High-resolution ultrasound in the diagnosis of failed carpal tunnel decompression: a study of 35 cases

We used high-resolution ultrasound to examine 35 median nerves (35 patients) with failed carpal tunnel decompression to identify the cause of failure. The carpal tunnel was examined before revision surgery, and the results were correlated with surgical findings. The cross-sectional area was measured, and nerve morphology was analysed at the sites of compression. We found persistent median nerve compression in 30 out of 35 patients. In 20 patients, the compression was caused by a residual transverse carpal ligament, in four by perineural fibrosis, in five by both of these causes and in one by tenosynovitis. In four patients, evidence of median nerve injury with an epineural/fascicular lesion was detected; and in one, no abnormalities were found. Surgical findings were consistent with the ultrasound findings except in one patient where tenosynovitis was associated with a giant cell tumour, which was missed by ultrasound. High-resolution ultrasound can provide helpful information in preoperative diagnosis of failed carpal tunnel decompression with good correlation between the ultrasound and surgical findings. Level of evidence: IV

Superficial peroneal nerve entrapment in ankle sprain in childhood and adolescence

Traumatic injuries of the ankle are the most common injuries in sports. Up to 40% of patients who have undergone inversion ankle sprain report residual symptoms. The primary purpose of the study is to evaluate the incidence of SPN entrapment as consequence of acute severe inversion ankle sprain in children and adolescents; the secondary is to report the diagnostic pathway and the results after surgical treatment. From 2000 to 2015 were reviewed to summarize patients under the age of 15 years treated for a first episode of severe inversion ankle sprain. Cases with persistent symptoms (more than 3 months) indicative for SPN neuropathy were then identified. Instrumental investigations were recovered and a pre-operative assessment of pain (VAS) was recorded. Patients were evaluated at minimum of 1-year post-operative follow-up. 981 acute ankle sprains have been evaluated. 122 were considered severe according to van Dijk criteria. 5 patients were considered affected by neuropathy of the SPN. All patients underwent surgery consisting in neurolysis and capsular retention and ligament reconstruction. At 25 months of follow-up AOFAS moved from 57.6 to 98.6. The study highlights a previously unreported condition of perineural fibrosis of the superficial peroneal nerve at the level of the ankle following first acute severe inversion ankle sprain in children.

Percutaneous Needle Electrolysis Reverses Neurographic Signs of Nerve Entrapment by Induced Fibrosis in Mice

Nerve entrapments such as carpal tunnel syndrome are the most common mononeuropathies. The lesional mechanism includes a scarring reaction that causes a vascular compromise. The most effective treatment is surgery, which consists of removing the scarred area, thus reverting the vascular impairment. In the present study, a more conservative therapeutic approach has been undertaken to release the nerve by means of galvanic current (GC) applied with a needle: percutaneous needle electrolysis (PNE). For this purpose, a mouse model of sciatic nerve entrapment has been created using albumin coagulated by glutaraldehyde (albumin 35% and glutaraldehyde 2% volume applied, 10 μl). After two weeks, a fibrous reaction was obtained which entrapped the nerve to the extent of causing atrophy of the leg musculature (14.7%, P < 0.05 compared to the control leg). Ultrasound imaging confirmed that the model’s image was compatible with that of nerve entrapment in patients. To quantify the degree of entrapment, nerve conduction recordings were made. The amplitude (peak-to-peak) of the compound muscle action potential (CMAPs) decreased by 32.2% ( P < 0.05 ), and the proximal latency increases by 17.7% ( P < 0.05 , in both cases). In order to release the sciatic nerve, PNE was applied (1.5 mA for 3 seconds and 3 repetitions; 1.5/3/3) by means of a solid needle in the immediacy of perineural fibrosis before and 5 minutes after the application of GC, and the proximal latency shows a decrease of 16% ( P < 0.05 ). The recovery of CMAPs amplitude was about 48.7% ( P < 0.05 ). Three weeks later, the CMAPs amplitude was almost completely recovered (94.64%). Therefore, with the application of GC by means of a solid needle, the sciatic nerve was definitively released from its fibrous entrapment.

Comparison between optical coherence tomography imaging and histological sections of peripheral nerves

OBJECTIVEOptical coherence tomography (OCT) is an imaging technique that uses the light-backscattering properties of different tissue types to generate an image. In an earlier feasibility study the authors showed that it can be applied to visualize human peripheral nerves. As a follow-up, this paper focuses on the interpretation of the images obtained.METHODSTen different short peripheral nerve specimens were retained following surgery. In a first step they were examined by OCT during, or directly after, surgery. In a second step the nerve specimens were subjected to histological examination. Various steps of image processing were applied to the OCT raw data acquired. The improved OCT images were compared with the sections stained by H & E. The authors assigned the structures in the images to the various nerve components including perineurium, fascicles, and intrafascicular microstructures.RESULTSThe results show that OCT is able to resolve the myelinated axons. A weighted averaging filter helps in identifying the borders of structural features and reduces artifacts at the same time. Tissue-remodeling processes due to injury (perineural fibrosis or neuroma) led to more homogeneous light backscattering. Anterograde axonal degeneration due to sharp injury led to a loss of visible axons and to an increase of light-backscattering tissue as well. However, the depth of light penetration is too small to allow generation of a complete picture of the nerve.CONCLUSIONSOCT is the first in vivo imaging technique that is able to resolve a nerve’s structures down to the level of myelinated axons. It can yield information about focal and segmental pathologies.

