Does Hamstring Graft Size Affect Functional Outcome and Incidence of Revision Surgery After Primary Anterior Cruciate Ligament (ACL) Reconstruction?

Purpose The primary outcome measure of this study was to determine the effect of hamstring graft size on the functional outcome of arthroscopic anterior cruciate ligament reconstruction (ACL-R) and the secondary outcome was to ascertain the effect on revision surgery at the two-year follow-up. Methods This is a prospective comparative study of 144 consecutive patients undergoing primary ACL reconstruction using a hamstring autograft. All patients underwent graft harvesting and ACL reconstruction with the standard technique. The graft diameter was recorded intraoperatively using a graft sizer. All patients were followed up with the Knee Injury and Osteoarthritis Outcome Score (KOOS) recorded at preop, six weeks, six months, one year, and two years and whether they underwent revision during this period was documented. Results The mean KOOS for patients with a ≤ 7mm graft diameter was 80.5±13.1, which was significantly lower compared to those with graft > 7 mm of 88.3±8.5, respectively (p<0.001) at the two years follow-up. Patients with graft ≤ 7mm did poorly, especially with mean KOOS subscores of sports and recreation and quality of life (p<0.05). Twenty-three point one percent (23.1%; 3 out 13) of patients with a graft < 7mm underwent revision, whereas only 5.8% and 2.6% of patients underwent revision with a graft diameter of 7.1-8.0 and 8.1-9.0 (p=0.027). Conclusions The smaller Hamstring graft diameter leads to poorer functional outcomes of the patient's ACL reconstruction. Though the number of revisions was high among those with a graft diameter of ≤ 7mm, multicentric studies with many revisions are required to confirm the relation.