Neuropathic arthropathy of the shoulder: Two cases of syringomyelia with cocaine use

Neuropathic arthropathy (NA) is a progressive, degenerative disorder associated with decreased sensory innervation of the involved joints. The shoulder joint is an uncommon presentation for NA, although syringomyelia is the most common cause for this joint. Two cases are presented of NA of the shoulder, with both patients having a history of syringomyelia and cocaine use. In both cases a work up for malignancy was negative, but imaging was consistent with NA. Although syringomyelia has been linked with this presentation in prior publications, the role of cocaine use may not be incidental, with complex biochemical interactions in bone metabolism. Cocaine has been shown to involve the Leptin, Neuromedin U (NmU), cocaine and amphetamine-regulated transcript (CART), and Receptor activator of nuclear factor kappa-B ligand (RANKL) pathways of bone remodeling. Treatment can be challenging, involving concurrent use of pharmacotherapy, surgical correction, and protective bracing.