Assessing ulnar neuropathy at the elbow using magnetoneurography

OBJECTIVE

To measure neuromagnetic fields of ulnar neuropathy patients at the elbow after electrical stimulation and evaluate ulnar nerve function at the elbow with high spatial resolution.

METHODS

A superconducting quantum interference device magnetometer system recorded neuromagnetic fields of the ulnar nerve at the elbow after electrical stimulation at the wrist in 16 limbs of 16 healthy volunteers and 21 limbs of 20 patients with ulnar neuropathy at the elbow. After artifact removal, neuromagnetic field signals were processed into current distributions, which were superimposed onto X-ray images for visualization.

RESULTS

Based on the results in healthy volunteers, conduction velocity of 30 m/s or 50% attenuation in current amplitude was set as the reference value for conduction disturbance. Of the 21 patient limbs, 15 were measurable and lesion sites were detected, whereas 6 limbs were unmeasurable due to weak neuromagnetic field signals. Seven limbs were deemed normal by nerve conduction study, but 5 showed conduction disturbances on magnetoneurography.

CONCLUSIONS

Measuring the magnetic field after nerve stimulation enabled visualization of neurophysiological activity in patients with ulnar neuropathy at the elbow and evaluation of conduction disturbances.

SIGNIFICANCE

Magnetoneurography may be useful for assessing lesion sites in patients with ulnar neuropathy at the elbow.

Nerve Transfer After Cervical Spinal Cord Injury: Who Has a "Time Sensitive" Injury Based on Electrodiagnostic Findings?

OBJECTIVE

To use the ulnar compound muscle action potential (CMAP) to abductor digiti minimi (ADM) to identify the proportion of individuals with cervical spinal cord injury (SCI) who have lower motor neuron (LMN) abnormalities involving the C8-T1 spinal nerve roots, within 3-6 months, and thus may influence the response to nerve transfer surgery.

DESIGN

Retrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database.

SETTING

Multi-center, academic hospitals.

PARTICIPANTS

We included 79 subjects (age=41.4±17.7, range:16-75; 59 men; N=79), who were classified as cervical level injuries 2 weeks after injury and who had manual muscle strength examinations that would warrant consideration for nerve transfer (C5≥4, C8<3).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The ulnar nerve CMAP amplitude to ADM was used as a proxy measure for C8-T1 spinal segment health. CMAP amplitude was stratified into very abnormal (<1.0 mV), sub-normal (1.0-5.9 mV), and normal (>6.0 mV). Analysis took place at 3 (n=148 limbs) and 6 months (n=145 limbs).

RESULTS

At 3- and 6-month post-injury, 33.1% and 28.3% of limbs had very abnormal CMAP amplitudes, respectively, while in 54.1% and 51.7%, CMAPs were sub-normal. Median change in amplitude from 3 to 6 months was 0.0 mV for very abnormal and 1.0 mV for subnormal groups. A 3-month ulnar CMAP <1 mV had a positive predictive value of 0.73 (95% CI 0.69-0.76) and 0.78 (95% CI 0.75-0.80) for C8 and T1 muscle strength of 0 vs 1 or 2.

CONCLUSION

A high proportion of individuals have ulnar CMAPs below the lower limit of normal 3- and 6-month post cervical SCI and may also have intercurrent LMN injury. Failure to identify individuals with LMN denervation could result in a lost opportunity to improve hand function through timely nerve transfer surgeries.

Volumetric assessment of ulnar nerves in cubital tunnel syndrome with 3D modeling of the MRI and its relationship with electrodiagnostic findings

BACKGROUND

Thickened nerve cross-sectional areas (CSA) have been investigated in compressive neuropathy, but the longitudinal extent of nerve swelling has yet to be evaluated. We did a volumetric assessment of the ulnar nerve in cubital tunnel syndrome (CuTS) with three-dimensional (3D) magnetic resonance imaging (MRI) modeling and investigated this relationship with clinical and electrodiagnostic parameters.

METHODS

We compared 40 CuTS patient elbow MRIs to 46 patient elbow MRIs with lateral elbow epicondylitis as controls. The ulnar nerve was modeled with Mimics software and was assessed qualitatively and quantitatively. The CSA and ulnar nerve volumes were recorded, and the area under the receiver operating characteristic (ROC) curve was calculated for diagnostic performance. We analyzed clinical and electrodiagnostic parameters to investigate their relationship with the 3D ulnar nerve parameters.

RESULTS

For the diagnosis of CuTS, the area under the curve value was 0.915 for the largest CSA and 0.910 for the volume in the ROC curve. The optimal cut-off was 14.53 mm2 and 529 mm3 respectively. When electrodiagnostic parameters were investigated, the 3D ulnar nerve volume was significantly inversely associated with motor conduction velocity, although there was no association between the largest CSA and any of the electrodiagnostic parameters.

CONCLUSIONS

The 3D ulnar nerve volume, which is an integration or multilevel measurement of CSAs, showed diagnostic usefulness similar to CSA, but it correlated better with conduction velocity, indicating demyelination or early-to-moderate nerve damage in CuTS.

High-frequency ultrasound imaging findings in the diagnosis of segmental schwannomatosis of the ulnar nerve: case report and literature review

Schwannomatosis is characterized by the development of multiple schwannomas without evidence of vestibular tumors. Segmental schwannomatosis is defined as being limited to one limb or five or fewer contiguous segments of the spine. We report a case of a 20-year-old male with the painful masses of the left upper extremity with associated numbness and paresthesia in the ulnar nerve distribution. The high-frequency ultrasound showed that the ulnar nerve fascicles were enlarged and expanded with beadlike growth. The patient underwent surgery twice and all the tumors were pathologically confirmed to be schwannomas. Together, the medical history, imaging, and pathology findings indicated the diagnosis of segmental schwannomatosis. By the imaging diagnostic tools, MRI is the most commonly used in assistance with diagnosis of segmental schwannomatosis while high-frequency ultrasonography is rare. In this paper, we discuss the value of high-frequency ultrasonography in the diagnosis of this rare disease. This case report provides a deeper understanding of segmental schwannomatosis and may help improve the accuracy of preoperative diagnosis.

Nerve entrapment complicating neurogenic thoracic outlet syndrome surgery: A 10-year retrospective study

Neurogenic thoracic outlet syndrome results from compression of the brachial plexus. The symptoms are mainly pain, upper-limb weakness and paresthesia. Management always starts with a rehabilitation program, but failure of rehabilitation may necessitate surgery. In practice, we observed that several patients developed secondary distal nerve entrapment in the months following surgery, with no preoperative compression. We aimed to assess the occurrence of distal nerve entrapment after surgery for neurogenic thoracic outlet syndrome in a retrospective cohort study. Seventy-four patients were included; 82% females; mean age, 39.4 ± 9.4 years. There were 36.5% with high intensity and 63.5% with low to moderate intensity work. Eighteen (24.3%) developed secondary upper-limb entrapment at 10.6 ± 5.8 months after surgery. Sixteen had a single entrapment and 2 had two different entrapments. In 10 cases (50%) the ulnar nerve was involved at the elbow, in 7 (35.0%) the radial nerve at the radial tunnel, and in 3 (15.0%) the median nerve. No differences were found between patients with and without secondary nerve entrapment in gender (p = 0.51), mean age (p = 0.44), symptom duration (p = 0.92) or work intensity (p = 0.26). Further studies are needed to confirm these results and to shed light on the underlying mechanisms.

Distal humerus fracture in older patients: ORIF vs. total elbow arthroplasty

Distal humerus fractures are a contemporary problem because the life expectancy, autonomy and functional demands of older patients continue to grow. This is combined with surgical advances in bone reconstruction, especially in fragile patients. A distal humerus fracture in an older adult is a serious injury with an uncertain prognosis. In fact, damage to the elbow joint in this complex anatomical area overwhelmed by low-quality bone occurs in patients who often have unfavorable characteristics (fragile skin, low physiological reserves, organ failure) combined with pharmaceutical treatments that can be iatrogenic. The treatment indication must not be based solely on the conventional radiographs used for classification purposes; the fracture and bone quality must be analyzed in three dimensions. Also, the surgeon must understand the patient's needs, worries and risks fully to decide between conservative treatment and anatomical locking plate fixation or elbow arthroplasty (hemi or total). In the end, the chosen treatment must allow at least 100̊ and preferably 120̊ of flexion-extension at the elbow. In this age range, the choice between arthroplasty and plate fixation is definitive; the surgical approach must make it possible to carry out either option, with arthroplasty implants available in case the trochlear fracture cannot be plated. The aim of this lecture is to provide a fresh perspective on the anatomy of the distal humerus, its fracture and the best surgical approaches, discuss how to decide on the indication, outline the safest and most reliable ways to reconstruct and stabilize the elbow, and lastly, summarize the expected outcomes and potential complications of each treatment option. Level of evidence: V; expert opinion.

