A patient develops a neuroma at the end of the tibial nerve stump after below-knee amputation, causing severe end-stump pain on prosthetic loading. The pain mechanism of a traumatic neuroma and the currently preferred surgical treatment to prevent recurrence are:

• A Neuroma pain is from demyelination — treated by chemical neurolysis with phenol
• B Disorganised axonal sprouting forms a painful nodule under load; targeted muscle reinnervation (TMR) — redirecting the nerve end into a motor nerve branch — prevents neuroma formation and reduces phantom and residual limb pain ✓
• C Simple excision of the neuroma at its proximal extent is curative in 95%
• D Neuroma pain is a phantom phenomenon and cannot be surgically addressed

Explanation

Traumatic neuromas form when transected axons attempt to regenerate but lack a distal target, creating a disorganised tangle of axons, Schwann cells, and fibroblasts (neuroma). Physical loading compresses this hyperalgisic nodule. Targeted Muscle Reinnervation (TMR) — surgically copting the cut nerve (e.g., tibial nerve) into a nearby small motor nerve branch so axons grow into muscle rather than forming a neuroma — is now the preferred technique both for primary prevention at amputation and for treatment of established symptomatic neuromas. TMR also reduces phantom limb pain and improves prosthetic myoelectric signal quality. Simple excision has a high recurrence rate (~30–50%) as proximal re-cutting leaves another distal stump without a target.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.