Median and Ulnar Nerve Compressions: Simplifying Diagnostics and Surgery at the Elbow and Hand.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Understand the anatomy of the median and ulnar nerves. 2. Perform clinical examination of the upper limb. 3. Analyze examination results to diagnose level of nerve compression. SUMMARY: Numbness and loss of strength are common complaints in the hand surgery clinic. Two nerves that are commonly entrapped (median and ulnar nerves) have several potential sites of entrapment, and in busy clinical practice, the less common sites may be overlooked, leading to wrong or missed diagnoses. This article reviews the anatomy of the median and ulnar nerves, provides tips to assist the busy clinician in diagnosis of site of entrapment(s), and discusses how to simplify surgery. The goal is to help the clinician be as efficient and accurate as possible when evaluating the patient with numbness or loss of strength in their hand.

Characteristics of surgically treated Guyon canal syndrome: A multicenter retrospective study.

Guyon canal (GC) syndrome is a rare peripheral neuropathy involving the distal part of the ulnar nerve. Several causes are associated with GC syndrome, including anatomic variations, space-occupying tumors, and trauma. Because of disease rarity, the only reported studies of GC syndrome are case series with small sample size. We conducted a multicenter study to identify the basic characteristics of patients with surgically treated GC syndrome and the risk factors for the disease. This retrospective multicenter study was conducted between January 2001 and December 2020. We screened 70 patients who underwent GC release surgery by seven hand surgeons at six institutes. A total of 56 patients were included in this study, including 38 patients (67.9%) who underwent isolated GC decompression and 18 (32.1%) who underwent combined peripheral nerve decompression. The mean patient age was 48.4 years (range: 20-89 years), and 40 patients (71.4%) were male. The average preoperative symptom duration was 18.5 months, and most patients were office workers. Ultrasound was positive for GC syndrome in 7/10 patients evaluated, CT in 2/5, MRI in 17/23, and electrodiagnostic studies in 35/44. The most common cause of GC syndrome was tumor (n = 23), followed by idiopathic (n = 17), trauma (n = 12), anatomic variants (n = 3), and inflammation (n = 3). In conclusion, most patients with GC syndrome in this study were male and had symptoms in one wrist. The most common cause of GC syndrome in this study was a tumor, including a ganglion cyst. Level of Evidence: Level IV case series.

Socioeconomic Factors in Patients with Ulnar Nerve Compression at the Elbow: A National Registry-Based Study.

AIMS: To investigate demographics and socioeconomic status in patients with ulnar nerve compression and the influence of socioeconomic factors on patient-reported outcome measurements (PROM) as evaluated by QuickDASH (short version of Disabilities of Arm, Shoulder and Hand) after surgery for ulnar nerve compression at the elbow. METHODS: Patients operated for primary ulnar nerve compression from 2010 to 2016 were identified in the National Quality Registry for Hand Surgery Procedures (HAKIR). Patients filled out questionnaires before and at three and 12 months after surgery. A total of 1346 surgically treated cases were included. Data from HAKIR were linked to data from Statistics Sweden (SCB) on socioeconomic status (i.e., education level, earnings, social assistance, immigrant status, sick leave, unemployment, and marital status). RESULTS: Patients surgically treated for ulnar nerve compression at the elbow differed from the general population with lower levels of education, higher social assistance dependence, a high proportion of unemployment, and lower earnings. However, the results were not clear concerning the influence of socioeconomic factors on the outcome of surgery, except for long-term sick leave. CONCLUSION: Patients surgically treated for ulnar nerve compression at the elbow are socioeconomically deprived, but only a history of long-term sick leave influences the outcome of surgery. This information is crucial in the diagnosis and treatment of these patients.

Ulnar tunnel syndrome: pathoanatomy, clinical features and management.

