Physiological and osseous reconstruction of the anterior wall of the vertebral canal after anterior cervical corpectomy and fusion: a retrospective and observational study

Abstract

Background. Anterior cervical corpectomy and fusion (ACCF) has been widely applied to the treatment of cervical spondylotic myelopathy (CSM), ossification of posterior longitudinal ligament (OPLL), cervical trauma and other cervical diseases, but few studies have reported osseous and physiological reconstruction of the anterior wall of vertebral canal following ACCF. And there is no agreement on standard for the reconstruction on computed tomography (CT) after ACCF. Objectives. To analyze the process of osseous and physiological reconstruction of the anterior wall of the vertebral canal following ACCF. To analyze the influence reconstruction had on titanium mesh cage (TMC) subsidence. Methods. Clinical and radiological analysis of consecutive patients with cervical diseases treated initially with ACCF. Growth rates (GR) reflecting the reconstruction extent were measured. Group comparisons of immediate and at least one-year after the surgery CTs from the same patient and a literature review conducted. Results. 48 patients were treated surgically at a mean age of 61.5±12.0 years. Median follow-up was 36 months, and 159 CT images were analyzed. GR values of remaining vertebral bodies on CT images immediately and 1 year after surgery were 0.505±0.077 and 0.650±0.022 (p<0.001), and the GR value of 4 years or more was 1. After ACCF, residual vertebral bodies on both sides grew from the periphery to the center on axial CT cuts. When fusion of vertebral bodies and the titanium cage was complete during the first year after ACCF, osteogenesis and remodeling initiated in the osseous anterior wall of the cervical canal. The reconstruction of osseous anterior wall of the vertebral canal was completed at the fourth year after surgery and it was smooth and cambered and did not re-compress the spinal cord on both axial and lateral CT cuts. According to literature review, more than 4 years after surgery, no TMC subsidence Conclusion. The anterior wall of the vertebral canal undergoes osseous and physiological reconstruction after targeted vertebral body corpectomy by ACCF. The reconstruction completed in the fourth year after surgery which helps prevent TMC subsidence and we think the standard for reconstruction should be recommended for prognostic evaluation. Key words: ACCF, cervical spine, bone reconstruction, osseous fusion, cerebrospinal fluid pulsation