The Effect of Microcurrent Stimulation on Postoperative Pain After Patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction [Abstract]

Sizer P, Sawyer S, Brismee J, Jones K, Bruce J, Slauterbeck J., Texas Tech University Health Sciences Center and University Medical Center, Lubbock, Texas, USA. Presented at the American Physical Therapy Association Annual Conference and Exposition, Indianapolis, Indiana; June, 2000.

PURPOSE: The purpose of this study was to determine the effectiveness of microcurrent electrical therapy in providing pain relief to a selected post-operative patient population.

SUBJECTS: Subjects were 19 females and 22 males (mean age of 21.1) who received arthroscopic bone-patellar tendon-bone anterior cruciate ligament (ACL) reconstruction.

METHODS AND MATERIALS: Subjects were randomly assigned to one of two treatment groups (“Microcurrent” or “Placebo” Groups) in a double blind experimental design. Using a portable microcurrent device (Alpha-Stim 100 by Electromedical Products International, Inc, Mineral Wells, Texas), the Microcurrent Group received 100 microamperes of microcurrent at 0.5 Hz with a 50% duty cycle, which was below the subject’s perception threshold. The Placebo Group followed the same protocol with a placebo stimulator. All subjects were instructed to use the microcurrent unit as needed for pain relief in one-hour sessions, with at least 30 minutes between sessions. The 10 days postoperative microcurrent protocol accompanied a standardized physical therapy rehabilitation program. The subjects made daily entries into a logbook, recording frequency of microcurrent use, pain medication intake, and constant pain levels on a visual analog scale (0 to 10).

ANALYSIS AND RESULTS: The subjects’ pain levels (dependent variable), which decreased over time, were lower for all 10 post-operative days in the Microcurrent Group (n=25) compared to the Placebo Group (n=16). A 2 (“Treatment Group”) x 10 (“Post-Operative Time”) ANOVA (with repeated measures on “Post-Operative Time”) demonstrated a significant between-subjects main effect for the "Treatment Group" factor [F(1,39)=9.29, p=0.004], indicating that a statistically lower degree of post-operative pain was experienced by the subjects receiving microcurrent. In addition, a significant within-subjects main effect for the "Post-Operative Time" factor ([F(9,9)=18.672, p<0.0001]) was obtained.

CONCLUSION: These results indicate that Alpha-Stim microcurrent electrical therapy is beneficial for post-operative pain control after ACL reconstruction.