The elastography of distal ulnar nerve branches in cyclists

INTRODUCTION

Forced elbow flexion and pressure during bicycling result in ulnar nerve traction and pressure exerted in Guyon's canal or the nerve's distal branches. The compression of the nerves causes a change in their stiffness related to edema and eventually gradual fibrosis.

PURPOSE

This study aimed to evaluate the elastography of terminal branches of the ulnar nerve in cyclists.

STUDY DESIGN

Cross-sectional study.

METHODS

Thirty cyclists, 32 healthy individuals, and 32 volunteers with ulnar nerve entrapment neuropathies participated in the study. Each participant underwent a nerve examination of the cubital tunnel, Guyon's canal and the deep and superficial branches of the ulnar nerve using shear wave elastography. The cyclist group was tested before and after a 2-hour-long workout.

RESULTS

Before cycling workouts, the ulnar nerve stiffness in the cubital tunnel and Guyon's canal remained below pathological estimates. Cycling workouts altered nerve stiffness in the cubital tunnel only. Notably, the stiffness of the ulnar terminal branches in cyclists was increased even before training. The mean deep branch stiffness was 50.85 ± 7.60 kPa versus 20.43 ± 5.95 kPa (p < 0.001) in the cyclist and healthy groups, respectively, and the mean superficial branch stiffness was 44 ± 12.45 kPa versus 24.55 ± 8.05 kPa (p < 0.001), respectively. Cycling contributed to a further shift in all observed values.

DISCUSSION

These observations indicate the existence of persistent anatomical changes in the distal ulnar branches in resting cyclists that result in increased stiffness of these nerves. The severity of these changes remains, however, to be determined.

CONCLUSIONS

These data show elastography values of the ulnar terminal branches in healthy individuals and cyclists where despite lack of clinical symptoms that they seem to be elevated twice above the healthy range.

A Morphological Study Of The Sensory Innervation Of Hand In South India With Its Clinical Implications

INTRODUCTION

The sensory innervation of the hand is getting a lot of attention because of the quick surge in the usage of local anesthesia and the progress of plastic surgeries. It is significant to know the likely disparities in the sensory innervation of the hand to prevent mistakes while analyzing the symptoms or misdiagnosing the nerve pathology. So this study aims to assess the sensory innervation of the hand.

MATERIALS AND METHOD

The study was carried out on 54 upper limbs. All the branches of the median, ulnar and radial nerve were traced. Variations in the distribution and anastomoses were noted.

RESULTS

Anastomosis between the median and ulnar nerve was found in 12.95% of cases. In all cadavers, 3 1⁄2 digits are supplied by the median nerve and 1 1⁄2 digits by the ulnar nerve bilaterally in the palms. In all cadavers 2 1⁄2 digits, each is supplied by radial and ulnar nerve bilaterally on the dorsum of hands.

CONCLUSION

These anatomic conclusions will aid hand surgeons in identifying differences in sensory losses after either dorsal or palmar injuries.

Bilateral snapping triceps syndrome: A case report

BACKGROUND

Snapping triceps syndrome (STS) is a rare disease, while occurrence of bilateral STS is extremely rare. It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important feature. However, to the best of our knowledge, there has been no report of bilateral STS in young active patient.

CASE SUMMARY

A 23-year-old male presented with a complaint of discomfort and snapping on the medial side of both elbows while performing push-ups. On physical examination, two distinct snaps that were both palpable and audible were detected on additional clinical examination. Dynamic ultrasonography showed that the ulnar nerve and the medial head of the triceps were dislocated anteriorly over the medial epicondyle of the elbow during flexion motion. Finally, he was diagnosed as dislocation of the ulnar nerve and STS. Staged anterior subcutaneous transposition of the ulnar nerve combined with partial resection of the snapping portion of the triceps was performed. The patient's pain and snapping symptoms were resolved immediately after surgery. Three months later, the patient was completely asymptomatic and returned to normal activity.

CONCLUSION

STS should be included in the differential diagnosis for active young patients who present with painful snapping on the medial side of the elbow joint, particularly when dislocation of the ulnar nerve is detected. Dynamic sonography is used to assist in accurate diagnosis and differentiation between isolated dislocation of the ulnar nerve and STS.

High-resolution ultrasound and magnetic resonance imaging of ulnar nerve neuropathy in the distal Guyon tunnel

OBJECTIVE

The aim of the present study is to describe the ultrasound (US) and magnetic resonance imaging (MRI) findings in patients with neuropathies affecting the deep (DB) and superficial (SB) branches of the Ulnar nerve (UN) and to investigate the potential role of imaging modalities in the diagnostic workup of these conditions.

MATERIALS AND METHODS

We screened our institutional imaging database to identify patients with a diagnosis of UN mononeuropathy, and among them, we reviewed the cases where US disclosed pathological findings affecting the UN terminal divisions. In this latter subgroup, we retrieved available data on MRI and electrodiagnostic tests performed by the patients during the diagnostic workup. All the patients were evaluated with US machines equipped with 17-5-MHz, 18-4-MHz, 24-8-MHz, or 22-8-MHz probes. MRI exams were performed on a 3-T unit equipped with a 64-channel head RF coil.

RESULTS

Among 166 patients with UN mononeuropathy, we retrieved 15 patients (9%) for which US detected pathological findings affecting the UN terminal divisions, consisting of 7 cases of DB neuropathy, 4 cases of SB neuropathy, and 4 cases of combined neuropathy involving both nerves. Seven (46.7%) patients were submitted to MRI to integrate US findings. Among patients with SB and DB neuropathies, imaging allowed the identification of 7 traumatic nerve injuries, 2 nerve tumors, and 6 entrapment neuropathies, including 4 cases of nerve compression by a ganglion cyst.

CONCLUSION

High-resolution US and MRI are accurate modalities for the investigation of patients with SB/DB neuropathy, can provide critical information on the cause of nerve damage, and guide therapeutic decisions.

CRITICAL RELEVANCE STATEMENT

High-resolution US and MRI are accurate modalities for the investigation of patients with superficial/deep branch of the ulnar nerve neuropathy. In the proper setting, US may be regarded as a first-line approach in patients with suspected neuropathies affecting these small branches.

KEY POINTS

• Neuropathies affecting the distal ulnar nerve often require multimodal investigations. • US and MRI can provide detailed morphological information about the terminal branches of the ulnar nerve. • US may be considered as a first-line approach in suspected distal ulnar nerve neuropathies.

Outcomes of Therapy and Ulnar Nerve Transposition for Elbow Stiffness After Pediatric Medial Epicondyle Fractures

Purpose

Following medial epicondyle fractures, a subset of pediatric patients has persistent limitations in elbow motion. This study soughted to understand the patient characteristics of this group and to assess the effectiveness of intensive therapy and ulnar nerve transposition in improving elbow range of motion and patient-reported outcomes.

Methods

A cohort of 31 pediatric patients with stiffness after elbow trauma was narrowed to 8 pediatric patients (7 female) ranging in age from 9 to 14 years, who were diagnosed with medial epicondyle fractures and underwent intensive therapy and ulnar nerve transposition with or without elbow joint release. We collected demographic and objective data as well as subjective data including Patient-Reported Outcome Measurement Information System (PROMIS) scores before and after ulnar nerve transposition.

