Identification of Tibial Stress Fractures Using Therapeutic Continuous Ultrasound

Abstract

Study Design: One-group discriminant analysis. Objective: To determine whether 1 MHz of continuous ultrasound can identify tibial stress fractures in subjects. Background: Stress fractures can lead to loss of function or to more serious nonunion fractures. Early diagnosis is important to reduce the risk of further injury and to assure a safe return to activity. Therapeutic ultrasound has been reported to be an accessible, less expensive alternative in diagnosing stress fractures compared with other diagnostic techniques. Methods and Measures: Twenty-six subjects (12 men, 20.33 2 1.37 years; 14 women, 20.78 2 3.8 years) with unilateral tibia pain for less than 2 weeks volunteered to participate in the study. Continuous, 1 MHz ultrasound was applied to the uninvolved and involved tibias at 7 increasing intensities for 30 seconds each. Subjects completed a visual analog scale after the application of each intensity to assess the pain response to ultrasound. Results from the visual analog scale were compared to magnetic resonance imaging (MRI) findings to determine if continuous ultrasound could predict whether subjects had a normal MRI, increased bone remodeling, or advanced bone remodeling consistent with a stress fracture. Results: Discriminant analysis on the visual analog scale correctly classified subjects into 1 of 3 clinical classification groups in 42.31 % of the cases. None of the subjects found to have a stress fracture by MRI were correctly identified by continuous ultrasound. This resulted in a predicted sensitivity of 0% and a predicted specificity of 100%. Conclusions: A protocol using visual analog scores after the application of 1 MHz continuous ultrasound is not sensitive for identifying subjects with tibial stress fractures. 1

Diagnosis of Medial Knee Pain: Atypical Stress Fracture About the Knee Joint

“…Only studies utilizing the ultrasound and tuning fork tests have reported sensitivity and specificity values ( Table 2). Authors that used ultrasound 5,10,28,34,38,43 used a variety of frequencies and intensities, and many of the studies did not document specific parameters utilized in their assessment of tibial stress fractures. Utility of the fulcrum test has only been reported in association with femoral shaft stress fractures.…”

The Ability of Clinical Tests to Diagnose Stress Fractures: A Systematic Review and Meta-analysis

“…36,51 Scintigraphy is able to diagnose stress fractures by identifying areas of increased uptake of the radioisotope 3 and has a reported sensitivity of 100% and specificity of 76%. 8,41 MRI has been shown to have comparable sensitivity 3,41 and superior specificity to scintigraphy for assessment of bone pathology.…”

Effect of Transducer Velocity on Intramuscular Temperature During a 1-MHz Ultrasound Treatment

“…This void is apparent when tracing references from several textbooks and published articles, which provide no data to support the suggested transducer velocity. [1][2][3][4][5]8,9,10,12,[16][17][18][20][21][22]24,[26][27][28] High beam nonuniformity ratio (BNR) is typically cited as a reason to move the transducer head in this fashion to decrease the risk of causing pain to the patient, while maximizing thermal effects. [6][7][8]23,29 Today, manufacturers are producing transducers that contain crystals with lower BNRs, which may allow for transducers to be moved at slower rates, while still protecting the patient.…”