Symptomatic Idiopathic Ulnar Nerve Instability in the Elbow Diagnostic Considerations and 1-Year Outcomes After Anterior Transposition of Ulnar Nerve.

BACKGROUND: Symptomatic idiopathic ulnar nerve instability (IUNI) in the elbow is an uncommon condition characterized by symptoms of ulnar neuritis resulting from frictional injury to the ulnar nerve from repetitive subluxation out of the cubital tunnel. This study reports the 1-year clinical outcomes after treatment of IUNI with anterior transposition of the ulnar nerve. METHODS: This is a retrospective case study of five patients. Ulnar nerve instability was diagnosed clinically based on the presence of ulnar neuritis symptoms in combination with a positive "ulnar nerve push past" test. Electromyography (EMG) was performed on all patients. After failure of nonsurgical treatment, five patients underwent anterior subcutaneous transposition of the ulnar nerve at the elbow. Clinical outcome scores and time to resolution of symptoms were recorded at a minimum follow-up of 12 months. RESULTS: The mean age of the patients at the time of surgery was 37.8 years (range: 18 to 57 years). The mean duration of symptoms prior to surgery was 15.7 ± 4.9 months. All five patients reported neuritis symptoms in the distribution of ulnar nerve in the hand and had ulnar nerve instability in the cubital tunnel on clinical examination. All patients were symptom free within 6 months after anterior transposition of the ulnar nerve.

Evaluation of the efficacy of low-level laser therapy in the treatment of ulnar neuropathy at the elbow in terms of symptoms and clinical and electrophysiological findings: a randomized, prospective, double-blind clinical trial.

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy and presents with symptoms such as pain, paresthesia, and weakness in the elbow. Provocative tests and electrophysiological examinations are helpful in the diagnosis of UNE. Low-level laser therapy is one of the conservative treatments of UNE however, limited results were reported on the effectiveness of low-level laser therapy (LLLT) in the treatment of UNE. In our study, we aimed to the efficacy of LLLT in reducing symptoms and providing clinical and electrophysiological improvement in patients with UNE. This study with a randomized-sham controlled, and double-blind design included 68 patients aged 18-60 years who were diagnosed with UNE. LLLT was applied to the first group, and sham laser was applied to the second group. The VAS pain, paresthesia, and weakness scores, grip strength, and provocative test positivity were evaluated in clinical examination. The QuickDASH questionnaire was administered to assess functional status. Electrophysiologically, motor distal latency (MDL) differences, sensory distal latency (SDL), motor and sensory nerve conduction velocity (NCV) were examined. Evaluations were performed before treatment and on the 15th day and at the third month after treatment. The LLLT group showed improvement in symptoms, clinical findings, motor NCV, and MDL at both post-treatment evaluations and sensory NCV on the post-treatment 15th day (p < 0.05). The comparison of post-treatment changes between the two groups revealed that the LLLT group had greater improvement in VAS day and night pain scores at both post-treatment evaluation times, QuickDASH scores at the third month, and sensory NCV on the 15th day (p < 0.05) compared to the SL group. There were no significant differences between the groups in terms of the post-treatment changes in VAS weakness scores, grip strength and electrophysiological findings (p > 0.05). It was observed that splinting alone was effective in UNE, but the addition of LLLT, one of the conservative treatment methods, enhanced treatment outcomes.

Diagnostic efficiency of conventional ultrasound, shear wave elastography, and superb microvascular imaging in evaluating ulnar neuropathy at the elbow.

