Bony encasement of the ulnar nerve secondary to heterotopic ossification of the elbow: an evaluation of long-term outcomes

BACKGROUND

Ulnar neuropathy at the elbow caused by heterotopic ossification (HO) is a rare condition. This retrospective study aims to report on 32 consecutive cases of ulnar nerve encasement caused by elbow HO and evaluate long-term outcomes of operative management and a standardized postoperative rehabilitation regimen.

METHODS

A retrospective case series was conducted on 32 elbows (27 patients) that underwent operative management of bony ulnar nerve encasement. All procedures were performed in the inpatient setting at an Academic Level 1 Trauma Center from September 1999 to July 2021 by one of 3 fellowship-trained shoulder and elbow. Postoperatively, all patients received formal physical therapy, HO prophylaxis (30 received indomethacin, 2 received radiation), and a structured continuous passive motion machine regimen. Patient demographics, age, gender, type of injury, history of tobacco use, and medical comorbidities were obtained to include in the analysis. Long-term follow-up examinations were performed to evaluate elbow flexion-extension arc of motion, Mayo Elbow Performance Score, and visual analog scale pain scores.

RESULTS

Thirty-two elbows with complete bony ulnar nerve encasement secondary to HO were identified (14 from burns, 15 from trauma, 3 closed head injuries). Following surgery, the mean flexion-extension arc of motion improved significantly, increasing from 21° to 100° at long-term follow-up (average 8.7 years, range 2-17 years), with statistically significant improvements in preoperative vs. long-term postoperative elbow extension (P < .001), flexion (P < .001), and total arc of motion (P < .001). There was a statistically significant improvement in pre- vs. postprocedure ulnar nerve function, as demonstrated by a decrease in average McGowan grade (1.2-0.7; P = .002). Additionally, 63% of patients with preoperative ulnar neuropathy symptoms (20/32) had either complete resolution or subjective improvement after surgery. The mean time from injury to surgery was 518 days (range 65-943 days). Age, gender, time to surgery, and medical comorbidities were not associated with outcomes. The complication rate was 9% (3/32). Patients had an average flexion-extension arc of motion of 97° and average Mayo Elbow Performance Score of 80 ("good") at long-term follow-up.

CONCLUSIONS

The combination of operative management, postoperative HO prophylaxis, and a regimented rehabilitation program has proven to be a durable solution for treating and ensuring good long-term functional outcomes for patients with elbow HO and bony ulnar nerve encasement. This treatment approach leads to superior range of motion, improved or resolved ulnar neuropathy, and good to excellent long-term functional outcomes.

Gray-Scale and Power Doppler Ultrasound Findings Predictive of Cubital Tunnel Syndrome Severity

BACKGROUND

The use of ultrasound in the diagnosis of cubital tunnel syndrome (CuTS) is an attractive alternative to electrodiagnostic (EDX) studies, but its utility is binary with poor severity correlation. We hypothesize that increasing ulnar nerve cross-sectional area (CSA) and power Doppler measurement of intraneural vascularity may predict the extent of disease.

METHODS

We identified 20 elbows from patients with a history of CuTS and 20 elbows in 10 asymptomatic controls. Electrodiagnosis was performed for symptomatic patients. Gray-scale ultrasound and power Doppler ultrasound were performed to measure CSA and intraneural vascularity in all participants. Functional measures, Boston Carpal Tunnel Questionnaire (BCTQ), and Patient-Reported Outcomes Measurement Information System surveys were also completed.

RESULTS

A strong positive correlation was found between CSA and motor nerve conduction velocity (MNCV) decrease between elbow and forearm, which increased when BCTQ >2 was used as a screening criterion. Increased CSA also demonstrated a high positive predictive value (PPV) in predicting MNCV changes, but poor ability to predict axonal loss. In contrast, power Doppler ultrasound demonstrated 100% PPV and 94% negative predictive value (NPV) in predicting severe CuTS (defined as compound motor action potential [CMAP] amplitude <6 mV and electromyography [EMG] findings).

CONCLUSIONS

Cross-sectional area is a sensitive method for identifying changes in MNCV and amplitude but does not stratify disease severity, as defined by diminished CMAP amplitude and/or evidence of denervation on EMG. The presence of increased intraneural vascularity is relatively sensitive but highly specific for axonal loss. The combination of nerve CSA, BCTQ screening, and power Doppler ultrasound may provide an alternative means for CuTS assessment.

Core outcomes in nerve surgery: development of a core outcome set for ulnar neuropathy at the elbow

OBJECTIVE

Ulnar neuropathy at the elbow (UNE) is common, affecting 1%-6% of the population. Despite this, there remains a lack of consensus regarding optimal treatment. This is primarily due to the difficulty one encounters when trying to assess the literature. Outcomes are inconsistently reported, which makes comparing studies or developing meta-analyses difficult or even impossible. Thus, there is a need for a core outcome set (COS) for UNE (COS-UNE) to help address this problem. The objective of this study was to utilize a modified Delphi method to develop COS-UNE.

METHODS

A 5-stage approach was utilized to develop COS-UNE: stage 1, consortium development; 2, literature review to identify potential outcome measures; 3, Delphi survey to develop consensus on outcomes for inclusion; 4, Delphi survey to develop definitions; and 5, consensus meeting to finalize the COS and definitions. The study followed the Core Outcome Set-STAndards for Development (COS-STAD) recommendations.

RESULTS

The Core Outcomes in Nerve Surgery (COINS) Consortium comprised 21 participants, all neurological surgeons representing 11 countries. The final COS-UNE consisted of 22 data points/outcomes covering the domains of demographic characteristics, diagnostics, patient-reported outcomes, motor/sensory outcomes, and complications. Appropriate instruments, methods of testing, and definitions were set. The consensus minimum duration of follow-up was 6 months, with the consensus optimal timepoints for assessment identified as preoperatively and 3, 6, and 12 months postoperatively.

CONCLUSIONS

The authors identified consensus data points/outcomes and also provided definitions and specific scales to be utilized to help ensure that clinicians are consistent in their reporting across studies on UNE. This COS should serve as a minimum set of data to be collected in all future neurosurgical studies on UNE. The authors hope that clinicians evaluating ulnar neuropathy will incorporate this COS into routine practice and that future studies will consider this COS in the design phase.

Comparison of electrodiagnostic findings in acute traumatic versus chronic non-traumatic ulnar neuropathy at the elbow

INTRODUCTION/AIMS

A common concept is that traumatic nerve injuries are more likely axonal, and that compressive neuropathies are more likely demyelinating. The purpose of this study was to compare traumatic versus non-traumatic ulnar neuropathy at the elbow (UNE) to look for electrodiagnostic differences between the two groups.

METHODS

A retrospective 3 year review of UNE patients at two academic health science centers was conducted. Patients were grouped into acute traumatic UNE versus chronic non-traumatic UNE based on clinical history. Electrodiagnostic measurements were compared between the two groups.

RESULTS

There were 50 subjects with acute traumatic UNE and 41 with chronic non-traumatic UNE. Mean age and sex distribution were similar but those with traumatic UNE had a 7 month duration of symptoms, while those with chronic UNE had 29 month duration (p < .001). All electrodiagnostic measurements were similar between the two groups including compound muscle action potential amplitudes, motor conduction velocities, frequency of conduction block, sensory nerve studies, and needle electromyography.

DISCUSSION

We did not find a difference between the two groups. One should not make inferences regarding acuity or etiology based on electrodiagnostic features alone.

