The most common failure reasons of an anterior cruciate ligament (ACL) graft are incorrect positioning of the drill channels and insufficient fixation. In many cases, one-stage revision with patellar tendon graft and the appropriate corrections are possible. For previous use of the ipsilateral patellar tendon third, an allograft seems favorable for reconstruction. So far, no study compared the results of revision surgery of autologous versus allogenous patellar tendon grafts for revision surgery of the ACL in a 5-year follow-up.
A retrospective study was conducted to analyze the clinical outcome and stability results 2 years (19.2 ± 5.8 months) and 5 years (68.8 ± 6.8 months) after revision of ACL reconstruction using middle-third patellar tendon allografts and autografts. The allografts were cleansed by mechanical means only. There were 15 patients in the allograft group and 14 in the autograft group. Patients with isolated re-rupture of the ACL graft were included in the study. Clinical results were evaluated by International Knee Documentation Committee 2000 forms (IKDC), Lysholm score, Tegner activity score, and visual analog scale. Stability was evaluated by means of KT-1000 arthrometer, Lachman test, and pivot-shift test. Location of drill holes was evaluated radiologically. Gonarthritis was graded according to Kellgren and Lawrence on the basis of radiographs.
There were no significant differences between the two groups in anterior translation, manual examination for stability, IKDC 2000 findings, Tegner activity score, or Lysholm score. Extension deficits were more frequent in the autograft group at the first follow-up (P = 0.010). Lateral gonarthritis and femoral tunnel widening were more common in the allograft group at the second follow-up (P = 0.049 and P = 0.023, respectively). Pain on walking downhill was significantly more frequent in the allograft group at the second follow-up (P = 0.027).
The functional results with allografts that had not undergone irradiation or chemical sterilization were comparable to those with autografts in ACL revision surgery. Allografts represent a good alternative to autogenous patellar tendons in revision surgery.