Phantom Limb Pain Assessment Tools: A Literature Review Exploring Strengths and Limitations

Abstract

Objective

To identify and categorize the pain instruments used to evaluate phantom limb pain (PLP), phantom limb sensations (PLSs), and residual limb pain (RLP) stratified by frequency of use, instrument completion time, and inclusion of descriptive terms to distinguish between the 3 phenomena.

Data Sources

MEDLINE/PubMed and Google Scholar from 1986 to 2024.

Study Selection

Cross-sectional, cohort, and case-control studies investigating the prevalence of PLP in adults (18y or older) with surgical and traumatic upper or lower limb amputation.

Data Extraction

Studies were identified and their methods were evaluated for mention of instruments used to assess for PLP. Tools were then evaluated for frequency of usage, completion time, differentiation of pain and sensations after limb amputation, and qualitative assessment using descriptor words associated with PLP and PLSs.

Data Synthesis

The review included 44 studies and identified 25 tools (5 unidimensional and 20 multidimensional). Unidimensional pain scales, particularly the Numeric Rating Scale, were the most frequently used. Of the multidimensional instruments identified, 9 of them were specific to PLP, and 6 distinguished between PLP, PLS, and RLP. Only one multidimensional instrument that was specific to PLP used descriptor words to differentiate between PLP and PLS. No tool was assessed for all 3 conditions and used descriptor words to distinguish between PLP and PLSs.

Conclusions

Based on this systematic review, no PLP-specific instrument is suitable for standardizing the diagnosis of PLP in its current form. Further research is needed to establish a standardized tool that can reliably distinguish between PLP, PLS, and RLP while incorporating qualitative assessments to ensure accurate diagnosis.