Association Between Gender, Body Mass Index, and Ulnar Nerve Entrapment at the Elbow: A Retrospective Study

Utilizing Diagnostic Musculoskeletal Ultrasound in the Evaluation of Cubital Tunnel Syndrome and Ulnar Nerve Pathology

Cubital Tunnel Syndrome (CTS), is a frequently encountered condition in clinical settings, typically arising from static or dynamic compression of the ulnar nerve. CTS is characterized by the irritation of the ulnar nerve within the cubital tunnel and is a common neuropathic condition that can significantly impact functional abilities and quality of life. This article explores the utility of diagnostic musculoskeletal ultrasound (MSK-US) in the evaluation of the cubital tunnel and the ulnar nerve. The cubital tunnel syndrome, a common entrapment neuropathy of the ulnar nerve, often presents diagnostic challenges. Traditionally, nerve conduction studies and electromyography have been the primary diagnostic tools used to diagnose CTS. Given the superficial nature of the ulnar groove and its adjacent structures, MSK-US imaging known for its non-invasive nature and high-resolution imaging capabilities, has become an increasingly valuable tool in the assessment and management of various musculoskeletal conditions. This article reviews the technical aspects of MSK-US, its advantages in visualizing the ulnar nerve and related structures, and its implications in clinical practice for rehabilitation providers. By integrating MSK-US in the evaluation of CTS, rehabilitation professionals can enhance diagnostic accuracy, tailor interventions, and improve patient outcomes.

Demographics of Common Compressive Neuropathies in the Upper Extremity

BACKGROUND

The purpose of this study was to compare the demographic differences of the most common peripheral nerve compressions in the upper extremity-carpal tunnel syndrome (CTS), ulnar nerve compression (UNC) at the elbow, combined CTS and UNC, radial tunnel syndrome (RTS), and posterior interosseous nerve syndrome (PINS)-as a means to better understand the etiologies of each.

METHODS

A retrospective chart review was performed of all patients over the age of 18 years seen at our institution in the 2018 calendar year. International Classification of Diseases, Tenth Revision codes were used to identify patients with diagnoses of upper extremity peripheral nerve compressions. Demographic details and relevant comorbidities were recorded for each patient and compared with controls, who were seen the same calendar year with no neuropathies. χ2 analyses, independent-samples t tests, and multivariate logistic regressions were performed (P < .05).

RESULTS

A total of 7448 patients were identified. Those with CTS were mainly women, former smokers, and diabetic (all P < .001) and with a greater average body mass index (BMI) (P = .006) than controls. Patients with UNC were more often men and younger when compared with controls (both P < .001). A history of smoking, diabetes, and average BMI were similar between patients with UNC and controls (all P > .05). Those patients with combined CTS/UNC were mainly men, former smokers, and diabetic (all P < .001) when compared with controls. Patients with RTS/PINS were also mostly men (P = .007), diabetic (P = .042), and were more often current smokers (P < .001).

CONCLUSIONS

The demographics of patients with various compressive neuropathies were not homogeneous, suggesting different etiologies.

The Unpredictable Ulnar Nerve-Ulnar Nerve Entrapment from Anatomical, Pathophysiological, and Biopsychosocial Aspects

Peripheral nerves consist of delicate structures, including a rich microvascular system, that protect and nourish axons and associated Schwann cells. Nerves are sensitive to internal and external trauma, such as compression and stretching. Ulnar nerve entrapment, the second most prevalent nerve entrapment disorder after carpal tunnel syndrome, appears frequently at the elbow. Although often idiopathic, known risk factors, including obesity, smoking, diabetes, and vibration exposure, occur. It exists in all adult ages (mean age 40-50 years), but seldom affects individuals in their adolescence or younger. The patient population is heterogeneous with great co-morbidity, including other nerve entrapment disorders. Typical early symptoms are paresthesia and numbness in the ulnar fingers, followed by decreased sensory function and muscle weakness. Pre- and postoperative neuropathic pain is relatively common, independent of other symptom severity, with a risk for serious consequences. A multimodal treatment strategy is necessary. Mild to moderate symptoms are usually treated conservatively, while surgery is an option when conservative treatment fails or in severe cases. The decision to perform surgery might be difficult, and the outcome is unpredictable with the risk of complications. There is no consensus on the choice of surgical method, but simple decompression is relatively effective with a lower complication rate than transposition.

