Improvement in "Jumping Stump" Syndrome Following Diagnostic Sciatic Nerve Block and Home Exercise Program in a Transtibial Amputee

Abstract

"Jumping Stump" syndrome is a rare postoperative complication seen in the residual limb of amputees, with only a few cases documented in the literature. It has been defined as a peripherally induced movement disorder leading to either dystonia, myoclonus, tremors, or choreiform movements in the amputated residual limb. It is often associated with significant discomfort and an inability to ambulate with a prosthetic limb. Treatment options remain inconclusive at this time. We present a case of "Jumping Stump" syndrome in a young female transtibial amputee following revision transtibial amputation (TTA) with myodesis and targeted muscle reinnervation. About six weeks after revision surgery, the patient started experiencing significant myoclonus of the right residual limb when extending the knee. She was trialed on various oral pharmacologic agents over six months and had multiple prosthetic adjustments without any symptomatic relief. Moreover, the patient was also prescribed a daily knee range of motion (ROM) and stretching program. Six months after symptom onset, she underwent a diagnostic right sciatic nerve block and right biceps femoris point block with immediate and significant improvement in symptoms. She had a greater ROM in the affected limb without myoclonus and was able to ambulate once again with her prosthetic limb. Our patient’s response to a diagnostic nerve and motor point block, as well as her marked improvement of symptoms with a consistent home exercise (stretching) program, suggests that desensitization of a muscle-tendon stretch response likely accounted for the improvement of symptoms. It is hypothesized that chemodenervation via botulinum toxin, in addition to the consistent home stretching program, would have accelerated the improvement of symptoms and should be further explored as a potential treatment modality for "Jumping Stump" syndrome.