Ulnar Nerve Management in Distal Humerus Fracture Surgery: A Case of Developing Ulnar Neuropathy After Open Reduction and Internal Fixation

In this case report, we want to show how a patient who underwent surgery for a distal humerus fracture developed postoperative ulnar neuropathy symptoms, how nonunion persisted even at the ninth month of follow-up, and whether the nonunion was connected to the ulnar neuropathy that developed. Due to this, we used this case to explore ulnar nerve care and whether ulnar nerve transposition, manipulation, or decompression should be carried out during surgery on patients with distal humerus fractures. A 52-year-old man with a bi-columnar distal humerus fracture from a fall on his right elbow underwent open reduction and internal fixation at an external center one year before. Elbow restriction, discomfort, numbness, and weakness in the fourth and fifth digits of the right hand were all symptoms the patient experienced eight months following the surgery. We discovered the distal right humerus' nonunion during the radiological exams. It became apparent that the patient had no signs of ulnar neuropathy before the injury. In the eighth month following the injury, the patient had implant removal, open reduction internal fixation with autograft, and ulnar nerve transposition. We discovered during follow-up that the patient's ulnar neuropathy symptoms had subsided. The surgeon's familiarity with the procedure and command of the anatomy of the elbow has a role in managing the ulnar nerve in distal humerus fractures. We concluded that more study is required to determine the connection between the onset of ulnar neuropathy and nonunion while treating distal humerus fractures.

Cubital Tunnel Syndrome: Does a Consensus Exist for Diagnosis?

PURPOSE

Cubital tunnel syndrome (CuTS) is the second most common compressive neuropathy of the upper extremity. We aimed to determine a consensus among experts using the Delphi method for clinical criteria that could be validated further for the diagnosis of CuTS.

METHODS

The Delphi method was used for establishing a consensus among a group of expert panelists, comprising 12 hand and upper-extremity surgeons, who ranked the diagnostic clinical importance of 55 items related to CuTS on a scale from 1 (least important) to 10 (most important). The average and SDs of each item were calculated, and Cronbach α was used to assess homogeneity among the panelist-ranked items.

RESULTS

All panelists answered the 55-item questionnaire. A Cronbach α value of 0.963 was obtained on the first iteration. The top criteria that were considered most clinically relevant to the diagnosis of CuTS among the group were determined based on the most highly ranked and correlated items among the expert panelist group. The criteria based on which there was agreement were as follows: (1) paresthesias in ulnar nerve distribution, (2) symptoms precipitated by increased elbow flexion/positive elbow flexion tests, (3) positive Tinel sign at the medial elbow, (4) atrophy/weakness/ late findings (eg, claw hand of the ring/small finger and Wartenberg or Froment sign) of ulnar nerve-innervated muscles of the hand, (5) loss of two-point discrimination in ulnar nerve distribution, and (6) similar symptoms on the involved side after successful treatment on the contralateral side.

CONCLUSIONS

Our study demonstrated a consensus among an expert panelist group of hand and upper-extremity surgeons on potential diagnostic criteria for CuTS. This consensus on diagnostic criteria may help clinicians readily diagnose CuTS in a standardized form; however, further weighting and validation are necessary prior to the development of a formal diagnostic scale.

CLINICAL RELEVANCE

This study is the first step in producing a consensus on how to diagnose CuTS.

Safety of Cubital Tunnel Release Under General versus Regional Anesthesia

Purpose

The aim of this study was to evaluate the occurrence of early (<6 weeks) post-operative complications following ulnar nerve decompressions at the cubital tunnel performed under regional anesthesia compared to those performed under general anesthesia.

Methods

In situ ulnar nerve decompressions at the cubital tunnel performed at a single institution from 2012 through 2019 were retrospectively reviewed. Post-operative complications were compared between subjects who underwent the procedure with regional versus general anesthesia.

Results

Ninety-one ulnar nerve in situ decompressions were included in the study, which were performed under regional anesthesia in 55 and general anesthesia in 36 cases. The occurrence of post-operative complications was not significantly different between patients who received regional (n = 7) anesthesia and general (n = 8) anesthesia. None of the complications were directly attributed to the type of anesthesia administered. The change in pre- and post-operative McGowan scores were not significantly different between anesthesia groups (p = 0.81).

Conclusion

In situ ulnar nerve decompression at the cubital tunnel under regional anesthesia does not result in increased post-operative complications compared to those surgeries performed under general anesthesia. In situ ulnar nerve decompression performed under regional anesthesia is a safe and reliable option for patients who wish to avoid general anesthesia.

Level of Evidence

III.

Pathophysiology of Work-Related Neuropathies

Work-related injuries are common. The cost of these injuries is around USD 176 billion to USD 350 billion a year. A significant number of work-related injuries involve nerve damage or dysfunction. Injuries may heal with full recovery of function, but those involving nerve damage may result in significant loss of function or very prolonged recovery. While many factors can predispose a person to suffer nerve damage, in most cases, it is a multifactorial issue that involves both intrinsic and extrinsic factors. This makes preventing work-related injuries hard. To date, no evidence-based guidelines are available to clinicians to evaluate work-related nerve dysfunction. While the symptoms range from poor endurance to cramping to clear loss of motor and sensory functions, not all nerves are equally vulnerable. The common risk factors for nerve damage are a superficial location, a long course, an acute change in trajectory along the course, and coursing through tight spaces. The pathophysiology of acute nerve injury is well known, but that of chronic nerve injury is much less well understood. The two most common mechanisms of nerve injury are stretching and compression. Chronic mild to moderate compression is the most common mechanism of nerve injury and it elicits a characteristic response from Schwann cells, which is different from the one when nerve is acutely injured. It is important to gain a better understanding of work-related nerve dysfunction, both from health and from regulatory standpoints. Currently, management depends upon etiology of nerve damage, recovery is often poor if nerves are badly damaged or treatment is not instituted early. This article reviews the current pathophysiology of chronic nerve injury. Chronic nerve injury animal models have contributed a lot to our understanding but it is still not complete. Better understanding of chronic nerve injury pathology will result in identification of novel and more effective targets for pharmacological interventions.

No Major Nerve Regeneration Seems to Occur during Recovery of Ulnar Neuropathy at the Elbow

Introduction: There are three main potential mechanisms of recovery after nerve lesion: (1) resolution of conduction block, (2) collateral reinnervation, and (3) nerve regeneration. Their relative contributions in recovery after focal neuropathies are not well established. Methods: In a group of previously reported prospective cohort of patients with ulnar neuropathy at the elbow (UNE), I performed a post-hoc analysis of their clinical and electrodiagnostic findings. I compared amplitudes of the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) on ulnar nerve stimulation, as well as qualitative concentric needle electromyography (EMG) findings in the abductor digiti minimi muscle on the initial and follow-up examinations several years later. Results: Altogether, 111 UNE patients (114 arms) were studied. During median follow-up period of 880 days (range: 385-1545 days), CMAP amplitude increased (p = 0.02), and conduction block in the elbow segment recovered (from median 17% to 7%; p < 0.001). By contrast, SNAP amplitude did not change (p = 0.89). On needle EMG, spontaneous denervation activity diminished (p < 0.001), motor unit potential (MUP) amplitude increased (p < 0.001), and MUP recruitment remained unchanged (p = 0.43). Conclusions: Findings of the present study indicate that nerve function in chronic focal compression/entrapment neuropathies seems to improve mainly due to the resolution of the conduction block and collateral reinnervation. Contribution of nerve regeneration seems to be minor; the majority of axons lost in chronic focal neuropathies probably never recover. Further studies using quantitative methods are needed to validate present findings.

Transscaphoid Transcapitate Perilunate Fracture-dislocation with Inferior Arc Injury and Acute Ulnar Nerve Compression: A Case Report

Introduction

Perilunate dislocations and perilunate fracture-dislocations (PLFD) are relatively uncommon injuries, comprising <10% of wrist injuries. Perilunate injuries are often complicated by median neuropathy reported in 23-45% of cases, whereas there are very few reported cases of associated ulnar neuropathy. Combined greater arc and inferior arc injuries are also rare. We report an unusual PLFD pattern with associated inferior arc injury and acute ulnar nerve compression.

