Therapeutic Ultrasound in Navicular Stress Injuries in Elite Track and Field Athletes.

OBJECTIVE

To ascertain whether therapeutic ultrasound (TUS) can be used to assess the progression of conservative management in navicular stress injuries.

DESIGN

This is a prospective, clinical case series. Level of evidence IV.

SETTING

All participants were examined and followed up in a private Sports Injury Clinic.

PARTICIPANTS

Ten elite track and field athletes with severe dorsal midfoot pain over the navicular bone participated in this study.

INTERVENTIONS

All patients underwent both TUS and magnetic resonance imaging (MRI) evaluation. The painful threshold of TUS on initial evaluation was a mean of 0.707 ± 149 W/cm, and MRI detected a navicular stress injury in all patients. The athletes received conservative treatment and underwent sequential TUS evaluations at 4, 8, 12 and 16 weeks.

MAIN OUTCOME MEASURES

Therapeutic ultrasound pain threshold values were recorded, and the patients were additionally asked to grade local tenderness on a Visual Analogue Scale. Time to return to play was also recorded.

RESULTS

The level of pain produced by the application of TUS on a navicular stress fracture seemed to correlate well with Visual Analogue Scale scores and the grade of fracture demonstrated on MRI. The initial low TUS painful mean value increased to a normal mean value of 1.97 ± 0.067 W/cm by 16 weeks. When clinical and TUS findings had returned to normal, the patients were allowed to return to sports activities, with no recurrences experienced during the study period.

CONCLUSIONS

The production of pain associated with the application of TUS on a navicular stress fracture is a safe and reproducible method of monitoring the resolution of these fractures. We have used it successfully in making return-to-play decisions for elite level track and field athletes.