C7 extension crosswise osteotomy: a novel osteotomy for correction of chin-on-chest deformity in a patient with ankylosing spondylitis

Extension crosswise osteotomy at C7 (C7 ECO) was developed for the correction of forward gaze in patients with chin-on-chest deformity due to ankylosing spondylitis. A modification of cervicothoracic extension osteoclasis (C/T EO), C7 ECO replaces osteoclasis of the anterior column with a crosswise cut of the C7 vertebral body to eliminate the risks of unintended dislocation of the cervical spine. C7 ECO also eliminates the risks of C7 and T1 pedicle subtraction osteotomies (C/T PSOs), in which a posteriorly based wedge excision may lead to stretching injuries of the lower cervical roots and/or failure to achieve the exact angle of excision required for an optimal correction. Furthermore, opening the osteotomy anteriorly, as in the authors’ method, instead of closing it posteriorly, as in PSO, eliminates the risks related to shortening of the posterior column, such as buckling of the dura, kinking of the spinal cord, and stretching of the lower cervical nerve roots. Here, the authors report the use of C7 ECO for the surgical treatment of a 69-year-old man with severe compromise of his forward gaze due to chin-on-chest deformity in the course of ankylosing spondylitis. After uneventful correction surgery, the patient regained the ability to see objects, namely faces of people, at the level of his head while standing and to perform work tasks at a desk.

Occipital Neuralgia

Patients with occipital neuralgia typically complain of intractable, posterior headaches. Prior attempts to treat this condition have traditionally consisted of various strategies to decompress or cut the greater occipital nerve. Some have even advocated the ablation of ganglia or cervical roots that give rise to the occipital nerve. However, such treatments are highly invasive, irreversible, and fraught with failure and complications. Modern strategies employing subcutaneous stimulation of the occipital nerve using linear stimulation arrays are quite effective and lower in invasiveness and risk. This chapter discusses the clinical hallmarks of occipital neuralgia and the technique by which these subcutaneous electrodes are implanted and utilized.

Posterior Cervical Keyhole Laminoforaminotomy: A Cadaveric Comparative Study to Evaluate Limits of Bony Resection

BACKGROUND The posterior cervical keyhole (KH) laminoforaminotomy has been described to involve the lateral portion of cervical laminae of the upper vertebra alone (small KH) or of both upper and lower vertebrae (large KH). OBJECTIVE To microscopically compare the two keyhole techniques in terms of their ability to expose the corresponding cervical roots. METHODS Ten cadaveric specimens were operated bilaterally from C3-4 to C6-7 level to expose a total of 80 nerve roots. The large KH was applied to the left side, the small KH to the right side. The maximal length of exposed nerve roots was measured under microscope. The virtual optimal KH surface area was determined using digital software. Each root was inspected for exposure of its root and axilla. RESULTS The maximal exposed nerve root length on the large KH side was significantly larger than on the small KH side at C3-4, C5-6, and C6-7 levels (P = .031, P = .002, P = .003). No significance was reported for C4-5 (P = .06). We could expose right axillae in (3/40) and left axillae in (33/40; P < .001). Optimal keyhole surface areas were 37.9, 38.2, 38.7, and 46.2 mm2 in craniocaudal order. CONCLUSION Large KH defects involving both upper and lower laminae and facets can expose the roots to greater extent than small KH defects at C3-4, C5-6, and C6-7 levels. Large KH defects may allow better exposure of nerve roots axillae than small KH defects.