Biomechanical comparison between single-bundle and double-bundle anterior cruciate ligament reconstruction with hamstring tendon under cyclic loading condition

Abstract

Purpose: The purpose of this study was to compare the anterior tibial translation (ATT) of the anterior cruciate ligament (ACL) reconstructed-knee between single-bundle and double-bundle ACL reconstruction under cyclic loading. Methods: Single-bundle and double-bundle reconstructions of the knee were performed sequentially in randomized order on the same side using eight human amputated knees. After each reconstruction, the reconstructed-knee was subjected to 500-cycles of 0 to 100-N anterior tibial loads using a material testing machine. The ATT before and after cyclic loading and "laxity increase", which indicated a permanent elongation of the graft construct, was also determined. Results: The ATT after cyclic loading increased in both single-bundle and double-bundle reconstruction techniques compared to that without cyclic loading. Changes in ATT before and after cyclic loading were 3.9 ± 0.9 mm and 2.9 ± 0.6 mm respectively, and were significantly different. Laxity increase was also significantly different (4.3 ± 0.9 mm and 3.2 ± 0.8 mm respectively). Although no graft rupture or graft fixation failure was found during cyclic loading, the graft deviated into an eccentric position within the tunnel. Conclusions:Although ATT was significantly increased in both single-bundle and double-bundle reconstruction with hamstring tendon after cyclic loading test, there was significant difference. Double-bundle reconstruction might be superior to prevent increasing ATT under cyclic loading. Deformation of hamstring tendon after cyclic loading might result in deterioration of knee stability after ACL reconstruction, and is one of disadvantages of soft tissue graft.

In Vivo Analysis of Dynamic Graft Bending Angle in Anterior Cruciate Ligament–Reconstructed Knees During Downward Running and Level Walking: Comparison of Flexible and Rigid Drills for Transportal Technique

“…The repetitive bending or the abrasive force at the sharp femoral tunnel aperture may cause excessive stress on the graft, which can be a possible cause of graft damage or poor healing after ACL reconstruction 40,44,45 . Graft deformation at the femoral aperture corner has been reported after anatomic ACL reconstruction when applying cyclic load to cadavers 46 . Since GBA is affected by intra-articular tunnel apertures and extra-articular tunnel exits, different tunnel locations and orientations created by two kinds of femoral drills can lead to varying GBA.…”

The Graft Bending Angle Can Affect Early Graft Healing After Anterior Cruciate Ligament Reconstruction: In Vivo Analysis With 2 Years’ Follow-up

“…20,27,33 Repetitive stress and traumatic forces to the ACL graft before biological graft incorporation may contribute to graft failure. 14,16,31 A steep graft bending angle (GBA) has been recently proposed as a biomechanical factor that could contribute to poor graft healing or graft damage. 1,17,30,39,45,50 The GBA is defined as the angle between the femoral bone tunnel and the line connecting the femoral and tibial tunnel apertures.…”

“…28,37,50 Graft deformation at the femoral aperture corner has been also reported after anatomic ACL reconstruction. 31 Because the GBA is determined by tunnel locations, it is also influenced by the position of the tibia relative to the femur, which is task dependent. Therefore, in vivo, dynamic weightbearing activities can provide a better indication of the GBA that is likely to affect the graft than static examinations.…”

Single-stage in situ suture repair of multiple-ligament knee injury: a retrospective study of 17 patients (18 knees)

“…Good knee range of motion and stability are important goals of treatment. Nohmi et al [ 37 ] reported that double-bundle reconstruction could prove more stable throughout knee range of motion than single-bundle reconstruction. To increase the strength of the suture, we used a special suture technique—baseball running cross-stitch—with 2-0 COBRAID (Smith & Nephew) nonabsorbable suture to repair the injured ligaments in situ.…”