Morphometric study of uncinate process of cervical vertebra and its surgical importance

Introduction: Uncinate process (UP) is a projection on the posterolateral margins of the superior surface of the body of the cervical vertebra. They are involved in the uncovertabral (Luschka's) joints, with intervertebral foramen in between, which is related to vertebral artery and spinal nerve roots. Osteophytes of UP cause narrowing of intervertebral foramen, resulting in cervical spondylotic radiculopathy. Objectives: (1) To measure the morphometric parameters of UP of the cervical vertebra. (2) To classify the cervical vertebra on the basis of the encroachment of UP on the adjacent intervertebral foramen. Materials and Methods: One hundred dry cervical vertebrae were obtained from regions in and around Mysore, Karnataka, India. Measurements were taken using digital Vernier calipers. Results: Mean average values of the parameters are: width – 3.389 ± 0.83 mm (right), 3.389 ± 0.86 mm (left); length – 10.42 ± 1.46 mm (right), 10.64 ± 1.88 mm (left); and height – 5.32 ± 1.36 mm (right), 5.21 ± 1.16 mm (left). Classification of UP according to its encroachment on intervertebral foramen which is traversed by neurovascular structures, which may be compressed. Conclusion: Comparing the results of te present study with previous studies in different regions will help neurosurgeons to determine the boundaries of UP and allow adequate decompression of neural elements with reduced risk of neurovascular structures during anterior decompression of the spine.