Does harvesting cancellous bone destabilize cervical spine in cervical interbody fusion? A prospective clinicoradiological analysis

Abstract

Background: To analyse the effect of graft harvesting from adjacent vertebral bodies in Anterior Cervical Discectomy and Fusion.Objective: The objective of this study is to analyze the effect of harvesting bone graft from adjacent vertebral bodies on cervical spine stability, vertebral segment height, and cervical lordosis in single-level anterior cervical discectomy and fusion (ACDF).Material and Methods: Thirty patients suffering from cervical radiculopathy and myelopathy were operated on using adjacent corticocancellous bone graft (ACBG) technique. In this technique, autologous cancellous bone is harvested from adjacent vertebral bodies and packed in the intervertebral body cage and the cavities in vertebral bodies are filled with tricalcium phosphate granules. Radiological studies with X-rays of the cervical spine were taken in lateral views preoperatively, immediate postoperatively, and during follow-up periods at intervals of 3-month duration, namely 3, 6, 9, 12 months, and at the end of 2 years postoperatively. Studies undertaken were – degree of fusion using modified Bridewell's formula, disc space settlement using Indigenous method, and vertebral segment height and lordotic angle using Cobb's angle.Results: Satisfactory bony fusion was seen achieved in all patients at the end of 1 year. Although the settlement of disc space was appreciated, vertebral segment height remained increased at the end of 1 year. Cervical lordosis increased over a period of time during fusion process. The average preoperative Cobb's angle of 15.61° ± 1.81° improved to 20° ± 1.37°degrees at the end of 2 years postoperatively.Conclusion: Harvesting bone from adjacent cervical vertebrae does not weaken spinal segment and the fear and skepticism that prevailed over the years are false. ACBG technique is a potential alternative to other existing techniques in ACDF.