Comparisono of Knee Strength And Stability In Primary And Revision Acl Reconstruction

Abstract

PURPOSE: The number of primary anterior cruciate ligament (ACL) reconstructions has increased in parallel with graft failures, with a resultant effect on revision surgery. Primary ACL reconstruction is successful for most patients, but some have had persistent giving-way symptoms and recurrent ruptures, such that revision surgery is required. Knee strength deficits are among the consequences of muscle weakness after ACL reconstruction. This study compared knee strength and stability in primary and revision ACL reconstruction. METHODS: This was a cross-sectional study with a total of 78 participants, in whom 38 revision surgeries were performed at a single hospital between April 2013 and May 2016. All revision reconstructions used tibialis anterior tendon allografts. Forty patients underwent primary ACL reconstruction using double-looped semitendinosus and gracilis autografts. Strength and stability results were compared in primary and revision ACL reconstruction. All participants were measured with an isokinetic device to assess the main outcome of knee strength; a KT-2000 arthrometer was used to measure anterior laxity. Knee function status was evaluated using International Knee Documentation Committee and Lysholm scores. Knee strength and stability results were compared for primary and revision ACL at 12 months post operatively. RESULTS: The stability results with revision surgery were inferior to those with primary reconstruction (1.5±1.1 mm vs. 2.6±1.5 mm: p = .001). However, there were no significant differences in knee extensor deficits at 60°/sec or 180°/sec (respectively, p = .213, p = .994) or in flexor muscle strength between primary and revision ACL reconstruction (respectively, p = .473, p = .609). The statistical comparison of functional scores in primary and revision surgery showed no significant differences. CONCLUSIONS: Knee extensor deficits and flexor muscle strength show no differences in a comparison of revision and primary ACL reconstruction. However, the results for stability were inferior to those of primary ACL reconstruction.