[The incidence and variation of tunnel enlargement after anterior cruciate ligament reconstruction].

ABSTRACT

OBJECTIVE: To investigate the incidence and variation of tunnel enlargement after anterior cruciate ligament (ACL) reconstruction. METHODS: ACL reconstructions using hamstring tendons were performed in 58 patients (58 knees) in the study. MRI scans were taken in a consistent manner at 1, 3, 6, 12 and 24 months after surgery to measure tibial and femoral tunnel expansion. RESULTS: Femoral tunnel enlargement was observed in 9 knees (9/58, 15.5%); Tibial tunnel enlargement was found in 12 knees (12/58, 20.7%). Of those with enlarged bone tunnels, there was no significant difference of tunnel diameters between 1 and 3 months after surgery (P>0.05). Six, 12 and 24 months postoperatively, the average tunnel diameters were larger than those of 1 or 3 months after surgery (P<0.05), however, no significant difference was found in between the tunnel diameters 6, 12 and 24 months postoperatively either (P>0.05). CONCLUSION: Tunnel expansion mainly occurs during 3 to 6 months after surgery, and it remains basically unchanged between 12 and 24 months postoperatively.