Abstract
OBJECTIVE: To determine the strength of the association between residual limb neuropathic pain intensity and the number of neuromas, prosthetic, functional, and participation outcomes, and assess whether ultrasound (US) biomarkers of neuromas differ between pain intensities. DESIGN: Cross-sectional study. SUBJECTS: Twenty-two participants with a transtibial amputation for more than 12 months, with and without residual limb neuropathic pain. METHODS: Participants completed questionnaires (Numerical Pain Rating Scale, Pain Disability Index (PDI), Prosthetic Profile of the Amputee-Locomotor Capabilities Index), and had their residual limbs examined by US. Whenever a neuroma was diagnosed during US, images of the neuroma(s) were recorded and US biomarkers were computed. RESULTS: Of the 27 neuromas diagnosed, pain intensity was associated with no use of walking aid, less daily prosthesis wearing time, a higher PDI score, and a neuroma at the common fibular nerve. The cross-sectional area, the thickness ratio, or the thickness of the overlying tissues was not associated with pain intensity. CONCLUSION: Though the results enrich currently available evidence on clinical variables potentially associated with the intensity of neuropathic pain in individuals living with a transtibial amputation, and on the limited value of US biomarkers studied to determine the association between neuroma(s) and pain intensity, future studies providing higher quality evidence remain needed.