INTRODUCTION/AIMS: The current diagnosis of ulnar neuropathy at the elbow (UNE) relies mainly on the clinical presentation and nerve electrodiagnostic (EDX) testing, which can be uncomfortable and yield false negatives. The aim of this study was to investigate the diagnostic value of conventional ultrasound, shear wave elastography (SWE), and superb microvascular imaging (SMI) in diagnosing UNE. METHODS: We enrolled 40 patients (48 elbows) with UNE and 48 healthy volunteers (48 elbows). The patients were categorized as having mild, moderate or severe UNE based on the findings of EDX testing. The cross-sectional area (CSA) was measured using conventional ultrasound. Ulnar nerve (UN) shear wave velocity (SWV) and SMI were performed in a longitudinal plane. RESULTS: Based on the EDX findings, UNE severity was graded as mild in 4, moderate in 10, and severe in 34. The patient group showed increased ulnar nerve CSA and stiffness at the site of maximal enlargement (CSA mean at the site of max enlargement [CSAmax] and SWV mean at the site of max enlargement [SWVmax]), ulnar nerve CSA ratio, and stiffness ratio (elbow-to-upper arm), compared with the control group (p < .001). Furthermore, the severe UNE group showed higher ulnar nerve CSAmax and SWVmax compared with the mild and moderate UNE groups (p < .001). The cutoff values for diagnosis of UNE were 9.5 mm2 for CSAmax, 3.06 m/s for SWVmax, 2.00 for CSA ratio, 1.36 for stiffness ratio, and grade 1 for SMI. DISCUSSION: Our findings suggest that SWE and SMI are valuable diagnostic tools for the diagnosis and assessment of severity of UNE.

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.

Length of affected nerve segment in ulnar neuropathies at the elbow.

OBJECTIVE: To establish length of the affected nerve segment (LANS) in ulnar neuropathy at the elbow (UNE). METHODS: In a group of our previously reported UNE patients we identified 2-cm segments with reduced motor nerve conduction velocity (MNCV) on electrodiagnostic (EDx) studies and increased nerve cross-sectional areas (CSA) on ultrasonographic (US) studies. LANS was obtained by summation of these abnormal 2-cm segments separately for each approach. We also studied effect of selected independent parameters on LANS. RESULTS: Altogether we studied 189 patients (194 arms). Mean (SD) LANS determined in 171 arms with reduced ulnar MNCV was 4.15 (1.89) cm, and was similar (p = 0. 21) to LANS obtained in 147 arms with increased CSA 4.46 (2.29) cm. Longer LANS were found in right arms, clinically severe UNE, axonal UNE and UNE due to entrapment. The most commonly affected 6 cm segment included 89% of abnormal 2-cm segments, with 50% of included 2-cm segments being normal. By contrast, the whole 10 cm segment included all abnormal 2-cm segments, with 66% of included segments being normal. CONCLUSIONS: In UNE both EDx and US studies revealed average LANS of around 4 cm. LANS was longer in more severe UNE. SIGNIFICANCE: LANS needs to be taken into account in discussion of the mechanisms of UNE and approach to EDx diagnosis of UNE, particularly length of the segment used in nerve conduction studies across the elbow.

The red flags of ulnar neuropathy in leprosy.

The diagnosis of pure neural leprosy is more challenging because patients share characteristics with other common pathologies, such as ulnar compression, which should be taken into consideration for differential diagnosis. In this study, we identify ulnar nerve conduction characteristics to aid in the differential diagnosis of ulnar neuropathy (UN) in leprosy and that of non-leprosy etiology. In addition, we include putative markers to better understand the inflammatory process that may occur in the nerve. Data were extracted from a database of people affected by leprosy (leprosy group) diagnosed with UN at leprosy diagnosis. A non-leprosy group of patients diagnosed with mechanical neuropathy (compressive, traumatic) was also included. Both groups were submitted to clinical, neurological, neurophysiological and immunological studies. Nerve enlargement and sensory impairment were significantly higher in leprosy patients than in patients with compressive UN. Bilateral impairment was significantly higher in the leprosy group than in the non-leprosy group. Leprosy reactions were associated to focal demyelinating lesions at the elbow and to temporal dispersion (TD). Clinical signs such as sensory impairment, nerve enlargement and bilateral ulnar nerve injury associated with eletrodiagnostic criteria such as demyelinating finds, specifically temporal dispersion, could be tools to help us decided on the best conduct in patients with elbow ulnar neuropathy and specifically decide if we should perform a nerve biopsy for diagnosis of pure neural leprosy.

