VALIDATING THE USE OF PERIPHERAL BONE SITES TO PREDICT THE RISK OF FEMORAL NECK FRACTURE

Open Access
Author:
Alba, Rachel L
Area of Honors:
Kinesiology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Dr. Allison Singles, Thesis Supervisor
  • Dr. Sandy Feinstein, Honors Advisor
Keywords:
  • pQCT
  • peripheral quantitative computed tomography
  • femoral neck fracture
  • peripheral bone sites
Abstract:
As the population of older adults increases, osteoporosis and osteoporotic fractures become more and more of a concern for our health care system. Osteoporosis is characterized by a lower bone mineral density (BMD), which typically occurs during the aging process. BMD is typically measured using dual x-ray absorptiometry (DXA), which is subject to error based on bone size due to its two-dimensional nature. A solution to this problem is peripheral quantitative computed tomography (pQCT), which is a three-dimensional imaging method that exposes the patient to minimal peripheral radiation, while increasing the accuracy of the measurement and diagnosis. The purpose of this study was to determine which parameters at the distal radius and distal tibia would best predict femoral neck parameters. pQCT was used to measure parameters at the distal tibia, distal radius, and femoral neck. Parameters at the distal tibia and distal radius were correlated to find the best model to predict femoral neck fractures. The parameters that significantly correlated to trochanteric BMD were tibial polar stress-strain index (R = 0.770), tibial orthogonal sectional stress-strain indices (R = 0.803 and R = 0.772 for x-coordinate and y-coordinate, respectively), tibial total BMD (R = 0.824), radial total bone mineral content (R = 0.732), and radial BMD (R = 0.758). The parameter that significantly correlated to trochanteric trabecular BMD was radial total BMD (0.746). The best prediction of femoral trochanter BMD was given by the tibial x-coordinate sectional stress-strain index alone (R = 0.803). The best prediction of femoral neck BMD was given by the combination of radial cross-sectional moment of inertia, radial total bone mineral content (BMC), and tibial y-coordinate sectional stress-strain index (R = 0.904). The best prediction of femoral trochanter trabecular BMD was given by the combination of tibial total BMD, tibial x- and y-coordinate sectional stress-strain index, radial total BMD, radial cross-sectional moment of inertia, and radial trabecular BMD (R = 1.000). The best prediction of femoral neck trabecular BMD was given by the combination of tibial total BMD, tibial x-coordinate sectional stress-strain index, and radial cross-sectional moment of inertia, total BMD, and total BMC (R = 0.988). And the best prediction of femoral head trabecular BMD was given by the combination of radial cross-sectional moment of inertia, radial total BMC, and tibial x-coordinate sectional stress-strain index (R = 0.965). The results suggest that there are multiple models to accurately predict parameters at various fracture-prone sites of the femoral neck. This study demonstrates that pQCT scans at the distal radius or distal tibia, along with traditional DXA scans, would give a more complete prediction of femoral neck fracture risk, which can lead to a more accurate diagnosis of osteoporosis. With hip fractures becoming more and more of a health problem in the older population and with all the complications that follow a hip fracture, using a quick pQCT scan as a tool to help accurately predict osteoporosis-related fracture risk could increase early detection and prevent fractures.