Bone remodeling during the development of osteoporosis in paraplegia
Osteoporosis developing during the first weeks after the onset of traumatic paraplegia was studied with cortical and cancellous samples of iliac crest and tibia of 14 patients, and compared to normals. We used a procedure of bone particle fractionation (according to degree of mineralization) that allowed us to establish a profile reflecting the metabolic remodeling of bone and to analyze the organic matrix of the newly synthesized tissue. In paraplegics, we observed a large increase in the proportion of little calcified bone in the cortical as well as in the cancellous bone. Based on amino acid analyses, we found a decreased number of hydroxyproline residues in the newly synthesized organic matrix from paraplegia bone resulting either from an alteration of the prolyl hydroxylation or from the presence of an excess of noncollagen polypeptides. These results, together with previously published data reporting increased urinary hydroxylproline and calcium kinetic parameters, suggest an enhanced rate of skeletal remodeling in acute paraplegia. When investigated 2 years after injury, the patterns of distribution approach that of normal subjects.
Key WordsOsteoporosis Paraplegia Bone remodeling Bone matrix Bone mineralization
Unable to display preview. Download preview PDF.
- 5.Chantraine A (1979) L'ostéoporose et les para-ostéo-arthropathies au cours de la paraplégie. Editions Arscia SA, Bruxelles, p 238Google Scholar
- 6.Lapiere ChM, Nusgens B (1970) Maturation-related changes of the protein matrix of bone. In: Balazs EA, (ed) Chemistry and molecular biology of the intercellular matrix, collagen, basal laminae elastin. Academic Press, London, New York, pp 55–98Google Scholar
- 7.Eastoe JE (1965) Methods for the determination of phosphate, calcium and protein in small portions of mineralized tissues. Proc 2nd European Symp on Calcified Tissues. Richelle LJ, Dallemagne MJ (eds) pp 265–374Google Scholar
- 11.Boyce BF, Scullion JE, Beastall G, Ferguson A, Cowan R, Fogelman I, Boyle IT (1982) Iliac bone histomorphometry in patients with femoral neck fracture in osteoporosis. Menczel J, Robin GC, Makin M, Steinberg R, (eds) Wiley Cichester, New York, pp 248–256Google Scholar
- 14.Uhthoff HK, Jaworski ZFG (1978) Bone loss in response to long-term immobilisation. J Bone Joint Surg 60B:420–429Google Scholar
- 15.Donaldson CL, Hulley SB, Vogel JM, Hattner RS, Bayers JH, McMillan DE (1970) Effect of prolonged bedrest on bone mineral metabolism, 19:1071–1084Google Scholar