Abstract
Aim: This investigation compares the tibial tunnel appearances at 1 year and again at 8 years post-operatively in 49 patients and reports on the clinical significance of these appearances. Materials and Methods:49 consecutive patients who underwent isolated central anterior cruciate ligament reconstruction using a four stranded hamstring tendon technique comprised the study group. The patients were reviewed clinically and with weight bearing AP and Lateral radiographs at one year and eight years (range 5–9years) from reconstruction. Two blinded observers measured the tunnel diameters using a digital caliper on the 1year and 8 year radiographs. Tunnel enlargement was calculated from the known drill size with correction for magnification. The findings were correlated with clinical outcome and various associations were studied. Results: At one year postoperatively tunnels had increased in diameter by a mean of 26% at the proximal end, and by 19% at the distal end. By 8 years both measurements had reduced to 20% and to 13% respectively and this decrease in tunnel enlargement was significant (p< 0.05). Tunnel enlargement was significantly greater in those knees with persistent effusion at one year. (P< 0.05). 10 patients (26%) had distal tibial tunnel diameters which were less than the original drill size and of these ten patients only one had a positive Lachman (side to side difference> 3mm) compared to 9 in the rest. (P< 0.05). Conclusion: Tunnel enlargement that occurs at 1yr reduces by 8 years from reconstruction. Decrease in tunnel enlargement at the distal end is associated with an improved and lasting stability.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
