Anterior Cruciate Ligament Reconstruction Using Femoral Cortical Button Fixation: A Case Series of Intraoperative Malpositioning

Abstract

Background: Malpositioning of the femoral button is a known technical complication after anterior cruciate ligament (ACL) reconstruction with cortical suspensory fixation. The incidence of malpositioning, as well as the efficacy of methods to prevent malpositioning of cortical suspensory fixation devices, has not been reported. Purpose: To determine the rate of malpositioned cortical suspensory fixation devices after ACL reconstruction, investigate which intraoperative technique yields the lowest rate of malpositioning, and determine the return-to-duty rate for active-duty service members with malpositioned buttons and the revision rate for malpositioned buttons. Study Design: Case series; Level of evidence, 4. Methods: The records of patients who underwent primary ACL reconstruction with a cortical suspensory fixation device between 2008 and 2018 were reviewed at our institution. Postoperative radiographs were reviewed for evidence of malpositioned femoral buttons. Malpositioned buttons were classified as (1) fully positioned in the bone tunnel, (2) partially positioned in the bone tunnel, (3) >2 mm from cortical bone, or (4) deployed over the iliotibial band. Operative reports were reviewed to determine the intraoperative methods undertaken to verify the button position. The rate of malpositioned cases with subjective instability and revision surgery performed were determined. The ability of patients to return to full military duty was reviewed for active-duty personnel. Results: A total of 1214 patients met the inclusion criteria. A 3.5% rate (42 cases) of malpositioned cortical suspensory fixation devices (femoral buttons) was identified. For patients with malpositioned buttons, 7 (16.7%) patients underwent revision surgery in the immediate postoperative period. Techniques used to avoid malpositioning included direct arthroscopic visualization, direct open visualization, intraoperative fluoroscopy, and first passing the button through the skin before positioning on the femoral cortex. There was a 4.6% malposition rate using direct arthroscopic visualization and a 5.1% malposition rate using passage of the button through the skin, while no malpositioning occurred with intraoperative fluoroscopy or direct open visualization ( P < .05). Overall, 12 (28.6%) patients with malpositioned buttons ultimately underwent revision surgery. Despite having been diagnosed with malpositioned buttons, 21 (63.6%) active-duty members were able to return to full duty. Conclusion: Malpositioning of femoral buttons during ACL reconstruction occurred in 3.5% of patients in this series. The techniques of intraoperative fluoroscopy and direct open visualization are encouraged to prevent malpositioning.