Expert consensus on the combined investigation of ulnar neuropathy at the elbow using electrodiagnostic tests and nerve ultrasound.

The addition of ultrasound (US) to electrodiagnostic (EDX) tests can significantly enhance the accuracy of testing for ulnar neuropathy at the elbow (UNE). We aimed to obtain expert consensus to guide clinicians on the combined use of EDX and US in UNE investigation. Consensus was achieved using the Delphi method. Two consecutive anonymised questionnaires were submitted to 15 experts, who were asked to choose their level of agreement with each statement. Consensus was pre-defined as ≥ 80% rating agreement. The experts concluded that all investigations of UNE should include both nerve conduction studies and US. There was consensus that US should include cross-sectional area measurement and assessment of nerve mobility at the elbow, and that the entire ulnar nerve should be imaged. This study defined expert opinion on the 'core' techniques that should be used routinely in the UNE investigation using EDX and US. Areas with lack of consensus highlighted some controversial issues in the current use of these diagnostic modalities and the need for future research. This document is an initial step to guide clinicians on the combined investigation of UNE using EDX and US, to be regularly updated as new research emerges.

Enhancing diagnostic accuracy using a side-to-side cross-sectional area ratio for the diagnosis of unilateral ulnar mononeuropathy at the elbow.

INTRODUCTION: Neuromuscular ultrasonography (NMUS) is a valuable adjunct to electrodiagnostic testing for the diagnosis of entrapment neuropathy. The aim of this study was to determine whether diagnostic accuracy of NMUS could be enhanced in patients with unilateral ulnar mononeuropathy at the elbow (UNE) by utilizing side-to-side ulnar nerve cross-sectional area (CSA) ratios. METHODS: Retrospective case-control analysis of unilateral UNE cases identified cutoff values for elbow segment ulnar nerve maximum CSA (MCSA) of the symptomatic/asymptomatic limb (M ratio), as well as side-to-side ratios comparing MCSA with ipsilateral CSA at the Guyon canal (E/G), middle forearm (E/F), and middle humerus (E/H). Diagnostic accuracy values were calculated. RESULTS: The optimal M-ratio cut-off was 1.22 (sensitivity, 92.9%; specificity, 97.8%; accuracy, 95.4%). Optimal cutoffs for inter-E/G, -E/F, and -E/H ratios were 1.07 (sensitivity, 98%; specificity, 78%; accuracy, 87.7%), 1.11 (sensitivity, 95%; specificity, 80%; accuracy, 87.2%), and 1.18 (sensitivity, 95%; specificity, 93%; accuracy, 94%), respectively. DISCUSSION: The M ratio and inter-E/H ratio exhibited high diagnostic accuracy for unilateral UNE. Prospective studies are needed to compare the accuracy of the new measures with a single MCSA measurement.

Ultrasonography in Distal Ulnar Nerve Neuropathy: Findings in 33 Patients.

PURPOSE: Although there are many case reports on the role of ultrasonography (US) in distal ulnar nerve neuropathy (Guyon canal syndrome), there is a paucity of large series in the literature because of its rarity. During an 8-year period, 33 instances of electrodiagnostically confirmed cases underwent US imaging. These cases were analyzed to determine the role of US in uncovering the cause of distal ulnar nerve neuropathy and its contribution to further management. METHODS: This was a retrospective study of patients diagnosed with distal ulnar nerve neuropathy based on electrodiagnostic criteria, who also had undergone US (measurement of the cross-sectional area and documentation of causes such as cysts and neuromas). RESULTS: US showed normal ulnar nerve in 5, cysts in 10, neuromas in 2, and nonspecific enlargement in 16 patients. Surgery was performed in 15 patients, and the US findings were corroborated in those with cysts and neuromas; 1 patient had an aberrant muscle, and two had fibrous bands constricting the ulnar nerve in the Guyon canal (not detected preoperatively by US imaging). CONCLUSIONS: US imaging detected the underlying cause of distal ulnar nerve neuropathy in a significant percentage of patients, potentially contributing to effective treatment.