Case Report

A 34-year-old male sustained a wrist injury after a motorcycle collision. Computed tomography scan revealed a trans-scaphoid, transcapitate, perilunate fracture-dislocation, and a distal radius lunate facet volar rim fracture with radiocarpal subluxation. Examination revealed acute ulnar neuropathy without median neuropathy. He underwent urgent nerve decompression and closed reduction, followed by open reduction internal fixation the next day. He recovered without complication.

Conclusion

This case emphasizes the importance of a thorough neurovascular examination to rule out less commonly seen neuropathies. With up to 25% of perilunate injuries misdiagnosed, surgeons should have a low threshold for advanced imaging in high-energy injuries.

A Tardy Ulnar Palsy with an Anomalous Course of Ulnar Nerve

Variations are inherent feature of the intricate brachial plexus. They can be at the level of origin, the course, or the innervation pattern of each peripheral nerve. Knowledge of the various described variations can be worthwhile during the routine hand surgery procedures. We present a case of an elderly patient with anomalous intramuscular course of the ulnar nerve presenting with ulnar neuropathy at the elbow. Level of Evidence:  IV.

A complete analysis of the surgical treatment for cubital tunnel syndrome: an umbrella review

BACKGROUND

Numerous original studies have been presented regarding various surgical treatments for cubital tunnel syndrome (CubTS). The results of these analyses regarding the different surgical treatments for CubTS frequently differ and, in some cases, contradict each other, creating confusion. Therefore, our umbrella review aimed to summarize the evidence from meta-analyses and systematic reviews regarding the surgical treatments of CubTS, and along with the new, more detailed outcomes, provide an evidence-based tool for surgeons performing these procedures.

MATERIALS AND METHODS

To perform this umbrella review, a systematic search was conducted for meta-analyses investigating CubTS in PubMed, Scopus, Embase, Web of Science, Google Scholar, Cochrane Library, BIOSIS, and EBSCO medical databases.

RESULTS

Detailed comparison of surgical outcomes, such as clinical improvement, complications, or reoperation rates, of different treatment methods for CubTS was performed. New risk ratios in all categories were established based on all of the primary studies available in the literature.

DISCUSSION

The goal of the present umbrella review was to gather and summarize all data about the surgical treatments for CubTS in the available literature and provide new outcomes and an evidence-based tool for surgeons performing these procedures. Each comparison of the surgical techniques has been discussed, and the present study's results were compared with the outcomes of the previous studies.

Outcome of unlinked total elbow arthroplasty for rheumatoid arthritis in patients younger than 50 years old

AIMS

There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA).

METHODS

We retrospectively reviewed the records of 26 elbows of 21 patients with RA who were aged less than 50 years who underwent primary TEA with an unlinked elbow prosthesis. The mean patient age was 46 years (35 to 49), and the mean follow-up period was 13.6 years (6 to 27). Outcome measures included pain, range of motion, Mayo Elbow Performance Score (MEPS), radiological evaluation for radiolucent line and loosening, complications, and revision surgery with or without implant removal.

RESULTS

The mean MEPS significantly improved from 47 (15 to 70) points preoperatively to 95 (70 to 100) points at final follow-up (p < 0.001). Complications were noted in six elbows (23%) in six patients, and of these, four with an ulnar neuropathy and one elbow with postoperative traumatic fracture required additional surgeries. There was no revision with implant removal, and there was no radiological evidence of loosening around the components. With any revision surgery as the endpoint, the survival rates up to 25 years were 78.1% (95% confidence interval 52.8 to 90.6) as determined by Kaplan-Meier analysis.

CONCLUSION

The clinical outcome of primary unlinked TEA for young patients with RA was satisfactory and comparable with that for elderly patients. A favourable survival rate without implant removal might support the use of unlinked devices for young patients with this disease entity, with a caution of a relatively high complication rate regarding ulnar neuropathy.Level of Evidence: Therapeutic Level IVCite this article: Bone Jt Open 2023;4(1):19-26.

Cubital Tunnel Syndrome Temporally after COVID-19 Vaccination

Coronavirus disease 2019 (COVID-19) is the most dramatic pandemic of the new millennium. To counter it, specific vaccines have been launched in record time under emergency use authorization or conditional marketing authorization and have been subjected to additional monitoring. The European Medicines Agency recommend reporting any suspected adverse reactions during this additional monitoring phase. For the first time in the available medical literature, we report a left cubital tunnel syndrome in a 28-year-old right-handed healthy male after seven days from the first dose of Spikevax^® (formerly Moderna COVID-19 Vaccine). Histochemistry for Alcian Blue performed on the tissue harvested from the cubital site reveals myxoid degeneration of the small nerve collaterals, a clear sign of nerve injury. It still remains unclear why the syndrome occurs in a localized and not generalized form to all osteofibrous tunnels. Today, modified messenger ribonucleic acid vaccines as Spikevax^® represent an avantgarde technological platform with a lot of potential, but one which needs careful monitoring in order to identify in advance those patients who may experience adverse events after their administration.

COVID-19 Peripheral Neuropathy: A Report of Three Cases

This study includes three patients with various peripheral neuropathies after contracting coronavirus disease 2019 (COVID-19) infection, treated both conservatively and surgically. While cases of neurological complications have been described, neuropathy associated with COVID-19 is under-reported in orthopaedic literature. These patients presented with ulnar neuropathy, critical care polyneuropathy (CCP) with anterior interosseous nerve (AIN) neuropathy, and lateral femoral cutaneous nerve (LFCN) neuropathy. COVID-19 infection may be associated with peripheral neuropathy in addition to various neurological sequelae. Orthopaedic surgeons should screen patients for recent infections and evaluate the severity of the illness to assess for risk of neurological sequelae of COVID-19 infection.

Cubital tunnel perfusion in different postures-An anatomical investigation

Introduction/Aims

For cubital tunnel syndrome, the avoidance of predisposing arm positions and the use of elbow splints are common conservative treatment options. The rationale is to prevent excessive stretching and compression of the nerve in the cubital tunnel, as this mechanical stress impedes intraneural perfusion. Data regarding those upper extremity postures to avoid, or whether elbow flexion alone is detrimental, are inconsistent. This study aimed to assess perfusion and size changes of the cubital tunnel during different postures in an experimental cadaver setup.

Methods

Axillary arteries in 30 upper extremities of fresh cadavers were injected with ultrasound contrast agent. High‐resolution ultrasound of the cubital tunnel was performed during five different arm postures that gradually increased tension on the ulnar nerve and caused cubital tunnel narrowing. Contrast enhancement within the tunnel was measured to quantify perfusion. Cubital tunnel cross‐sectional area was measured to detect compression.

Results

Increasing tension significantly reduced perfusion. When isolated, neither shoulder elevation, elbow flexion, pronation, nor extension of wrist and fingers impaired perfusion. However, combining two or more of these postures led to significant decreases. Significant narrowing of the cubital tunnel was seen in full elbow flexion and shoulder elevation.

Discussion

Combinations of some upper extremity joint positions reduce nerve perfusion, but isolated elbow flexion does not have a significant impact. We hypothesize that elbow splints alone may not influence cubital tunnel perfusion but may only prevent direct compression of the ulnar nerve. Advising patients about upper extremity postures that should be avoided may be more effective.

