No abstract

Rotational kinematics of the knee is not fully restored after single-bundle anterior cruciate ligament (ACL) reconstruction. Cadaveric experiments using knee testing machines have suggested anatomical reconstruction replacing the anteromedial and posterolateral bundles could restore knee kinematics more effectively than single-bundle reconstruction. However, practical tools to objectively assess knee rotational laxities clinically have not been available. We used an optically based computer-assisted navigation system to measure the tibiofemoral motion kinematics in four fresh whole cadavers. Standard clinical knee laxity tests (anterior drawer, Lachman, and pivot shift) were performed and the kinematics described in terms of tibial axial rotation and anteroposterior translation. Data were obtained for intact knees after excision of the ACL and sequential reconstruction of the anteromedial and posterolateral bundles. In the ACL-deficient knee, the mean maximum tibial rotation during the pivot shift test was 27 degrees and mean maximum translation 11 mm. Reconstruction of the anteromedial bundle reduced the rotational component to 18 degrees and translation to 7 mm. Reconstruction of the posterolateral bundle reduced rotation to 14 degrees . This pilot study suggests computer assisted navigation could provide a practical method to objectively measure the pivot shift and may be used clinically to demonstrate differences in the control of tibiofemoral rotation kinematics afforded by single and two-bundle ACL reconstructions.

The purpose of this multicenter retrospective study was to analyze the causes for failure of ACL reconstruction and the influence of meniscectomies after revision. This study was conducted over a 12-year period, from 1994 to 2005 with ten French orthopaedic centers participating. Assessment included the objective International Knee Documenting Committee (IKDC) 2000 scoring system evaluation. Two hundred and ninety-three patients were available for statistics. Untreated laxity, femoral and tibial tunnel malposition, impingement, failure of fixation were assessed, new traumatism and infection were recorded. Meniscus surgery was evaluated before, during or after primary ACL reconstruction, and then during or after revision ACL surgery. The main cause for failure of ACL reconstruction was femoral tunnel malposition in 36% of the cases. Forty-four percent of the patients with an anterior femoral tunnel as a cause for failure of the primary surgery were IKDC A after revision versus 24% if the cause of failure was not the femoral tunnel (P = 0.05). A 70% meniscectomy rate was found in revision ACL reconstruction. Comparison between patients with a total meniscectomy (n = 56) and patients with preserved menisci (n = 65) revealed a better functional result and knee stability in the non-meniscectomized group (P = 0.04). This study shows that the anterior femoral tunnel malposition is the main cause for failure in ACL reconstruction. This reason for failure should be considered as a predictive factor of good result of revision ACL reconstruction. Total meniscectomy jeopardizes functional result and knee stability at follow-up.

Retrospective case series, Level IV.

No abstract