Bone Density and Insertion Torque as Predictors of Anterior Cruciateligament Graft Fixation Strength

Abstract

Bone mineral density and insertion torque cannot be used to estimate the strength of interference screw fixation in anterior cruciate ligament reconstruction.

Soft Tissue Tendon Graft Fixation in Serially Dilated or Extraction-Drilled Tibial Tunnels

“…Because proximal tibia and distal femur BMD tends to degrade with age and hormonal changes, 2,45,48 specific bone tunnel preparation methods have also been devised to increase tunnel wall BMD in hopes of improving soft tissue tendon graft fixation. 6,14,19 Step dilation and compaction drilling have been used in an attempt to increase tunnel wall bone volume (BV); however, their capacity for increasing soft tissue tendon graft fixation has displayed differing results. 10,20,[36][37][38][39]46 Regardless of tibial tunnel preparation method, soft tissue tendon graft fixation using a bioabsorbable interference screw is only effective if the screw has proper alignment.…”

The Effect of Cyclic Loading on Rotated Bone-Tendon-Bone Anterior Cruciate Ligament Graft Constructs

“…4,35 Cyclic loading has been advocated by multiple authors. † Among other investigations, it has been used to evaluate various methods of graft fixation, 20,21,24,36,38,41 graft elongation in the early recovery period, 17,37 initial graft tension, 31 and the effects of radiation. 9 To our knowledge, cyclic loading of rotated BPTB tendons has not been previously reported.…”

“…No specific rationale was provided for this value. Jarvinen et al 20 In this study, after preconditioning, we chose to test each specimen for 10 000 cycles at 2 different loading forces. This value is an order of magnitude larger than that recommended by Beynnon and Amis 4 and was chosen to maximize loading of the graft construct.…”

Contact pressure on ACL hamstring grafts in the bone tunnel with interference screw fixation — Dynamic adaptation under load

“…However, due to poor performance of the pressure indicating film in the humid environment of actual bone, and observed experimental variation attributed to heterogeneity of the porcine bone density and structure [1,5], composite polyurethane foam Sawbone blocks were used as a test surrogate for human bone (Nr 1522-11, Sawbones Europe AB, Malmö, Sweden). The cancellous region of the bone had a density of 20 g/cm 3 [6] and was laminated with a 1 mm cortical layer of 64 g/cm 3 polyurethane foam. Blocks were cut to a dimension of 4 × 3 × 5 cm.…”