Evaluation of Ultrasonic Neuroma Size With Residual Limb Pain in Above-Knee Amputees

Background: The formation of neuromas, a fusiform swelling of a nerve or nerve ending, is a
well documented response to limb amputation. Likewise, Residual Limb Pain (RLP), pain felt
from the remaining portion of the amputated limb, is common among amputees. Neuromas are
found in more than 90% of lower extremity amputations, of which 30-50% are pain-generating
for the patient . And while surgical techniques reveal the commonly held belief that neuroma
formation is one of the causal drivers behind RLP, there has been no study to demonstrate
that the two events - namely the magnitude of neuroma formation and the magnitude of pain
experienced by amputees - are correlated. If this correlation, or lack thereof, were
elucidated with the use of ultrasonography, this would provide the preliminary data which
could lead to further studies in neuroma minimization and/or proliferation.

Objective: This study seeks to use ultrasonography (US) to quantify the degree to which
neuroma size and the nature of surrounding tissue correlate with the experience of RLP in
trans-femoral amputees.

Setting and Subjects: This study will enroll 30 trans-femoral amputees, male and female, who
are over the age of 18. The study will take place in the OHSU Orthopaedic Outpatient Clinic,
and OHSU Imaging Department.

Intervention: None. This is an observational clinical study in which we will characterize
the sciatic nerve/neuroma and surrounding tissue using ultrasound.

Measurements: We will use US to measure the cross sectional area of the neuroma at its
widest point and compare this to the cross section of the same neuron at the lesser
trochanter. Furthermore, we will describe the morphology of the neuroma. To quantify the
subject's pain experience we will utilize the Questionnaire for Persons with Transfemoral
Amputation (Q-TFA), Trinity Amputation & Prosthetic Experience Scale (TAPES), Visual Analog
Scale (VAS), and the Short Form 36 (SF-36).

Analysis: The statistical analysis will employ a Pearson correlation coefficient and linear
regression analysis.