Transcutaneous electrical nerve stimulation (TENS) is characterized by the application of an electric pulsed current through electrodes positioned on the skin. It can be an alternative for pain management after surgery for total hip arthroplasty (THA), since it is a safe and cost-effective therapeutic tool, allowing the patient to move early due to pain relief. Therefore, the study aims to evaluate the acute effects of TENS associated with standard physical therapy compared with standard physical therapy on the intensity of pain, hip range of motion and morphine consumption in the rehabilitation of patients after THA.

The study included patients who underwent THA surgery in the Hospital de Clínicas de Porto Alegre (HCPA) and met the study eligibility criteria. The sample was randomly divided into experimental group, which received conventional physical therapy associated with the application of TENS, and control group, which held only conventional physical therapy, both on the first day after the surgery. The pain level, the range of motion of the operated hip and the administration of morphine. The experimental group received TENS application held by four self-adhesive electrodes size 5x9cm positioned about five centimeters from the edges of the surgical scar. TENS was applied in conventional mode, emitting a pulsed biphasic, symmetrical rectangular wave with frequency of 100 Hz and pulse duration of 100 µs, for 30 minutes. The intensity was set according to the tolerance of the patient and was gradually increased during the application. The device used was the Neurodyn II model, by Ibramed. Subsequently, the conventional physical therapy was performed. The patients realized active exercises of plantar flexion and dorsal flexion of the ankles, flexion and extension of the knees and adduction and abduction of the hips, in both lower limbs. All exercises were performed with the patient in the supine position in the bed, in one serie of 10 repetitions. Control group received only conventional therapy consisting of the exercises in both lower limbs, identical to those performed in the experimental group.

Inclusion Criteria:

• patients who underwent THA surgery due to primary or secondary coxarthrosis; both sexes; age between 40 and 90 years.

Exclusion Criteria:

• patients who refused to participate of the study; THA indication for fractures and bone tumors; THA review surgery; postoperative infection; congenital anatomical alterations; neurological disorders; lack of understanding of commands; sensitivity alterations in the lower limbs; decompensated heart disease or cardiac pacemaker use.

24 hours.

The exclusion criteria of the experiment included contraindications for the use of TENS: neurological disorders; lack of understanding of commands; sensitivity alterations in the lower limbs; decompensated heart disease or cardiac pacemaker use. None of the included subjects presented those conditions, therefore the risk of adverse events was zero, since they were exposed to no risk therapies and were followed by a therapist during the data collection.

The subjects had difficulty to understand visual analogic pain scale, the sample was small, and there was not a TENS placebo group, which could allow other comparisons on the effectiveness of TENS in this population.