Ulnar Nerve Dislocation and Subluxation from the Cubital Tunnel Are Common in College Athletes

Background: Hypermobility of the ulnar nerve from the cubital tunnel reportedly occurs in healthy people without symptoms of ulnar neuropathy. However, the occurrence rate in athletes is unknown. We examined the occurrence rate of ulnar nerve hypermobility using ultrasonography, symptoms, and physical findings in athletes and compared the results of four types of sports. Methods: Medical charts of college athletes competing in baseball, rugby, soccer, and long-distance running between March and November 2018 were retrospectively examined. Dynamic evaluation of the ulnar nerve was performed using ultrasonography and categorized as Types N, S, and D respectively, indicating normal position, subluxation, and dislocation. Subjective and objective findings were evaluated. Results: The present study included 246 male athletes (mean age, 19.7 years; 492 elbows) including 46% Type D, 29.8% Type S, and 24.2% Type N. Subjective findings showed pain and dysesthesia in 9% and 4.5% of participants, respectively, whereas objective findings showed Tinel sign in 6%, nerve tension test in 1.3%, Froment’s sign in 0.5%, and weakness of strength of opponens digiti minimi muscle in 8% of patients with Types D and S. Conclusions: There was a high-frequency hypermobility of the ulnar nerve from the cubital tunnel with or without subjective and objective findings in college athletes.

Comparison of In Situ Versus Subcutaneous Versus Submuscular Transpositions in the Management of McGowan Stage III Cubital Tunnel Syndrome

Background: The objective of the study was to evaluate and compare the clinical outcomes of in situ decompression with subcutaneous and submuscular transpositions for surgical management of advanced (McGowan stage III) cubital tunnel syndrome (CuTS). Methods: A retrospective review of patients in our institution undergoing primary surgery for CuTS from February 1989 to May 2009 was performed. Patients with advanced CuTS with a minimum of 12 months of follow-up without any previous bony or soft tissue procedures around the elbow were included. Seventy-four patients underwent 80 primary ulnar nerve surgeries. Patients' demographics, presenting symptoms, physical examination, electrodiagnostic findings, and perioperative complications were recorded. Primary surgical techniques were compared and the risk factors for revision surgery were assessed. Results: Of the 80 surgical procedures, there were 17 decompressions (21%), 47 subcutaneous transpositions (59%), and 16 submuscular transpositions (20%). Fifty-two percent of patients had resolution of their symptoms after primary surgery. The overall complication rate after primary surgery was 12.5%. Nineteen patients (24%) had revision surgery at a median of 30 months after their primary procedure. Eight patients (42%) had symptomatic improvement after revision surgery. Patients with their dominant extremity affected, static 2-point discrimination (S2PD) greater than 10 mm, and age less than 50 years at presentation had a higher rate of revision surgery. Three patients had a second revision surgery and neurolysis for persistent symptoms. Conclusions: The overall revision rate in advanced CuTS was 24%. Forty-two percent of patients had reported subjective symptomatic improvement after revision surgery. Younger age at presentation and a greater S2PD were associated with a higher rate of revision surgery.

Optimal Choice of Ultrasound-Based Measurements for the Diagnosis of Ulnar Neuropathy at the Elbow: A Meta-Analysis of 1961 Examinations

OBJECTIVE. The purpose of this study was to determine the optimal ultrasound (US) measurement technique and cutoff value for the diagnosis of ulnar neuropathy at the elbow. MATERIALS AND METHODS. A systematic literature search was conducted of the PubMed, Embase, Scopus, and Web of Science databases for studies evaluating the diagnostic accuracy of US of patients with ulnar neuropathy at the elbow before April 2019. Random-effects modeling was performed to compare the sensitivity, specificity, and diagnostic odds ratio (DOR) of different US measurements, including diameter and cross-sectional area (CSA) of the nerve at the medial epicondyle or proximal and distal levels, maximal diameter, maximal CSA, and nerve ratios. Sensitivity and metaregression analyses were performed to assess the impact of clinical and imaging-based variables on the DOR of US. RESULTS. Among 820 retrieved studies, 19 studies (1961 examinations) were included. Measuring the CSA of the ulnar nerve at the medial epicondyle with a cutoff value greater than 10-10.5 mm² had higher sensitivity (80.4%, 95% CI, 75.4-84.7%) than other techniques. Nerve ratios had higher specificity (89.1%, 95% CI, 85.8-91.8%) than other measurements; however, the definition of ratios and cutoff values varied across studies. ROC analysis showed higher diagnostic performance for measuring CSA at the medial epicondyle (AUC, 0.931). The mean CSA value was a significant predictor of the DOR of US (β coefficient, 0.307 ± 0.074; p < 0.001). Every 1-mm² larger CSA was associated with a 36% increase in DOR. The diagnostic performance of US was the same in any degree of elbow flexion. CONCLUSION. Measuring CSA of the ulnar nerve at the medial epicondyle has sensitivity and diagnostic performance superior to those of other techniques for the diagnosis of ulnar neuropathy at the elbow.

An Additional Electrodiagnostic Tool for Ulnar Neuropathy: Mixed across the Elbow

Background  Diagnosing ulnar neuropathy at the elbow (UNE) remains challenging despite guidelines from national organizations. Motor testing of hand intrinsic muscles remains a common diagnostic method fraught with challenges.

Objective  The aim of the study is to demonstrate utility of an uncommon nerve conduction study (NCS), mixed across the elbow, when diagnosing UNE.

Methods  Retrospective analysis of 135 patients, referred to an outpatient University-based electrodiagnostic laboratory with suspected UNE between January 2013 and June 2019 who had motor to abductor digiti minimi (ADM), motor to first dorsal interosseus (FDI), and mixed across the elbow NCS completed. To perform the mixed across the elbow NCS, the active bar electrode was placed 10-cm proximal to the medial epicondyle between the biceps and triceps muscle bellies. The median nerve was stimulated at the wrist followed by stimulation of the ulnar nerve at the ulnar styloid. The difference between peak latencies, labeled the ulnar-median mixed latency difference (U-MLD), was used to evaluate for correlation between the nerve conduction velocities (NCV) of ADM and FDI.

Results  Pearson r -values = −0.479 and −0.543 ( p  < 0.00001) when comparing U-MLD to ADM and FDI NCV across the elbow, respectively. The negative r -value describes the inverse relationship between ulnar velocity across the elbow and increasing U-MLD.

Conclusion  Mixed across the elbow has moderate–strong correlation with ADM and FDI NCV across the elbow. All three tests measure ulnar nerve function slightly differently. Without further prospective data, the most accurate test remains unclear. The authors propose some combination of the three tests may be most beneficial when diagnosing UNE.

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.

Simultaneous bilateral ulnar neuropathy: an unusual complication caused by neuroleptic treatment-induced tardive dyskinesia: A Case Report

RATIONALE

In the past decade, only a few studies have focused on simultaneous bilateral ulnar neuropathy.

PATIENT CONCERNS

A 54-year-old Asian male who has suffered from paranoid schizophrenia for 2 years. He reported that flexion contracture occurring over his fourth and fifth fingers on both hands appeared since six months after he started taking the antipsychotic drug. The electromyogram revealed bilateral ulnar neuropathy with chronic axonal degeneration at the elbow level. McGowan classification was performed to evaluate the severity of the ulnar nerve injury, and the patient was diagnosed with a grade 3 injury on his left hand and a grade 2 injury on his right hand.

DIAGNOSIS

Simultaneous bilateral ulnar neuropathy at the elbow, a complication caused by tardive dyskinesia in a patient under the high-dose, first-generation, antipsychotic drug.

INTERVENTIONS

We consulted a psychiatrist to assist in adjusting the patient's kind of the antipsychotic drug and performed the anterior transposition of ulnar nerve to avoid nerve entrapment caused by tardive dyskinesia.

OUTCOMES

Numbness of the palms continued to regress over the following 6 months after the anterior transposition of the ulnar nerve. Regression of the involuntary movements, including repeated bending of the elbows, and shaking of both feet, was noted from the patient but was incomplete.

LESSONS

Two literatures concluded that parkinsonian rigidity is the main cause of simultaneous bilateral ulnar neuropathy by Sampath et al and Kurlan et al. Unlike the cases of stereotyped posture-caused neural compression reported previously, we inferred that repeated involuntary motion caused by first-generation antipsychotic drug might have been one of the causes of the patient's nerve compression.

