A different perspective on calcium pyrophosphate deposition disease: observational cross-sectional ultrasonographic and electrophysiological study

This study aimed to diagnose calcium pyrophosphate deposition (CPPD) disease with nonspecific hand and finger pain using ultrasonography (US) and, to examine the effect of CPPD crystals on nerve conduction studies. This cross-sectional study involved 155 painful hands of 103 patients, aged 26–71 who had hand (finger) and/or wrist pain symptoms for over a year and no prior diagnosis. The study recorded electrophysiological data, radiological evaluations (Kellgren-Lawrence grading), and ultrasonographic examinations for all joints on both hands. Pain in the 1st carpometacarpal joint was the most commonly reported in 123 hands (79.4%). US revealed calcification in the radiocarpal joint in 43 hands (27.7%), and in the triangular fibrocartilage (TFC) in 37 hands (23.9%). Right wrist calcification negatively affected right ulnar nerve sensory nerve conduction velocity (SNCV) (p = 0.036). TFC calcification negatively affected both ulnar nerve sensory nerve action potentials (SNAP) amplitude (right: p = 0.005; left: p = 0.007) and ulnar nerve SNCV (right: p = 0.001; left: p = 0.001). Ultrasound effectively identifies CPPD. To our knowledge, this study is the first study to evaluate the effects of CPPD crystals on nerve conduction studies. It found CPPD-related TFC calcification negatively affects the ulnar nerve SNAP amplitude and SNCV. This is the first report of a negative significant association between wrist calcification and ulnar nerve SNCV.