RT Journal Article SR Electronic T1 Analysis of calcium deposits in calcific periarthritis. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 809 OP 813 VO 28 IS 4 A1 J Hamada A1 W Ono A1 K Tamai A1 K Saotome A1 T Hoshino YR 2001 UL http://www.jrheum.org/content/28/4/809.abstract AB OBJECTIVE: To determine if hydroxyapatite (HAP), octacalcuim phosphate (OCP), or tricalcium phosphate (TCP) can be found in the calcium deposits in calcific periarthritis. METHODS: Thirty-six specimens from 34 patients who had acute inflammation and roentgenographically recognized calcification in soft tissue were analyzed. Twenty-three patients with calcific tendinitis in the shoulder and 11 with calcific periarthritis at other sites were included. We prepared 2 kinds of samples from each specimen; a dried sample (washed and dried calcific deposit), and a sample heated to 1,000 degrees C. All were analyzed by X-ray diffraction, Raman spectroscopy, infrared absorption spectroscopy, and X-ray fluorescence spectrometry for calcium and phosphorus molar ratio. Synthetic HAP was used as the control in each analysis. RESULTS: The X-ray diffraction patterns of all dried samples were similar to those of HAP and carbonate apatite. We found no diffraction patterns of OCP or TCP. However, an OH- group at 3570cm(-1) was observed with Raman spectroscopy for samples heated to 1,000 degrees C and synthetic HAP, but not for the dried samples. Infrared absorption spectroscopy also confirmed an OH- group for samples heated to 1,000 degrees C and synthetic HAP, and confirmed that dried samples contained carbonate. CONCLUSION: Calcium deposits are composed of carbonate apatite. HAP, OCP, and TCP were not identified in any deposits.