Hyperostosis of ribs: association with vertebral ossification

Costal hyperostosis occurring with vertebral disorders, although not well known, has been described in patients with diffuse idiopathic skeletal hyperostosis (DISH). Our purpose was to examine the possible association of similar hyperostosis in other spinal conditions.

We investigated the frequency of hyperostotic rib changes on routine radiographs in 191 patients with various spinal disorders, including DISH (51 cases), ankylosing spondylitis (AS) (58 cases), psoriasis (21 cases) and quadriplegia (61 cases), and in a healthy control group (191 cases).

Results showed that the frequency of rib hyperostosis was significantly higher in DISH (21.6%), AS (10.3%) and quadriplegia (6.6%) than in the healthy control group (0.5%). There was no significant difference in the frequency of right and left-sided involvement. The main radiographic features were a short segment of cortical thickening and sclerosis, which predominated in the medial aspect of the posterior portion of the rib. Some patients had a long segment of bone enlargement and extensive sclerosis. The resulting radiographic features simulated the appearance of Paget's disease. Osseous excrescences of adjacent costovertebral articulations were significantly related to the rib hyperostosis, seen in 73% of instances of rib involvement.

Our observations suggest that diseases that lead to bone formation and resultant hypomobility of costovertebral articulations are associated with rib hyperostosis.