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.

Anconeus Epitrochlearis Muscle Associated With Cubital Tunnel Syndrome: A Case Series

Background: Cubital tunnel syndrome is a common compressive neuropathy of the upper extremity. The anconeus epitrochlearis muscle is an unusual but occasional contributor. We review our experience with this anomalous muscle in elbows with cubital tunnel syndrome. Methods: We retrospectively reviewed charts of 13 patients noted to have an anconeus epitrochlearis muscle associated with cubital tunnel syndrome. Results: Ten patients had unilateral ulnar neuropathy supported by nerve conduction studies. Three had bilateral cubital tunnel syndrome symptoms with 1 of those having normal nerve conduction studies for both elbows. Eight elbows were treated with myotomy of the anconeus epitrochlearis muscle and submuscular transposition of the ulnar nerve. The other 8 elbows were treated with myotomy of the anconeus epitrochlearis muscle and in situ decompression of the ulnar nerve only. All but 1 patient had either clinical resolution or improvement of symptoms at follow-up ranging from 2 weeks to 1 year after surgery. The 1 patient who had persistent symptoms had received myotomy and in situ decompression of the ulnar nerve only. Conclusions: An anomalous anconeus epitrochlearis occasionally results in compression of the ulnar nerve but is usually an incidental finding. Its contribution to compression neuropathy can be tested intraoperatively by passively ranging the elbow while observing the change in vector and tension of its muscle fibers over the ulnar nerve. Regardless of findings, we recommend myotomy of the muscle and in situ decompression of the ulnar nerve. Submuscular transposition of the ulnar nerve may be necessary if there is subluxation.

Case Series: A Minimally Invasive Tunneling Approach for Cubital Tunnel Syndrome

Background

Cubital tunnel syndrome (CuTS) is the second most common peripheral neuropathy in the United States. All three current surgical treatment approaches, consisting of in situ decompression, medial epicondylectomy, and transposition, require large curvilinear incisions and dissections that cross the medial epicondyle. However, the use of a large curvilinear incision may not be necessary for in situ decompression and may be achieved with small incisions proximal and distal to the medial epicondyle. This may limit the risk of peri-incisional pain and numbness, similar to the benefits provided by endoscopy.

Objective

The aim of this study is to evaluate a minimally invasive tunneling approach for in situ ulnar nerve decompression utilizing 2 cm incisions proximal and distal to the medial epicondyle.

Methods

A retrospective chart review was performed for patients at Emory University Hospital with CuTS who underwent minimally invasive tunneling for in situ decompression. Seven cases were identified. Patient demographics and data on post-operative complications were collected. Pre-operative severity was graded as a Modified McGowan severity. The primary outcome was evaluated using the post-surgical Messina Criterion. Secondary outcomes were reports of peri-incisional pain or numbness evaluated at follow-up. Descriptive statistics are presented.

Results

Pre-operatively, one of the seven cases was Grade I McGowan and the remaining six were Grade 2a or 2b. Post-operatively, on the Messina Criterion, four of seven patients were rated as having “Good” outcomes, two of seven had “Fair”, while one of seven had “Poor.” There was one post-operative surgical site infection. Among the other six cases, there were no reports of peri-incisional pain or numbness.

Conclusions

The use of less-invasive tunneling approach to in situ decompression yielded positive outcomes in this case series with no reports of peri-incisional pain or numbness. A prospective trial may be useful to explore the theoretical benefits of this novel tunneling approach.

Ulnar Nerve Complications After Ulnar Collateral Ligament Reconstruction of the Elbow: A Systematic Review

BACKGROUND

While ulnar collateral ligament reconstruction (UCLR) of the elbow is an increasingly commonly performed procedure with excellent results reported in the published literature, less attention has been paid to specifically on the characterization of postoperative ulnar nerve complications, and it is unclear what operative strategies may influence the likelihood of these complications.

PURPOSE

The purpose of this study is to examine the prevalence and type of ulnar nerve complications after UCLR of the elbow based on the entirety of previously published outcomes in the English literature. In addition, this study examined how the rate of ulnar nerve complications varied as a function of surgical exposures, graft fixation techniques, and ulnar nerve management strategies.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review of the literature was completed using the MEDLINE, PubMed, and Ovid databases. UCLR case series that contained complications data were included. Ulnar neuropathy was defined as any symptoms or objective sensory and/or motor deficit(s) after surgery, including resolved transient symptoms. Meta-analysis of the pooled data was completed.

RESULTS

Seventeen articles (n = 1518 cases) met the inclusion criteria, all retrospective cohort studies. The mean prevalence of postoperative ulnar neuropathy was 12.0% overall after any UCLR procedure at a mean follow-up of 3.3 years, and 0.8% of cases required reoperation to address ulnar neuropathy. There were no cases of intraoperative ulnar nerve injury reported. The surgical approach associated with the highest rate of neuropathy was detachment of flexor pronator mass (FPM) (21.9%) versus muscle retraction (15.9%) and muscle splitting (3.9%). The fixation technique associated with the highest rate of neuropathy was the modified Jobe (16.9%) versus DANE TJ (9.1%), figure-of-8 (9.0%), interference screw (5.0%), docking technique (3.3%), hybrid suture anchor-bone tunnel (2.9%), and modified docking (2.5%). Concomitant ulnar nerve transposition was associated with a higher neuropathy rate (16.1%) compared with no handling of the ulnar nerve (3.9%). Among cases with concomitant transposition performed, submuscular transposition resulted in a higher rate of reoperation for ulnar neuropathy (12.7%) compared with subcutaneous transposition (0.0%).

CONCLUSION

Despite a perception that UCLR has minimal morbidity, a review of all published literature revealed that 12.0% of UCLR surgeries result in postoperative ulnar nerve complications. UCLR techniques associated with the highest rates of neuropathy were detachment of the FPM, modified Jobe fixation, and concomitant ulnar nerve transposition, although it remains unclear whether there is a causal relationship between these factors and subsequent development of postoperative ulnar neuropathy due to limitations in the current body of published literature.

Quantitative Measures of Physical Risk Factors Associated with Work-Related Musculoskeletal Disorders of the Elbow: A Systematic Review

Background: Work-related musculoskeletal disorders at the elbow are a common health problem, which highly impacts workers’ well-being and performance. Besides existing qualitative information, there is a clear lack of quantitative information of physical risk factors associated with specific disorders at the elbow (SDEs). Objective: To provide evidence-based quantitative measures of physical risk factors associated with SDEs. Methods: Studies were searched from 2007 to 2017 in Medline, EMBASE, and Cochrane Work. The identified risk factors were grouped in main- and sub-categories of exposure using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework for rating evidence. Results: 133 different risk-factor specifications were identified in 10/524 articles and were grouped into 5 main- and 16 sub-categories of exposure. The risk factors were significantly associated with lateral epicondylitis, medial epicondylitis, or ulnar neuropathy. Significant risk factors such as wrist angular velocity (5°/s, with increasing prevalence ratio of 0.10%/(°/s), or forearm supination (≥45° and ≥5% of time combined with forceful lifting) were found. Conclusions: This review delivers a categorization of work-related physical risk-factor specifications for SDEs with a special focus on quantitative measures, ranked for evidence. These results may build the base for developing risk assessment methods and prospective preventive measures.

Complications of open reduction and internal fixation of distal humerus fractures

Treatment of distal humerus fractures is demanding. Surgery is the optimal treatment and preoperative planning is based on fracture type and degree of comminution.

Fixation with two precontoured anatomical locking plates at 90^o:90^o orthogonal or 180^o parallel is the optimal treatment.

The main goal of surgical treatment is to obtain stable fixation to allow immediate postoperative elbow mobilization and prevent joint stiffness.

Despite evolution of plates and surgical techniques, complications such as mechanical failure, ulnar neuropathy, stiffness, heterotopic ossification, nonunion, malunion, infection, and complications from olecranon osteotomy are quite common.

