Is the bone tissue of the femoral neck demineralised in patients with hip fracture?

• Published in: Injury Vol. 51; pp. S4 - S11
• Main Authors: Cano, J.R., Crespo, P.V., Cruz, E., Rivas-Ruiz, F., Sánchez-Quevedo, M.C., Guerado, E., Campos, A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.04.2020
• Subjects: Absorptiometry, Photon; Aged; Aged, 80 and over; Bone Density; Bone metabolism; Female; Femur Neck - diagnostic imaging; Hip fracture; Hip Fractures - blood; Hip Fractures - diagnostic imaging; Hip Fractures - surgery; Hip osteoarthritis; Humans; Linear Models; Male; Microstructural trabecular bone; Mineralisation; Osteoarthritis, Hip - blood; Osteoarthritis, Hip - diagnostic imaging; Osteoporosis; Osteoporosis - blood; Osteoporosis - diagnostic imaging; Surgical treatment; Vitamin D - blood; X-Ray Microtomography; Osteoporosis; Hip fracture; Microstructural trabecular bone; Surgical treatment; Hip osteoarthritis; Mineralisation; Bone metabolism
• ISSN: 0020-1383; 1879-0267; 1879-0267
• DOI: 10.1016/j.injury.2020.02.013

•A decrease in serum levels of Ca and P in patients with hip fracture is not correlated with any such decrease in bone levels.•The patients with hip fracture presented differences in organic bone structure, with reduced trabecular length and thickness.•There is no correlation between serum levels of vitamin D and bone levels of Ca and P, between patients with hip fracture and those with hip osteoarthritis.•Treatment for osteoporosis should be aimed at increasing the synthesis of bone trabeculae, to reinforce their structure. The aim of this study is to establish the falsifiability of the "osteoporotic hypothesis" for hip fracture, according to which the bone density and mineral composition of bone tissue in patients with hip fracture is poorer than when no such fracture is present, and that this circumstance is relevant to the occurrence of a fracture. The study population consisted of forty patients treated with arthroplasty. Twenty patients with femoral neck fracture and another twenty with hip osteoarthritis received the same diagnostic protocol and the same antibiotic, anaesthetic, surgical and antithrombotic prophylaxis. Levels of calcium (Ca), phosphorus (P) and vitamin D in blood, amongst other values, were determined, and five samples of bone tissue from the proximal femoral metaphysis were obtained and characterised by optical microscopy and microanalytical analysis. No statistically significant differences were observed between the two groups with respect to the trabecular number, area or thickness, or inter-trabecular distance. However, there were differences in the length of the trabeculae, which was greater in the patients with hip osteoarthritis (p = 0.002), but not when the groups were compared by gender. When compared by age, a greater inter-trabecular distance was observed in the patients aged over 75 years (p = 0.036) but there were no differences in the remaining parameters. Serum levels of Ca (p = 0.03), P (p < 0.01) and vitamin D (p < 0.01) were lower in the fracture group. In the quantitative microanalytical analysis, no significant differences were observed in bone levels of Ca or P or in the Ca/P index, nor was there any correlation between serum and levels of bone Ca or P (Ca-0.197:p = 0.314;P-0.274:p = 0.158).Multiple linear regression revealed no correlation between the diagnoses, vitamin D and bone levels of Ca or P. Despite the reduced serum levels of Ca and P in the patients with hip fracture, no correlation was observed with bone levels of Ca and P,which were similar in both groups. There were differences in the organic bone structure, in terms of length and inter-trabecular distance. For patients with osteoporosis, treatment should be aimed at increasing the synthesis of bone trabeculae to reinforce their structure. Nevertheless, no such treatment can prevent falls, and therefore no reduction in hip fractures amongst this population can be assured.