Biomechanical evaluation of supra-acetabular insufficiency fracture utilizing finite aspect evaluation.
J Orthop Sci. 2018 Jun 01;:
Authors: Tanaka H, Yamako G, Kurishima H, Yamashita S, Mori Y, Chiba D, Chosa E, Itoi E
BACKGROUND: Supra-acetabular insufficiency fractures (SAIFs) happen within the higher acetabulum and are uncommon in contrast with insufficiency sacral, femoral head, or ischial fractures. Nevertheless, SAIFs are recognized to happen in low grade trauma, and the underlying mechanism continues to be remained unclear.
METHODS: We carried out biomechanical evaluation utilizing finite aspect evaluation to make clear the mechanisms underlying the event of SAIFs. Affected person-specific fashions and bone mineral density (BMD) have been derived from pelvic computed tomography information from two sufferers with SAIF (unaffected aspect) and two wholesome younger adults. The bone was assumed to be an isotropic, linearly elastic physique. We assigned Younger’s modulus of every aspect to the pelvis primarily based on the BMD, and reported the relationships for BMD-modulus. Clinically related loading conditions-walking and climbing stairs-were utilized to the fashions. We in contrast the area of failure threat in every acetabulum utilizing a most principal pressure criterion.
RESULTS: The typical supra-acetabular BMD was lower than that of the hemi-pelvis and femoral head, however was greater than that of the femoral neck and larger trochanter. Larger minimal principal pressure was concentrated within the supra-acetabular portion in each the SAIF and wholesome fashions. Within the SAIF fashions, the upper area of the failure threat matched the fracture web site on the acetabulum.
CONCLUSIONS: Relative fragility causes compressive pressure to pay attention within the higher acetabulum when strolling and climbing stairs. When offered with a affected person complaining of hip ache with out obvious trauma or irregular X-ray findings, physicians ought to think about the potential of SAIF and carry out magnetic resonance imaging for the analysis of SAIF.
PMID: 29866524 [PubMed – as supplied by publisher]