Osteoarthritic cartilage contains increased calcium, magnesium and phosphorus.
Using plasma emission spectroscopy, we measured the calcium (Ca), phosphorus (P), magnesium (Mg), and sulphur (S) concentration in femoral head cartilage from 7 patients with osteoarthritis (OA) and 22 normal patients. We found that in OA cartilage Ca = 271.9 +/- 32.7 mmol/kg dry weight compared to Ca = 113.2 +/- 12.6 mmol/kg dry weight in normal controls. The Ca:P molar ratio in OA cartilage was 1.93 compared to Ca:P = 2.27 in normals, and Ca:P = 1.67 in apatite crystals. We conclude that OA cartilage has a greater binding capacity for Ca, Mg, and P than does normal cartilage. Apatite crystals, if present, comprise maximally 0.4% wet weight of OA cartilage.
Pritzker
K P
KP
Department of Pathology, Mount Sinai Hospital/University of Toronto, Canada.
Châteauvert
J M
JM
Grynpas
M D
MD
D000293:Adolescent; D000328:Adult; D000368:Aged; D002356:Cartilage / Q000032:analysis / Q000378:metabolism*; D002358:Cartilage, Articular / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D008274:Magnesium / Q000032:analysis / Q000378:metabolism*; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism*; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism*; D013057:Spectrum Analysis; D013455:Sulfur / Q000032:analysis / Q000378:metabolism
D010758:Phosphorus; D013455:Sulfur; D008274:Magnesium