BACKGROUND: Knee kinematics and in situ forces resulting from anterior cruciate ligament reconstructions with 2 femoral tunnel positions were evaluated. HYPOTHESIS: A graft placed inside the anatomical footprint of the anterior cruciate ligament will restore knee function better than a graft placed at a position for best graft isometry. STUDY DESIGN: Controlled laboratory study. METHODS: Ten cadaveric knees were tested in response to a 134-N anterior load and a combined 10-N.m valgus and 5-N.m internal rotation load. A robotic universal force-moment sensor testing system was used to apply loads, and resulting kinematics were recorded. An active surgical robot system was used for positioning tunnels in 2 locations in the femoral notch: inside the anatomical footprint of the anterior cruciate ligament and a position for best graft isometry. The same quadrupled hamstring tendon graft was used for both tunnel positions. The 2 loading conditions were applied. RESULTS: At 30 degrees of knee flexion, anterior tibial translation in response to the anterior load for the intact knee was 9.8 +/- 3.1 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 13.8 +/- 4.6 mm; position 2: 16.6 +/- 3.7 mm; P < .05). There was a significant difference between the 2 tunnel positions. At the same flexion angle, the anterior tibial translation in response to the combined load for the intact knee was 7.7 +/- 4.0 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 10.4 +/- 5.5 mm; position 2: 12.0 +/- 5.2 mm; P < .05), with a significant difference between the tunnel positions. CONCLUSION: Neither femoral tunnel position restores normal kinematics of the intact knee. A femoral tunnel position inside the anatomical footprint of the anterior cruciate ligament results in knee kinematics closer to the intact knee than does a tunnel position located for best graft isometry. CLINICAL RELEVANCE: Anatomical femoral tunnel position is important in reproducing function of the anterior cruciate ligament.
BACKGROUND: Knee kinematics and in situ forces resulting from anterior cruciate ligament reconstructions with 2 femoral tunnel positions were evaluated. HYPOTHESIS: A graft placed inside the anatomical footprint of the anterior cruciate ligament will restore knee function better than a graft placed at a position for best graft isometry. STUDY DESIGN: Controlled laboratory study. METHODS: Ten cadaveric knees were tested in response to a 134-N anterior load and a combined 10-N.m valgus and 5-N.m internal rotation load. A robotic universal force-moment sensor testing system was used to apply loads, and resulting kinematics were recorded. An active surgical robot system was used for positioning tunnels in 2 locations in the femoral notch: inside the anatomical footprint of the anterior cruciate ligament and a position for best graft isometry. The same quadrupled hamstring tendon graft was used for both tunnel positions. The 2 loading conditions were applied. RESULTS: At 30 degrees of knee flexion, anterior tibial translation in response to the anterior load for the intact knee was 9.8 +/- 3.1 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 13.8 +/- 4.6 mm; position 2: 16.6 +/- 3.7 mm; P < .05). There was a significant difference between the 2 tunnel positions. At the same flexion angle, the anterior tibial translation in response to the combined load for the intact knee was 7.7 +/- 4.0 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 10.4 +/- 5.5 mm; position 2: 12.0 +/- 5.2 mm; P < .05), with a significant difference between the tunnel positions. CONCLUSION: Neither femoral tunnel position restores normal kinematics of the intact knee. A femoral tunnel position inside the anatomical footprint of the anterior cruciate ligament results in knee kinematics closer to the intact knee than does a tunnel position located for best graft isometry. CLINICAL RELEVANCE: Anatomical femoral tunnel position is important in reproducing function of the anterior cruciate ligament.
Authors: Yung Han; David Kurzencwyg; Adam Hart; Tom Powell; Paul A Martineau Journal: Knee Surg Sports Traumatol Arthrosc Date: 2011-10-11 Impact factor: 4.342
Authors: Carola F van Eck; Andrew K Wong; J J Irrgang; Freddie H Fu; Scott Tashman Journal: Knee Surg Sports Traumatol Arthrosc Date: 2011-10-05 Impact factor: 4.342
Authors: James E Voos; Volker Musahl; Travis G Maak; Thomas L Wickiewicz; Andrew D Pearle Journal: Knee Surg Sports Traumatol Arthrosc Date: 2010-05-18 Impact factor: 4.342
Authors: Robert F LaPrade; Samuel G Moulton; Marco Nitri; Werner Mueller; Lars Engebretsen Journal: Knee Surg Sports Traumatol Arthrosc Date: 2015-05-10 Impact factor: 4.342
Authors: Charles Crawford; John Nyland; Sarah Landes; Richard Jackson; Haw Chong Chang; Akbar Nawab; David N M Caborn Journal: Knee Surg Sports Traumatol Arthrosc Date: 2007-05-30 Impact factor: 4.342