Anterior Lumbar Interbody Fusion (ALIF) for Lumbar Hemivertebra in an Adult Using Three-Dimensional-Printed Patient-Specific Implants and Virtual Surgery Planning: A Technical Report

Abstract

Introduction: Hemivertebrae are a common defect of vertebral formation, potentially resulting in debilitating congenital scoliosis and necessitating highly traumatic surgery. Virtual surgical planning (VSP) and 3D-printed patient-specific implants (PSIs) have increasingly been applied to complex spinal surgery, and offer a range of potential benefits. Research Question: We report the use of 3D-printed PSIs and VSP as part of a two-level anterior lumbar interbody fusion (ALIF) for the management of lateral hemivertebra and congenital scoliosis. Material and Methods: A 53-year-old male with chronic low-back pain, due to L4 hemivertebra and mild congenital scoliosis, presented with new-onset leg pain. CT revealed L4/5 and L5/S1 degeneration and foraminal stenosis. Given the complex anatomy and extensive multi-level osteophytosis, 3D-printed PSIs were designed, manufactured, and implanted as part of a two-level ALIF. Results: Excellent implant fit was achieved intraoperatively, confirmed via postoperative imaging. VSP assisted with navigating challenging bony and vascular anatomy. Three-month postoperative imaging demonstrated construct stability, early signs of bony fusion, with implant placement, spinal curvature, and disc height corrections closely matching the VSP. Clinically, the patient’s pain and functional impairment had effectively resolved by nine-month follow up, as demonstrated through subjective and objective measures. Discussion and Conclusions: Virtual surgical planning and 3D-printed PSIs can be useful surgical aids in the management of the often-complex cases involving hemivertebrae and congenital scoliosis. This case of congenital pathology adds to the growing reports of PSI application to a variety of complex spinal pathologies, with analyses showing a close match of the postoperative construct to the preoperative VSP.