Comparison of pulsed and continuous ultrasound on tendon repair in rats

Abstract

In tendon injuries treatment, the use of ultrasound appears as a therapeutic option, despite the lack of their clinical effects. The aim was to evaluate two therapeutic ultrasound protocols, continuous or pulsed, on the pain and swelling after tendinous trauma. Twenty-one Wistar rats were subjected to traumatic injury in the tendon and divided in three groups: sham (GS), continuous ultrasound (GUC), and pulsed ultrasound (GUP). The injury occurred on right Achilles tendon lateral aspect, with energy of 0.40 J. The pain was assessed by the functional disability test and edema by latero-lateral diameter. The evaluations were performed before the injury; after 1 hour of the lesion induction; after the 1st treatment; 2, 8 and 24 hours after injury; and after the 5th day. The treatment was made for 5 consecutive days, with transductor of 1 MHz, for 3 minutes on the trauma site, with a dose of 0.4 W/cm² SATA. The results of functional disability for GS showed increased nociception. For GUC, there was increased when comparing evaluation 1 (EV1) with evaluations 2 (EV2), 3 (EV3) and 4 (EV4); comparing EV2 to evaluations 5 (AV5) and 6 (AV6), there was decreased values. To GUP there was increased when comparing EV1 with EV2 and EV3, but when comparing EV2 with the following, there was a significant decrease starting from EV4. Edema, treatment groups produced an initial increase with a reduction in recent evaluations. The therapeutic ultrasound produced pain and edema reduction in rats with tendon trauma, and early in the pulsed.