Atlanto-axial subluxation in patients with seronegative spondylarthritis.

Two patients with seronegative HLA-B27-connected spondylarthropathy, associated in one case with psoriasis and in the other with Reiter's disease, who had atlanto-axial subluxation (AAS) are reported. The AAS caused muscle weakness and intractable occipito-cervical pain. Both patients were treated operatively with a Gallie type C1-C2 fusion. The symptoms subsided following surgery and the patients remained free of cervical spine discomfort. The report also indicates that the rarer variants of the HLA-B27 associated chronic seronegative spondylarthropathies may cause AAS complicated by neurological symptoms and that the disorder is amenable to surgical intervention.