Distal humerus fractures still present a significant technical challenge and need meticulous technique and experience to achieve optimal results.

Cite this article: EFORT Open Rev 2018;3:558-567. DOI: 10.1302/2058-5241.3.180009

Management of an Acute Exacerbation of Chronic Neuropathic Pain in the Emergency Department: A Case to Support Ultrasound-Guided Forearm Nerve Blocks

BACKGROUND

Acute on chronic neuropathic pain is often refractory to analgesics and can be challenging to treat in the emergency department (ED). In addition, systemic medications such as opiates and nonsteroidal inflammatory drugs have risks, including hypotension and kidney injury, respectively. Difficulties in managing pain in patients with neuropathy can lead to prolonged ED stays, undesired admissions, and subsequent increased health care costs.

CASE REPORT

We describe the case of a 51-year-old woman who presented to the ED on two separate occasions for left forearm pain secondary to chronic ulnar neuropathy. During her first ED visit, the patient received multiple rounds of intravenous opiates and required hospital admission, which was complicated by opiate-induced hypotension. During her second visit, she underwent an ultrasound-guided ulnar nerve block performed by the emergency physician; her pain resolved and she was discharged home. WHY SHOULD EMERGENCY PHYSICIANS BE AWARE OF THIS?: Ultrasound-guided nerve blocks are an effective, safe, and relatively inexpensive alternative to opioids. Our case demonstrates that emergency providers may be able to perform ultrasound-guided regional anesthesia to treat an acute exacerbation of chronic neuropathic pain.

Neuromuscular ultrasound in electrically non-localizable ulnar neuropathy

INTRODUCTION

The aim of this study was to determine the value of high-resolution ultrasound (HRUS) in patients with ulnar neuropathy whose electrophysiology displayed an axonal, non-localizing pattern.

METHODS

A prospective study of patients referred to an electromyography laboratory for ulnar neuropathy was performed. Of the 56 patients with clinical and electrodiagnostic (EDx) evidence of ulnar neuropathy, 12 were identified with non-localizing electrophysiology who subsequently underwent HRUS of the ulnar nerve.

RESULTS

HRUS localized the ulnar neuropathy in all patients. In 2 patients, HRUS demonstrated structural lesions not at the elbow.

DISCUSSION

HRUS often adds complementary information to standard EDx studies, including ulnar neuropathy. Thus, HRUS should be employed in patients with a non-localizing ulnar neuropathy on EDx studies. Muscle Nerve 58: 655-659, 2018.

Is triceps hypertrophy associated with ulnar nerve luxation?

INTRODUCTION

The mechanism of ulnar nerve luxation is unclear, but the triceps brachii muscle may be a contributing factor. Therefore, we explored whether hypertrophy of the triceps brachii muscle is more frequently accompanied by nerve luxation.

METHODS

In this investigation we used a cross-sectional design to study a group of amateur bodybuilders (n = 31) in a comparison with a group of age-matched healthy controls (n = 31). Triceps hypertrophy was determined clinically and sonographically. The position of the ulnar nerve in relation to the medial epicondyle was classified according to a graded (0-4) scale.

RESULTS

In full flexion of 62 hypertrophic arms, 22 (35.5%) revealed subluxation and 27 (43.5%) complete luxation. In the controls, 21 (33.9%) demonstrated subluxation and 10 (16.1%) complete luxation.

DISCUSSION

The higher frequency of ulnar nerve luxation in arms with hypertrophic triceps indicates that triceps muscle mass may be a factor contributing to ulnar nerve luxation. Muscle Nerve 58: 523-527, 2018.

Short segment sensory nerve stimulation in suspected ulnar neuropathy at the elbow: A pilot study

INTRODUCTION

Routine ulnar nerve conduction studies may be normal in very mild ulnar neuropathies at the elbow (UNE). Short segment ulnar sensory stimulation across the elbow may detect mild abnormalities in these cases.

METHODS

Short segment ulnar sensory nerve stimulation was performed in 20 controls and 15 patients with clinically suspected mild UNE. Greatest peak latency shift and amplitude drop between 2 adjacent stimulation sites were calculated.

RESULTS

The upper limit of normal for peak latency shift and amplitude reduction between sites was 0.7 ms and 15%, respectively. Abnormal latency shift was detected in 12 of 15 patients and focal sensory conduction block in 6 of 15 patients. In 5 of 7 patients in whom all other studies were normal, sensory inching was abnormal.

DISCUSSION

Ulnar sensory short segment stimulation may provide diagnostic confirmation and localization of the site of nerve compression in mild UNE, and may improve UNE detection when all other studies are normal. Muscle Nerve 59:125-129, 2019.

Prevalence of carpal tunnel syndrome presenting with symptoms in an ulnar nerve distribution: A prospective study

INTRODUCTION

Patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution may be noted to have exclusive median mononeuropathy at the wrist on subsequent electrodiagnostic testing. There has been limited research looking at the prevalence of this clinical presentation.

METHODS

A cohort of adults were surveyed to assess for severity and localization of hand symptoms using the Katz hand diagram and Boston Carpal Tunnel Questionnaire Symptoms Severity Scale. Thirty volunteers met our case definition for ulnar neuropathy and underwent a standardized physical examination, electrodiagnostic testing, and nerve ultrasound.

RESULTS

Eleven of 30 subjects (37%) were found to have exclusive median mononeuropathy at the wrist.

DISCUSSION

Carpal tunnel syndrome should remain high on the differential for patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution. Muscle Nerve 59:60-63, 2019.

Surgical Approaches and Their Outcomes in the Treatment of Cubital Tunnel Syndrome

Purpose: This review was undertaken in order to provide an updated summary of the current literature on outcomes for various surgical treatments for cubital tunnel syndrome.

Methods: Studies reporting outcomes for surgical treatment of cubital tunnel syndrome were collected through the PubMed database. Study structure, number of participants/procedures, mean follow-up times, scoring scales, and outcomes were collected according to the type of surgery: open decompression, endoscopic decompression, minimal incision, subcutaneous transposition, intramuscular transposition, and submuscular transposition.

Results: Our findings indicate varying but comparable levels of success among all surgical techniques reviewed. Many different scoring scales were utilized, limiting direct quantitative comparison between most studies.

Discussion: While some studies directly compared two or more techniques, there was rarely a statistically significant difference between groups. In comparisons that did reach statistically significant differences, there were others yet that found no difference in comparing the same techniques.

Conclusions: None of the techniques in this review has demonstrated universal superiority above all others, but all appear to be effective in the treatment of cubital tunnel syndrome. The only consensus seems to be that transposition is preferred where the ulnar nerve tends to subluxate either on preoperative or intraoperative examination.

Optimal Measurement Level and Ulnar Nerve Cross-Sectional Area Cutoff Threshold for Identifying Ulnar Neuropathy at the Elbow by MRI and Ultrasonography

PURPOSE

Imaging criteria for diagnosing compressive ulnar neuropathy at the elbow (UNE) have recently been established as the maximum ulnar nerve cross-sectional area (UNCSA) upon magnetic resonance imaging (MRI) and/or ultrasonography (US). However, the levels of maximum UNCSA and diagnostic cutoff values have not yet been established. We therefore analyzed UNCSA by MRI and US in patients with UNE and in controls.

METHODS

We measured UNCSA at 7 levels in 30 patients with UNE and 28 controls by MRI and at 15 levels in 12 patients with UNE and 24 controls by US. We compared UNCSA as determined by MRI or US and determined optimal diagnostic cutoff values based on receiver operating characteristic curve analysis.