An electrodiagnostic grading system for ulnar neuropathy at the elbow.

INTRODUCTION: Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy. Our goal was to create and analyze a grading system for UNE electrodiagnostic severity. METHODS: We retrospectively analyzed EMG reports with UNE. We then classified 112 limbs as having mild, moderate, or severe grade UNE based on electrodiagnostic findings. The association between presenting symptoms and signs, EMG findings, treatment type, and electrodiagnostic grade was statistically analyzed. RESULTS: Seventeen limbs (15.2%) had mild, 80 (71.4%) had moderate, and 15 (13.4%) had severe UNE. Symptoms (P = .016), exam findings (P < .001), and treatment type (P = .043) were significantly associated with electrodiagnostic grade. DISCUSSION: Our UNE grading system was significantly related to symptoms, physical exam, and treatment selection and may be useful to measure electrodiagnostic severity.

Distal radius fractures: an evidence-based approach to assessment and management.

Distal radius fractures account for one in five bony injuries in both primary and secondary care. These are commonly the result of a fall on outstretched hands or high-energy trauma. On assessment, clinicians should determine the mechanism of injury, associated bony or soft tissue injuries, and neurovascular symptoms. Investigations should always include radiographs to evaluate for intra-articular involvement and fracture displacement. Owing to the heterogeneous injury patterns and patient profiles, the preferred management should consider the severity of the fracture, desired functional outcome and patient comorbidities. Non-operative management in select patients can give good results, especially in older adults. Immobilisation with or without reduction forms the mainstay of non-operative treatment. Surgical management options include closed reduction and application of a cast, percutaneous K-wires, open reduction and internal fixation with plates, or external fixation. Patients should be encouraged to mobilise as soon as it is safe to do so, to prevent stiffness. Median nerve compression is the most common complication followed by tendon rupture, arthrosis and malunion. This article outlines the British Orthopaedic Association Standards for Trauma and Orthopaedics for the management of distal radius fractures.

In situ decompression vs conservative treatment for mild ulnar neuropathy at the elbow.

INTRODUCTION: The best treatment strategy for mild ulnar neuropathy at the elbow (UNE) is not known, due to lack of trials comparing surgery vs conservative treatment. METHODS: We recruited patients with clinical symptoms and signs of mild UNE and an electrophysiologically or sonographically confirmed diagnosis. Patients were randomly allocated to either in situ decompression or conservative treatment. The primary outcome was the proportion of patients with subjective symptom improvement at short-term (3 months) and long-term (6-12 months) follow-up. RESULTS: One hundred seventeen patients were included: 56 and 61 patients were allocated to surgery and conservative treatment, respectively. A larger proportion of surgically treated patients showed improvement at short-term follow-up (85% vs 50%; odds ratio, 5.6; P < .001), but no differences were observed at long-term follow-up. DISCUSSION: In situ decompression for mild UNE may result in faster relief of symptoms when compared with conservative treatment, but at long-term follow-up no differences were observed.

Perineural Dextrose and Corticosteroid Injections for Ulnar Neuropathy at the Elbow: A Randomized Double-blind Trial.

