Twist and turn
A 25 year old professional football player presented to an orthopaedic clinic reporting knee instability, especially on turning. He said that five weeks ago he had been playing when he suddenly heard a snap after changing direction. His knee was slightly flexed when it happened, and it immediately got swollen. Afterwards, he was not able to continue playing. The examination showed some effusion, along with positive Lachman and pivot shift tests. Other tests proved negative.
After a history suggesting an injury to the anterior cruciate ligament, doctors should do a clinical examination incorporating different tests. In the Lachman test, the patient must lie flat with the knee flexed to about 20 degrees (fig 4). One hand should fixate the thigh, while the other pulls the leg towards you, just like when opening a drawer. In case of a positive test (rupture of the ligament), the tibia is displaced towards you,