Thesis

Pelvic tilt and anterior pelvic plane inclination in normal individuals between different postures of daily life

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Awarding institution
  • University of Strathclyde
Date of award
  • 2015
Thesis identifier
  • T14218
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Pelvic tilt is known to affect the functional outcome of total hip arthroplasty. Postural changes in individual pelvic tilt can greatly alter the final orientation of the acetabular cup from the surgeon's expectations. This affects bearing surface performance, potentially resulting in impingement and dislocation. Predicting change in pelvic tilt and accounting for its effect remains a problem in navigated surgery. This study measured 12 healthy individuals in standing, seated, supine and lateral decubitus position, using Vicon motion capture. The standard pelvic tilt, as defined by the ISB, and the sagittal inclination angle of the anterior pelvic plane (APP) were measured independently. We documented postural changes in pelvic tilt and examined gender differences and the relationship between APP-inclination and ISB-defined pelvic tilt. It was found that, in standing, the APP tilted posteriorly to the vertical (-2.84°±11.37°), while in the supine position, where the APP is typically registered on theatre, it had a mean anterior inclination. Male participants tended to have an extended pelvis, while female pelves were more flexed in supine. This study further supports that APP is not vertical in standing, nor horizontal in supine, as it used to be assumed. In agreement with the literature, a posterior APP tilt occurred in the transition from supine to the erect posture (-4.9°±9.59°), without recording any significant differences. However, supine APP tilt differed significantly from the lateral decubitus tilt and this may raise concerns on current protocols in navigation. There was a high negative pelvic tilt in the seated position (-29.76°±23.23°), significantly different from all other postures. Finally, ISB-defined pelvic tilt represented the position of the pelvis in higher flexion angle values, as compared to the APP-registered pelvic tilt. APP angles were highly variable, as related to ISB angles, possibly due to anatomical variations. However, a positive linear relationship was determined (r=0.803).
Resource Type
DOI
Date Created
  • 2015
Former identifier
  • 1247836

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