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.

Do Socioeconomic Factors Affect Symptom Duration and Disease Severity at Presentation for Cubital Tunnel Syndrome?

BACKGROUND

Socioeconomic factors have been implicated in delayed presentation for compressive neuropathies of the upper extremity. Our article seeks to elucidate the effect of socioeconomic factors on self-reported symptom duration and objective disease severity at presentation for cubital tunnel syndrome.

METHODS

This retrospective cohort study included 207 patients with surgical management of cubital tunnel syndrome at 2 institutions between June 1, 2015, and March 1, 2020. Exclusion criteria included age under 18 years, revision surgery, lack of preoperative electrodiagnostic studies, and concurrent additional surgeries. Response variables were self-reported symptom duration, time from presentation to surgery, McGowan grade, and electrodiagnostic measures. Explanatory variables included age, sex, white race, diabetes mellitus, depression, anxiety, and the Distressed Communities Index.

RESULTS

Symptom duration was associated with nonwhite race, and time from presentation to surgery was associated with insurance provider. More clinically severe disease was associated with older age, male sex, and not having carpal tunnel syndrome. Nonrecordable sensory nerve action potential latency was associated with older age, higher body mass index, male sex, diabetes mellitus, and unemployment. Nonrecordable conduction velocities were associated with older age, and having fibrillations at presentation was associated with older age, male sex, and unemployment.

CONCLUSIONS

Economic distress is not associated with self-reported symptom duration, time from presentation to surgery, or presenting severity of cubital tunnel syndrome. White patients presented with shorter self-reported symptom duration. Insurance type was associated with delay from presentation to surgery. Older age and male sex were risk factors for more clinically severe disease at presentation.

Factors Associated With Severity of Cubital Tunnel Syndrome at Presentation

BACKGROUND

The outcomes of cubital tunnel syndrome surgery are affected by preoperative disease severity. The aim of this study was to identify factors associated with clinical and electrodiagnostic severity of cubital tunnel syndrome at presentation.

METHODS

We retrospectively identified 213 patients with electrodiagnostically confirmed cubital tunnel syndrome who underwent cubital tunnel surgery from July 2008 to June 2013. Our primary response variable was clinical cubital tunnel syndrome severity assessed by the McGowan grade. Our secondary response variables were sensory nerve action potential (SNAP) recordability, presence of fibrillations, and motor nerve conduction velocities (CVs) in the abductor digiti minimi (ADM) and first dorsal interosseous (FDI). Bivariate analysis was used to screen for factors associated with disease severity; significant variables were selected for multivariable regression analysis.

RESULTS

Older age was associated with higher McGowan grade and diabetes mellitus was associated with unrecordable SNAPs on bivariate analysis. No other variables met inclusion criteria for multivariable regression analysis for McGowan grade or unrecordable SNAPs. Multivariable regression analysis showed older age and higher Distressed Communities Index (DCI) to be associated with decreased motor nerve CVs in ADM. Multivariable regression analysis showed higher body mass index (BMI) and higher DCI to be associated with decreased motor nerve CVs in FDI. No variable was associated with the presence of fibrillations.

CONCLUSIONS

A subset of patients with cubital tunnel syndrome may benefit from earlier referral for hand surgery evaluation and earlier surgery. Older patients, with higher BMI, with diabetes mellitus, and with economic distress are at higher risk for presentation with more severe disease.