Results

Following initial intensive therapy, elbow range of motion improved by an average of 56°, and 7 of the 8 patients reached a functional motion arc of 100°. Subsequently, following ulnar nerve surgery with or without elbow release, motion improved by an average of 22°, and 5 of the 8 patients demonstrated improvement from this intervention. Surgery led to improvements in subjective outcomes with an improvement in PROMIS mobility scores by an average of 9 points, pain interference by 6 points, and upper extremity scores by 3 points. Based on a previously determined minimally important difference of three points, these indicate significant clinical improvements.

Conclusions

A subset of pediatric patients with persistent stiffness following medial epicondyle fractures may benefit from additional interventions, including intensive therapy, transposition of the ulnar nerve, and open capsular release. However, not all patients were improved after ulnar nerve surgery, and the identification and treatment of ulnar nerve irritability may not fully resolve preoperative symptoms in all patients.

Type of study/level of evidence

Therapeutic IV.

Comparative analysis of pinning techniques for supracondylar humerus fractures in paediatrics: A systematic review and meta-analysis of randomized controlled trials

Purpose

Supracondylar humeral fractures (SCHFs) rank among the frequently observed fractures in children. Nonetheless, there exists a dearth of consensus regarding the optimal surgical approach. This meta-analysis aims to thoroughly evaluate and compare two distinct pinning techniques (cross pinning versus lateral pinning) for SCHFs, using data from Randomized controlled trials (RCTs).

Methods

Literature review was done using PubMed, CINAHL, Scopus, and The Cochrane Library for RCTs comparing the two pinning methods and providing information on at least one of the following: Loss of Baumann's angle, loss of carrying angle, elbow function assessed based on Flynn criteria, pin tract infection, and iatrogenic ulnar nerve injury. Random effect model was used to calculate standardized mean difference or Odds Ratio (OR) for the outcomes. Review Manager 5.4.1. was used to perform quality assessment and statistical analysis.

Results

A total of 22 RCTs were included. 20 studies reported data for iatrogenic ulnar nerve injury, the OR was calculated to be 3.76 (95% CI 1.75-8.06), showing a significantly lower risk of surgical ulnar nerve injury with the lateral technique. However, no significant difference was found between the pinning techniques in regard to the other outcomes.

Conclusion

In comparison to lateral pinning, the utilization of cross pinning technique exposes the patient to a heightened susceptibility of iatrogenic nerve injury. Therefore, it is recommended that surgeons prioritize the implementation of the lateral pinning technique whenever feasible, as it offers greater protection against iatrogenic ulnar nerve injury. For the other intraoperative and postoperative outcomes, both surgical techniques yield comparable results.

Ulnar nerve anteposition with adipofascial flap, an alternative treatment for severe cubital syndrome

BACKGROUND

Ulnar nerve entrapment at the elbow is the second most common cause of nerve entrapment in the upper limb. Surgical techniques mainly include simple decompression, decompression with anterior transposition and medial epicondylectomy.

METHODS

We performed decompression with anterior transposition and protected ulnar nerve by adipofascial flap (a random flap with radial based vascularization, harvested through the avascular plane of Scarpa's fascia. We analyzed patients who underwent ulnar nerve ante-position from 2015 to 2022 according to inclusion and exclusion criteria for a total of 57 patients. All patients included were graded on the McGowan's classification Messina criteria and the British Medical Research Council modified by Mackinnon and Dellon.

RESULTS

The average McGowan's score was 2.4 (± 0.6), Messina's criteria 91.2% indicated a satisfactory or excellent result, sensibility at 6 months was 98.5% S3 or more. A preferential technique has not yet been defined.

CONCLUSIONS

The adipofascial flap offers numerous advantages in providing a pliable, vascular fat envelope, which mimics the natural fatty environment of peripheral nerves and creates favorable micro-environmental conditions to contribute to neural regeneration via axon outgrowth.

Median artery persistence in coexistence with a bifid median nerve and interconnections of the median with the ulnar nerve and vice versa

PURPOSE

This report describes a bilateral persistent median artery (PMA) originating from the ulnar artery and terminating at different levels of the upper limb. The PMA coexisted with a bilateral bifid median nerve (MN) and two bilateral interconnections (ICs characterized with the symbol -) of the MN with the ulnar nerve (UN) (MN-UN) and a unilateral reverse IC (UN-MN). Emphasis was given to the artery's developmental background.

METHODS

The PMA was identified in an 80-year-old formalin-embalmed donated male cadaver.

RESULTS

The right-sided PMA terminated at the wrist, posterior to the palmar aponeurosis. Two neural ICs were identified: the UN joined the MN deep branch (UN-MN), at the forearm's upper third, and the MN deep stem joined the UN palmar branch (MN-UN), at the lower third (9.7 cm distally to the 1st IC). The left-sided PMA ended in the palm giving off the 3rd and 4th proper palmar digital arteries. An incomplete superficial palmar arch was identified by the contribution of the PMA, radial, and ulnar arteries. After the MN bifurcation into superficial and deep branches, the deep branches formed a loop, that was penetrated by the PMA. The MN deep branch communicated with the UN palmar branch (MN-UN).

CONCLUSIONS

The PMA should be evaluated as a causative factor of carpal tunnel syndrome. The modified Allen's test and the Doppler ultrasound may detect the arterial flow and the angiography may depict the vessel thrombosis in complex cases. PMA could also be a "salvage" vessel for the hand supply, in radial and ulnar artery trauma.

The consequences of a thoracic outlet syndrome's entrapment model on the biomechanics of the ulnar nerve - Cadaveric study

STUDY DESIGN

A cross sectional cadaveric measurement study.

INTRODUCTION

The etiology of entrapment neuropathies, such as carpal tunnel syndromes or thoracic outlet syndromes (TOS), is usually not only linked with the compressive lesion of the nerve but can also be associated with fibrosis and traction neuropathy.

PURPOSE OF THE STUDY

This work studies the biomechanics of the ulnar nerve in a cadaveric model of thoracic outlet syndrome (TOS). We explored the biomechanical impact of a restriction of mobility of the ulnar nerve. We measured if it could significantly affect the deformation undergone by the nerve on the rest of its path.

METHODS

We studied 14 ulnar nerves from 7 embalmed cadavers. We opened three 6.5cm windows (at the wrist, forearm, and arm), and two optical markers 2cm apart were sutured to the ulnar nerve. We then studied the deformation of the ulnar nerve in three successive tensioning positions inspired by the ULNT3 manoeuvre (Upper Limb Neural Test 3). We then fixed the brachial plexus to the clavicle to mimic a nerve adhesion at the thoracic outlet.

RESULTS

Fixing the brachial plexus to the clavicle bone had significant effects on ulnar nerve mobility. In the position of intermediate tension, the nerve deformation increased by +0.68% / +1.43% compared to the control measure. In the position of maximum tension, it increased by +1.16% / +1.94%, pushing the nerve beyond the traumatic threshold of 8% of deformation causing reversible damage to axonal transport and vascularization.

CONCLUSIONS

Our nerve adhesion at the thoracic outlet showed significant effects on the mobility of the ulnar nerve compared to the control situation, by significantly increasing the deformation undergone throughout the rest of the nerve's course, and by taking it over the 8% of physiological traumatic deformation.

Modern Treatment of Cubital Tunnel Syndrome: Evidence and Controversy

Cubital tunnel syndrome is the second most common peripheral mononeuropathy in the upper extremity. However, the diagnosis and treatment of cubital tunnel syndrome remains controversial without a standard algorithm. Although diagnosis can often be made from the patient's history and physical examination alone, electrodiagnostic studies, ultrasound, computed tomography (CT), and magnetic resonance image (MRI) can also be useful in diagnosing the disease and selecting the most appropriate treatment option. Treatment options include conservative nonoperative techniques as well as various surgical options, including in situ decompression with or without transposition, medial epicondylectomy, and nerve transfer in advanced disease. The purpose of this review is to summarize the most up-to-date literature regarding cubital tunnel syndrome and propose a treatment algorithm to provide clarity about the challenges of treating this complex patient population.

[Application of ulnar nerve diameter changes examined by HRUS in patients with cubital tunnel syndrome]

OBJECTIVE

To evaluate the value of high-resolution ultrasound the diagnosis and prognosis of cubital tunnel syndrome.

