Value of polydirectional tomography in the assessment of the postoperative spine after anterior decompression and vertebral body autografting.

With the growing number of orthopedic reconstructive spinal procedures, the use of bone grafting has steadily increased in the past decade. An understanding of the biology of bone grafting is essential for both the clinician and radiologist. Despite the advent of computed tomography and magnetic resonance imaging, conventional polydirectional tomography remains an important tool in the evaluation of vertebral body autografts. Trispiral or hypocycloidal tomography plays a valuable role in the assessment of bone graft fusion and possible complications, especially in the presence of metallic fixation devices. We present our imaging experience derived from 375 patients with cervical, thoracic, or lumbar anterior spinal fusion. True graft complications occurred in 27 patients (7%) and consisted of fracture (4%), malpositioning (3%), and infection (less than 1%).