RESULTS

The UNCSA was significantly larger in the UNE group than in controls at 3, 2, 1, and 0 cm proximal and 1, 2, and 3 cm distal to the medial epicondyle for both modalities. The UNCSA was maximal at 1 cm proximal to the medial epicondyle for MRI (16.1 ± 3.5 mm²) as well as for US (17 ± 7 mm²). A cutoff value of 11.0 mm² for MRI and US was found to be optimal for differentiating between patients with UNE and controls, with an area under the receiver operating characteristic curve of 0.95 for MRI and 0.96 for US. The UNCSA measured by MRI was not significantly different from that by US. Intra-rater and interrater reliabilities for UNCSA were all greater than 0.77. The UNCSA in the severe nerve dysfunction group of 18 patients was significantly larger than that in the mild nerve dysfunction group of 12 patients.

CONCLUSIONS

By measuring UNCSA with MRI or US at 1 cm proximal to the ME, patients with and without UNE could be discriminated at a cutoff threshold of 11.0 mm² with high sensitivity, specificity, and reliability.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Ulnar neuropathy due to heterotopic ossification: A rare complication after stroke

Heterotopic ossification (HO) is a rare complication (0.5 to 1.2%) after stroke. Although there are few reports on ulnar neuropathy (UN) due to HO at the elbow after traumatic brain injury, thermal burn or upper limb trauma, there has been no case reported after stroke. Herein, we present a 32-year-old male patient with UN due to HO after stroke.

Normative Ulnar Nerve Conduction Study: Comparison of Two Measurement Methods

Background:

Given the high prevalence rate of ulnar neuropathy and importance of its proper management, to have a baseline information about the normative value of motor nerve conduction of first dorsal interosseous (FDI) muscle and abductor digiti minimi muscle (ADM) and their differences as well as their relation with different demographic characteristics of our population, we aimed to determine and compare the mean value of motor conduction velocity of FDI and ADM at forearm and across the elbow among the normal population.

Materials and Methods:

In this cross-sectional study, healthy participants were enrolled in the study. Ulnar nerve motor nerve conduction velocity (MNCV) was recorded from the ADM and the FDI at forearm and across the elbow. Mean MNCV of the ulnar nerve recorded from ADM and FDI was compared. In addition, MNCV of the ulnar nerve measured at the forearm and across the elbow was compared also.

Results:

During this study, 165 healthy volunteers selected and participated in the study. Mean of ulnar nerve MNCV for ADM was significantly lower than FDI, both at forearm and across the elbow (P < 0.001). Mean of ulnar nerve MNCV was significantly lower at forearm comparing than elbow level for both ADM and FDI (P < 0.001).

Conclusion:

The findings of the current study provide us a baseline data regarding the normative mean value of ulnar nerve MNCV in different locations, which could be used for providing an appropriate diagnostic protocol for ulnar nerve neuropathy. However, further studies among patients suspected with ulnar nerve neuropathy are needed.

Prevalence and clinical outcomes of heterotopic ossification after ulnar collateral ligament reconstruction

BACKGROUND

Ulnar collateral ligament (UCL) reconstruction has become increasingly popular in elite athletes. However, the prevalence of heterotopic ossification (HO) formation after UCL reconstruction has not yet been reported. We sought to determine the prevalence of HO formation after UCL reconstruction and the clinical outcomes following HO treatment.

MATERIALS AND METHODS

From October 2005 to April 2014, 179 patients underwent primary UCL reconstruction. Of the 179 patients, 161 with a minimum of 2 years of follow-up were retrospectively reviewed to evaluate HO formation and clinical outcomes.

RESULTS

Among 161 patients, HO was detected in 8 cases (5%). Of these 8 patients, 2 were asymptomatic and another 2 complained about transient ulnar neuropathy. The remaining 4 patients had pain; 2 were treated with open excision, and 1 underwent arthroscopic excision. The odds of HO in patients in whom transient ulnar neuropathy develops after UCL reconstruction are 6 times higher than those without transient ulnar neuropathy (odds ratio, 5.957; 95% confidence level, P = .04). Of the 8 patients, 7 returned to the same level or a higher level of competition. HO was found, on average, 5 months (range, 3-9 months) after UCL reconstruction.

CONCLUSION

The prevalence of HO formation was approximately 5% after UCL reconstruction and increased with transient ulnar neuropathy. After UCL reconstruction, the surgeon should carefully observe HO formation, especially in the early stages after the operation. With appropriate treatment, the clinical outcomes of HO treatment after UCL reconstruction are favorable.

Is ulnar nerve entrapment at wrist frequent among patients with carpal tunnel syndrome occupationally exposed to monotype wrist movements?

OBJECTIVES

Association between carpal tunnel syndrome (CTS) and ulnar nerve entrapment at wrist remains controversial. The aim of the study has been to investigate the prevalence of Guyon's canal syndrome amongst patients diagnosed with the CTS, occupationally exposed to repetitive wrist movements.

MATERIAL AND METHODS

The retrospective analysis of 310 patients (268 females, 42 males) representing the mean age of 52±7 years old hospitalized for the suspected occupational CTS was performed.

RESULTS

In the analyzed cohort, 4 patients had undergone decompression of the Guyon's canal in the right limbs. Nerve conduction studies (NCS) in the ulnar nerves performed during the hospitalization of those patients did not show any abnormalities. Nerve conduction studies revealed signs of the ulnar neuropathy (UN) at the wrist affecting exclusively sensory fibers for 6 patients. Only those 4 patients who had undergone the operation suffered from clinical symptoms of the UN before the surgery. In the case of the remaining patients, despite the NCS changes, signs suggestive of the UN at the wrist were not detected. In the case of the patients with the occupational CTS, no signs of the ulnar nerve dysfunction were recorded.

CONCLUSIONS

The frequency of ulnar nerve entrapment at the wrist among patients with the CTS is lower than that already reported. The low prevalence of ulnar involvement (3.2%) for the CTS patients in our study may be related to the relatively small number of the CTS hands with the severe changes in the NCS and/or other personal factor including anatomical variation of the Guyon's canal borders and its contents. Int J Occup Med Environ Health 2017;30(6):861-874.

A novel points system to predict the prognosis of ulnar neuropathy at the elbow

INTRODUCTION

In this study we aimed to identify prognostic factors of ulnar neuropathy at the elbow (UNE) and developed a scoring system to establish the prognosis.

METHODS

We collected baseline clinical, electrophysiologic, and ultrasonographic data from 2 cohorts. The outcomes for all patients were determined on follow-up. Prognostic factors were determined using single and multiple variable analyses. A points system was developed to determine the risk for an unfavorable outcome.

RESULTS

Of the 220 patients with UNE 178 (81%) could be re-evaluated. Four variables were retained in the prediction model for a points system. An unfavorable outcome was associated with right-sided UNE, more severe weakness of the abductor digiti minimi (ADM), and more pronounced ulnar nerve thickening. A compound muscle action potential amplitude reduction across the elbow of ≥16% (particularly if ≥ 50%) was associated with a more favorable outcome.

CONCLUSION

Outcome in UNE may be predicted by scoring 4 parameters. Muscle Nerve 55: 698-705, 2017.

Inter-rater reliability determination for two tests of ulnar nerve conduction across the elbow

INTRODUCTION

The inter-rater variability in determination of ulnar nerve conduction across the elbow compromises test accuracy. The extent of this variability is unknown. The objective of this study was to determine and compare inter-rater reliability of variables derived from 2 different ulnar nerve conduction studies (NCSs) across the elbow.

METHODS

Two investigators performed a standard ulnar NCS and a 6-cm conduction time (Six-Centimeter Conduction Time test, SCCT) on 60 extremities of asymptomatic subjects. In the standard test, below-elbow (BE) and above-elbow (AE) stimulation points were ≥ 10 cm apart, measured along a curved path, to calculate across-elbow NCV. In SCCT, BE and AE were precisely 6 cm apart measured linearly to calculate CTE (conduction time elbow). Inter-rater reliability was assessed by means of intraclass correlation coefficients (ICC).