METHODS

From January 2018 to June 2019, 47 patients with cubital tunnel syndrome were treated with ulnar nerve release and anterior subcutaneous transposition. There were 41 males and 6 females, aged from 27 to 73 years old. There were 31 cases on the right, 15 cases on the left, and 1 case on both sides. The diameter of ulnar nerve was measured by high-resolution ultrasound pre-and post-operatively, and measured directly during the operation. The recovery status of the patients was evaluated by the trial standard of ulnar nerve function assessment, and the satisfaction of the patients was assessed.

RESULTS

All the 47 cases were followed up for an average of 12 months and the incisions healed well. The diameter of ulnar nerve at the compression level was (0.16±0.04) cm pre-operatively, and the diameter of ulnar nerve was (0.23±0.04) cm post-operatively. The evaluation of ulnar nerve function:excellent in 16 cases, good in 18 cases and fair in 13 cases. Twelve months post-operatively, 28 patients were satisfied, 10 patients were general and 9 patients were dissatisfied.

CONCLUSION

The preoperative examination of ulnar nerve by high-resolution ultrasound is consistent with the intuitive measurement during operation, and the result of postoperative examination of ulnar nerve by high-resolution ultrasound is consistent with follow-up results. High-resolution ultrasound is an effective auxiliary method for the diagnosis and treatment of cubital tunnel syndrome.

Tendon Transfer versus Nerve Transfer for the Reconstruction of Key Pinch and Grip Strength in Isolated High Traumatic Injuries of the Ulnar Nerve: A Systematic Review

Background: Primary repair for traumatic injuries to the ulnar nerve alone does not always restore satisfactory hand function, particularly in injuries above the elbow where the long distances for regeneration limit motor reinnervation. Reductions in key pinch and grip strength are some of the main complaints. Tendon transfers have traditionally been used to improve key pinch and grip strength as a late salvage where primary nerve regeneration has run its course. Nerve transfers have been proposed as an alternative procedure and may be offered early to augment recovery, lengthen the window for reinnervation or provide motor reinnervation where the results of nerve repair are expected to be poor. This review sought to identify whether one type of procedure was superior to the other for reconstructing key pinch and grip strength. Methods: Medline, Embase and Cochrane Library were searched to identify articles that concerned nerve or tendon transfer following isolated traumatic injury to the ulnar nerve. Articles were excluded if patients had polytrauma or degenerative diseases of the peripheral nerves. Results: A total of 179 articles were screened for inclusion. And 35 full-text articles were read and assessed for eligibility, of which seven articles were eligible. Following citation search, two additional articles were included. Five tendon transfer articles and four nerve transfer articles were included. Key pinch and grip strength outcomes for both procedures were roughly similar, though tendon transfers carried a much higher risk of complications. Conclusions: Based on the key pinch and grip strength outcomes, tendon transfer and nerve transfer restore a similar degree of function following traumatic ulnar injury. Reported nerve transfer outcomes for grip strength were slightly better. Return to useful function was faster following tendon transfers. Preoperative data and more patient-reported outcome measures should be recorded in future studies to provide more context for each procedure type. Level of Evidence: Level III (Therapeutic).

Intraoperative electrical stimulation promotes the short-term recovery of patients with cubital tunnel syndrome after surgery

BACKGROUND

This study was designed to investigate whether intraoperative electrical nerve stimulation has effects on the short-term recovery of cubital tunnel syndrome patients after ulnar nerve release.

METHODS

Patients diagnosed as cubital tunnel syndrome were selected. At the same time, they received conventional surgery treatment. The patients were divided by a randomized digits table into two groups. The control group underwent conventional surgery, and the electrical stimulation (ES) group underwent intraoperative electrical stimulation. All the patients were tested for sensory and motor functions, grip strength, key pinch strength, motor conductivity velocity (MCV), and maximum compound muscle action potential (CMAP) before operation and 1 month and 6 months after operation.

RESULTS

In patients treated with intraoperative ES, the sensory and motor functions and the strength of muscle were significantly improved after 1-month and 6-month follow-up than the control group. After the follow-up, the patients in the ES group had significantly higher grip strength and key pinch strength than the control group. After the follow-up, the patients in the ES group had significantly higher MCV and CMAP than the control group.

CONCLUSION

Intraoperative electrical stimulation of nerve muscle can significantly promote the short-term recovery of nerve and muscle functions after the surgery in cubital tunnel syndrome patients.

Anatomic Study of the Motor Branch of the Ulnar Nerve Regarding Carpal Tunnel Surgery: A Cadaveric Study

Background: Motor branch of the ulnar nerve (MUN) injury during carpal tunnel surgery is rare and it should never be injured during carpal tunnel release (CTR). However, an iatrogenic injury of the MUN can cause catastrophic physical and mental suffering. The aim of our study is to understand the anatomy of the MUN in relation to carpal tunnel in order to prevent iatrogenic injury during CTR. Methods: We dissected 34 fresh cadaver hands and located the MUN in relation to the anatomical axis used for carpal tunnel surgery. Possible mechanisms of injury and the vulnerable area of the MUN were determined along the dissection. Results: The MUN turned towards the thumb distal to hook of hamate. It then travelled on the floor of the carpal tunnel which was formed by intrinsic hand muscles under flexor tendons. The nerve located at 29.39 ± 7.41, 35.01 ± 3.14 and 38.79 ± 4.03 mm (Mean ± SD) in the central axis of ring finger, the vertical axis of the third web-space and the central axis of middle finger respectively. The nerve's turning point, 10.9 ± 2.63 mm distal to the centre of hook of hamate where it lies just below the level of the transverse carpal ligament. Conclusions: Surgeons should be aware of the nerve's location. Surgical dissection or passing of any surgical instruments around the hook of hamate should be done with care. Level of Evidence: Level IV (Therapeutic).

Cubital tunnel syndrome of the ulnar nerve caused by an epineural ganglion cyst: a case report and review of the literature

BACKGROUND

The ulnar nerve has a long and complex anatomical course, originating from the brachial neural plexus in the neck with nerve trunk formation at the posterior neck triangle, and on to the axilla. This intricate anatomical pathway renders the nerve susceptible to compression, direct injury, and traction throughout its course. Compression of the ulnar nerve is the second most common compression neuropathy of the median nerve adjacent to the wrist joint, after carpal tunnel syndrome.

CASE PRESENTATION

A 45-year-old Sudanese housewife complained of progressive right forearm and hand muscle wasting, pain, and neuropathic symptoms. She was diagnosed with right-sided cubital tunnel syndrome. The diagnosis was derived intraoperatively from a nerve conduction study suggesting the level of conduction block and recommending decompression. Magnetic resonance imaging was not done preoperatively due to financial limitations. An epineural ganglion (15 × 20 mm²) compressing and flattening the ulnar nerve was diagnosed intraoperatively. Surgical decompression of the ulnar nerve and removal of the epineural ganglion achieved a remarkable postoperative result and pleasing outcome.

CONCLUSION

Surgical management is the cornerstone of treatment for compressive neuropathy and ranges from simple nerve decompression to complex neurolysis procedures and nerve transposition to adjust the anatomical course of the nerve.

Anatomical variants complicating the posterior approaches towards the elbow joint

INTRODUCTION

Anatomical variants observed during the posterior approach to the elbow joint require special attention due to their clinical relevance. We aim to present a compendious review of described variants potentially encountered during the posterior approach towards the elbow joint to the experts in the elbow surgery.

METHODS

A narrative review of surgical and anatomical textbooks, as well as search of scientific databases was carried out.

RESULTS

Variability of the subcutaneous nerves is important during incision planning. Accessory muscles such as dorsoepitrochlearis, chondroepitrochlearis, epitrochleoanconeus, subanconeus or supernumerary flexor carpi ulnaris may confuse even the senior surgeon during the dissection and possibly complicate the fracture reduction. Some bony variants such as supratrochlear foramen may lead to fracture or possibly interfere with the osteosynthesis placement. Accessory bones are also present in the region of the elbow joint. Those situated intra-articular may present with symptoms.

CONCLUSION

Many variants can be encountered in the area of the elbow joint and their knowledge is essential to truly understand its anatomy. The presented review enables easier orientation in the current literature with the aim on the posterior approach towards the elbow joint.

