Lower back and extremity pain in the amputee patient can be challenging to
classify and treat. Radicular compression in a patient with lower limb amputation
may present as or be superimposed upon phantom limb pain, creating diagnostic
difficulties. Both patients and physicians classically find it difficult to discern phantom
sensation from phantom limb pain and stump pain; radicular compression is often
not considered. Many studies have shown back pain to be a significant cause of
pain in lower limb amputees, but sciatica has been rarely reported in amputees.
We present a case of L4/5 radiculitis in an above-knee amputee presenting as
phantom radiculitis. Our patient is a 67 year old gentleman with new onset 10/10
pain in a phantom extremity superimposed upon a 40 year history of previously
stable phantom limb pain. MRI showed a central disc herniation at L4/5 with
compression of the traversing left L4 nerve root. Two fluoroscopically guided left
transforaminal epidural steroid injections at the level of the L4 and L5 spinal nerve
roots totally alleviated his new onset pain. At one year post injection, his phantom
radiculitis pain was completely gone, though his underlying phantom limb pain
remained. Lumbar radiculitis in lower extremity amputee patients may be difficult
to differentiate from baseline phantom limb pain. When conservative techniques
fail, fluoroscopically guided spinal nerve injection may be valuable in determining
the etiology of lower extremity pain. Our experience supports the notion that
epidural steroid injections can effectively treat phantom lumbar radiculitis in lower
extremity amputees.
Key words: amputee, phantom pain, phantom sensation, phantom radiculitis,
disc herniation, interlaminar, transforaminal, epidural steroid injection