PT  - JOURNAL ARTICLE
AU  - Amirhossein Borjali
AU  - Mahdi Mohseni
AU  - Mahmoud Chizari
TI  - Biomechanical Modeling of a Bone Tunnel Enlargement Post ACL Reconstruction
AID  - 10.1101/2020.09.03.281915
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.09.03.281915
4099  - http://biorxiv.org/content/early/2020/09/04/2020.09.03.281915.short
4100  - http://biorxiv.org/content/early/2020/09/04/2020.09.03.281915.full
AB  - Background Bone tunnel enlargement is considered as a potential problem following ACL reconstruction and can cause a fixation failure and complicate its revision surgery. This study evaluates post tibial tunnel expansion in ACL reconstruction using an interference screw.Methods A series of in-vitro experimental tests on animal bone and tissues were used to simulate post ACL reconstruction. The study believes an unbalanced lateral force can cause a local enlargement on the contact zone inside the tunnel. Grayscale X-ray images were used to assess the screw alignment inside the tunnel.Results They showed a slight misalignment between the screw and the tunnel axis as the tendon strands moved along the side of the tunnel, and the screw had partial contact with the tendon and bone along the tunnel. According to the results, increased stress in the tunnel wall causes tunnel enlargement. Although the tunnel created away from the tibial central axis produced a higher strength, it results in higher stress on the wall of the tunnel which can increase the risk of tunnel expansion.Conclusions The current study believes the use of an unguided interference screw insertion potentially increases risks of the misaligned fixation and cause a tunnel enlargement. This risk may be controlled by restricting the post-operative rehabilitation.Competing Interest StatementThe authors have declared no competing interest.