Criteria for radiological evaluation of incorporation of stand-alone expandable cervical vertebral body replacement devices

Corpectomy is an important treatment option for various cervical pathologies and evaluation of treatment success on imaging can be even more difficult than for interbody fusion. Since for routine postoperative courses CT scanning seems not justified for evaluation of the fusion status this paper proposes markers for detailed evaluation of new on plain radiographs. Methods: In a retrospective analysis of prospectively collected consecutive patients were included from whom a minimum 2 year clinical and radiological follow-up was available of stand-alone VBR after cervical corpectomy for degenerative stenosis. All patients received an expandable cage of rectangular shape. For assessment of bony incorporation of VBR devices we introduce the footprint sign in addition to McAfee´s sentinel sign. Three observers evaluated the lateral x-rays of the patients.