It generally is believed generalized joint laxity is one of the risk factors for failure of anterior cruciate ligament (ACL) reconstruction. However, no consensus exists regarding whether adverse effects on ACL reconstruction are attributable to joint-specific laxity or are related to the severity of generalized joint laxity. We therefore asked whether knee stability and functional outcomes would be related to joint-specific laxity and would differ according to the severity of generalized joint laxity. The Beighton and Horan criteria were used to assess joint laxity in 272 subjects. All elements are added to give an overall joint laxity score ranging from 0 to 5. Knee translation did not increase in proportion to the severity of the generalized joint laxity. Patients with scores less than 4 showed similar knee stability. When all variables, including the severity of generalized joint laxity, were considered, only hyperextension of the knee independently predicted knee stability and function. In patients with knee hyperextension, a bone-patellar tendon-bone autograft provided superior stability and function compared with a hamstring tendon autograft. Our data suggest knee hyperextension predicts postoperative stability and function regardless whether patients have severe generalized joint laxity.
Level of evidence: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.