Protocol for Endoscopic Versus Open Cubital tunnel release (EVOCU): an open randomized controlled trial : EVOCU trial: Endoscopic Versus Open Cubital tunnel release

BACKGROUND

Cubital tunnel syndrome is the second most common entrapment neuropathy of the upper extremity. Surgical decompression of the ulnar nerve aims to improve complaints and prevent permanent damage to the nerve. Open and endoscopic release of the cubital tunnel are both used in common practice, but none has proven to be superior. This study assesses patient reported outcome and experience measures (PROMs and PREMs respectively), in addition to objective outcomes of both techniques.

METHODS

A prospective single-center open randomized non-inferiority trial will take place at the Plastic Surgery Department in the Jeroen Bosch Hospital, the Netherlands. 160 patients with cubital tunnel syndrome will be included. Patients are allocated to endoscopic or open cubital tunnel release by randomization. The surgeon and patients are not blinded for treatment allocation. The follow-up time will take 18 months.

DISCUSSION

Currently, the choice for one of the methods is based on surgeon's preferences and degree of familiarity with a particular technique. It is assumed that the open technique is easier, faster and cheaper. The endoscopic release, however, has better exposure of the nerve and reduces the chance of damaging the nerve and might decrease scar discomfort. PROMs and PREMs have proven potential to improve the quality of care. Better health care experiences are associated with better clinical outcome in self-reported post-surgical questionnaires. Combining subjective measures with objective outcomes, efficacy, patient treatment experience and safety profile could help differentiating between open and endoscopic cubital tunnel release. This could aid clinicians in evidence based choices towards the best surgical approach in patients with cubital tunnel syndrome.

TRIAL REGISTRATION

This study is registered prospectively with the Dutch Trial Registration under NL9556. Universal Trial Number (WHO-UTN) U1111-1267-3059. Registration date 26-06-2021. The URL: https://www.trialregister.nl/trial/9556.

Topography of the deep branch of the ulnar nerve between genders: a cadaveric study with potential clinical implications

The lack of meticulous knowledge concerning the topographical anatomy of the deep branch of the ulnar nerve (DUN) may pose difficulties, leading to a delay or a misdiagnosis of a DUN injury. Identification of the DUN is quite difficult without precise anatomical landmarks as reference points. The current study investigates the topography of the DUN between genders, taking as a reference point a well-known landmark, the Kaplan line, used in hand surgery for carpal tunnel release. Twenty-two (15 males and 7 female) fresh frozen adult cadaveric hands were dissected by using magnifying loupes (3.5 and 5.0 x). We marked values proximal to the Kaplan line as positive (+), while we marked distal ones as negative (-). The mean distance DUN-Kaplan line was 1.69 ± 4.45 mm. In male hands, the mean distance was 4.17 ± 1.88 mm, distal to the Kaplan line, while in females, the mean distance was -4.92 ± 0.69 mm proximal to the Kaplan line. Gender dimorphism was detected, with higher statistically significant values in male hands (p = 0.001). Cadaveric studies of the DUN topography, course, and distribution pattern are uncommon. The current study provides an accurate description of the DUN topography, taking the Kaplan line as a reference point, emphasizing gender differences. The DUN is located distally in males and proximally in females. Knowledge of these predictable anatomical relations may help hand surgeons intraoperatively when dealing with a DUN lesion, because of hand trauma or during the decompression of the DUN.

Brachial arteries sympathetic innervation: A contribution to anatomical knowledge

BACKGROUND

The sympathetic nervous system makes medium and large peripheral arteries smaller to slow the blood flowing through them.

AIM

To observe brachial artery sympathetic innervation.

METHODS

We developed a neurophysiological autonomous test that measured the effects of peripheral sympathetic fibres on peripheral arteries. Our specific objective was to find the sympathetic innervation of the brachial artery. To accomplish this purpose, the brachial artery baseline diameter and flow rate were measured in the right arm of the patients. Afterwards, electrical stimulus was applied to the medial nerve for 5 s. Through electrical sympathetic activation, the vessel diameter and overall flow rate will decrease. After 7 d, a similar experiment was repeated using the ulnar nerve.

RESULTS

The differences in diameter and flow rate of the brachial artery in response to median and ulnar nerve activation were compared. In the total group, no significant difference in diameter was seen between medial and ulnar nerve stimulation (P = 0.648). The difference in absolute slowdown of flow rate between median nerve stimulation and ulnar nerve stimulation was not statistically significant for the entire group (P = 0.733).

CONCLUSION

As a target organ, the brachial artery receives an equal amount of sympathetic innervation from the median and the ulnar nerves.

Location of Ulnar Nerve Branches to the Flexor Carpi Ulnaris during Surgery for Cubital Tunnel Syndrome

OBJECTIVE

Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications.

METHODS

A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle.

RESULTS

There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation.

CONCLUSION

In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

Prospective outcome analysis of ulnar tunnel syndrome: Comparing traumatic versus non-traumatic etiologies

BACKGROUND

Ulnar tunnel syndrome (UTS) is relatively uncommon compared to the carpal tunnel or cubital tunnel syndromes. Few reports dedicated to the functional outcomes after surgical intervention of the UTS exist. Herein we compare the outcomes of patients with UTS of different etiologies.

METHODS

Patients diagnosed with UTS between 2016 and 2020 were recruited. Ulnar tunnel release was performed in all patients, along with other necessary osteosynthesis or reconstructive procedures in the traumatic group. Patients were followed-up every six months post-operatively. Outcomes measured include: objective evaluations, subjective questionnaires, records of clinical signs, and grading of the British Medical Research Council scale for intrinsic muscle strength.

RESULTS

21 patients were recruited, and favorable results were noted in all of them after surgery. Traumatic UTS patients had a worse initial presentation than the non-traumatic cases, but had a greater improvement after surgery and yielded outcomes comparable with those of the patients without trauma. Patients with aberrant muscles in their wrists had better outcomes in some objective measurements than those without aberrant muscles.

CONCLUSIONS

Ulnar tunnel release improves the outcome of patients regardless of the etiology, especially in patients with trauma-induced UTS. Thus, a proper diagnosis of the UTS should be alerted in all patients encountering paresthesia in the ulnar digits, ulnar-sided pain, weakness of grip strength, or intrinsic weakness to ensure good outcomes.

Dynamic analysis of the ulnar nerve and cubital tunnel morphology using ultrasonography: a cadaveric study

BACKGROUND

The causes of ulnar neuropathy at the elbow are unclear. The authors hypothesized that the humeral trochlea protrudes into the cubital tunnel during elbow flexion and causes a dynamic morphologic change of the ulnar nerve in the cubital tunnel.

METHODS

An ultrasonic probe was fixed to the ulnar shafts of 10 fresh cadavers with an external fixator, and dynamic morphology of the cubital tunnel and ulnar nerve was observed. The distance from the Osborne band to the trochlea (OTD), distance from ulnar nerve center to the trochlea (UTD), and the short- and long-axis diameters of the nerve at 30°, 60°, 90°, and 120° of elbow flexion were recorded. We compared the OTD, UTD, and the flattening of the ulnar nerve at the different angles of flexion using single-factor analysis of variance. Correlation between the ulnar nerve flattering, OTD, and UTD was examined using Spearman correlation coefficient. A P value less than .05 was used to denote statistical significance.

RESULTS

Flattening of the ulnar nerve progressed with increasing elbow flexion and was significantly different between 0° and 60°, 90°, and 120° (P = .03 at 60°, P < .01 at 90° and 120°). OTD decreased with elbow flexion, and there was a significant difference at all elbow flexion angles (all P < .01). UTD decreased significantly from 0° flexion to 90° flexion (P = .03). Flattening of the nerve was significantly correlated with the OTD (r = 0.66, P < .01).

CONCLUSIONS

A positive correlation was found between the protrusion of the humeral trochlea into the cubital tunnel during elbow flexion and ulnar nerve flattening using cadaveric elbow and ultrasonography.

Human Amniotic Membrane Wrapping of the Ulnar Nerve During Cubital Tunnel Surgery Reduces Recurrence of Symptoms

Background

Compare the recurrence rate of paresthesias in patients undergoing primary cubital tunnel surgery in those with and without wrapping of the ulnar nerve with the human amniotic membrane (HAM).

