Overview of Crystal-Induced Arthritides By Sarah F Keller, MD, MA, Cleveland Clinic, Department of Rheumatic and Immunologic Diseases Reviewed / Revised Jul 2022 | Modified Sep 2022 View Patient Education Arthritis can result from intra-articular deposition of crystals: Monosodium urate Calcium pyrophosphate dihydrate Basic calcium phosphate (apatite) Rarely, others such as calcium oxalate crystals Definite diagnosis requires synovial fluid analysis.