Tuberculous lesions of the posterior vertebral arch

Tuberculous spondylodiscitis; is the most frequent expression of osseous tu berculosis; lesions involving the body and the disk are typical. Localizati on in the posterior arch is less frequent and can occur either by contiguit y or as a solitary localization. We report 10 cases of vertebral tuberculos is with posterior arch involvement. Standard x-rays were obtained in all cases with tomographies in 2 and CT sc ans in 7 (with CT myelogram in one). Magnetic resonance imaging was used in 2 cases. Female sex predominated with 8 cases. Mean patient age was 35 yea rs. Clinically, a spinal or sublesional syndrome was observed. The most fre quent localization was the lumbar level (5 cases). Major involvement of the vertebral body was observed in 8 cases and minimal involvement in 1. The l esion was limited to the posterior arch in 1 case. Lytic lesions were evide nced radiographically. Posterior arch involvement remains infrequent and is found in 2% of cases. Usually, the posterior lesion is contiguous. Exceptionally the posterior ar ch lesion is unique, involving all the parts of the arch. The gravity of th is this localization is related to the enlargement of the epidural space le ading to neurological pain.