Comparison of results after anterior cruciate ligament reconstruction using a four-strand single semitendinosus or a semitendinosus and gracilis tendon

Purposes: To compare the clinical and functional results of anterior cruciate ligament (ACL) reconstruction using an autologous four-strand single semitendinosus (ST) tendon or a ST and gracilis tendon. It was hypothesized that successful ACL reconstruction using a single ST tendon without the gracilis tendon could provide comparable knee stability and reduce donor site morbidity. Methods: This study evaluated 144 cases of single-bundle ACL reconstruction using an autologous hamstring tendon. The ST group included 85 cases of reconstruction using a single ST tendon, and the ST/G group included 59 cases of reconstruction using a ST tendon and a gracilis tendon. An extracortical suspension device and a suture tied around a screw post with an additional bioabsorbable screw were used to fix the femoral and tibial tunnels, respectively. Clinical evaluations involved the Lachman, pivot-shift, and one-leg hop tests; an isokinetic test; a KT-2000 arthrometer; an assessment of return to pre-injury activities; and Lysholm, Tegner activity, and International Knee Documentation Committee (IKDC) subjective scores. Results: No significant differences were found between the ST and ST/G groups with respect to the Lysholm, Tegner activity, and subjective IKDC scores; the Lachman, pivot-shift, and one-leg hop tests; KT-2000 arthrometer side-to-side differences; or return to pre-injury activities. However, mean peak torque deficit, as determined using the isokinetic test during flexion at 60°/s, was significantly lower in the ST group than in the ST/G group (p = 0.047). Conclusion: This study showed good results for ACL reconstruction using a single ST tendon without deterioration of stability. This provides the evidence that ACL reconstruction using a single ST tendon without the gracilis tendon decreases donor site morbidity without compromising joint stability. Level of evidence: IV.