Histological Osteoarthritic Changes in the Human Cervical Spine Facet Joints Related to Age and Sex.

STUDY DESIGN: Cross-sectional autopsy study.

OBJECTIVE: Quantify histological changes in the lower cervical spine facet joints with regard to age and sex using systematic random sampling of entire joints.

SUMMARY OF BACKGROUND DATA: Neck pain is a common debilitating musculoskeletal condition and one of the highest ranked causes of years lived with disability. The cause of neck pain is multifactorial and osteoarthritis is one potential cause. The cervical spine facet joints have been implicated in the etiology of chronic neck pain. Hence, a detailed description of their anatomy and age- and sex-related changes is needed.

METHODS: The lower four cervical spine segments (C4-C7 included) were obtained from 72 subjects during autopsy; 29 women (median age 53 years [22-77]) and 43 men (median age 38 years [20-78]). A total of 1132 articular facets were embedded in toto in hard plastic and sliced into 3-mm thick sections from where 10 μm thick histological sections were produced. Morphological variables were evaluated microscopically and histomorphometric variables were retrieved using random sampling methods. Data were analyzed with a linear regression model.

RESULTS: Significant associations were found between increasing age and in particular splitting, fissures, osteophytes, thickness of the calcified cartilage, and subchondral bone plate. The thickness of the calcified cartilage and subchondral bone plate increased with increasing age, whereas the hyaline cartilage thickness decreased. Males had more extensive degenerative changes in the cartilage.

CONCLUSION: Using semiquantitative histological methods, degenerative findings were observed at all spinal levels involving the articular cartilage and the osseous structures of the cervical spine facet joints similar to those observed in larger weight-bearing joints. In particular, the thickening of the calcified cartilage and the subchondral bone identified the osteocartilaginous junction as an important area in osteoarthritis. These findings may be relevant for the pathogenesis of osteoarthritis.

LEVEL OF EVIDENCE: 3.