Abstract
Introduction: Neck hyperextension (NH) is defined as a progressive increase of lordosis associated with a limitation in flexion of the cervical spine, which ultimately results in an inability to approximate the chin to the sternum. NH may occur in relation to several myopathies. It is characterized by a general weakness and contractures of the axial muscles which produces a progressive increase of lordosis associated with a limitation in flexion of the cervical spine, that forces the patient to assume awkward compensatory postures to maintain balance and level vision. This study reports on operative complications, the degree of correction, the achievement of a solid arthrodesis, the maintenance of the correction and the clinical assessment of 7 patients.
Material and methods: Seven patients affected by various myophaties and NH were included. The mean age was 16.5 years (10–28 years). All underwent surgery, in which the paravertebral muscles were detached from the spinous processes and then transversally sectioned in order to bilaterally expose the laminas of vertebrae C2 to C7. The space between C1–C2 appeared mobile, while the spinous processes from C2 to C7 were close together and thus allowed only a very limited motion in between them. Ligamenti interspinosus and nuchae were detached and the facet joints from C2 to C7 were enlarged by capsulotomy. With a spreader rongeur, the interspinous spaces at each level were gently opened. Cortical cancellous autologue graft were shaped into wedges. After careful opening of each interspinous space, the bone wedges were driven between the spinous processes to maintain the achieved correction. The average follow-up time was 10.4 years (2.4–16.5 years).
Results: No major surgical complications occurred. At follow-up, the average angle between C2–C7 in neutral position had decreased (p = 0.016) from 50.7 (40–70) to 21.4 (2–50). The range of motion in the C1–C2 joint remained unaffected, while it decreased in C2–C7 (p = 0.016) from 33.5 (15–64) to 1.8 (0–8). In all cases, a solid arthrodesis was achieved.
Discussion and conclusion: The follow-up showed significant clinical improvement of posture in all patients. Our study has shown surgical treatment of NH to be an effective method within the whole series of seven patients, achieving both good immediate and good long-term results.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
