Two-year outcomes following ACL reconstruction with allograft tibialis anterior tendons: a retrospective study

The outcomes of 18 patients (11 females, 7 males; age, 40.4±11 years) at 2 years after ACL reconstruction with cryopreserved tibialis anterior allografts using a double bundle technique are presented. Most subjects (72%) described themselves as being moderately active before surgery. After providing written informed consent, subjects completed the 2000 IKDC Knee Form, underwent arthrometric knee measurements, and performed one-leg hop and isokinetic quadriceps and hamstring torque tests (60°/s). Ninety-four percent (17/18) of the subjects had normal or near-normal grades for manual knee ligament tests. Knee arthrometry measurements revealed a mean 1.1-mm involved side increase at 134 N (8.9±2 mm vs 7.8±3 mm) and a 2-mm involved side increase during manual maximum testing (11.3±2 mm vs 9.3±3 mm). Group means revealed active knee flexion (136±8° vs 139±6°) and knee hyper-extension (3±2° vs 5±2°), which were slightly reduced at the involved knee. One-leg hop testing revealed a 15% mean deficit at the involved side (0.81±0.3 m vs 0.95±0.3 m). Isokinetic testing revealed an 11% mean deficit at the involved side (143.4±60 Nm vs 161.8±54 Nm) for the quadriceps and 7% greater strength at the involved side (105.9±35 Nm vs 98.8±35 Nm) for the hamstrings. Side-to-side comparisons revealed that many patients displayed less than normal quadriceps femoris torque (72%, 13/18), hamstring torque (28%, 5/18) and hop test (28%, 5/18) performance. Moderate positive correlations existed between involved side quadriceps (r=0.80) and hamstring (r=0.83) torque/bodyweight and hop test performance. Scores were 77.6±21 (range 28.7–100) and 78.1±16 (range 41.7–100) for the 2000 IKDC Subjective Knee Evaluation and Health Assessment forms. Most subjects (83%, 15/18) rated their current function at ≥91% of pre-injury levels and all subjects continued to participate at their pre-injury perceived activity level. At 2 years after ACL reconstruction with tibialis anterior allografts, this subject group displayed satisfactory functional outcomes. Tibialis anterior allograft use provides an effective ACL reconstruction alternative, particularly for older individuals who want to continue recreational sports.