384 Use of A Dry Swab During ACL Hamstring Tendon Graft Preparation May Lead to Decreased Graft Diameter at Implantation with Subsequent Rebound in Graft Diameter When Exposed to Haemarthrosis – A Porcine Tendon Study

Introduction ACL reconstruction surgery commonly utilises a hamstring tendon graft. Grafts are normally covered with a wet swab prior to implantation. The aim of this study was to determine the variance in graft diameter when comparing the traditional wet swab to a dry swab. Method Flexor tendons from a selection of fresh pig trotters were isolated and prepared with a standard ACL graft preparation technique. Half of the grafts were covered with a wet swab; the other half were covered with a dry swab. Graft diameters were measured at 10-minute intervals. After 30 minutes the grafts were submerged in Hartmann’s solution to simulate the post-operative haemarthrosis, diameters were checked again after 1 hour in the solution. Results Use of a dry swab resulted in a 0.5mm greater reduction in diameter than the wet swab group. The dry swab group also showed an increase in diameter by 0.5mm when soaked in Hartmann’s solution, this was not seen in the wet swab group. Conclusions Using a dry swab produces a smaller graft diameter, this would allow smaller bone tunnels, retaining bone stock. The subsequent rebound in diameter when in solution may increase the press fit mechanism and facilitate improved integration into the bone tunnel.