MRI features of symptomatic amputation neuromas

Evaluation of MRI features of neuromas in oncological amputees, and the relation to pain

OBJECTIVE

The impact of time on neuroma growth and morphology on pain intensity is unknown. This study aims to assess magnetic resonance imaging (MRI) differences between symptomatic and non-symptomatic neuromas in oncological amputees, and whether time influences MRI-detected neuroma dimensions and their association with pain.

MATERIAL AND METHODS

Oncological patients who underwent traditional extremity amputation were included. Post-amputation MRIs were assessed before decision for neuroma surgery. Chart review was performed for residual limb pain (numeric rating scale, 0-10) and the presence of neuropathic symptoms. Neuromas were classified as symptomatic or non-symptomatic, with neuroma size expressed as radiological neuroma-to-nerve-ratio (NNR).

RESULTS

Among 78 neuromas in 60 patients, the median NNR was 2.0, and 56 neuromas (71.8%) were symptomatic with a median pain score of 3.5. NNR showed no association with symptomatology or pain intensity but correlated with a longer time-to-neuroma-excision interval and a smaller nerve caliber. Symptomatic neuromas were associated with lower extremity amputation, T2 heterogeneity, and the presence of heterotopic ossification. Lower extremity amputation, T2 heterogeneity, perineural edema, and presence of heterotopic ossification were associated with more painful neuromas.

CONCLUSION

MRI features associated with symptomatic neuromas and pain intensity were identified. Awareness of the potential clinical significance of these imaging features may help in the interpretation of MRI exams and may aid clinicians in patient selection for neuroma surgery in oncological amputees.

Neuroma-to-Nerve Ratio: Does Size Matter?

BACKGROUND AND OBJECTIVES

Anatomic features of neuromas have been explored in imaging studies. However, there has been limited research into these features using resected, ex vivo human neuroma specimens. The aim of this study was to investigate the influence that time may have on neuroma growth and size, and the clinical significance of these parameters.

METHODS

Patients who underwent neuroma excision between 2022 through 2023 were prospectively included in this study. Neuroma specimens were obtained after operative resection. Standardized neuroma size measurements, expressed as a neuroma-to-nerve ratio (NNR), were conducted with ImageJ software. Pain data (numeric rating scale, 0-10) were prospectively recorded during preoperative evaluation, and patient factors were collected from chart reviews.

RESULTS

Fifty terminal neuroma specimens from 31 patients were included, with 94.0% of the neuromas obtained from individuals with amputations. Most neuromas were excised from the lower extremities (n = 44, 88.0%). The neuromas had a median NNR of 2.45, and the median injury to neuroma excision interval was 6.3 years. Larger NNRs were associated with a longer injury to neuroma excision interval and with a smaller native nerve diameter. In addition, sensory nerves were associated with a larger NNR compared with mixed nerves. NNR was not associated with preoperative pain or with anatomical nerve distribution.

CONCLUSION

This study suggests that neuromas seem to continue to grow over time and that smaller nerves may form relatively larger neuromas. In addition, sensory nerves develop relatively larger neuromas compared with mixed nerves. Neuroma size does not appear to correlate with pain severity. These findings may stimulate future research efforts and contribute to a better understanding of symptomatic neuroma development.

Postoperative Imaging of Bone and Soft Tissue Tumors in the Extremity: A Comprehensive Review

Postoperative imaging of musculoskeletal tumors poses a significant diagnostic challenge for radiologists. The complexity arises from the need to differentiate between expected postoperative changes, potential complications, and local recurrence. The choice of imaging modality depends on the type of primary tumor. Standard radiological modalities such as radiography, computed tomography (CT), and magnetic resonance imaging (MRI) are widely utilized. Radiography and CT are especially valuable for assessing primary bone tumors, as they provide detailed views of bone structures and alignment, as well as revealing postoperative complications. MRIs are particularly effective for evaluating soft tissue tumors and identifying local recurrences due to its superior soft tissue contrast. The advanced imaging techniques, such as diffusion-weighted imaging and dynamic contrast-enhanced MRI, have significantly improved diagnostic accuracy in detecting tumor recurrence. An in-depth understanding of surgery-specific imaging findings, as well as the ability to detect recurrent disease, is crucial for early diagnosis of complications and improved patient outcomes. Familiarity with normal postoperative changes helps radiologists distinguish them from abnormal findings indicative of complications or tumor recurrence. This review article aims to outline the surgical options for musculoskeletal tumors, detail the various imaging techniques used in postoperative surveillance, and discuss the potential complications. By understanding the role of different imaging modalities and their applications associated with various surgical procedures, clinicians and radiologists can provide accurate and timely diagnoses.

Magnetic Resonance Imaging appearance of regenerative peripheral nerve interface

PURPOSE

To describe the MRI appearance of regenerative peripheral nerve interface (RPNI) and the potential association between the MRI appearance and RPNI revision.

MATERIAL AND METHODS

A retrospective assessment was undertaken of the MRI appearance of RPNIs performed at our institution between 1/1/2010 and 7/29/2023 with clinical correlation.

RESULTS

Fourteen patients (8 men and 6 women, age range 31-80 years, median age 51 years) with technically adequate MRI of RPNIs were included in this study including 5 patients with below knee amputation with 5 tibial and 4 common peroneal nerves RPNI, 8 patients with above knee amputations (AKA) with sciatic RPNIs, and 1 patient following forequarter amputation with a brachial plexus RPNI. Two patients underwent revision RPNI surgery thrice (AKA-sciatic nerve) for a total of 6 RPNI revisions. On T1 weighted sequences, all RPNIs were isointense to the muscle and blended with the surrounding scar and muscle tissues whereas on T2 weighted sequences, all RPNIs were hyperintense in signal compared to the muscle. All but 1 RPNI underwent post contrast enhancement in variable patterns. No statistically significant difference in MRI appearance was found between RPNIs with or without a following RPNI revision surgery.

CONCLUSION

RPNI on MRI typically have a bright and intermediate signal on T2 and T1 weighted sequences, respectively, and typically undergo postcontrast enhancement in variable patterns without a statistically significant difference between the cases with and without follow-up RPNI revision. However, enhancement of RPNI should not be misconstrued as pathological.

The Peripheral Nerve Surgeon's Role in the Management of Neuropathic Pain

Neuropathic pain (NP) underlies significant morbidity and disability worldwide. Although pharmacologic and functional therapies attempt to address this issue, they remain incompletely effective for many patients. Peripheral nerve surgeons have a range of techniques for intervening on NP. The aim of this review is to enable practitioners to identify patients with NP who might benefit from surgical intervention. The workup for NP includes patient history and specific physical examination maneuvers, as well as imaging and diagnostic nerve blocks. Once diagnosed, there is a range of options surgeons can utilize based on specific causes of NP. These techniques include nerve decompression, nerve reconstruction, nerve ablative techniques, and implantable nerve-modulating devices. In addition, there is an emerging role for preoperative involvement of peripheral nerve surgeons for cases known to carry a high risk of inducing postoperative NP. Lastly, we describe the ongoing work that will enable surgeons to expand their armamentarium to better serve patients with NP.

Presurgical Perspective and Postsurgical Evaluation of the Diabetic Foot

Management of the diabetic foot is complex and challenging, requiring a multidisciplinary approach. Imaging plays an important role in the decision-making process regarding surgery. This article discusses the presurgical perspective and postsurgical evaluation of the diabetic foot.