RESUMO
Costo-vertebral and costo-transverse joints are often involved during rheumatoid pelvispondylitis. Their involvement may lead to thoracic ankylosis and decreased respiratory capabilities. These arthritis may also cause intercostal or pseudo-visceral pains. The authors report three cases of lower costo-vertebral arthritis, revealed by pseudo-urological, acute or subacute pains. The diagnosis was made on clinical findings (especially mobilization of the lower ribs) and confirmed by X-Rays (especially tomodensitometry). One of the cases presents an image of unilateral pedicle opacity secondary to costovertebral arthritis. The pseudo-urological manifestation of the pain is likely explained by the anatomical relationship between costo-vertebral joints and the sympathetic communicating rami. This close anatomical relationship was confirmed by dissection. Through the communicating rami, the costo-vertebral joints are thus in relation with the sympathetic system, which is responsible for the sensory innervation of the renal space. The pseudo-urological revelation of this arthritis should be compared to that of costal sprains.