriceps, which help compensate for what the ligament was doing.
• This is genuinely different from the ACL, where instability tends to persist.

When reconstruction is considered

• When the laxity is severe rather than mild.
• When the PCL is injured together with other ligaments, particularly at the back and outer corner of the knee. Combined injuries behave differently and are usually treated more actively.
• When instability persists after a proper rehabilitation programme has been completed rather than abandoned.
• When there is a bony fragment pulled off with the ligament, which is a different operation and often better fixed early.

What assessment involves

• Examination for backward sag of the tibia, X-rays, and usually an MRI where a combined injury is suspected. Stress views are sometimes used to measure the degree of laxity.