title: Therapeutic ultrasound enhances medial collateral ligament repair in rats.
abstract: The purpose of this study was to evaluate the effects of therapeutic ultrasound (US) on medial collateral ligament healing. A total of 36 3-month-old male Sprague-Dawley rats with transected medial collateral ligaments were studied. Subjects were given 5-min pulsed US therapy (duty cycle; one application in 4 ms; 1:4) daily with different durations (1 day, 5 days and 10 days) and intensities (0, 0.5 and 2.3 W/cm2). After each treatment, the level of transforming growth factor beta-1 (TGF-beta1) of the ligament was measured. TGF-beta1 was not detected in the 1-day group. In the 5-day and 10-day groups, the levels of TGF-beta1 were significantly up-regulated in the high-dose subgroup (p < 0.05). The 10-day group also registered a significantly higher expression of TGF-beta1 than did the 5-day group (p < 0.05). The present findings suggest that pulsed US therapy may enhance ligament repair by up-regulating the extent of TGF-beta1 in a high-dose application. Long-term treatment with this therapy could obtain further improvement.
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China. rsmcpleung@polyu.edu.hk
authors.forename: Mason C P
authors.initials: MC
authors.lastname: Leung
authors.forename: Gabriel Y F
authors.initials: GY
authors.lastname: Ng
authors.forename: K K
authors.initials: KK
authors.lastname: Yip
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D007718:Knee Injuries / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000276:immunology / Q000293:injuries* / Q000473:pathology; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000032:analysis; D014464:Ultrasonic Therapy / Q000379:methods*; D015854:Up-Regulation; D014945:Wound Healing
chemical_list: D016212:Transforming Growth Factor beta