The use of intra-operative fluoroscopy for tibial tunnel placement in anterior cruciate ligament reconstruction

OBJECTIVES Our aim was to assess the use of intra-operative fluoroscopy in the assessment of the position of the tibial tunnel during reconstruction of the anterior cruciate ligament (ACL). METHODS Between January and June 2009 a total of 31 arthroscopic hamstring ACL reconstructions were performed. Intra-operative fluoroscopy was introduced (when available) to verify the position of the guidewire before tunnel reaming. It was only available for use in 20 cases, due to other demands on the radiology department. The tourniquet times were compared between the two groups and all cases where radiological images lead to re-positioning of the guide wire were recorded. The secondary outcome involved assessing the tibial interference screw position measured on post-operative radiographs and comparing with the known tunnel position as shown on intra-operative fluoroscopic images. RESULTS Of the 20 patients treated with fluoroscopy, the imaging led to repositioning of the tibial guide wire before reaming in three (15%). The mean tourniquet time with intra-operative fluoroscopy was 56 minutes (44 to 70) compared with 51 minutes (42 to 67) for the operations performed without. Six patients (30%) had post-operative screw positions that were > 5% more posterior than the known position of the tibial tunnel. CONCLUSION Intra-operative fluoroscopy can be effectively used to improve the accuracy of tibial tunnel positions with minimal increase in tourniquet time. This study also demonstrates the potential inaccuracy associated with plain radiological assessment of tunnel position.