Methods

A retrospective investigation of patients undergoing primary cubital tunnel surgery with a minimum 90-day follow-up was performed. Patients were excluded if the nerve was wrapped using another material, associated traumatic injury, simultaneous Guyon's canal release, or revision procedures. Failure was defined as those patients who experienced initial complete resolution of symptoms (paresthesias) but then developed recurrence of paresthesias.

Results

A total of 57 controls (CON) and 21 treated with HAM met our inclusion criteria. There was a difference in the mean age of CON (48.4 ± 13.5 years) and HAM (30.6 ± 15) (P< 0.0001). There was no difference in gender mix (P=0.4), the severity of symptoms (P=0.13), and length of follow-up (P=0.084). None of 21 (0%) treated with HAM developed recurrence of symptoms compared to 11 of 57 (19.3%) (P=0.03) (CON). Using a multivariate regression model adjusted for age and procedure type, CON was 24.4 (95% CI=1.26-500, P=0.0348) times higher risk than HAM of developing a recurrence of symptoms.

Conclusion

The HAM wrapping used in primary cubital tunnel surgery significantly reduced recurrence rates of paresthesias. Further prospective studies with randomization should be carried out to better understand the role HAM can play in cubital tunnel surgery.

Treatment of Ulnar Neuropathic Pain with Peripheral Nerve Stimulation: Two Case Reports

Ulnar neuropathy is a condition that manifests with symptoms of neuropathic pain, numbness, tingling, and even possible motor deficits in the ulnar distribution of the arm. This debilitating painful condition may be refractory to conservative, pharmacologic, and surgical interventions. Peripheral nerve stimulation (PNS) technology has advanced significantly in recent years allowing for conditions such as ulnar neuropathy to be treated in a minimally invasive manner. Here we report the first case reports in the literature (to our knowledge) of two patients with intractable ulnar neuropathy who underwent minimally invasive PNS Bioventus implants. Both patients experienced at least 75% pain relief based on NRS scores at 6 months after ulnar nerve PNS implantation. The patients also experienced significant improvement in functional outcomes, including return to employment, ability to perform activities of daily living without any impairment, and improved quality of life measures. While the results presented in our two case reports are promising, we only provide observational data over a 6 to 15-month period post-implantation. Future well-powered, large-scale, and long-term randomized controlled trials are warranted to determine efficacy and long-term pain and functional outcomes from PNS therapy for treatment of ulnar neuropathy.

A new measurement method: The Cha method

"Supercharge" end-to-side (SETS) nerve transfer for lesions of the proximal ulnar nerve is a recognized novel option, but improvement in motor function after surgery has not been properly evaluated. We therefore propose a modified method for quantitative evaluation of improvement in the intrinsic hand strength. We screened 216 patients with proximal ulnar nerve lesions who presented to our outpatient department from 2012 to 2020. Of these, 101 met our inclusion/exclusion criteria and were evaluated just before surgery. We used a novel method to measure finger abduction ("2nd-abd"), adduction ("5th-add"), and ring and little finger flexion strength ("4,5 grip"), and analyzed correlations with established pinch strength data. The male:female sex ratio was 86:15, and the ratio dominant to nondominant arm involvement was 68:33. All strength measurements were analyzed as percentage affected to contralateral normal side. On Pearson correlation analysis, the strength ratios for "4,5 grip", "2nd-abd", and "5th-add", but not "5 fingers (total) grip", showed significant positive correlation with key and oppositional pinch strength (all p &lt; 0.001). Additionally, linear regression analysis showed identical results for each strength correlation with key/oppositional pinch, except for "5 fingers total) grip" (all, p &lt; 0.001). SETS is a reasonable alternative for lesions of the proximal ulnar nerve. The measurement method we propose is feasible for specific assessment of intrinsic muscle strength, which improves after surgery. LEVEL OF EVIDENCE: Diagnostic, level IV.

[Feasibility study of protecting ulnar nerve by ultrasound in treating children with supracondylar fracture of humerus by closed reduction and intercross needle fixation]

OBJECTIVE

To explore feasibility of protecting ulnar nerve by ultrasound in treating children with supracondylar fracture of humerus by closed reduction and intercross needle fixation.

METHODS

From January 2018 to December 2019, 63 children with supracondylar fractures of humerus were divided into two groups(ultrasound group and X-ray group) depend on the different ways of guidance. Therer were 32 children in ultrasound group treated with closed reduction and Kirschner wire fixation guided by ultrasound, including 20 males and 12 females, aged from 3 to 11 years old with an average of (6.06±2.02) years old. There were 31 children in X-ray group treated with closed reduction and Kirschner wire fixation guided by X-ray, including 17 males and 14 females, aged from 2 to 10 years old with an average of (5.61±1.96) years old. Operation time, X-ray times, fracture healing time, ulnar nerve injury and postoperaqtive Flynn clinical function assessment at 1 year between two groups were recorded and compared.

RESULTS

All patients were followed up. The follow-up time of ultrasound group ranged from 9 to 12 months with an average of (11.53±0.76) months, and X-ray group ranged from 10 to 13 months with an average of (11.51±0.72) months. There was no significant difference in operation time, follow-up time and fracture healing time between two groups(P>0.05). The number of intraoperative electrodialysis in ultrasound group was (3.06±1.24) times, and that in X-ray group was (21.65±5.58) times, which was significantly higher than that in ultrasound group(P<0.01). No iatrogenic ulnar nerve injury occurred in ultrasound group, and 2 cases of ulnar nerve injury occurred in X-ray group, the incidence of ulnar nerve injury in ultrasound group was lower than that in X-ray group, but the difference was not statistically significant(P>0.05). At 1 year after operation, Flynn clinical function assessment results in ultrasound group was excellent in 27 cases, 4 cases good and 1 case fair, in X-ray group 23 cases got excellent result, 6 cases good, 1 fair and 1 poor, there was no significant difference between two groups(P>0.05 ).

CONCLUSION

Ultrasound guided and X-ray guided treatment of supracondylar fractures of humerus in children have similar effect of opertaion time and fracture healing, while ultrasound guidance could clearly detected the position of ulnar nerve, and avoid occurrence of iatrogenic ulnar nerve injury caused by ulnar puncture, which is a safe and effective treatment method.

The prevalence of the anatomical variation in a Turkish population: supernumerary muscle-anconeus epitrochlearis

INTRODUCTION

The anconeus epitrochlearis (AE) muscle is an accessory muscle located between the medial cortex of the olecranon and the inferior surface of the medial epicondyle, posterior to the ulnar nerve. This muscle may compress the ulnar nerve causing a clinical neuropathy. We aimed to determine the gender and side characteristics of the AE muscle in patients who underwent elbow magnetic resonance imaging (MRI) and report its prevalence in a Turkish population.

MATERIALS AND METHODS

A total of 209 patients (210 elbows) who underwent elbow MRI between January and December 2020 were retrospectively evaluated. Cases with the AE muscle were included in the study. The craniocaudal (CC) dimension was examined from the coronal section, and the transverse (TR) and anteroposterior (AP) dimensions from the axial sections. Statistical analyses were performed to determine the relationship between the presence of the AE muscle and age, gender, and side (right/left). Differences between sexes and sides in terms of muscle sizes were evaluated using statistical tests.

RESULTS

The AE muscle was detected in 17 patients (18 elbows) (8.1%). The mean age of the patients was 41.52 ± 14.63 years. There was no statistically significant difference between the male and female patients in terms of age. This accessory muscle was found in nine female (9.8%) and eight male (6.3%) patients in total. There was one (0.5%) patient with the bilateral AE muscle, who was female. The accessory muscle was located in the right elbow in 13 patients (10.71%), and left elbow in five (4.10%). It was more common in the right elbow in both genders. The muscle was larger in the male patients and the right elbow, but this was not statistically significant.

CONCLUSION

The prevalence of the AE muscle was determined to be 8.1% in a Turkish population, and this muscle was more common among the women and in the right elbow.

