Hydroxyapatite Crystal Deposition Disease with Multiple Joint Involvement Resulting in Severe Lumbar Spinal Canal Stenosis: A Case Report

Abstract

Objectives: To describe a rare complication of hydroxyapatite (HA) crystal deposition disease (HADD) – spinal canal stenosis. To discuss clinical features and surgical management of this entity.

Background: HADD is a crystal-induced arthropathy caused by para-articular and/or intra-articular deposition of HA crystals. Etiology is uncertain, predisposing factors include microtrauma, local ischemia, end-stage renal disease. Commonly, glenohumeral joint is affected, less often - elbow, wrist, hand, hip, knee, ankle, foot and spine. Rarely – deposition of crystals is associated with spinal canal stenosis. 

Methods: We report a case of 34-year-old male who was admitted to the hospital with recurrent fever and elevated inflammatory markers for the past few months. Patient had a history of stage 5 chronic kidney disease treated with hemodialysis, anabolic-androgenic steroid use, arterial hypertension, tertiary hyperparathyroidism and multiple calcium deposits along glenohumeral, iliofemoral joints bilaterally, left foot and lumbar spine. Computed-tomography showed hyperdense calcifications in soft tissue along lumbar spine with minimal intraspinal involvement. Over the course of a few weeks’ symptoms worsened, the patient presented with lower back pain radiating in both legs, progressive lower paraparesis, walking difficulties. Magnetic-resonance imaging showed hypointense periarticular lesions with fluid levels on both T1 and T2-weighted images from L1 to L3 extending intraspinally with severe spinal canal stenosis, medullary cone compression. Surgical resection of the pathological tissue was indicated.

Results: The patient underwent L1-L3 laminectomy and resection of the lumbar soft tissue and intraspinal extradural calcified depositions. Histopathological examination confirmed diagnosis of HADD associated spinal canal stenosis. Physical rehabilitation followed, progressive recovery was seen, with almost complete resolution of motor deficits 6 months post-surgery.

Conclusions: HADD, affecting lumbar spine, can lead to inflammation, swelling and stenosis of the spinal canal resulting in severe back pain and progressive neurological deficits. Surgical treatment in such cases can be curative and lead to good outcomes.