Disclosures: Isaiah Levy, MD: No financial relationships or conflicts of interest

Case Diagnosis: Diagnosis and management of phantom radiculopathy in patients with lower extremity amputations

Case Description: Three patients with lower extremity amputations (two male, one female), aged 56-81, were evaluated for low back pain with radiation into their phantom limb. All had traumatic amputations (one left transfemoral, one right transtibial, one left transmetatarsal). Two patients had previously diagnosed herniated discs with one requiring previous L5-S1 lumbar discectomy and the other receiving lumbar epidural steroid injections at the left L3-L4 and L4-L5 levels. They presented with phantom radiculopathy that began after their initial amputations (22-34 years). On exam, one patient demonstrated exacerbating pain into phantom limb with increased dural tension signs. Examinations were not consistent with neuroma.

Setting: Outpatient amputee clinicAssessment/

Results: MRIs obtained demonstrated L4-L5 central and left paracentral protrusion with displacement of the left L5 nerve for the transfemoral patient, bilateral foraminal narrowing and encroachment of the exiting L4 nerve roots for the transtibial patient, and disc extrusion at L5-S1 with flattening of the exiting L5 nerve for the transmetatarsal patient. Two patients improved with conservative management including gabapentin and socket revision to minimize excess socket movement exacerbating back pain. One patient unresponsive to conservative measures underwent L4-S1 decompression and redo-discectomy at L4-S1 with posterior spinal fusion with significant long-term resolution of symptoms.

Discussion: Low back pain affects over 50% of amputees. Risk factors include residual-limb problems, poor socket fit, and phantom limb pain which contribute to maladaptive gait patterns and altered pain mechanisms which lead to low back pain. While low back pain is common, phantom radiculopathy is relatively rare with only 22 previously documented cases referenced in the literature. It can be mistaken for neuroma or phantom limb pain.

Conclusion: For patients with lower extremity amputations with worsening phantom limb pain in a particular dermatome, radiculopathy should be considered as a part of the differential.

Level of Evidence: Level V

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/phantom-radiculopathy-in-the-lower-extremity-amputee-a-case-series/