A Comprehensive Review of Cubital Tunnel Syndrome

Cubital Tunnel Syndrome (CuTS) is the compression of the ulnar nerve as it courses through the cubital tunnel near the elbow at the location colloquially referred to as the "funny bone". CuTS is the most commonly diagnosed mononeuropathy after carpal tunnel syndrome. Cubital tunnel syndrome can manifest as numbness, tingling, or pain in the ring/small fingers and dorsoulnar hand. Repetitive pressure, stretching, flexion, or trauma of the elbow joint are known causes of CuTS. Chronic ulnar nerve compression and CuTS, when left untreated, can lead to atrophy of the first dorsal interosseus muscle and affect one's quality of life to the point that they are no longer able to participate in daily activities involving fine motor function. It is estimated that up to 5.9% of the general population have had symptoms of CuTS. CuTS is underdiagnosed due to lack of seeking of treatment for symptoms. Compression or damage to the ulnar nerve is the main cause of symptoms experienced by an individual with CuTS. Repetitive elbow pressure or a history or elbow joint trauma or injury are additional known causes that can lead to CuTS. Common presentations of CuTS include paresthesia, clumsiness of the hand, hand atrophy and weakness. The earliest sign of CuTS is most commonly numbness and tingling of the ring and 5th finger. Older patients tend to present with motor symptoms of chronic onset; younger patients tend to have more acute symptoms. Pain and point tenderness at the medial elbow may also be seen. CuTS lacks universally agreed upon diagnostic and treatment algorithms. CuTS can be diagnosed by physical exam using Tinel's sign, flexion-compression tests, palpating the ulnar nerve for thickening presence of local tenderness along the nerve. Ultrasound and nerve conduction studies may be used in combination with physical exam for diagnosis. Conservative treatment for CuTS is almost always pursued before surgical treatment and includes elbow splints, braces, and night-gliding exercises. Surgical treatment may be pursued in severe CuTS refractory to conservative treatment. Surgical options include open and endoscopic in-situ decompression, medial epicondylectomy, and anterior transposition of the ulnar nerve. CuTS is a prevalent disease that, if left untreated, can significantly alter an individual's quality of life. Therefore, an accurate diagnosis and appropriate treatment is paramount in reducing further damage and preventing worsening or future symptoms.

Some Misconceptions in the Treatment of Cubital Tunnel Syndrome, Radial Tunnel Syndrome, and Median Nerve Compression in the Forearm

This article discusses ulnar, median, and radial nerve compression in the proximal forearm and elbow and some possible common misconceptions. In particular, the ligament of Struthers extremely rarely causes ulnar neuropathy. Lacertus syndrome and flexor superficialis-pronator syndrome can be diagnosed separately. Surgical release can be through a small incision. Acronyms for compression to radial nerve in proximal forearm can be simplified to radial tunnel syndrome, which includes a mild type (classical radial tunnel syndrome) and a severe type (posterior interosseous nerve (PIN) compression).

Diagnosing ulnar neuropathy at the elbow on MRI: importance of the longitudinal extent of the hyperintense ulnar nerve

OBJECTIVE

To evaluate the usefulness of the longitudinal extent (LE) of high ulnar nerve signal intensity (SI) for the diagnosis of ulnar neuropathy at the elbow (UNE).

MATERIALS AND METHODS

This retrospective study included 68 patients who underwent elbow MRI. Twenty-seven and 41 patients were enrolled in the UNE and control groups, respectively. Qualitative and quantitative analyses of the SI and size of the ulnar nerve at the cubital tunnel, proximal, and distal to the cubital tunnel were performed. Cross-sectional area (CSA) and nerve-to-muscle contrast ratio (NMCR) were measured at each level. The LE of the hyperintense ulnar nerve was evaluated using axial and coronal images. The presence of space-occupying lesions (SOLs), subluxation, and muscle denervation were recorded. Univariate and multivariate analyses were performed to identify independent predictive factors.

RESULTS

Ulnar nerve hyperintensity at and distal to the cubital tunnel, presence of compression, SOL, muscle denervation, LE of hyperintense ulnar nerve, NMCR, and CSA at and distal to the cubital tunnel significantly differed between the two groups. Multivariate logistic regression analysis showed that the LE of the hyperintense ulnar nerve and CSA at the cubital tunnel were independent predictive factors for UNE (p < 0.05).

CONCLUSION

LE of the hyperintense ulnar nerve could be a useful predictive factor for UNE.

Treatment of upper extremity nerve defects by direct suturing in high elbow or wrist flexion

PURPOSE

To evaluate functional outcomes after direct suturing of upper extremity nerve defects in high elbow or wrist flexion.

METHODS

A retrospective review was conducted in patients treated for median, ulnar, or radial nerve defects between 2011 and 2019. Inclusion criteria were a defect > 1 cm and a minimal follow-up period of 1 year. Nerve defects were bridged by an end-to-end suture in 90° elbow flexion or 70° wrist flexion for 6 weeks.

RESULTS

Nine patients with a mean age of 30.2 years were included. The patients presented with two ulnar nerve defects, four median nerve defects, and three radial nerve defects at various levels. The mean time to surgery was 13.5 weeks for recent injuries. The mean defect length was 2.9 cm, and the mean follow-up time was 22.4 months. Two patients had joint stiffness that was more likely related to the associated injuries than the 6-week immobilization. Successful outcomes were achieved in eight of the nine patients. Meaningful motor recovery was observed in seven patients, and all recovered meaningful sensation. Excellent nerve recovery was noted in pediatric patients and in those with distal nerve defects.

CONCLUSION

Temporary high joint flexion allows for direct coaptation of upper extremity nerve defects up to 4 cm located near the elbow or wrist. In this small and heterogenous cohort, functional outcomes seemed to be comparable to those obtained with short autografting.

Research reporting in cubital tunnel syndrome studies: an analysis of the literature

PURPOSE

There is a strong need for a set of consensus outcomes to be utilized for future studies on cubital tunnel syndrome. The goal was to assess the outcome measures utilized in the cubital tunnel syndrome literature as a way of measuring popularity/acceptability and then to perform a literature review for the most commonly used outcomes.

METHODS

A literature search was performed using the pubmed.gov database and Medical Subject Headings (MeSH). For each article, the following data were abstracted: study type, motor outcome(s), sensory outcome(s), composite outcome(s), patient-reported outcome (PRO) metric(s), pain outcome(s), psychological outcome(s), electrodiagnostic outcome(s), and any other outcomes that were used.

RESULTS

A composite outcome was reported in 52/85 (61%) studies, with the modified Bishop score (27/85; 32%) most common. A motor outcome was reported in 44/85 (52%) studies, with dynamometry (38/85; 45%) most common. The majority of studies (55%) did not report a sensory outcome. The majority of studies (52%) did not report a PRO. A specific pain outcome was reported in the minority (23/85; 27%), with the visual analogue scale (VAS) (22/85; 26%) most common. Pre- and postoperative electrodiagnostic results were presented in 22/85 studies (26%).

DISCUSSION

Understanding current clinical practice and historical outcomes reporting provides a foundation for discussion regarding the development of a core outcome set for cubital tunnel syndrome. We hope that the data provided in the current study will stoke a discussion that will culminate in a consensus statement for research reporting in cubital tunnel syndrome studies.

The Gantzer transfer - Assessment of the feasibility of using the nerve supplying the Gantzer muscle for end-to-side supercharging of the ulnar nerve

Our study aimed at assessing the anatomical feasibility of using the nerve supplying the Gantzer muscle (GM) to supercharge the ulnar nerve following injury. The GM nerve was dissected and measured in 36 forearms. The distance between its origin and the lateral epicondyle of humerus and between the GM nerve and the ulnar nerve was measured. The GM was present in 15 forearms (47%). The average distance between the origin of the GM nerve and the lateral epicondyle was 7.34 cm (range 3.3-9.1 cm). The average length of the GM nerve was 3.05 cm (range 1.6-4.5 cm) from origin to neuromuscular junction. The average distance from the ulnar nerve was 2.56 cm (range 1.8-13 3.4 cm). The length of the GM nerve was significantly greater (p < 0.05) than the perpendicular distance between its origin and the ulnar nerve, allowing ample margin for side-to-side or end-to-side supercharging of the ulnar nerve with minimal or no need for further translocation or dissection. The use of the GM nerve as donor following ulnar nerve injury may provide an alternative to the pronator quadratus nerve for supercharged end-to-side transfer, or as an addition, thus supercharging the ulnar nerve twice.

