Reconstruction of knees with combined cruciate deficiencies: a biomechanical study.

摘要: Background: Clinical results of dual cruciate-ligament reconstructions are often poor, with a failure to restore normal anterior-posterior laxity. This could be the result improper graft tensioning at time surgery and stretch-out one or both grafts from excessive tissue forces. The purpose this study was measure laxities forces in knees before after cruciate ligaments performed specific graft-tensioning protocol. Methods: Eleven fresh-frozen cadaveric knee specimens underwent laxity testing installation load cells record native as were passively extended 120° -5° no applied tibial force, 100 N anterior posterior 5 N-m internal external torque. Both reconstructed bone-patellar tendon-bone allograft. Only isolated deficiencies studied. We determined nominal levels tension that restored within 2 mm those intact 20 ligament during passive extension. tensioned 30° flexion, first. Measurements repeated their fixed its level opposing 40 above level. Results: tensions found interrelated; applying changed other (fixed) displaced tibia relative femur. had first consistently achieve combination mean flexion. At these levels, under nearly all test conditions. However, significantly higher than full extension Anterior-posterior between 0° 90° flexion force levels. Overtensioning by increased 110° but it did not change In contrast, overtensioning angles 95° decreased except Conclusions: It possible find positions counterparts motion. Our protocol represented compromise competing objectives. aimed major shortcoming dramatically produced near Relevance: Applying high relatively ineffective unwanted effect producing abnormally key controlling tension. Clinically, surgeons apply o