ACL Replacement with Synthetic vs. Biological Tendon Grafts: Long-Term Follow-Up Comparison Using Objective Evaluations

Background and aim of the study: Anterior cruciate ligament (ACL) tears are among the most common articular injuries in sports and can be responsible for knee instability and reduced articular performance. Treatment can be either conservative or operative, and ligament reconstruction may be carried out using biological autologous grafts or synthetic materials. Several studies have sought to evaluate and compare functional results in treated patients. However, there is still very limited information available on long-term follow-up and clinical outcomes are generally evaluated only using subjective scores. In this study, we assessed long-term functional and biomechanical results in patients treated with biologic and synthetic ligaments using objective measures. Materials and methods: Patients were divided according to whether ACL reconstruction was biologic or synthetic. The Tegner activity scale was used before and after surgery. Post-operative subjective scores such as the IKDC Questionnaire and the Tegner-Lysholm score were also recorded. The Y Balance Test was used to assess global stability and mobility of the lower limb. Kinematic Rapid Assessment (KiRA) was used to evidence and estimate ligamentous laxity during the Pivot Shift and Lachman tests. Results: Clinical subjective patient and operator-dependent scores as well as objective biomechanical findings were similar and comparable in patients treated with biologic and synthetic reconstructions after more than 10 years of use. Conclusions: Both synthetic and biological tendon grafts may represent good reconstructive approaches to treat torn ACLs, and remain effective even for a long period of time if implanted in suitable target patients.