The use of intra-operative image intensifier control for the ACL surgeon.

Tunnel placement during anterior cruciate ligament reconstruction surgery is an important factor in determining the outcome of surgery. Tibial and femoral tunnel placement depends on the experience of the operating surgeon in order to achieve an isometric graft position. We performed a case series to study how often tunnel placement was adequate, as perceived by the surgeon, and if intra-operative image guidance could improve tunnel position. Over 3 years, a single surgeon and his team operated on 55 patients using single bundle patellar tendon bone or hamstring graft. The surgeon placed the guidewires where he felt they would achieve an isometric graft position. A transtibial jig was used for femoral tunnel positioning. At each step, the guidewires were checked using an image intensifier and repositioned as necessary. The number of times that the guidewire position could be improved using the image intensifier was documented. Follow up was between 1 to 3 years. The tibial guidewire was repositioned in 13 out of 55 cases and the femoral guidewire in 16 out of 55 cases. Forty-five out of 55 patients returned to their pre injury state. There were no cases of graft failure in the follow up period. The study concludes that tunnel placement is not always successful despite the surgeon's perception of adequate placement. The use of an intra-operative image intensifier can help the surgeon to achieve accurate and reproducible tunnel placement in ACL reconstruction surgery. We recommend this technique to all surgeons carrying out such procedures.