Editorial Commentary: Knee Lateral Collateral Ligament Injury Is More Common Than We Thought.

Detection of a knee lateral collateral ligament (LCL) tear, in combination with an anterior cruciate ligament tear, may be facilitated by the heel height test, which seems a modification of Hughston's external rotation recurvatum test for posterolateral rotatory instability. The radiographic and arthroscopic stress tests are also valuable. We have found that varus stress will increase varus opening by 1° to 4° for isolated LCL tears and 5° to 9° for combined (LCL) popliteus injury; an arthroscopic stress evaluation will note a normal opening of 5 to 6 mm increasing to 9 to 10 mm in combined LCL popliteus injury. Generally, in our opinion and experience, partial injuries to the lateral side of the knee heal, and only with 9 to 10 mm of arthroscopic opening is posterolateral reconstruction required.