Double-bundle anterior cruciate ligament reconstruction: four versus eight strands of hamstring tendon graft

Abstract

Purpose: The purpose of this study was to compare the clinical results of a double-bundle anterior cruciate ligament (ACL) reconstruction with 4 strands versus 8 strands of hamstring tendon graft.

Methods: Seventy-six patients with chronic ACL rupture were randomly separated into two groups for double-bundle ACL reconstruction. In the 4-strand hamstring graft (4SHG) group, the semitendinosus tendon was used to make two 2-stranded hamstring tendon grafts, whereas in the 8-strand hamstring graft (8SHG) group, the semitendinosus tendon was used to make one 4SHG and the gracilis tendon was used to make the other 4SHG. The 4SHG group comprised 33 patients and the 8SHG group comprised 35 patients, with a minimum follow-up of 2 years. International Knee Documentation Committee (IKDC) and Lysholm scales were used to evaluate the clinical results.

Results: In the 4SHG group the side-to-side difference was less than 3 mm in 26 patients (78.8%), 3 to 5 mm in 4 patients (12.1%), and 6 to 10 mm in 3 patients (9.0%), with a mean value of 2.8 +/- 0.5 mm; the pivot-shift test was negative in 29 patients (89.9%) and positive in 4 (12.1%). In the 8SHG group the side-to-side difference was less than 3 mm in 32 patients (91.4%), 3 to 5 mm in 2 patients (5.7%), and 6 mm in 1 patient (2.9%) (P = .004), with a mean value of 1.3 +/- 0.4 mm (P = .0003); the pivot-shift test was negative in 34 patients (97.1%) and positive in 1 (2.9%). According to the IKDC scale, 29 patients (87.9%) in the 4SHG group and 33 patients (94.3%) in the 8SHG group had a grade of normal or nearly normal. In the 4SHG and 8SHG groups the mean IKDC subjective knee evaluation results were 86.4 +/- 4.2 and 96.3 +/- 2.8 (P = .0007), respectively, and the mean Lysholm scores were 89.6 +/- 3.7 and 96.5 +/- 2.9 (P = .0006), respectively.

Conclusions: On the basis of KT-1000 examination (MEDmetric, San Diego, CA) and clinical measures, double-bundle ACL reconstruction with 8SHG yields significantly better results than double-bundle ACL reconstruction with 4SHG, with a mean side-to-side difference in anterior knee laxity of 1.3 +/- 0.4 mm versus 2.8 +/- 0.5 mm (P = .0003), IKDC subjective result of 96.3 +/- 2.8 versus 86.4 +/- 4.2 (P = .0007), and Lysholm score of 96.5 +/- 2.9 versus 89.6 +/- 3.7 (P = .0006).

Level of evidence: Level II, lesser-quality randomized controlled trial.