Inter-sterno-costo-clavicular ossification.

The clinical and radiological features of four patients with inter-sterno-costo-clavicular ossification are described. The process was associated with established seronegative spondyloarthropathy in three cases of whom four had long standing psoriasis, the other having ankylosing spondylitis. In the fourth case no associated arthropathy was present. A review of the literature is presented.