Effect of the positional relationship between the interference screw and the tendon graft in the bone tunnel in ligament reconstruction

Abstract

To reveal the effects of the positional and length relationships between the interference screws (ISs) and the tendon graft in the bone tunnel on the fixation strength in ligament reconstruction. Methods: We compared three IS positions on the anterior (the Anterior group) or posterior (the Posterior group) or side (the Side group) of the tendon graft in relation to the pullout direction. The tendon graft was pulled at 0 , 30 , 60 , and 90 to the bone tunnel, and the maximum pullout load at each angle was compared among the groups. We also investigated the relationship between the length of the tendon graft and the length of the IS in the bone tunnel. The direction of the pullout force was the same as that of the Anterior group, and the maximum load was compared between groups in which the tendon graft was longer or shorter than the IS. Results: The maximum loads of the Anterior group were significantly greater than those of the Posterior and Side groups at the traction angles of 30 and 60 , respectively. An IS shorter than the tendon graft was found to provide significantly superior fixation strength compared to an IS longer than the tendon graft. Conclusions: Better fixation strength was achieved when the IS was placed on the side of the anchorage tunnel on which the tendon graft was loaded and the IS was shorter than the tendon graft.

Ex-vivo biomechanical analysis of an original repair of canine calcaneal tendon rupture using a synthetic implant as mechanical support fixed by sutures in the proximal tendinous part and by an interference screw in the bone distal part

“…For example, a synthetic implant secured with an interference screw in a tunnel drilled in an epiphyseal area ( Blanc et al ., 2019 ) will have lower pull-out strength than if fixed in a bone with higher density, such as the calcaneus ( Morton et al ., 2015b ). The drilling axis of the bone tunnel also influences the pull-out strength of the interference screw fixation ( Zhang et al ., 2007 ; Aoki et al ., 2019 ). The choice of drilling a second perpendicular tunnel in the calcaneus as a distal fixation point was made for two reasons: first, in order to increase the mechanical strength ( Zhang et al ., 2007 ; Aoki et al ., 2019 ) of the DCF, thus allowing the formation of a 90° angle with the axis of application of in-situ mechanical forces, through the calcaneal tendon; second, because the perpendicular tunnel allows easier tensioning of the augmented canine calcaneal tendon with the UHMWPE implant before its reinsertion into the calcaneus by the interference screw ( Buttin et al ., 2020a ).…”

“…The drilling axis of the bone tunnel also influences the pull-out strength of the interference screw fixation ( Zhang et al ., 2007 ; Aoki et al ., 2019 ). The choice of drilling a second perpendicular tunnel in the calcaneus as a distal fixation point was made for two reasons: first, in order to increase the mechanical strength ( Zhang et al ., 2007 ; Aoki et al ., 2019 ) of the DCF, thus allowing the formation of a 90° angle with the axis of application of in-situ mechanical forces, through the calcaneal tendon; second, because the perpendicular tunnel allows easier tensioning of the augmented canine calcaneal tendon with the UHMWPE implant before its reinsertion into the calcaneus by the interference screw ( Buttin et al ., 2020a ). The DCF failed in only one way, i.e., damage and slippage of the UHMWPE implant through the two bone tunnels at the bone/implant/interference screw interface without ever breaking.…”

Comparison of two methods of fixation with interference screw for cranial cruciate ligament reconstruction in canine cadaver model

“…A gold standard for years, the interference screw is the preferred means of attachment associated with the use of these implants during ACL rupture. Numerous biomechanical studies carried out on human anatomical pieces have compared various axes and tunnel diameters in order to optimize these fixings (Aoki et al 2019). The objective of this ex-vivo study will be to compare the biomechanical properties of two interference screw implantation techniques chosen as the fixation system for a synthetic UHMWPE implant used in the surgical treatment of LCC rupture in dogs.…”