The Recurrence of Painful Neuromas of the Limbs Following TMR

Abstract

Background/Objectives: Neuropathic pain associated with neuromas is a complex clinical problem to treat. Targeted Muscle Reinnervation (TMR) has been demonstrated to treat pain both as a prophylactic procedure in amputated patients and in patients affected by painful neuromas. It is not clear what its role could be in chronic situations: the literature reports amazing results but also unsuccessful pain relief. Methods: A retrospective analysis was conducted on patients treated with TMR for long-lasting painful neuromas in the upper and lower limbs. Following a clinical and instrumental diagnosis, all patients responded positively to a local anesthetic block. During follow-up visits, the NRS and DN4 questionnaires were used to assess improvement in pain. Results: Three patients were included in this study. TMR was performed 45 months after trauma. Two TMRs involved nerves of the upper extremity, in one case, the tibial nerve. The recipient muscles were the second lumbricalis, pronator quadratus, and flexor digitorum longus of the foot. After surgery, pain decreased for 3 months, but patients experienced a relapse that returned to levels close to the pre-operative period. The types of pain, as reported in DN4 questionnaire, changed slightly compared to those in the pre-surgical period. Follow-up ranged between 12 and 19 months. Conclusions: This small series collected the results of TMR in patients affected by long-lasting symptomatic neuromas in the upper and lower extremities. Despite what is published in other series, this procedure reduced pain for up to 6 months. At final follow-up, the type of pain changed slightly as reported in the DN4 questionnaire, and pain scores reduced by just one point as shown by the NRS. Our experience suggests that TMR might have a slight effect on long-lasting painful neuromas and in these cases, only short-term pain relief could be expected. This suggests using TMR as close as possible to the trauma in order to increase the chances of relieving pain.

Keywords: TMR; chronic pain; nerve injury; painful neuroma.

Figure 1

The ulnar digital nerve of the middle finger is sutured to the second lumbricalis motor nerve, flipped distally to allow direct suture beyond the palmar arch.

Figure 2

The proximal stump of the tibial nerve (*) is sutured to the two motor branches of the flexor digitorum longus of the foot (§).