HYDROXYAPATITE DEPOSITION DISEASE OF THE TEMPOROMANDIBULAR-JOINT IN APATIENT WITH RENAL-FAILURE

It has been reported that nearly two thirds of chronic hemodialysis pa tients suffer from single or multiple joint arthropathies.(1,2) These joint problems fall under three main categories: crystal-induced metab olic arthropathies, infections, and avascular necrosis. The crystal-in duced arthropathies are characterized by the deposition of abnormal cr ystal precipitates in and around joint soft tissues. This deposition o ften results in an acute and painful inflammatory response referred to as a crystal-induced synovitis/arthritis or ''acute joint syndrome.'' Renal failure patients under chronic hemodialysis are more susceptibl e to the formation of these joint precipitates because of hyperuricemi a, poor control of serum calcium and phosphate concentrations, and the tendency to develop secondary hyperparathyroidism. The crystal-induce d metabolic arthropathies are a heterogeneous group of diseases includ ing pseudogout (calcium pyrophosphate deposition disease), gout, oxala te deposition disease, and hydroxyapatite deposition disease. The hips , knees, shoulders, hands, and feet are the most commonly involved joi nts. For reasons that are not clearly understood, the temporomandibula r joint is usually unaffected by the crystal-induced arthropathies. To the best of our knowledge, a hemodialysis-related hydroxyapatite depo sition arthropathy of the temporomandibular joint (TMJ) has not been p reviously reported. We present here a case report of acute hydroxyapat ite deposition periarthritis: of the TMJ in a patient with end-stage r enal disease.