vitamin-d-2 and Femoral-Fractures

Discrepancies in bone healing between osteoporotic and non-osteoporotic bone remain uncertain. The focus of the current work is to evaluate potential healing discrepancies in a metaphyseal defect model in rat femora. Female Sprague-Dawley rats were either ovariectomized (OVX, n=14) and combined with a calcium-, phosphorus- and vitamin D3-, soy- and phytoestrogen-free diet or received SHAM operation with standard diet rat (SHAM, n=14). Three months post-ovariectomy, DEXA measurement showed a reduction of bone mineral density reflecting an osteoporotic bone status in OVX rats. Rats then underwent a 3 mm wedge-shaped osteotomy at the distal metaphyseal area of the left femur stabilized with a T-shaped mini-plate and allowed to heal for 6 weeks. Biomechanical competence by means of a non-destructive three-point bending test showed significant lower flexural rigidity in the OVX rats at 3 mm lever span compared to SHAM animals (p=0.048) but no differences at 10 mm lever span. Microcomputer tomography (μCT) showed bridging cortices and consolidation of the defect in both groups, however, no measurable differences were found in either total ossified tissue or vascular volume fraction. Furthermore, histology showed healing discrepancies that were characterized by cartilaginous remnant and more unmineralized tissue presence in the OVX rats compared to more mature consolidation appearance in the SHAM group. In summary, bone defect healing in metaphyseal bone slightly differs between osteoporotic and non-osteoporotic bone in the current 3 mm defect model in both 3mm lever span biomechanical testing and histology.

Topics: Animals; Bone Density; Calcium; Cholecalciferol; Disease Models, Animal; Ergocalciferols; Female; Femoral Fractures; Fracture Healing; Osteoporosis; Osteoporotic Fractures; Ovariectomy; Rats; Rats, Sprague-Dawley; Vitamin D Deficiency

A high incidence of long-bone fractures has been observed in children and young adults with quadriplegic cerebral palsy in residential care. This study aimed to determine factors that contribute to these fractures and to institute preventive treatment. Twenty individuals (12 males, eight females) of a cohort of 88 residents with spastic quadriplegia in residential care in Gauteng, South Africa who had sustained fractures were compared with a random sample of age-matched control participants (10 males, 10 females) from the same facility. Participants ranged in age from 6 to 29 years (median 17.5 years). The majority of fractures were in the upper extremities. There was radiological and biochemical evidence of rickets and osteomalacia in both groups. However, the severity of the disease was more pronounced in the group with fractures. There was a significant relation (p=0.002) between the number of fractures and the use of anticonvulsant therapy (ACT). Three months of vitamin D administration (calciferol 5000 iu/day) resulted in a marked clinical improvement. There were no fractures during this period in either group. In addition, the mean serum calcium (Ca) and phosphate (Pi) levels increased (Ca from 2.17 to 2.35 mmol/L and Pi from 1.13 to 1.66 mmol/L) and mean total alkaline phosphatase level decreased (from 1123 to 423 U/L). We concluded that vitamin D deficiency was the major factor contributing to the occurrence of fractures in this population. Unless sunlight exposure can be guaranteed, vitamin D supplementation should be considered for children and adults in residential care, especially if they are on ACT, even in areas with year-round sunshine.

Topics: Adolescent; Alkaline Phosphatase; Anticonvulsants; Calcium; Cerebral Palsy; Child; Cohort Studies; Ergocalciferols; Femoral Fractures; Humans; Incidence; Light; Long-Term Care; Nutritional Status; Osteomalacia; Prevalence; Radiography; Rickets; Seizures; Severity of Illness Index; South Africa; Vitamin D Deficiency

This study demonstrates the effect of essential fatty acid deficiency on the postnatal skeletal development in the rat. Four groups (n = 10) of newborn Wistar rats were fed diets containing high and low proportions of essential fatty acids in the lipid fraction until day 16 after birth. Suckled littermates were used as controls. X-ray and histological studies showed the occurrence of multiple pathological fractures of the long bones in 1-month-old rats fed a diet deprived of essential fatty acids. No effect of high (51,000 IU/100 g diet) and low (5,100 IU/100 g diet) concentrations of vitamin D2 was observed in our experiment. Thus, these data suggest the importance of essential fatty acids for bone pathology in the rat.

Topics: Animals; Bone Diseases, Developmental; Dietary Fats; Ergocalciferols; Fatty Acids; Femoral Fractures; Rats; Rats, Wistar; Tibial Fractures