Calcium pyrophosphate deposition disease mimicking spinal neuroarthropathy.

Abstract

A 75-year-old male with degenerative joint disease status-post T12-L5 fusion five years ago presented with new-onset left lower extremity weakness. He denied any sensory abnormalities, saddle anaesthesia, or dysfunction of the bladder or bowels. Physical examination was notable for 2/5 left quadriceps and gastrocnemius strength, compared with 5/5 on the right side. CT scan shows erosion and sclerosis of the T10 and T11 end plates with gas within the disk space, consistent with Charcot spinal neuroarthropathy (Fig. 1A). Due to the persistent neurological deficits, the epidural mass was resected and a dural patch graft was placed. Histopathology revealed fibrocartilaginous tissue fragments with degenerative changes and deposition of positively birefringent crystals consistent with calcium pyrophosphate deposition disease (CPPD) (Fig. 1B). One month after resection, the patient’s lower extremity weakness had fully resolved. CPPD can mimic many joint pathologies, including gout and osteoarthritis, in atypical locations. In this case, the radiographic appearance of destruction, debris, distention, disorganization, and density changes resembled Charcot neuroarthropathy but in an unexpected location without the typical antecedent sensory neuropathy [1]. This case illustrates that, when radiographic evidence seems to contradict clinical signs and symptoms of joint disease, clinicians should reserve a high index of suspicion for CPPD [2]. Informed consent has been obtained.