Schwannoma Arising from the Deep Motor Branch of the Ulnar Nerve - A Case Report and Review of Literature

Schwannomas of the ulnar nerve in the hand are uncommon and those arising from the deep motor branch of the ulnar nerve (DMBUN) are rare. We were able to find only five reports of a schwannoma of the DMBUN. We report a schwannoma arising from DMBUN beyond the Guyon canal and summarise the literature on schwannomas involving the DMBUN. Level of Evidence: Level V (Therapeutic).

Ulnar Nerve Injury Following Distal Radius Fracture Assessed by Ultrasonography: Management of an Ulnar Nerve Lesion

A fracture of the distal radius with an associated injury to the ulnar nerve is rare. The management of the ulnar nerve lesion is unclear. We present a patient with a closed distal radius fracture related to an injury to the ulnar nerve associated with diminished sensation and a claw deformity. This was assessed by ultrasonography (US) that showed the nerve to be in continuity without any evidence of compression. The nerve was deviated towards the volar side at the distal end of the ulna and was enlarged at the same point. Open reduction and internal fixation was performed for the fracture. Emergent nerve exploration was not performed. The function of the ulnar nerve was completely restored at 16 weeks after injury. In cases presenting with ulnar nerve injury, we recommend US to evaluate the condition of the ulnar nerve. Nerve exploration should be performed when neurological deficits were found on US or symptoms did not recover over 4 months observation. Level of Evidence: Level V (Therapeutic).

Neurolymphomatosis of the Ulnar Nerve Presenting as Cubital Tunnel Syndrome: A Case Report

Lymphoma is a malignant tumour of the lymphatic system. Neurolymphomatosis occurs when lymphoma cells invade the peripheral nervous system (PNS). Neurolymphomatosis has been reported involving the sciatic nerve, nerve roots and within the axilla and the upper arm. It can cause nerve dysfunction depending on the involved nerve. Neurolymphomatosis involving the ulnar nerve is rare. We report a patient with neurolymphomatosis of the ulnar nerve around the elbow that presented with features of cubital tunnel syndrome. A high index of suspicion is necessary in patients with cubital tunnel syndrome that present with uncommon symptoms such as sudden onset, rapid progression and/or severe pain. Level of Evidence: Level V (Therapeutic).

Normative Values for the Sonographic Measurement of the Pediatric Median and Ulnar Nerves

RATIONAL AND OBJECTIVES

Ultrasound investigation of peripheral nerves, long used in the adult population, has been shown to be of value in diagnosing a variety of peripheral nerve abnormalities. More recently, nerve sonography has also been shown to be of use in pediatrics. However, normative values for nerve size in children have been lacking. As such, the goal of this research was to establish normative data for cross sectional area (CSA) measurements of the median and ulnar nerves in children.

MATERIALS AND METHODS

The median and ulnar nerves of 48 children ranging in age from 2 years to 17 years were imaged by ultrasound. CSA measurements were made at 2 separate sites for each nerve and measured independently by 6 pediatric radiologists. Reliability of ultrasound measurements between the radiologists was assessed by calculating intraclass correlation coefficients. Linear mixed-effects modeling was performed to develop prediction models for nerve cross sectional area for each nerve segment; 95% prediction values were generated from these models to approximate normal ranges.

RESULTS

Agreement in nerve cross-sectional area measurements among the 6 radiologists for all nerve segments was good (ICC 0.82, 95% CI 0.78 to 0.85). CSA for both the median and ulnar nerves is larger in older children. However, statistical models to predict CSA using height perform better rather than those using a child's age. The range of normal nerve segment CSA using these prediction models based on child height are reported.

CONCLUSION

Median and ulnar nerve CSA can be reliably measured with ultrasound. Normal reference values for ulnar and median nerve CSA correlate with patient age but may be more optimally determined based on a child's height.

Imaging the intermuscular septum in the context of ulnar neuropathy

Impingement/entrapment of the ulnar nerve by the intermuscular septum at the distal arm is a common cause of recurrent or recalcitrant ulnar neuropathy following ulnar nerve decompression or anterior transposition. Primary entrapment/impingement of the ulnar nerve along the intermuscular septum may also occur. Evaluation with both ultrasound (US) and MRI can identify entrapment of the ulnar nerve at the intermuscular septum, while dynamic assessment with US can also identify dynamic subluxation of the ulnar nerve over the intermuscular septum.

Sonographic normal values for the cross-sectional area of the ulnar nerve: a systematic review and meta-analysis

PURPOSE

Nerve size is a commonly used sonographic parameter when assessing suspected entrapment of the ulnar nerve. We aimed to create a robust set of normal values, based on a critical review of published normal values.

METHODS

We performed a systematic evaluation of studies on normal ulnar nerve sizes, identified in PubMed, Embase, and Cochrane databases. Using meta-analyses, we determined pooled mean cross-sectional area (CSA) values for different anatomical locations of the ulnar nerve throughout the arm. Subgroup analyses were performed for gender, probe frequency, in- or exclusion of diabetic patients, position of the elbow and Asian versus other populations.

RESULTS

We identified 90 studies of which 77 studies were included for further analyses after quality review, resulting in data from 5772 arms of 3472 participants. Subgroup analyses show lower CSA values at at the wrist crease and proximal to the wrist crease when using low frequency probes (< 15 MHz) and at the wrist crease, proximal to the wrist crease, proximal forearm and the distal upper arm in Asians. CSA values were lower when in flexed position compared to extended position for the cubital tunnel inlet only. No difference was found for gender.

CONCLUSIONS

Our systematic review provides a comprehensive set of normal values at sites along the entire length of the ulnar nerve. This provides a foundation for clinical practise and upon which future studies could be more systematically compared.

The muscular branching patterns of the ulnar nerve in fetal forearms

OBJECTIVE

We aimed to present our findings systematically by examining the muscular branching patterns of the ulnar nerve (UN) in the forearms of fetuses.

METHODS

This study was conducted on the 52 forearms of 26 formalin-fixed fetal cadavers with gestational ages varying between 19 and 37 weeks. The anatomical dissection was performed by using stereomicroscope with × 8 magnification. The numbers of muscular branches leaving UN and their order of leaving main nerve were noted down. The findings were classified according to the muscles they reached, and branching typing was done.

RESULTS

It was found that a total of 2-6 muscular branches left UN to reach flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP). UN was classified by separating into five main types according to the number of muscular branches, and these types were classified into 16 different branching patterns according to the order of branches leaving from the main trunk and going to FCU and FDP. The pattern where two branches left UN was classified as Type I (n = 6), three branches left was classified as Type II (n = 18), four branches left was classified as Type III (n = 24), five branches left was classified as Type IV (n = 3), and six branches left was classified as Type V (n = 1). Martin-Gruber connection occurred in 17 (32.7%) fetal forearms.

CONCLUSION

We believe that the information that UN can demonstrate different branching patterns on the forearm can help the surgeons to prevent complications that may develop in potential nerve injury during the selection and transfer of relevant branch.

Diagnosis of ulnar nerve entrapment anterior to the medial epicondyle by ultrasound elastography and diffusion tensor imaging with fiber tractography: a case report

Ulnar/cubital tunnel syndrome is the second most common compressive neuropathy of the upper limb. Permanent location of the ulnar nerve anterior to the medial epicondyle is extremely rare, with only five cases reported in the literature. Using ultrasound elastography and diffusion tensor imaging with fiber tractography, we diagnosed a case in which ulnar nerve entrapment was associated with anterior nerve location. Surgical release confirmed the diagnosis and the patient was symptom free 3 months after surgery.

Diagnostic characterization

Martin-Gruber communicating branch may be a confounding factor in the diagnosis of ulnar neuropathy at the elbow. It may also lead to a surprising level of motor function conservation despite evident neuropathy. We present a patient with ulnar nerve section at the elbow who underwent early treatment by nerve suture. At 7 months, function was good, despite sonographic findings of neurotmesis at the elbow. Electroneurography revealed Martin-Gruber communicating branch. This type of communicating branch can be associated with functional conservation despite ulnar nerve section. Electrophysiological and ultrasound findings can be highly contributive in defining these conditions.