Vancomycin-Soaked Quadriceps Tendon Autografts but Not Hamstring Tendon Autografts Are Associated with Early Graft Failure (Graft Resorption) After Primary Anterior Cruciate Ligament Reconstruction: A Single-Center Experience.

Introduction: Anterior cruciate ligament (ACL) injuries are among the most common orthopedic injuries. While Hamstring Tendon (HT) autograft reconstructions have been the most frequent graft type over the last decade, quadriceps tendon (QT) autografts have become increasingly popular in the past 2 years. The procedure of vancomycin graft soaking has become the state-of-the-art in many institutions as it avoids septic knee arthritis after anterior cruciate ligament reconstruction (ACLR). In the present study, we analyzed all patients presenting with an ACL rupture who subsequently underwent primary ACLR using either HT or QT autografts soaked in vancomycin during a 12-month study period. We specifically focused on the occurrence of graft resorption leading to early graft failure, comparing outcomes between HT and QT autografts. Materials and Methods: Relevant data of all patients presenting with a primary anterior cruciate ligament (ACL) rupture and subsequently undergoing ACL reconstruction (ACLR) using either a hamstring tendon (HT) or quadriceps tendon (QT) autograft were collected between April 2022 and April 2023. Patients who later presented to our outpatient clinic with clinical signs of recurrent knee instability, with or without a preceding trauma, underwent magnetic resonance imaging (MRI) to evaluate graft integrity.Early graft failure was defined as recurrent instability within 12 months after the index ACLR, confirmed by MRI evidence of an absent or nonfunctional graft, and-if revision surgery was performed-arthroscopic confirmation of graft absence. Results: A total of 468 patients underwent anterior cruciate ligament reconstruction (ACLR) using autografts, including 421 hamstring tendon (HT) and 47 quadriceps tendon (QT) grafts. During the 12-month follow-up period, early graft failure occurred in 22 patients (all QT autografts), corresponding to a failure rate of 46.8% in the QT group and 0% in the HT group. Nineteen of the affected patients underwent revision ACLR, while three declined further surgery. Discussion: The markedly higher rate of early graft failure in the QT group raises concern regarding the safety of combining vancomycin soaking with quadriceps tendon autografts. These findings should be interpreted with caution and considered hypothesis-generating. Further prospective and experimental studies are required to confirm these observations and clarify the underlying mechanisms.