Posterior cruciate ligament tear

Findings

a)      Acute – acute painful swelling following a history of trauma. The sag sign may be positive.

b)      Subacute and chronic – a history of trauma followed by an unstable knee. The tibia subluxes in a posterior direction with the knee flexed at 90 degrees, producing the sag sign. The posterior draw sign, which increases the sag sign, is positive.

Cause

Trauma to the knee and rupture of the posterior cruciate ligament, which may also be part of a major ligamentous disruption.

Treatment

a)      Usually is conservative. A similar management programme to the anterior cruciate ligament tear may be followed, but with a greater emphasis on quadriceps strength than on the strength on the hamstrings.

b)      Surgical repair.

Sports

See anterior cruciate ligament tears.

This isolated injury is far less common than anterior cruciate ligament tears, and requirements for surgery are much more debatable.

"Concise guide to sports injuries, 2^nd edition",Churchill Livingstone, Malcolm T.F. Read,  foreword by Bryan English