Ulnar tunnel syndrome is compression of the ulnar nerve at the level of the wrist within Guyon's canal. It is most commonly caused by a ganglion cyst but may also be secondary to fractures, inflammatory conditions, neoplasm, vascular anomalies, aberrant musculature or a combination of these. Assessment should include a detailed history focusing on duration, site and progression of symptoms. The level of compression can be estimated clinically on examination by assessing motor and sensory changes in the hand. Investigations are used to confirm diagnosis or to clarify the underlying cause. X-rays and computed tomography can be used to exclude fractures. Ultrasound is used to diagnose ganglion cysts and vascular anomalies, and can localise the level of compression. Nerve conduction studies can be used to support the diagnosis and look for proximal compression. Mild symptoms can be managed non-operatively. Surgical exploration and decompression is the gold standard treatment for neuro-compressive causes with largely good outcomes.

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.

Hypothenar Hammer Syndrome with Ulnar Nerve Neuropathy.

Hypothenar hammer syndrome is a rare medical condition that is usually associated with repetitive hand trauma. In this article, we delineate the importance of the nerve conduction velocity study to help determine objectively whether neuropathy is significant to the point that surgical means should be considered in absence of obvious ischemic change.

Report of a Transligamentous Ulnar Nerve Sensory Branch.

Background: Several anatomical variations of the median nerve recurrent motor branch have been described. No previous reports have described the anatomical variation of the ulnar nerve with respect to transverse carpal ligament. In this article, we present a patient with symptomatic compression of the ulnar nerve found to occur outside the Guyon canal due to a transligamentous course through the distal transverse carpal ligament. Methods: A 59-year-old, right-hand-dominant male patient presented with right hand pain, subjective weakness, and numbness in both the ulnar and the median nerve distributions. Electromyography revealed moderate demyelinating sensorimotor median neuropathy at the wrist and distal ulnar sensory neuropathy. At the time of planned carpal tunnel and Guyon canal release, a transligamentous ulnar nerve sensory common branch to the fourth webspace was encountered and safely released. Results: There were no surgical complications. The patient's symptoms of numbness in the median and ulnar nerve distribution clinically improved at his first postoperative visit. Conclusions: We have identified a case of transligamentous ulnar nerve sensory branch encountered during carpal tunnel release. To our knowledge, this has not been previously reported. While the incidence of this variant is unknown, hand surgeons should be aware of this anatomical variant as its location puts it at risk of iatrogenic injury during open and endoscopic carpal tunnel release.

Smoking is associated with ulnar nerve entrapment: a birth cohort study.

Ulnar nerve entrapment is the second most common compression neuropathy of the upper extremity. It has been associated with smoking in cross-sectional studies. Our aim was to study whether smoking is associated with ulnar nerve entrapment. The study population consisted of the Northern Finland Birth Cohort 1966 participants, who attended the 31-year follow-up in 1997 (N = 8,716). Information on smoking, body mass index (BMI), long-term illnesses, and socio-economic status were recorded at baseline in 1997. Data on hospitalizations due to ulnar nerve entrapment neuropathies was obtained from the Care Register for Health Care, 1997-2016. Hazard ratios (HR) with 95% confidence intervals (CI) and population attributable risk (PAR) were calculated adjusted for gender, BMI and socio-economic status. 66 patients were diagnosed with ulnar nerve entrapment in the follow-up 1997-2016. Before the age of 31 years, smoking ≤10 pack years associated with more than doubled (HR = 2.57, 95% CI = 1.29-5.15) and smoking >10 pack years with more than five-folded (HR = 5.61, 95% CI = 2.80-11.23) risk for ulnar nerve entrapment compared to non-smokers in the adjusted analyses. Adjusted PAR for smoking (reference of no smoking) was 53.6%. In our study, smoking associated with increased risk for ulnar nerve entrapment, accounting for considerable proportion of increased risk.

Tardy Ulnar Nerve Palsy.

