Effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative pain intensity and mobility after hip fracture: A double-blinded, randomized trial

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is a noninvasive modality which may be used to reduce acute postoperative pain. Intense perioperative pain within the first few days after hip fracture surgery is common and is related to negative consequences such as restricted and delayed ambulation. OBJECTIVE: The objective of the present study was to examine the effect of incorporating TENS treatment on pain intensity, and mobility, with standard rehabilitation care during the acute post-operative phase following Gamma-nail surgical fixation of extracapsular hip fractures. MATERIALS AND METHODS: Forty-one patients were randomly assigned to a supplement of 30 mins of active TENS or sham TENS. The standard rehabilitation care included five daily 30 mins physical therapy treatments beginning 24 hrs after surgery. Outcome measures were: pain intensity at rest, at night and during ambulation (assessed with the Numeric Rating Scale; Functional Ambulation Classification instrument; time to complete five sit-to-stand tests; and two-minute walk test). Data were analyzed with Wilcoxon score rank tests. Significance was set at p≤0.05. RESULTS: Significantly greater pain reduction during walking was noted in the active TENS group compared to sham TENS group (differences between the fifth and the second days: 2.55±1.37 vs 1.06± 1.11, respectively; p=0.0011). Additionally, advantage of active TENS was demonstrated in greater increase in walking distance on the fifth day and higher level of mobility compared to the sham TENS group. No additional effects of active TENS were noted on pain intensity at rest and at night and on five times sit-to-stand performance. CONCLUSION: Addition of TENS to the standard care of elderly patients in the early days following Gamma nail surgical fixation of extracapsular hip fracture is recommended for pain management while walking and functional gait recovery. The effect of TENS on long-term functional outcomes should be explored in future studies. TRIAL REGISTRATION: The trial was registered at the ISRCTN registry: ID ISRCTN32476360.