A Randomized Controlled Study to Evaluate the Efficacy of Noninvasive Limb Cover for Chronic Phantom Limb Pain Among Veteran Amputees

Hsiao A-F, York R, Hsiao I, Hansen E, Hays RD, Ives J, Coulter ID. A randomized controlled study to evaluate the efficacy of noninvasive limb cover for chronic phantom limb pain among veteran amputees. Arch Phys Med Rehabil 2012;93:617-22. Objective: To assess the efficacy of a noninvasive limb cover for treating chronic phantom limb pain (PLP). Design: Randomized, double-blind, placebo-controlled trial. Setting: Outpatient clinic. Participants: We randomly assigned 57 subjects to 2 groups: true noninvasive limb cover (n=30) and sham noninvasive limb cover (n=27). Inclusion criteria included age of 18 years or greater, upper or lower extremity amputation with healed residual limb, and 3 or more episodes of PLP during the previous 6 weeks. Interventions: Subjects received 2 true or sham noninvasive limb covers to be worn over the prosthesis and residual limbs 24 hours a day for 12 weeks. Main Outcome Measures: Primary outcome measure was the numerical pain rating scale of PLP level (0-10). Secondary outcomes included overall pain level (0-10), PLP frequency per week, and the Veterans RAND 12-Item Health Survey (VR-12). We collected data at baseline and at 6- and 12-week follow-up visits. Results: Demographic and clinical characteristics were not significantly different between groups. The true noninvasive limb cover group reported nonsignificant reductions in PLP from 5.9 +/- 1.9 at baseline to 3.9 +/- 1.7 at the 12-week follow-up. The sham noninvasive limb cover group also had nonsignificant reducations in PLP from 6.5 +/- 1.8 to 4.2 +/- 2.3. PLP did not differ significantly between the 2 groups at 6 weeks (mean difference, 0.8; 95% confidence interval [CI], -1.4 to 3) or at 12 weeks (mean difference, 0.2; 95% CI, -1.9 to 2.3). Similarly, overall pain level, PLP episodes per week, and VR-12 physical and mental health component scores did not differ between the 2 groups at 6 and 12 weeks. Conclusions: A true noninvasive limb cover did not significantly decrease PLP levels or the frequency of PLP episodes per week, overall bodily pain levels, or VR-12 physical and mental health component scores compared with a sham noninvasive limb cover in our veteran amputee sample.