Repair and regeneration of vertebral body after antero-lateral partial vertebrectomy using beta-tricalcium phosphate

Antero-lateral partial vertebrectomy (ALPV) was used for decompression in 91 patients with multilevel cervical disorders. The high-speed drill was used to excise about 1/3 of the vertebral body for relief of anterior compression of the cord and nerve roots under the operating microscope. The key point was opening of the medial wall of the foramen of transverse process at the beginning of the ALPV, allowing the determination of the lateral borders of the ALPVs. To repair and regenerate the vertebral body, a beta-tricalcium phosphate (β-TCP) block was trimmed into a cuneiform shape and implanted into the sites of the ALPV excluding the upper and lowermost vertebral bodies. Postoperative computed tomography confirmed that β-TCP was gradually replaced by newly formed bone from the surface towards the center of the block, and that the affected vertebral body was remodeled by 6 to 12 months after the implantation of β-TCP. The cortical bone borders on the bone marrow at the site of the regeneration. The pedicles on the side of the ALPVs were rebuilt during regeneration of the affected vertebrae. Thus, the vertebral foramen of the cervical spine was widened in the anterior direction at the levels of the ALPVs, resulting in restoration of the physiological size of the cervical cord. The cervical curvature remained unchanged and a certain degree of cervical mobility (mean 86%) was preserved in this series. (author)