Common Peroneal Entrapment Neuropathy Secondary to a Popliteal Lipoma: Ultrasound Superior to Magnetic Resonance Imaging for Diagnosis

Surgical Outcomes of Common Peroneal Nerve Entrapment Neuropathy Associated with L5 Radiculopathy

Impingement of the common peroneal nerve, a branch of the L5 nerve root, causes common peroneal nerve entrapment neuropathy (CPNE). Although there are cases of CPNE associated with L5 radiculopathy, surgical intervention's effectiveness remains to be elucidated. This retrospective case-control study aimed to evaluate the efficacy of surgery in patients with CPNE associated with L5 radiculopathy. Twenty-two patients (25 limbs) with surgically treated CPNE between 2015 and 2022 were retrospectively reviewed. The limbs were classified into two groups: group R (limbs of CPNE associated with L5 radiculopathy) and group O (limbs of CPNE without L5 radiculopathy). The durations from onset to surgery, the nerve conduction studies (NCSs), and postoperative improvement rates for motor weakness, pain, and dysesthesia were compared between the groups. Group R included 15 limbs (13 patients), and group O included 10 limbs (9 patients). There were no significant differences in the duration from onset to surgery or abnormal findings of NCS between the two groups. The postoperative improvement rates were 88% and 100% (p = 0.62) for muscle weakness, 87% and 80% (p = 0.53) for pain, and 71% and 56% (p = 0.37) for dysesthesia in group R and group O, respectively, without significant differences between groups. CPNE associated with L5 radiculopathy is common, and the results of the present study showed that the surgical outcomes in such cases were satisfactory and comparable to those in CPNE without L5 radiculopathy.

Fibrolipomatous Hamartoma of the Median Nerve: An Outcome of Surgical Management in Six Consecutive Cases

Background

Lipoma is a nonneurogenic benign tumor. Neurolipoma and fibrolipomatous hamartoma are variants of this universal tumor. All these variants are grouped under lipomatosis of the nerve. Majority of these tumors are asymptomatic, which can be observed. Symptomatic patients require surgery, which is not standardized. As there are insufficient number of cases, no randomized controlled studies have been performed in the treatment of fibrolipomatous hamartoma. The aim of our study was to determine the pattern of presentation of fibrolipomatous hamartoma, surgical management offered, and the outcome in the form of recovery and complications.

Materials and Methods

This retrospective descriptive study includes six patients diagnosed with fibrolipomatous hamartoma over a period of 12 years. Patient details were collected from the medical records. Patients diagnosed of fibrolipomatous hamartoma in the hand were included. Patients with other soft-tissue tumors were excluded from the study. Out of six patients, four required excision of nerve followed by reconstruction using sural nerve graft and two underwent microsurgical dissection of neural element. Patients were instructed to take care of the operated hand during the recovery phase. Institutional physiotherapy protocol was started during the 3^rd postoperative week. Follow-up period was between 1 and 3 years.

Results

All the six patients were free from symptoms postoperatively. Minimal complications were noted in two patients, which were managed conservatively.

Conclusion

Surgical excision of fibrolipomatous hamartoma of median nerve below elbow, with nerve dissection or with nerve reconstruction using sural nerve graft, followed by proper postoperative care and physiotherapy has proven beneficial for the patients in our study.

Fibrolipomatous Hamartoma (FLH) of Median Nerve: A Rare Case Report and Review

INTRODUCTION

Fibrolipomatous hamartoma (FLH) is a benign tumorous condition of adipose tissue. It is a slow growing, rare tumour involving peripheral nerves with uncertain aetiology. The clinical presentation varies as per presenting severity. The gold standard to diagnose this rare entity is MRI and its management is still controversial. In this report, we have described one such rare presentation of FLH involving Median Nerve in an adolescent male who successfully witnessed resolution of symptoms following our surgical intervention for the same.

CASE PRESENTATION

A 17-year-old male presented to our hospital with a history of swelling in his left hand since past 1 year. The detailed clinical evaluation revealed an irregular fusiform swelling extending from the ulnar aspect of wrist proximally to the thenar eminence along with involvement of the base of 2nd, 3rd and 4th fingers of left hand with consistency varying from soft to firm, tinel's sign positive and a terminal restriction of palmar and dorsiflexion movements. Notably, motor weakness and sensory loss were not elicited. The definitive diagnosis was established by MRI of the left hand. With due consent, the patient was undertaken for surgical intervention whereby his carpal tunnel was decompressed and biopsy of the lesion was sent for further histopathological evaluation as per the protocol. The absolute resolution in symptoms was reported by the patient following our intervention.

