NO LONG-TERM EFFECTS OF ULTRASOUND THERAPY ON BIOABSORBABLE SCREW-FIXED LATERAL MALLEOLAR FRACTURE

Background and Aims: The present study was initiated to evaluate the long-term effects of low-intensity ultrasound therapy on bioabsorbable screw-fixed lateral malleolar fractures, which has not been studied earlier. Patients and Methods: The study design was prospective, randomized, double-blinded, and placebo-controlled. Sixteen dislocated lateral malleolar fractures were fixed with one bioabsorbable self-reinforced poly-L-lactide screw. The patients used an ultrasound device 20 minutes daily for six weeks without knowing it was active (eight patients) or inactive (eight patients). The follow-up time was 18 months. The radiological bone morphology was assessed by multidetector computed tomography (MDCT) scans, the bone mineral density by dual-energy X-ray absorptiometry scans, and the clinical outcome by Olerud-Molander scoring and clinical examination of the ankle. Results: The MDCT scans revealed that all fractures were fully healed, and no differences were observed in radiological bone morphology at the fracture site. The bone mineral density of the fractured lateral malleolus tended to increase slightly during the 18-month follow-up, the increase being symmetrical in both groups. No differences were observed in the clinical outcome or Olerud-Molander scores. Conclusions: The six-week low-intensity ultrasound therapy had no effect on radiological bone morphology, bone mineral density or clinical outcome in bioabsorbable screw-fixed lateral malleolar fractures 18 months after the injury.