Tardy ulnar nerve palsy is a chronic clinical condition characterized by a delayed onset ulnar neuropathy after an injury to the elbow. Typically, tardy ulnar nerve palsy occurs as a consequence of nonunion of pediatric lateral condyle fractures at the elbow, which eventually lead to a cubitus valgus deformity. While the child grows, the deformity worsens and the ulnar nerve is gradually stretched until classic symptoms of ulnar nerve neuropathy appear. Other childhood elbow trauma has also been associated with tardy ulnar nerve palsy, including supracondylar fractures resulting in cubitus varus, fractures of the medial condyle and of the olecranon, as well as radial head or Monteggia fractures/dislocation, with or without deformity. The clinical assessment includes obtaining a complete history, physical examination, nerve conduction tests, and elbow imaging studies. Treatment consists of ulnar nerve decompression, with or without corrective osteotomy, with overall successful results usually achieved.

Compressive Ulnar Neuropathy Caused by Olecranon Bursitis and Concomitant Epidermal Cyst: A Case Report.

Epidermal cyst is a dermal or subcutaneous epithelial cyst that contains keratin and is lined by true epidermis. Although extremely rare, it can cause pathology including nerve compression syndrome. We report a rare case of ulnar nerve compression in the elbow that was caused by olecranon bursitis and concomitant epidermal cyst in a 67-year-old man. The ulnar nerve was immediately adjacent to the olecranon bursa and was significantly compressed. There was no connection between the tumor and the ulnar nerve. Pain, numbness, and weakness in his ring and little fingers disappeared after resection of the cyst and bursa.

The cubital tunnel syndrome caused by the intraneural or extraneural ganglion cysts: Case report and review of the literature.

Cubital tunnel syndrome is the second most common nerve compression syndrome in peripheral nerve compression disease. Although potential ulnar nerve entrapment can occur at multiple points along its course, such as the arcade of struthers, the medial intermuscular septum, the medial epicondyle, the cubital tunnel, and the deep flexor pronator aponeurosis, the most common site of entrapment is the cubital tunnel. However, cubital tunnel syndrome could also be caused by the occupying masses along the course of ulnar nerve, such as intraneural or extraneural ganglia. The cubital tunnel syndrome caused by intraneural or extraneural ganglion cysts has been rarely reported. In our hospital, there were 184 patients with cubital tunnel syndrome who underwent surgical treatment from January 2010 to January 2014. Of these patients, 16 had extraneural cysts and 3 had intraneural ganglion cysts. The incidence rate of cysts in the cubital tunnel was 10.33%. Electromyography was used as routine examination. Ultrasound was used only in some patients in whom elbow mass was suspected. In the surgery of the cubital tunnel syndrome combined with cyst, if any other cysts were found, we should be remove completely the cyts and decompress the ulnar nerve thoroughly with the ulnar nerve being anterior transposition. These cysts were confirmed by histopathological examination. Finally, we compared the clinical features of patients who had a medial elbow ganglion with those of patients who had only cubital tunnel syndrome. B ultrasound can significantly improve the diagnosis. All patients were followed up for 4 months to 2 years, and the curative effect was good.

Intraneural microcystic lymphatic malformation of the ulnar nerve at the Guyon canal: Unusual cause of ulnar pain in a child.

We present a case of an unusual cause of ulnar pain on a 9-year-old patient. The patient had pain on the ulnar side of the wrist after a fall. MRI showed a poorly defined lesion on the ulnar nerve at Guyon's canal. The initial diagnosis was traumatic neuropathy. Following conservative treatment of symptoms for one year, the pain started again. Therefore, a new MRI was performed where progression of the lesion was observed. Excision of the lesion was performed and the specimen sent for pathologic analysis. The diagnosis was of microcystic lymphatic malformation. The patient had a satisfactory evolution, with complete resolution. This is the first description of a microcystic lymphatic malformation in an intraneuronal location.

Anterior subcutaneous transposition for persistent ulnar neuropathy after neurolysis.