RESULTS

ICC for across-elbow NCV and CTE were 0.726 and 0.801, respectively.

CONCLUSIONS

Reliability of CTE and across-elbow NCV are similar. Shorter distances, if measured linearly, can be used to determine across-elbow ulnar nerve conduction. Muscle Nerve 55: 664-668, 2017.

Peripheral neuropathies

Peripheral neuropathies are diseases of the peripheral nervous system that can be divided into mononeuropathies, multifocal neuropathies, and polyneuropathies. Symptoms usually include numbness and paresthesia. These symptoms are often accompanied by weakness and can be painful. Polyneuropathies can be divided into axonal and demyelinating forms, which is important for diagnostic reasons. Most peripheral neuropathies develop over months or years, but some are rapidly progressive. Some patients only suffer from mild, unilateral, slowly progressive tingling in the fingers due to median nerve compression in the wrist (carpal tunnel syndrome), while other patients can be tetraplegic, with respiratory insufficiency within 1-2 days due to Guillain-Barré syndrome. Carpal tunnel syndrome, with a prevalence of 5% and incidence of 1-2 per 1000 person-years, is the most common mononeuropathy. Population-based data for chronic polyneuropathy are relatively scarce. Prevalence is estimated at 1% and increases to 7% in persons over 65 years of age. Incidence is approximately 1 per 1000 person-years. Immune-mediated polyneuropathies like Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are rare diseases, with an annual incidence of approximately 1-2 and 0.2-0.5 per 100 000 persons respectively. Most peripheral neuropathies are more prevalent in older adults and in men, except for carpal tunnel syndrome, which is more common in women. Diabetes is a common cause of peripheral neuropathy and is associated with both mono- and polyneuropathies. Among the group of chronic polyneuropathies, in about 20-25% no direct cause can be found. These are slowly progressive axonal polyneuropathies.

Shoulder position increases ulnar nerve strain at the elbow of patients with cubital tunnel syndrome

BACKGROUND

Previous studies have shown that the shoulder internal rotation elbow flexion (SIREF) test, which is a modified elbow flexion (EF) test, has significantly higher sensitivity than the EF test in patients with cubital tunnel syndrome (CubTS). Here, we hypothesized that this increase in sensitivity was due to increase in the ulnar nerve strain around the elbow introduced by the additional shoulder position.

METHODS

Ulnar nerve strain at the elbow was intraoperatively measured at both the EF test and SIREF test positions in 20 patients with CubTS before simple decompression. Statistical analysis was performed with the Wilcoxon signed rank test at a confidence level of 99% (P < .001).

RESULTS

Mean ulnar nerve strain in the EF test position was 18.9% ± 12.1%, whereas that in the SIREF test position was 24.7% ± 14.0%. Ulnar nerve strain was higher in the SIREF than in the EF test position in all cases, and the difference was significant (mean, 5.8% ± 0.9%; 95% confidence interval, 3.90%-7.73%).

CONCLUSION

This study indicated that increased sensitivity in the SIREF test compared with the EF test was due to the increase in ulnar nerve strain around the elbow. To the best of our knowledge, this is the first study showing that shoulder position changes the ulnar nerve strain around the elbow in living patients with CubTS.

Analysis of the Papal Benediction Sign: The ulnar neuropathy of St. Peter

The origin of the Papal Benediction Sign has been a source of controversy for many generations of medical students. The question has been whether the Papal Benediction Sign posture is the result of an injury to the median nerve or to the ulnar nerve. The increasingly popular use of online "chat rooms" and the vast quantities of information available on the internet has led to an increasing level of confusion. Looking in major anatomy texts, anatomy and board review books as well as numerous internet sites the answer remains unresolved. Through the analysis of functional anatomy of the hand, cultural and religious practices of the early centuries of the Common Era and church art a clear answer emerges. It will become apparent that this hand posture results from an ulnar neuropathy.

Anteriorly positioned ulnar nerve at the elbow: a rare anatomical event: case report

Two patients with an anteriorly positioned ulnar nerve at the elbow, identified during cubital tunnel release, are presented. Upon encountering an empty cubital tunnel, additional dissection found the ulnar nerve to course posterior to and to penetrate through the intermuscular septum 3 to 5 cm proximal to the medial epicondyle. It then ran anterior to the pronator-flexor mass before entering the forearm between the ulnar and the humeral heads of the flexor carpi ulnaris. Although a rare anatomical anomaly, an anteriorly positioned ulnar nerve is potentially an underreported finding. In individuals with cubital tunnel syndrome, diagnosis and surgical treatment may be negatively affected if the surgeon fails to recognize the aberrant anatomy. Upper extremity surgeons should also be mindful of this rare anomaly when performing elbow arthroscopy or medial epicondyle release to prevent inadvertent injury to the nerve.

Does the ulnar nerve enlarge after surgical transposition?

OBJECTIVES

The purpose of this study was to test the hypothesis that symptomatic transposed ulnar nerves have a larger average cross-sectional area (CSA) than symptomatic in situ ulnar nerves.

METHODS

We conducted a retrospective review of the charts and sonograms of 68 patients who had failed ulnar nerve transposition compared to 48 patients with cubital tunnel syndrome who had not undergone surgical management. In addition, postoperative sonograms were compared with preoperative studies when available. Failure was defined as persistence or recurrence of symptoms of ulnar neuropathy postoperatively. The cross-sectional area of the nerve, subjective echogenicity, and residual sites of compression were recorded. Groups were subsequently compared by t tests.

RESULTS

The failed ulnar nerve transposition group showed a mean cross-sectional area ± SD of 17.26 ± 9.93 mm(2), whereas the control group showed a mean cross-sectional area of 13.45 ± 7.33 mm(2). This difference was statistically significant (P= .018). Nontransposed nerves were more likely to have identifiable sites of compression (P< .05). There was a trend toward postoperative enlargement in the 6 patients with available preoperative imaging (P = .17). No difference in subjective echogenicity was found in this analysis.

CONCLUSIONS

Patients with failed ulnar nerve transposition show a significantly enlarged cross-sectional area when compared to symptomatic nerves in situ. Although a specific etiology for this difference cannot be determined, the data suggest that the reference ranges for the cross-sectional area of the ulnar nerve may need to be revised for those who have undergone surgery.

The association between cubital tunnel morphology and ulnar neuropathy in patients with elbow osteoarthritis

BACKGROUND

Morphologic changes in the cubital tunnel during elbow motion in patients with elbow osteoarthritis have not been examined in vivo. We examined changes in cubital tunnel morphology during elbow motion and characteristics of medial osteophyte development to elucidate whether cubital tunnel area and medial osteophyte size are factors contributing to cubital tunnel syndrome in patients with elbow osteoarthritis.

METHODS

We performed computed tomography of 13 primary osteoarthritic elbows in patients with cubital tunnel syndrome (group A) and 25 primary osteoarthritic elbows in patients without cubital tunnel syndrome (group B) at full extension, 90° of flexion, and full flexion. Cubital tunnel area, humeral and ulnar osteophyte area, and proportion of osteophytes within the cubital tunnel were analyzed at each position.

RESULTS

Humeral osteophytes and osteophyte proportion within the cubital tunnel were larger at full flexion (24.7 mm(2) and 49.9% in group A; 18.7 mm(2) and 39% in group B) and 90° of elbow flexion (20.3 mm(2) and 45.3% in group A; 10.2 mm(2) and 30.2% in group B) than at full extension (9.0 mm(2) and 31.3% in group A; 2.3 mm(2) and 12.5% in group B). These parameters were significantly greater in group A than in group B at full extension and 90° of flexion.

CONCLUSIONS

The effect of medial osteophytes on the ulnar nerve, especially on the humeral side, rather than narrowing of the cubital tunnel, may be a causative factor for cubital tunnel syndrome with elbow osteoarthritis.