Socioeconomic Differences between Sexes in Surgically Treated Carpal Tunnel Syndrome and Ulnar Nerve Entrapment

We aimed to investigate socioeconomic differences between sexes and the influence on outcome following surgery for carpal tunnel syndrome (CTS) or ulnar nerve entrapment (UNE) at the elbow. Patients with CTS (n = 9000) or UNE (n = 1266) registered in the Swedish National Register for Hand Surgery (HAKIR) 2010-2016 were included and evaluated using QuickDASH 12 months postoperatively. Statistics Sweden (SCB) provided socioeconomic data. In women with CTS, being born outside Sweden, having received social assistance, and more sick leave days predicted worse outcomes. Higher earnings and the highest level of education predicted better outcomes. In men with CTS, more sick leave days and having received social assistance predicted worse outcomes. Higher earnings predicted better outcomes. For women with UNE, higher earnings predicted better outcomes. In men with UNE, only sick leave days predicted worse outcomes. In long-term follow up, socioeconomic status affects outcomes differently in women and men with CTS or UNE.

Unique Concerns of the Woman Cyclist

Previously a male-dominated activity, female cyclists now make up nearly half of all cyclists in the United States. Although cycling provides a significant number of health benefits, it is an activity that carries risk of injury, both traumatic and nontraumatic. Sex differences are seen in chest trauma and breast injury, as well as pelvic, given the inherent differences in anatomy. Understanding the relationship of the bicycle to the anatomy of the rider can help mitigate risks for injury.

Risk factors of asymptomatic reduction of motor conduction velocity of the ulnar nerve across the elbow

INTRODUCTION

The aim of the study was to check the risk factors for subjects with motor conduction velocity (MCV) reduction of the ulnar nerve across the elbow without symptoms/signs of ulnar neuropathy at the elbow (UNE) using a database of a previous multicenter case-control study on UNE patients.

METHODS

From the previous database, we extracted all asymptomatic UNE (A-UNE) and matched for age and sex with a control and UNE groups with a ratio of 1:2. Anthropometric factors were measured and all participants filled in a questionnaire on demographic, lifestyle factors, and medical history. One-sample proportion test and univariate and multivariate logistic regression analyses were performed.

RESULTS

We enrolled 64 A-UNE, 124 UNE, and 124 controls (mean age 53 years). There were more males with A-UNE than females (74.2%). The predominantly or exclusively concerned side of A-UNE was the right. Logistic regression showed that A-UNE was associated with diabetes (OR = 2.99, 95% CI = 1.21-7.39) and width of cubital groove (CGW) (OR = 0.89, 95%  CI = 0.81-0.97).

DISCUSSION

Risk factors for A-UNE are different from UNE. The prevalence of right side in A-UNE was not due to particular elbow postures. Diabetes is a risk factor, probably because MCV reduction of the ulnar nerve across the elbow was an early manifestation of asymptomatic polyneuropathy in diabetes. A-UNE is associated with narrow CGW as already demonstrated in UNE, even if the OR was higher in UNE than in A-UNE. Only future longitudinal studies will be able to check whether the A-UNE subjects develop symptoms and signs of true mononeuropathy with time.

Ulnar Neuropathy at the Elbow: From Ultrasound Scanning to Treatment

Ulnar neuropathy at the elbow (UNE) is commonly encountered in clinical practice. It results from either static or dynamic compression of the ulnar nerve. While the retroepicondylar groove and its surrounding structures are quite superficial, the use of ultrasound (US) imaging is associated with the following advantages: (1) an excellent spatial resolution allows a detailed morphological assessment of the ulnar nerve and adjacent structures, (2) dynamic imaging represents the gold standard for assessing the ulnar nerve stability in the retroepicondylar groove during flexion/extension, and (3) US guidance bears the capability of increasing the accuracy and safety of injections. This review aims to illustrate the ulnar nerve's detailed anatomy at the elbow using cadaveric images to understand better both static and dynamic imaging of the ulnar nerve around the elbow. Pathologies covering ulnar nerve instability, idiopathic cubital tunnel syndrome, space-occupying lesions (e.g., ganglion, heterotopic ossification, aberrant veins, and anconeus epitrochlearis muscle) are presented. Additionally, the authors also exemplify the scientific evidence from the literature supporting the proposition that US guidance is beneficial in injection therapy of UNE. The non-surgical management description covers activity modifications, splinting, neuromobilization/gliding exercise, and physical agents. In the operative treatment description, an emphasis is put on two commonly used approaches-in situ decompression and anterior transpositions.