OBJECTIVE Little is known about optimal treatment if neurolysis for ulnar nerve entrapment at the elbow fails. The authors evaluated the clinical outcome of patients who underwent anterior subcutaneous transposition after failure of neurolysis of ulnar nerve entrapment (ASTAFNUE). METHODS A consecutive series of patients who underwent ASTAFNUE performed by a single surgeon between 2009 and 2014 was analyzed retrospectively. Preoperative and postoperative complaints in the following 3 clinical modalities were compared: pain and/or tingling, weakness, and numbness. Six-point satisfaction scores were determined on the basis of data from systematic telephonic surveys. RESULTS Twenty-six patients were included. The median age was 56 years (range 22-79 years). The median duration of complaints before ASTAFNUE was 23 months (range 8-78 months). The median interval between neurolysis and ASTAFNUE was 11 months (range 5-34 months). At presentation, 88% of the patients were experiencing pain and/or tingling, 46% had weakness, and 50% had numbness of the fourth and fifth fingers. Pain and/or tingling improved in 35%, motor function in 23%, and sensory disturbances in 19% of all the patients. Improvement in at least 1 of the 3 clinical modalities was found in 58%. However, a deterioration in 1 of the 3 modalities was noted in 46% of the patients. On the patient-satisfaction scale, 62% reported a good or excellent outcome. Patients with a good/excellent outcome were a median of 11 years younger than patients with a fair/poor outcome. No other factor was significantly related to satisfaction score. CONCLUSIONS A majority of the patients were satisfied after ASTAFNUE, even though their symptoms only partly resolved or even deteriorated. Older age is a risk factor for a poor outcome. Other factors that affect outcome might play a role, but they remain unidentified. One of these factors might be earlier surgical intervention. The modest results of ASTAFNUE should be mentioned when counseling patients after failure of neurolysis of ulnar nerve entrapment to manage their expectations. Patients, especially those who are elderly, might even consider not undergoing a secondary procedure. A randomized trial that includes a conservative treatment group and groups undergoing one of the several possible surgical procedures is needed to find the definitive answer for this clinical problem.

Hamate hook nonunion initially mistaken for ulnar nerve compression: a case report with review of literature.

BACKGROUND: Hamate hook (HH) stress fractures are rare, often presenting with misleading symptoms and easily overlooked/misdiagnosed. These fractures occur frequently in individuals participating in sports activities involving racquets, bats, or clubs. Symptoms are non-specific and often mimic other clinical conditions, such as ulnar nerve entrapment or ulnar vessel thrombosis. CASE REPORT: A 17-year-old tennis player with no history of trauma presented with dominant hand weakness together with pain and paresthesia on the ulnar side, which exacerbated with tennis play. The patient was treated for ulnar nerve compression with activity cessation and rest for 2 months. After 6 months of persistent symptoms, the patient underwent open Guyon tunnel release, although preoperative electromyoneurography revealed no signs of nerve damage and bone scans showed a small area of increased uptake in the hypothenar region. Postoperatively, symptoms resumed and the patient reported to our department for a second opinion. Point tenderness over HH, hypothenar muscles hypotrophy, paresthesia, hand weakness and pain with ulnar deviation, and flexion of distal phalanges of the two ulnar fingers were observed. HH fracture was suspected. Computerized tomography scan revealed fractured HH and the patient underwent hook excision. One month postoperatively, the pain intensity reduced together with function and strength improvement; 2 months postoperatively, the patient was pain free and had returned to tennis. CONCLUSIONS: In patients involved in racquet sports with hypothenar pain and paresthesia of the ulnar side of the hand, HH fracture should be suspected. Symptoms can mimic ulnar nerve entrapment and may lead to overlooking the correct diagnosis. Treatment of choice is fractured fragment excision.

Ulnar Tunnel Syndrome, Radial Tunnel Syndrome, Anterior Interosseous Nerve Syndrome, and Pronator Syndrome.