OBJECTIVE: To assess the effects of perineural corticosteroid and 5% dextrose water (D5W) injections in patients with mild to moderate ulnar neuropathy at the elbow (UNE). DESIGN: Prospective, randomized, double-blind, controlled trial (6-month follow-up). SETTING: Outpatients of local medical center settings. PARTICIPANTS: Patients (N=36) with mild to moderate UNE were randomized, and 33 participants were included in the final data analysis. INTERVENTIONS: Patients were administered a single perineural injection with 5 mL D5W and 3 mL corticosteroid (triamcinolone acetonide, 10mg/mL) mixed with 2 mL normal saline under ultrasound guidance in the dextrose and steroid groups, respectively. MAIN OUTCOME MEASURES: The visual analog scale digital pain or paresthesia/dysesthesia score was the primary outcome. The secondary outcomes were the Disabilities of the Arm, Shoulder, and Hand questionnaire, motor nerve conduction velocity, and cross-sectional area (CSA) of the ulnar nerve. The measurement assessment was conducted before and 1, 3, 4, and 6 months after injection. RESULTS: Thirty-three patients completed the study. Both injections were found to be equally effective at most measurement points, although the dextrose group experienced larger reductions in symptom severity and CSA of the ulnar nerve from the third month onward. CONCLUSIONS: We suggest D5W as a more suitable injectate for perineural injection in patients with UNE.

The needle electromyography findings in the neurophysiological classification of ulnar neuropathy at the elbow

Background/aim: Although ulnar neuropathy at the elbow (UNE) is the second most common entrapment mononeuropathy, there are few reports on its neurophysiological classification. In this study, we tried to find out the role of needle electromyography (EMG) in the neurophysiological classification of UNE. Materials and methods: UNE patients who met the clinical and neurophysiological diagnostic criteria and healthy individuals were included in this study. Reference values of nerve conduction studies were obtained from healthy individuals. Needle EMG was performed to all UNE patients. According to the neurophysiological classification proposed by Padua, UNE patients were classified as mild, moderate, and severe. Results: Thirty-one controls and thirty-five UNE patients were included in the study. There was mild UNE in 23 patients, moderate UNE in 8, and severe UNE in 4. Abnormal needle EMG findings were present in all patients with moderate and severe UNE and in 12 patients with mild UNE. Conclusion: Abnormal needle EMG findings are seen in most of the UNE patients. Therefore, it is not practical to use needle EMG findings in the neurophysiological classification. Needle EMG abnormalities may also be present in patients with mild UNE due to axonal degeneration or motor conduction block.

Ulnar neuropathy at the elbow in 413 Japanese patients: An assessment of pathological elbow lesions and neurological severity.

BACKGROUND: Various pathological elbow lesions are often complicated with ulnar neuropathy at the elbow (UNE), although the precise pathology, incidence, and clinical and neurological features of these lesions have not been identified. We therefore investigated elbow pathology and neurological severity in Japanese patients with UNE. METHODS: The medical records of 457 Japanese UNE patients who were surgically treated among 6 hospitals were retrospectively examined. Eligible patients had UNE diagnosed by physical findings and nerve conduction studies according to the criteria of the American Association of Electrodiagnostic Medicine. The elbows were analyzed with regard to age, gender, occupation, pathology at the elbow, and severity of nerve palsy. RESULTS: A total of 398 patients with 413 UNE elbows of a mean age of 63 years (range: 15-87) met the inclusion criteria. UNE elbows were predominantly in male patients (69.0%). Overall, 310 elbows (75.1%) had 1 or more elbow lesions: 238 elbows (76.8%) had a single lesion and 72 elbows (23.3%) had 2 or more lesions. The most common lesion was primary elbow osteoarthritis (EOA) occurring in 54.5% of elbows, followed next by medial elbow ganglion in 8.5% and cubitus valgus in 6.5%. Most elbows with medial elbow ganglion or cubitus valgus were associated with EOA. Entrapment sites were at the cubital tunnel in 84.5%-91.3% of UNE elbows, regardless of an association with elbow lesion. The incidence of McGowan grade III lesion was 50.8% in elbows with primary EOA, which was higher than the 35.0% in elbows with no lesion. CONCLUSIONS: This study revealed that UNE had various isolated or combined elbow lesions. In Japanese UNE, primary or secondary EOA was found in 62.2% of cases and severe motor weakness was noted in 47.2%. The incidences of EOA and severe ulnar nerve palsy in the Japanese UNE are higher than those in Caucasians. LEVEL OF EVIDENCE: Level IV; Prognostic-Investigating the effect of a patient characteristic on the outcome of a disease; Case series.

