Preliminary results of tibial bone transports with pulsed low intensity ultrasound (Exogen™)

Objective: This study assessed whether the use of noninvasive, pulsed low intensity ultrasound (Exogen(TM)) reduced external fixation time for bone transport patients with large, segmental tibial defects. Design: This was a prospective study compared to a previously treated control group. Setting: All surgeries and postoperative care were done at the senior author's hospital facilities. Patients/Participants: Eight patients with large tibial segmental defects, acute or chronic, were studied. All patients were male, mean age 34 years (range 18-50). Intervention: All patients were treated with a single-level bone transport. Bone transports started 5 to 10 days after a metaphyseal corticotomy and progressed with one-quarter millimeter advancement 2 to 4 times per day. Exogen was applied to the regenerate site in the second postoperative week and to the docking site after docking was complete. The treatment was used for 20 minutes daily at each site. The patients were followed weekly for the first 4 weeks. They were then followed bimonthly for 2 months and then monthly until consolidation had occurred. Main Outcome Measures: The 2 main outcome measures used were the external fixation time measured in months and the external fixation index (time in the frame per cm of bone transported) measured in months per cm. Results: The mean follow-up from frame removal to the time of the last clinic visit was 12.4 months (range 4-32). The mean external fixation time was 13.91. The mean external fixation index was 1.34 months per cm transported for the Exogen group and 2.02 months per cm for the control group. Although not statistically significant because of small numbers, the external fixation index was reduced by 17.21%. Conclusion: These data further confirm already published data on the acceleration of fracture healing by low intensity Pulsed ultrasound and, in our case, regenerate consolidation. Shorter treatment periods reduce complications and expenses and return patients back to regular activities more quickly.