Five-strand versus four-strand hamstring autografts in anterior cruciate ligament reconstruction - A prospective randomized controlled study.

Abstract Purpose The purpose of this 2-year follow-up study is to compare the clinical outcomes of the routine use of 5-strand hamstring grafts (where possible) with those of 4-strand grafts in primary anterior cruciate ligament (ACL) reconstruction. The hypothesis was that the routine use of 5-strand grafts would lead to superior clinical outcomes. Methods A total of 64 patients were enrolled in a prospective randomized controlled study comparing the use of 5-strand and 4-strand semitendinosus-gracilis autografts in single bundle ACL reconstruction (n=32 in each group). 4 participants in each group were lost to follow-up, and were excluded from the outcomes analysis. The outcomes of 28 patients in the 5-strand group and 28 patients in the 4-strand group were analyzed. The diameters of all grafts were measured intra-operatively. Patients were assessed post-operatively at 2-years with objective assessments (anterior knee laxity using the KT-2000 arthrometer, Lachman test, Pivot-shift test, Hop test) and patient reported outcome scores (Lysholm knee score, KOOS, IKDC subjective knee score, SF-36 physical and mental components, Tegner activity scale). Post-operative graft ruptures were also noted. Results There were improvements in all outcome measures post-operatively regardless of the number of graft strands. Comparing the study and control groups, there were no significant differences in all subjective and objective outcome measures except the KOOS symptoms score (5-strand group 93.3 ± 9.2 vs 4-strand group 86.2 ± 14.7, p=0.04). The KT-2000 side to side difference was 2.79 ± 2.11mm in the 5-strand group, and 2.54 ± 1.75mm in the 4-strand group (p=0.63). The 5-strand study group had two graft ruptures at 1 year, while the 4-strand control group had one partial graft rupture at 6 months. Conclusions At the 2-year follow-up, the routine use of the 5-strand hamstring tendon autograft was not superior to that of the quadrupled or 4-strand graft in primary ACL reconstruction.