A prospective randomized comparison of two distinct allogenic tissue constructs for anterior cruciate ligament reconstruction

Background: Conduct a prospective randomized study to compare clinical outcomes of anterior cruciate ligament (ACL) reconstruction using quadrupled hamstring tendon (HT) allograft or doubled tibialis anterior (TA) allograft. Limited level 1 data exist comparing outcomes of different soft tissue allograft constructs for ACL reconstruction. We hypothesized no difference would exist in the patient reported outcomes (PRO), arthrometric testing, or rate of re-rupture between the two constructs.

Methods: Ninety eight subjects undergoing primary ACL reconstruction were randomized to HT (n=47) or TA (n=51) allograft. Subjects completed validated (PRO) measures pre-operatively, and six months and two years post-operatively. Arthrometric testing was performed at six months to assess integrity of the reconstruction.

Results: Fifty-eight percent of subjects (57/98) completed a two-year follow up. Allograft re-tear rates were similar between groups (6.2% HT vs. 4.0% TA, respectively, p=1.0). The relative risk of re-tear in the HT group was 1.5 compared to the TA group (p=0.7). The TA group improved significantly more on the physical portion of the VR-12 (p=0.046) and Lysholm score (p=0.014) compared to the HT group. There was no difference in the change from baseline for the other PRO scores at two years.

Conclusions: Our data indicate no difference in graft failure rate and similar improvement from baseline in most PRO scores between treatment groups after two years. Based on these findings, TA allograft appears to provide a reliable and satisfactory option for patients who elect to undergo allograft ACL reconstruction.