We would like to thank Drs. Lindsay, Pyati, Buchheit, and Shaw for their interest in our study1and for raising the important issue of residual limb pain. As they correctly point out, our study had a small sample size and did not differentiate between subtypes of residual limb pain. However, based on data from previous studies by Bach et al .2and Nikolajsen et al .,3our clinical trial was designed to study phantom limb pain (phantom limb pain intensity at 6 months was our primary endpoint), whereas residual limb pain was only one of several secondary outcomes.
At the 6-month follow-up, our study did not show any difference between treatment and control groups with regard to residual limb pain, and in fact only one or two patients in each group (including the control group) had any residual limb pain. Therefore, we believe that even if we had looked at subclassifications of residual limb pain, we would not be able to show any significant differences because of small sample size and the need to use Bonferroni correction, to avoid spurious “significant” findings due to multiple comparisons.
Of course, we agree that residual limb pain after amputation is an important issue that deserves more study. A clinical trial designed to evaluate subtypes of residual limb pain would be very interesting and could provide answers to some important questions. However, such a study probably would need a bigger sample size and perhaps a simpler study design so that multiple comparisons and the need for Bonferroni correction would not be an issue, as was the case in our study.