OBJECTIVE: To study the effects of low intensity ultrasound irradiation applied on the spinal cord, in the regeneration of the rat's sciatic nerve after a controlled crush injury, evaluating the functional results of the sciatic functional index as measured on video recorded images of the foot sole. METHODS: Eighteen rats were submitted to a controlled crush injury of the right sciatic nerve, and divided into two groups according to the treatment: Group 1 (n=9), simulated irradiation; Group 2 (n=9), effective irradiation. Low-intensity ultrasound irradiation was started on the 7th postoperative day and applied daily for 6 weeks. Images of the animals´ foot soles were video recorded on a transparenttreadmill belt at weekly intervals until the 6th week of irradiation, and the corresponding sciatic functional index (SFI) was measured usingspecific software. RESULTS: The SFI during the first and last week of treatment was -59.12 and -12.55 in Group 1, -53.31 and -1.32 in Group 2, indicating improvements of 79% and 97%, respectively, but differences between the groups were only significant (p<0.05) during the third week of treatment. CONCLUSION: The authors conclude that low intensity therapeutic ultrasound enhances nerve regeneration, with significance during the 3rd week of treatment. Level of Evidence: Level II, prospective comparative study.
Internal Fixators; Osteotomy; Bone Plates; Bone Screws
