Healing of Stress Fracture in an Animal Model

Abstract

This project aims to develop effective ways to prevent or treat stress fractures. We have successfully established a reproducible stress fracture model in the rodent. We have investigated the role of an exercise program in the prevention of stress fractures using the ulna axial compression loading model. Loading was applied on right ulnas using a 2-Hz haversine waveform with a peak force of 17 N for 360 cycles/day, three days per week for five consecutive weeks. After adaptation to mechanical loading was determined by assessing both the material and structural properties of each ulna, ulnas (loaded vs. nonloaded) were loaded at a constant peak load of 25 N using a 5 Hz haversine waveform until fatigue failure. Loading improved both the material and structural properties of the ulna, especially minimum second moment of area increasing about 2-fold. Loaded ulnas failed in fatigue after 1.3 million cycles, compared to the 16,850 cycles required for non-loaded ulnas, suggesting that the mechanical loading program increased the fatigue resistance by 80-fold. In addition, animal experimental parts regarding the individual and combined roles of anti-inflammatory agent (cyclooxygenase-2 inhibitor) and low-intensity pulsed ultrasound in the treatment of stress fractures were done.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2004
Accession Number
ADA433113

Entities

People

  • Jiliang Li

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Anti-Inflammatory Agents
  • Biomedical Research
  • Bone Fractures
  • Compression
  • Electronic Mail
  • Information Operations
  • Inhibitors
  • Intensity
  • Materials
  • Resistance
  • Structural Properties
  • Ultrasounds
  • Universities
  • Waveforms

Fields of Study

  • Engineering

Readers

  • Circadian Sleep-Wake Regulation and Chronobiology
  • Mechanical Engineering/Mechanics of Materials.
  • Neurotrauma and Rehabilitation Medicine.