Magnesium disorders can cause calcium pyrophosphate deposition disease: A case report and literature review

Calcium pyrophosphate deposition (CPPD) disease, also known as pseudogout, is one of the most common forms of inflammatory arthritis. A variety of comorbidities and metabolic conditions have been recognized to predispose to CPPD. We describe here a patient with chronic CPP arthritis due to hypomagnesemia, which is one of the metabolic etiologies associated with CPPD, especially in younger patients. We also performed a literature search and reviewed all reported cases of CPPD disease associated with hypomagnesemia. All cases of hypomagnesemia and its etiologies leading to CPP arthropathy identified in the literature by this systematic search are summarized in this paper.

Destructive pseudo-neuroarthropathy associated with calcium pyrophosphate deposition

BACKGROUND

Calcium pyrophosphate deposition (CPPD) disease is a metabolic disorder characterized by soft tissue calcific deposits formed primarily in articular cartilage. What can result is a crystal-induced arthropathy often referred to as pseudogout, which is variable in both presentation and severity. A particularly destructive and deforming arthritis is an uncommon but well-recognized subtype of this disease. Radiologically resembling the neuroarthropathy described by Charcot, a pattern of joint fragmentation and structural collapse occurs in the absence of peripheral neuropathy. This pseudo-neuroarthropathy is rarely reported in the foot and ankle.

METHODS

A total of 15 cases of pseudo-neuroarthropathy involving some previously unreported joints within the foot and ankle are described in this case series of 9 patients.

RESULTS

All patients presented with disease involving multiple joints. Clinical deformity was apparent in each case, and extensive joint destruction was seen on plain radiographs. In 6 patients, histopathological CPPD disease was confirmed on tissue biopsy of the affected joints. In the remaining 3 patients a clinical diagnosis was made on the basis of the classic appearance of pseudo-neuroarthropathy in the foot, with additional recognized features of CPPD. Operative management with deformity correction using joint arthrodesis produced satisfactory clinical and radiological results.

CONCLUSIONS

In the absence of peripheral neuropathy and systemic disease, the pseudo-neuroarthropathy of CPPD should be considered when a progressively deforming and destructive arthritis is seen in the foot and ankle.

LEVEL OF EVIDENCE

Level IV, case series.

The structural consequences of calcium crystal deposition

Calcium pyrophosphate dihydrate and basic calcium phosphate (BCP) crystals are the most common calcium-containing crystals associated with rheumatic disease. Clinical manifestations of calcium crystal deposition include acute or chronic inflammatory and degenerative arthritides and certain forms of periarthritis. The intra-articular presence of BCP crystals correlates with the degree of radiographic degeneration. Calcium crystal deposition contributes directly to joint degeneration. Vascular calcification is caused by the deposition of calcium hydroxyapatite crystals in the arterial intima. These deposits may contribute to local inflammation and promote further calcification, thus aggravating the atherosclerotic process. Calcium crystal deposition results in substantial structural consequence in humans.