ACL reconstruction: effect of bone dowel on tibial tunnel enlargement

Purpose: To evaluate prospectively if the impaction of a bone dowel in the tibial tunnel prevents the tunnels from enlarging beyond their original diameter. Methods: Seventeen patients underwent arthroscopically assisted ACL reconstruction with hamstring autologous graft. All patients underwent CT of the knee on the day of surgery, at 3. months and 12. months post-op. Results: On the day of surgery, the median cross-sectional areas of the tunnels were 77.0 and 79.0mm2, respectively at 15mm and 20mm from the tip of the posterior wall of the tunnel. At 3months, the median cross-sectional areas of the tunnels were 70.0 and 65.0mm2, at 15mm and 20mm. At 12months post-op, the median cross-sectional areas of the tunnels were 69.0 and 69.0mm2. The median enlargement of the tunnels between 3months and 12months post-op was 0.0mm2 at 15mm and -2.0mm2 at 20mm. Conclusions: The impaction of an autologous bone dowel in the tibial tunnel during hamstring ACL reconstruction keeps the tunnels from enlarging beyond their original diameter, and there is no further enlargement of the tunnels after 3. months post-op.