Comorbidities, anthropometric, demographic, and lifestyle risk factors for ulnar neuropathy at the elbow: A case control study

We performed a prospective multicenter case-control study to explore the association between ulnar neuropathy at elbow (UNE) and body and elbow anthropometric measures, demographic and lifestyle factors, and comorbidities. Cases and controls were consecutively enrolled among subjects admitted to four electromyography labs. UNE diagnosis was made on clinical and neurographic findings. The control group included all other subjects without signs/symptoms of ulnar neuropathy and with normal ulnar nerve neurography. Anthropometric measurements included weight, height, waist, hip circumferences, and external measures of elbow using a caliper. The participants filled in a self-administered questionnaire on personal characteristics, lifestyle factors, and medical history. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) by fitting unconditional logistic regression models adjusted by center and education level. We enrolled 220 cases (males 61.8%; mean age 51.7 years) and 460 controls (47.4% males; mean age 47.8 years). At multivariable analysis, UNE was associated to male gender (OR = 2.4, 95%CI = 1.6-3.7), smoking habits (>25 pack-years (OR = 2.3, 95%CI = 1.3-4.1), body mass index (OR = 1.05, 95%CI 1.01-1.10), polyneuropathies (OR = 4.1, 95%CI 1.5-11.5), and leaning with flexed elbow on a table/desk (OR = 1.5, 95%CI 1.0-2.2). Cubital groove width (CGW) turned out to be negatively associated with UNE (OR = 0.80, 95%CI = 0.74-0.85). Our study suggests that some personal factors especially anthropometric measures of the elbow may play a role in UNE pathogenesis as the measures of wrist in CTS. We demonstrated that for each millimeter of smaller CGW the risk of idiopathic UNE increases of 25%.

The external elbow measure as surrogate of the anatomical width of cubital groove and possible risk factor of ulnar neuropathy at the elbow

Introduction: There are no studies on elbow anthropometry in ulnar neuropathy at the elbow (UNE). We aimed to test the interrater agreement of external elbow measurements with caliper, the matching of external width of cubital groove (WCG) measures with those obtained through conventional radiography (XR) and ultrasonography (US). The final aim was to evaluate the differences of anthropometric elbow and body measures between UNE cases and controls with multicenter prospective study.Materials and methods: After common training of five observers for external elbow and body anthropometric measurements, we assessed the interrater agreement of measures in a single blind measurement session in 16 healthy volunteers. Then we verified if external WCG measures in eight and four of the above 16 subjects matched with those obtained with US and XR. Finally, we enrolled 40 consecutive idiopathic UNE cases in four electromyographic labs matched for sex and age with 40 controls to evaluate the differences of anthropometric measures.Results: There was high interrater agreement of all anthropometric body and elbow measures (Kendal's and interclass correlation coefficients between 0.84 and >0.9). We found high relations between WCG caliper measures and those obtained with US and XR (r > 0.9). WCG was smaller in cases than in controls (13.2 vs.15.7 mm, p < 0.001). There were no differences in body anthropometric measures (BMI and waist-to-hip ratio).Conclusion: The external measurement of WCG is reliable and reproducible and may be risk factor of UNE. Future studies should be performed in lager samples evaluating the relations with lifestyle and occupational factors.

Constitutional risk factors for focal neuropathies in patients referred for electromyography

BACKGROUND AND PURPOSE

It is well established that patient-related constitutional features predispose to focal peripheral neuropathies. Some of these risk factors were investigated in common focal neuropathies encountered in patients referred for electromyography.

METHODS

Gender, age, height and body mass index (BMI) were analysed retrospectively as risk factors for 11 focal neuropathies. In all, 9686 patients (age range 18-96 years; 58% women) were included from three different centres, with identical methods and equipment.

RESULTS

High BMI was related to carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow (UNE), combined CTS and UNE, meralgia paraesthetica and lumbar radiculopathy. In women, CTS and Morton's metatarsalgia were more common, whilst long thoracic neuropathies, suprascapular neuropathies and UNE were more common in men. Older age increased the risk for CTS, UNE, Morton's metatarsalgia and radiculopathies.

CONCLUSIONS

Age, gender and BMI are important risk factors for many common focal neuropathies.