Basic Calcium Phosphate Crystal Deposition Disease and Calcium Oxalate Crystal Deposition Disease By Sarah F Keller, MD, MA, Cleveland Clinic, Department of Rheumatic and Immunologic Diseases Reviewed / Revised Jul 2022 | Modified Sep 2022 View Patient Education Basic calcium phosphate (apatite) and calcium oxalate crystal disorders tend to cause clinical manifestations similar to those of other crystal-induced arthritides.