On page 1582 of The Journal, Monaco et al present useful information allowing another step forward in our understanding of the anterior cruciate ligament. The article also demonstrates several recurrent lessons in the changing world of orthopedic surgery.
The first lesson is in regard to nomenclature. A locked knee is one that cannot be moved in either flexion or extension and implies a major joint disruption. A blocked knee is one in which full extension or flexion cannot be achieved. Essentially, the authors are talking about a blocked knee. An important point that confuses the issue of diagnosis is that a blocked knee can also be caused by a significant joint effusion. Most of the patients in the study had a significant effusion, and blocking, therefore, may not be assigned only to the partial tear of the anterior cruciate.
A second lesson is in the area of diagnosis and the