Short term evaluation of the hamstring graft diameter after ACL reconstruction

Background. Graft embodiment process that occurs in the twelve weeks following reconstruction surgery is well described. However, the short-term performance characteristics of graphs, in terms of graft size and diameter, used in anterior cruciate ligament reconstructions is currently unknown. The purpose of this study was to measure the diameter of quadruple hamstring autograft with an MRI at two weeks post-op, before it undergoes any of the ligamentization process, and to compare it with the intra-operative graft measure. Material and methods. A prospective, observational study design was used. The MRI measured hamstring graft diameter at two weeks post-op from 38 study participants was compared to intraoperative diameter measurement of hamstrings graft during the ACL reconstruction surgery. Coronal plane T2 imaging was used to capture images in the intercondylar region near the tibial tunnel. Results. The average of the intra-operative graft diameter measurements was 7.9 mm (SD: 0.7 mm; range: 6.5 -9 mm). The average post-operative measurement obtained via MRI imaging within two weeks post-op was 7.1 mm (SD: 0.8 mm; range: 5.1 -8.6 mm). There was a significant decrease in the diameters of the graft over the first two weeks postoperatively (p < 0.001). Conclusions. The diameters of quadruple hamstrings knee grafts used for reconstructions of the anterior cruciate ligament decreased by 9.68% on average between the moment of the surgery and two weeks after surgery. This information can be used to guide graft preparation, reconstruction planning, rehabilitation and post-operative counseling of the patient as to their risk of rupture.