Outcome of arthroscopic ACL avulsion fixation using adjustable Endobutton: a case series report of new surgical technique.

Introduction: Anterior cruciate ligament (ACL) avulsion fractures, also referred to as tibial spine fractures, are increasingly encountered in both pediatric and adult populations. Although multiple fixation techniques have been described, the optimal surgical approach - particularly for displaced and comminuted fractures - remains controversial. Arthroscopic fixation using an adjustable-loop cortical Endobutton has emerged as a minimally invasive and potentially reliable option. Methods: This case series includes five consecutive male patients (aged 15-31) with displaced ACL avulsion fractures (four Meyers-McKeever Type III and one Type IV) treated arthroscopically using an adjustable-loop cortical Endobutton. All procedures were performed within 3-10 days following injury. Clinical evaluation included International Knee Documentation Committee score, range of motion (ROM), clinical stability tests, and KT-1000 arthrometer measurements. Radiographic follow-up was performed to assess fracture union. Results: All five patients achieved complete radiographic union within 3 months postoperatively. At 12-month follow-up, four patients demonstrated full ROM and stable knee with normal KT-1000 side-to-side differences (<3 mm). One patient sustained a subsequent high-energy sports injury at 9 months postoperatively, resulting in an intrasubstance ACL rupture confirmed by magnetic resonance imaging; however, fracture union was complete and fixation remained intact. No postoperative complications were observed. Four of five patients returned to their pre-injury activity level. Conclusion: Arthroscopic fixation of displaced ACL avulsion fractures using an adjustable Endobutton provides stable fixation, avoids intra-articular hardware irritation, and allows early rehabilitation. This technique appears to be a reliable option for Meyers-McKeever Type III and IV fractures.