Pull-out strength of 0°/30° Kirschner wire syringe external fixators with and without polymer augmentation: a biomechanical study
Atthakomol, P.; Wangjiraphan, N.; Krudtong, S.; Panya, J.; Leuvitoonvejchakij, S.; Kraisarin, J.; Sananpanich, K.
Journal of the Medical Association of Thailand 98(1): 82-87
2015
ISSN/ISBN: 0125-2208 PMID: 25775736 Document Number: 16803
A number of different bone geometries have been reported to be correlated with osteoporosis, bone mineral density and fractures. Those correlations are used for diagnosis, treatment and prediction of fracture risk in osteoporosis cases. However there have been no studies of significant bone parameters predicting osteoporosis and hip fracture in Thailand To evaluate the correlation between geometric parameters of the proximal femur and both the Singh index and bone mineral density as well as to investigate the relationship between those two metrics and osteoporotic hip fracture in the Thai population. Forty-four Thai patients with osteoporotic hip fractures andforty-five healthy Thai people matched for age and gender were included in the present study. Bone mineral density and bone geometry from plain hip radiographs of non-fracture sites in the fracture group and proximal femur radiographs of the same site in the healthy group were measured That data were analyzed to determine levels of correlation. Bone geometries were also analyzed to determine hip fracture predictive capacity. Correlation between the Singh index and bone mineral density was significant (p < 0.01), with a moderate degree of agreement. The radiograph measurement of the width ofthefemoral medial neck cortex was the only parameter which was statistically significantly correlated with both osteoporosis and with osteoporotic hip fracture (p = 0.014 and p = 0.035, respectively). Each 1 mm reduction in the width of the femoral medial neck cortex increased the osteoporotic hip fracture risk by a factor of 2.7 (OR = 0.37, 95% CI = 0.15-0.93). In the Thai population, bone geometry from plain radiographs can help predict the risk of osteoporotic hip fracture. Osteoporosis is correlated with a low Singh index value. The width of the femoral medial neck cortex is a reliable predictor of hip fracture risk. Hand external fixators are in use worldwide and insulin syringes can generally be found in an operating room. To compare the pull-out strength between degrees of Kirschner wire fixation (0° and 30°) and the effect of filling an insulin syringe with polymer Pull-out strength was compared between a syringe externalfixator and a bone or plastic tube model. Fifty-two plastic tube models and 20 dry phalangeal bones were included The syringe external fixator was attached via two Kirschner wires. Four variations were studied: 0° non-polymer 0° with polymer augmentation, 30° non-polymer and 30° with polymer augmentation. The pull-out strength was measured in each group. The strength of polymer augmentation was higher than non-polymer augmentation at 0° (p = 0.0003) and 30° (p = 0.0002). The Kirschner wire at 30° provided more pull-out strength than at 0° (p = 0.0003) using the syringe with no polymer However, using the syringe with polymer augmentation, there was no significant difference (p = 0.5136). Polymer augmentation significantly increases the pull-out strength at both degrees offixation. The degree of fixation significantly increases the pull-out strength only in the non-polymer group, where pinning at 30° was superior to 0°.
Document emailed within 1 workday