Ultrasound of the Brachial Plexus

Examination of the brachial plexus with ultrasound is efficient because it allows many parts of the brachial plexus as well as the surrounding soft tissues to be assessed with high spatial resolution. The key to performing good ultrasound of the brachial plexus is being familiar with the anatomy and the common variants. That makes it possible to concentrate solely on the ultrasound appearances free of simultaneously wondering about the anatomy. Ultrasound of the brachial plexus is particularly good for assessing nerve sheath tumor, perineural fibrosis, metastases, some inflammatory neuropathies, neuralgic amyotrophy, and posttraumatic sequalae. It is limited in the assessment of thoracic outlet syndrome and in the acute/subacute trauma setting. This review addresses the anatomy, ultrasound technique, as well as pathology of the brachial plexus from the cervical foramina to the axilla.

Ultrasound-Guided Pulsed Radio Frequency Treatment in Morton's Neuroma

Background Morton's neuroma is a perineural fibrosis of an intermetatarsal plantar nerve. Burning, numbness, paresthesia, and tingling down the interspaces of involved toes may also be experienced. Taking into account all of this information, we designed a prospective open-label study to evaluate the efficacy of pulsed radio frequency on Morton's neuroma. Methods Twenty patients with Morton's neuroma were experiencing symptomatic neuroma pain in the foot not relieved by routine conservative treatment. All of the patients had been evaluated by a specialized orthopedist and were offered pulsed radio frequency as a last option before having surgery. Initially, pain level (numerical rating scale), successful pain control (a ≥50% pain decrease was accepted as successful pain control), comfort when walking (yes or no), and satisfaction level (satisfied or not satisfied) were evaluated. Results We found a decrease in the pain level in 18 of 20 patients, successful pain control in 12, and wearing shoes and walking without pain in 16. Overall, satisfaction was rated as excellent or good by 12 patients with Morton's neuroma in this series. Conclusions This evidence indicates that ultrasound-guided pulsed radio frequency is a promising treatment modality in the management of Morton's neuroma pain.

Study the effect of the omental pedicle flap in sciatic nerve healing

This study was done to observe the effect of omental pedicle flap in neuroraphies , sciatic nerve of 8 dogs which divided into equal two groups .The neuroraphy was performed, after that greater omentum was prepared by median laporotomy which later pass through a tunnel formed in the inguinal region by preserving its vascular supply and adapted then wrapped around the zone of neuroraphy in treated group.asciatic nerves of control group were severed and primary neuroraphy was done without applying omental flap. The histological examination of the biopsy specimens was done in the 60th day for both groups. The amount of regenerated axons and intra neural connective tissue in two groups were examined. In the revasculorized neuroraphies by omental flap, there was a significant increase the number of regenerated nerve fibres and reduced perineural fibrosis when compared with control group

Canaletto implant in revision surgery for carpal tunnel syndrome: 21 case series

Revision carpal tunnel surgery varies from 0.3% to 19%. It involves a delayed neurolysis and prevention of perineural fibrosis. Despite numerous available procedures, the results remain mediocre. The aim of this study is to evaluate the results of the Canaletto implant in this indication. Our series includes 20 patients (1 bilateral affection) reoperated for carpal tunnel between October 2008 and December 2009. After the first operation, the symptom-free period was 112 weeks, on average. The average incision was 27 mm. After neurolysis, the Canaletto implant was placed in contact with the nerve. Immediate postoperative mobilization was commenced. Sensory (pain, DN4, and hypoesthesia), motor (Jamar, muscle wasting), and functional (disabilities of the arm, should, and hand; DASH) criteria were evaluated. Nerve conduction velocity (NCV) of the median nerve was measured. Average follow up was 12.1 months. All measurements were improved after insertion of the Canaletto implant: pain (6.45–3.68), DN4 (4.29–3.48), Quick DASH (55.30–34.96), Jamar (66.11–84.76), NCV (29.79–39.06 m/s), hypoesthesia (76.2–23.8%), wasting (42.9–23.8%). Nevertheless, four patients did not improve, and pain was the same or worse in six cases. Our results show that in recurrent carpal tunnel syndrome, Canaletto implant insertion gives results at least as good as other techniques, with the added advantage of a smaller access incision, a rapid, less invasive technique, and the eliminated morbidity of raising a flap to cover the median nerve.