Comparisons of femoral tunnel enlargement in 169 patients between single-bundle and anatomic double-bundle anterior cruciate ligament reconstructions with hamstring tendon grafts.

PURPOSE: Authors have hypothesized that the incidence and the degree of femoral tunnel enlargement after the hamstring ACL reconstruction may be significantly less in the anatomic double-bundle procedure than in single-bundle procedure. The purpose of this study is to test this hypothesis.

METHODS: Seventy-two patients who underwent single-bundle reconstruction (Group S) and 97 patients who underwent anatomic double-bundle reconstruction (Group D) were followed up for 2 years after surgery. The hamstring tendon grafts were used in each procedure. All of the 169 patients were examined with computed radiography, and the standard clinical evaluation methods.

RESULTS: In Group S, the incidence of femoral tunnel enlargement was 48.6 and 54.2% in the anteroposterior and lateral views. In Group D, the incidence of femoral anteromedial and posterolateral tunnel enlargement was 36.1 and 23.7%, respectively, in the anteroposterior view, and that of femoral anteromedial and posterolateral tunnel enlargement was 33.0 and 21.6%, respectively, in the lateral view. The incidence of femoral tunnel enlargement was significantly less in Group D than in Group S (P < 0.0133). Concerning the degree of the tunnel enlargement, a similar tendency with statistical significance was observed (P < 0.0001). In each group, there were no significant relationships between the degree of tunnel enlargement and each clinical measure.

CONCLUSION: Both the incidence and the degree of femoral tunnel enlargement after anatomic double-bundle reconstruction with the hamstring tendon grafts are significantly less than those after single-bundle reconstruction with the same graft.

LEVEL OF EVIDENCE: Prospective comparative cohort study, Level II.