Residual limb pain is not a diagnosis: a proposed algorithm to classify postamputation pain.

BACKGROUND Although postamputation pain (PAP) syndromes have been described since the 16th century, taxonomy of these conditions remains ill-defined. The term "Residual Limb Pain" fails to distinguish between distinct diagnostic entities such as neuroma, complex regional pain syndrome, and somatic pathology. Even phantom limb pain (PLP), although easily distinguished from residual limb pain (RLP), has not been consistently delineated from other PAP syndromes. METHODS A systematic review of the literature was conducted to identify the degree of delineation of various post amputation pain states and what diagnostic criteria were utilized if any. Furthermore, papers that involved treatment modalities were reviewed to determine efficacy of treatment. RESULTS Of the 151 papers reviewed, none further categorized RLP into more specific diagnostic criteria. Furthermore, the literature contains numerous case reports, case series, letters to the editors, and grossly underpowered studies demonstrating significant positive results, yet few high-quality randomized controlled trials. CONCLUSIONS Describing and defining the distinct clinical entities, intuitively, is a prerequisite to developing optimal treatments. The reported variation in the incidence of PAP phenomena may well represent inconsistency in assessment tools and diagnostic categories rather than variation in prevalence of these conditions. In this paper, we review the historical evolution of the current understanding of these syndromes and propose an algorithm for uniform classification.