Repairable posterior menisco-capsular disruption in anterior cruciate ligament injuries.

Two hundred thirty-four consecutive patients with a positive Lachman test underwent examination under anesthesia and diagnostic arthroscopy to include complete evaluation of both posterior menisco-capsular attachments. Knees which had had previous arthrotomy were excluded. Complete repairable posterior menisco-capsular disruptions occurred in 31 of 112 (27.7%) acute cases and 36 of 122 (29.5%) knees in the chronic group. These lesions are not predictable by physical examination or by routine clinical grading of instability. Thorough arthroscopic examination to include direct visualization of the posterior menisco-capsular junction is necessary for complete diagnosis in anterior cruciate ligament injuries.