Scott F. Farrell, Peter G. Osmotherly, Jon Cornwall, Darren A. Rivett

Innervation of anatomical structures is fundamental to their capacity to generate nociceptive impulses. Cervical spine meniscoids are hypothesised to be contributors to neck pain, however their innervation is not comprehensively understood. To examine the presence and morphology of nerve fibres within cervical spine meniscoids and adjacent joint capsules. Cross-sectional study. Cervical hemispines of 12 embalmed cadavers (mean [SD] age 82.9 [6.5] years, six female, six left). Cervical spine meniscoids and adjacent joint capsules were excised from lateral atlantoaxial and cervical zygapophyseal (C2-3 - C6-7) joints (n=67), then paraffin embedded. Meniscoids were sectioned sagittally (5 µm), slide mounted, and immunohistochemistry performed using primary antibodies to neurofilament heavy (NF-H) and pan-neurofilament (Pan-NF) to identify nerve tissue. The study was supported by institutional graduate student funding. The authors have no conflicts of interest to declare. Seventy-seven meniscoids (23 lateral atlantoaxial, 54 cervical zygapophyseal) were extracted and processed (154 sections in total). Sixty-four individual nerve fibre bundles were identified (26 NF-H positive, 38 Pan-NF positive) from 14 meniscoids. Nerves immunoreactive to both NF-H and Pan-NF were identified in 13/77 meniscoids (10/14 lateral atlantoaxial joint) from 11 joints (8 cadavers). Nerves were always located in joint capsules except three exclusively Pan-NF immunoreactive nerve fibre bundles from two adipose meniscoids. The low nerve prevalence in elderly cervical spine meniscoids, with nerves only found in two adipose type meniscoids, suggests these structures may play a minimal role in cervical nociception generation in this demographic. The more frequently innervated joint capsules are more likely nociception generators in the elderly. Joint capsule nerves were mostly NF-H positive indicating potential Aδ-fibre presence.