Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Orthop. Feb 18, 2012; 3(2): 10-14
Published online Feb 18, 2012. doi: 10.5312/wjo.v3.i2.10
Innervation of cervical ventral facet joint capsule: Histological evidence
Srinivasu Kallakuri, Yan Li, Chaoyang Chen, John M Cavanaugh
Srinivasu Kallakuri, Yan Li, Chaoyang Chen, John M Cavanaugh, Department of Biomedical Engineering, Wayne State University, 818 W Hancock, Detroit, MI 48201, United States
Author contributions: Kallakuri S contributed to the study design, harvesting samples, performing staining procedures and preparation of the manuscript; Li Y contributed in performing immunostaining; Chen CY contributed to tissue harvesting and manuscript preparation; Cavanaugh JM contributed to the study design, manuscript preparation and review.
Supported by Grants from Centers for Disease Control to Cavanaugh JM, No. R49-CCR519751 and R49-CE000455
Correspondence to: Srinivasu Kallakuri, PhD, Department of Biomedical Engineering, Wayne State University, 818 W Hancock, Detroit, MI 48201, United States. skallakuri@wayne.edu
Telephone: +1-313-5773440 Fax: +1-313-5778333
Received: August 19, 2011
Revised: November 22, 2011
Accepted: February 16, 2012
Published online: February 18, 2012
Abstract

AIM: To assess the presence of nerves in ventral facet joint capsules as facet capsules are generally implicated in neck pain.

METHODS: Twenty-four ventral cervical facet joint capsules were harvested from 3 unembalmed cadavers. Paraffin sections from these capsules were processed to identify neurofilament and substance P immunoreactive fibers. Nerve fiber presence was also verified by a silver impregnation method.

RESULTS: Neurofilament reactive fibers were observed in sections from 9 capsules. They were observed in areas with collagen fibers and areas with irregular connective tissue. Substance P reactive nerve fibers were found in sections from 7 capsules in similar areas. Silver impregnation also revealed the presence of nerve fibers. The nerve fibers were also found as bundles in the lateral margins of the capsule. A Pacinian corpuscle-like ending was also observed in one specimen.

CONCLUSION: Nerve fibers revealed by neurofilament immunoreactivity and silver staining support innervation of the ventral aspect of the facet joint capsule. The presence of substance P reactive fibers supports the potential role of these elements in mediating pain. The presence of a Pacinian-like ending implicates a potential role in joint movement.

Keywords: Cervical facet joint capsule; Whiplash; Nerve fibers; Neurofilament; Substance P; Pain