Abstract
Aim: To confirm previous studies and reports of tunnel widening following anterior cruciate ligament (ACL) reconstruction. To report the medium term behaviour and the effect of tunnel widening on the clinical results.
Methods: A retrospective analysis of the ACL database comparing BPTB autograft versus HT autograft and interference screw fixation was carried out. All procedures were performed by the same surgeon using an identical endoscopic, single-incision, surgical technique and a single method of fixation (7 x 25mm Titanium RCI screws). Patients who had a radiographic series at two and five years were included in the study. All patients had an isolated ACL injury.
Patients underwent a continuous follow up evaluation including clinical examination IKDC, Lysholm knee score and KT-1000 man max testing. Tibial tunnel widening was calculated from lateral radiographs digitalised and corrected for magnification. The tunnel shape was classified according to Peyrache.
Results: The median HT tunnel area increased significantly for the first two years (p = 0.00) and was unchanged from two to five years. The median PT tunnel area decreased significantly during the first two years (p = 0.03), and decreased again from two to five years (p = 0.02). A significant difference in tunnel shape existed between HT and PT groups (p = 0.00).
Conclusion: Tibial tunnel widening was confirmed in 79% of HT and 24% of PT ACL reconstructions utilising a single Titanium RCI screw fixation in each. Graft choice was shown to influence tibial tunnel shape; 21% of HT developed a cavity shape and 29% of PT exhibited tunnel disappearance. All patients with a decrease in tunnel area had a negative pivot shift. This was significantly different from the tunnel-widening group.
The abstracts were prepared by Professor A. J. Thurston. Correspondence should be addressed to him at the Department of Surgery, Wellington School of Medicine, PO Box 7343, Wellington South, New Zealand