In addition to the more common carpal tunnel and cubital tunnel syndromes, orthopaedic surgeons must recognize and manage other potential sites of peripheral nerve compression. The distal ulnar nerve may become compressed as it travels through the wrist, which is known as ulnar tunnel or Guyon canal syndrome. The posterior interosseous nerve may become entrapped in the proximal forearm as it travels through the radial tunnel, which results in a pain syndrome without motor weakness. The median nerve may become entrapped in the proximal forearm, which can result in a variety of symptoms. Spontaneous neuropathy of the anterior interosseous nerve of the median nerve can be observed without external compression. Electrodiagnostic and imaging studies may aid surgeons in the diagnosis of these syndromes; however, a thorough physical examination is paramount to localize compressed segments of these nerves. An understanding of the anatomy of each of these nerve areas allows practitioners to appreciate a patient's clinical findings and helps guide surgical decompression.

[Nerve injuries after elbow luxation fractures in childhood : Indication and timing for surgical revision]. / Nervenverletzungen nach Ellenbogenluxationsfraktur im Kindesalter : Indikation und Zeitpunkt zur operativen Revision.

BACKGROUND: Supracondylar humerus fractures are very common in pediatric populations. In cases of dislocated fractures, closed reduction and percutaneous K­wire fixation is recommended. Initially, 10-16 % of the patients also present lesion of the ulnar nerve as well as median nerve palsy in 6.4% and radial nerve palsy in 2.6 % of cases, respectively. METHOD: We present the case of a 10-year-old boy with a dislocation of the elbow and fracture of the medial epicondyle. After closed reduction and K­wire fixation from medial, he presents a median nerve palsy. That a lesion of the ulnar nerve is also present is only noticed 3½ years posttraumatically. A surgical decompression and neurolysis of the ulnar and median nerve is performed and the postoperative grip and key strength presented. DISCUSSION: With the help of the presented case we discuss the indication and the point of surgical revision. Clinical assessment and neurosonography are essential for an exact diagnosis.

Cervical dermatomal zona misdiagnosed as ulnar nerve entrapment.

Herpes zoster is a secondary reactivation of primary contagious varicella-zoster virus in the dorsal root ganglia. While thoracic zona is common, cervical dermatomal zona is a rare segmental complication of herpes zoster and can be easily misdiagnosed as other diseases. This article describes a patient with initial neuralgia without dermatomal lesions that was treated as ulnar nerve entrapment syndrome until manifestation of herpetiform cutaneous lesions appeared. It is important that clinicians should be aware of the possibility of zoster infection when evaluating the onset of neuralgia in a dermatomal distribution in the upper limb, especially without rash.

MR neurography of ulnar nerve entrapment at the cubital tunnel: a diffusion tensor imaging study.

OBJECTIVES: MR neurography, diffusion tensor imaging (DTI) and tractography at 3 Tesla were evaluated for the assessment of patients with ulnar neuropathy at the elbow (UNE). METHODS: Axial T2-weighted and single-shot DTI sequences (16 gradient encoding directions) were acquired, covering the cubital tunnel of 46 patients with clinically and electrodiagnostically confirmed UNE and 20 healthy controls. Cross-sectional area (CSA) was measured at the retrocondylar sulcus and FA and ADC values on each section along the ulnar nerve. Three-dimensional nerve tractography and T2-weighted neurography results were independently assessed by two raters. RESULTS: Patients showed a significant reduction of ulnar nerve FA values at the retrocondylar sulcus (p = 0.002) and the deep flexor fascia (p = 0.005). At tractography, a complete or partial discontinuity of the ulnar nerve was found in 26/40 (65%) of patients. Assessment of T2 neurography was most sensitive in detecting UNE (sensitivity, 91%; specificity, 79%), followed by tractography (88%/69%). CSA and FA measurements were less effective in detecting UNE. CONCLUSION: T2-weighted neurography remains the most sensitive MR technique in the imaging evaluation of clinically manifest UNE. DTI-based neurography at 3 Tesla supports the MR imaging assessment of UNE patients by adding quantitative and 3D imaging data. KEY POINTS: • DTI and tractography support conventional MR neurography in the detection of UNE • Regionally reduced FA values and discontinuous tractography patterns indicate UNE • T2-weighted MR neurography remains the imaging gold standard in cases of UNE • DTI-based ulnar nerve tractography offers additional topographic information in 3D.