Ulnar neuropathy at the elbow: Reappraisal of the wrist-upper arm latency difference between ulnar and median nerves.

OBJECTIVES: To evaluate the sensitivity and specificity of the latency difference (DLat) between ulnar and median nerves of the arm after stimulation at the wrist; one of the easiest techniques proposed for recognizing ulnar neuropathy at the elbow (UNE). As latency difference is not a standardized technique, we set up a multicenter study to recruit large numbers of normal subjects and patients with UNE or generalized neuropathy. METHODS: Six centers participated in the study with data obtained from three groups of participants, controls (CTRLs), patients with UNE and patients with generalized neuropathy (GNP). We first verified the anatomical superposition of the ulnar and median nerves in cadaver examination. The optimal recording site for these two nerves was found to be 10 cm above the medial epicondyle. We then standardized the position of the arm with full extension of the elbow and stimulated first the median and then the ulnar nerves at the wrist. CTRLs were examined on both arms at two consecutive visits. RESULTS: We recorded 32 idiopathic UNE cases, 44 GNP patients and 62 controls. We demonstrated that a DLat cut-off value of 0.69 ms brings a sensitivity of 0.86 and specificity of 0.89 to discriminate CTRLs from UNE. We also validated that intra-examiner reproducibility was good. CONCLUSION: We report a lower normal value for DLat than reported in several non-standardized studies and CTRL and UNE groups have clearly separated DLat values. SIGNIFICANCE: Due to its high sensitivity, our standardized technique could be used as a first-line diagnostic tool when UNE is suspected.

Pilot study: Differences in echo intensity ratios between ulnar and median innervated muscles in ulnar neuropathy.

BACKGROUND: This study evaluated muscle echo intensity (EI) ratio in patients with ulnar neuropathy at the elbow (UNE) and healthy controls. METHODS: In this prospective study, 28 patients with electrodiagnostically confirmed unilateral UNE and 12 healthy controls were ultrasonographically assessed for EI ratios of the hypothenar and thenar muscles. The affected and unaffected hands between the UNE patients and controls and patient subgroups (subdivided according to electrodiagnostic severity) were compared to determine any significant differences. RESULTS: In patients with UNE, the EI ratio of the hypothenar to thenar muscles was significantly higher for the affected side than for the unaffected side (1.08 ± 0.11 and 0.97 ± 0.18, respectively) or the control group (0.95 ± 0.05). A significant difference in the EI ratio was observed among the subgroups (mild vs. severe subgroup, P < 0.01). CONCLUSIONS: Ultrasonographic EI measurement may be a useful parameter in the evaluation and screening of UNE.

Quantitative muscle ultrasound in upper extremity mononeuropathies.

INTRODUCTION: We assessed the potential use of quantitative ultrasound (QUS) in the evaluation hand muscles affected by upper extremity mononeuropathies. METHODS: The gray scale levels (GSLs) of abductor pollicis brevis (APB), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) of 30 healthy and 30 upper extremity mononeuropathy patients were measured and compared with standard electrophysiological values. RESULTS: Mean GSL was elevated in 34 APBs of carpal tunnel syndrome patients and 18 FDIs of ulnar neuropathy patients (e.g., FDI mean GSL (interquartile range) 31.5 (27.3~43.8) arbitrary units for patients and 24.0(23.0~29.0) for healthy subjects (P = 0.020)). GSL correlated with motor response amplitudes (Spearman's rho (ρ) = -0.39, P = 0.002 in APB, ρ = -0.72, P = 0.002 in FDI, and ρ = -0.43, P = 0.013 in ADM). The APB GSL correlated with electromyographic severity and disease duration (ρ = 0.46, P < 0.001 and ρ = 0.45, P = 0.003). CONCLUSIONS: Muscle QUS may serve as a useful tool in upper extremity mononeuropathy evaluation. Further study of this concept is recommended.