CONCLUSION

A meticulous clinical and radiological correlation is required to diagnose such rare clinical entity for improvising the functional quality of life. There is no definitive treatment for lipomatosis of nerve. However, a conservative approach is commonly advocated with successful results from decompression as in our patient.

Thread common peroneal nerve release-a cadaveric validation study

OBJECTIVE

To determine if the thread release technique can be applied to common peroneal nerve entrapment at the fibular neck.

METHODS

The thread common peroneal nerve release was performed on 15 fresh frozen cadaveric lower extremity specimens. All procedures were performed under ultrasound guidance and immediately underwent post-procedural gross anatomic inspection for completeness of decompression and presence or absence of iatrogenic neurovascular injury.

RESULTS

All 15 specimens demonstrated complete transection of the deep fascia of the peroneus longus overlying the common peroneal nerve. The transections extended to the bifurcation of the superficial peroneal and deep peroneal nerves. There was no evidence of any iatrogenic damage to the neurovascular bundle or adjacent tendons. The average operating time was less than 30 min.

CONCLUSION

This cadaveric validation study demonstrates the accuracy of the thread common peroneal nerve release. Future pilot studies are warranted to ensure the safety of this procedure in the clinical setting.

Peripheral nerve lipoma: Case report of an intraneural lipoma of the median nerve and literature review

Adipose lesions rarely affect the peripheral nerves. This can occur in two different ways: Direct compression by an extraneural lipoma, or by a lipoma originated from the adipose cells located inside the nerve. Since its first description, many terms have been used in the literature to mention intraneural lipomatous lesions. In this article, the authors report a case of a 62-year-old female who presented with an intraneural median nerve lipoma and review the literature concerning the classification of adipose lesions of the nerve, radiological diagnosis and treatment.

Magnetic resonance neurography of common peroneal (fibular) neuropathy

OBJECTIVE

To examine diagnostic accuracy of semiquantitative and qualitative magnetic resonance neurography criteria in common peroneal nerve (CPN) neuropathy.

MATERIALS AND METHODS

Institutional review board approval was obtained with a waiver of informed consent for this Health Insurance Portability and Accountability Act-compliant retrospective study. A review of 28 knees in 28 subjects (12 males and 16 females; age range, 13-84 years; mean [SD] age, 42 [20] years) who had undergone magnetic resonance neurography of the knee was performed. Thirteen patients who had a final diagnosis of CPN were classified as cases, and 15 patients who lacked a final diagnosis of CPN neuropathy were classified as controls. Morphological characteristics of the CPN, including nerve T2 signal intensity, nerve size, nerve course, fascicles morphology, regional muscle edema, and fatty infiltration, and an overall assessment of the CPN as being normal or abnormal were evaluated by 2 independent radiologists blinded to the clinical history. Overall sensitivity, specificity, and accuracy compared against our reference standards were expressed as percentages. Interobserver agreements were assessed using linear weighted κ statistics.

RESULTS

Common peroneal nerve T2 signal abnormality had the highest sensitivity (77%) in identifying CPN neuropathy. Except for T2 signal abnormality, overall specificity for the nerve morphological parameters and muscle denervation change assessed was fairly high, ranging from 94% to 100%. The consensus accuracy ranged from 68% to 79% for the morphological characteristics assessed. The interobserver reproducibility was very good (k = 0.90 to 0.91) for assessment of regional muscle denervation changes and moderate (k = 0.46 to 0.59) for morphological CPN characteristics.

CONCLUSION

Magnetic resonance neurography is a useful modality in supplementing the diagnosis of CPN. Using predefined classification criteria helps standardize the morphological criteria of CPN neuropathy diagnosis.

Ultrasonography in the diagnosis of peripheral nerve disease

INTRODUCTION

High-resolution ultrasound (US) of the peripheral nerves is now a standard means of assessing neuromuscular disorders in many centers. Currently used in conjunction with electrodiagnostic (EDX) studies, nerve US is especially effective in the diagnosis of entrapment neuropathies.

AREAS COVERED

This article reviews the basic physics of peripheral nerve US, guidelines for its current use and future directions. Advantages of using nerve US alongside EDX studies are outlined along with current limitations of testing. The role of US in the diagnosis of entrapment neuropathy is emphasized, particularly in carpal tunnel syndrome (CTS). US assisted diagnosis of peripheral nerve tumors, hereditary neuropathy and dysimmune neuropathy and traumatic injuries is also described.

EXPERT OPINION

US is a powerful tool in the assessment of peripheral nerve disease. Nerve US is an evolving, young discipline. There is still much to learn, but current evidence supports US imaging of all patients presenting for evaluation of possible mononeuropathy. With improvements in resolution, the introduction of US contrast agents and objective measures of nerve echogenicity, there is promise for further expanding its role in the diagnosis of all peripheral neuropathies.