Posterior Interosseous Nerve Syndrome due to Schwannoma - A Case Report.

Posterior interosseous nerve syndrome is the most frequent syndrome of radial nerve compression, with the arcade of Frohse being the main site of compression. Its symptoms include difficulties in finger and wrist extension with possible radial deviation. Herein, we present a case of posterior interosseous syndrome caused by a schwannoma, a type of neurological tumor.

Radial neuropathy.

Radial neuropathy is the third most common upper limb mononeuropathy after median and ulnar neuropathies. Muscle weakness, particularly wrist drop, is the main clinical feature of most cases of radial neuropathy, and an understanding of the radial nerve's anatomy generally makes localizing the lesion straightforward. Electrodiagnosis can help confirm a diagnosis of radial neuropathy and may help with more precise localization of the lesion. Nerve imaging with ultrasound or magnetic resonance neurography is increasingly used in diagnosis and is important in patients lacking a history of major arm or shoulder trauma. Radial neuropathy most often occurs in the setting of trauma, although many other uncommon causes have been described. With traumatic lesions, the prognosis for recovery is generally good, and for patients with persistent deficits, rehabilitation and surgical techniques may allow substantial functional improvement.

Multiple tendon transfer for a case of radial nerve palsy in hereditary neuropathy with liability to pressure palsy.

Hereditary neuropathy with liability to pressure palsy (HNPP) is a rare autosomal dominant disease characterized by focal, recurrent, demyelinating peripheral neuropathies. It is caused by deletions of the gene encoding for peripheral myelin protein 22 (PMP22) on chromosome 17. While it may range widely, the most common clinical presentation is an acute, focal mononeuropathy with numbness or muscle weakness after trauma or compression. Diagnostic tools include electrophysiological studies, genetic tests and nerve biopsies. There is no standard surgical or pharmacological treatment. The course of the disease is usually benign, with spontaneous improvement after most episodes of peripheral nerve palsy. HNPP is best managed by early detection, preventative measures, and subsequent treatment of symptoms. According to the medical literature, operative treatment was undertaken in few cases and limited to decompression of the nerve at the classic entrapment sites of the carpal or cubital tunnels. We present a case of multiple tendon transfer (pronator teres to extensor carpi radialis brevis and flexor carpi radialis to extensor digitorum communis) with a two-year follow-up in a 24-year-old woman with HNPP who was affected by irreversible radial nerve palsy, and conclude with a review of the medical literature related to the disease.

Split Brachioradialis Tendon Causing Wartenberg Syndrome in a Professional Baseball Pitcher.

Wartenberg syndrome can occur when external factors compress the superficial radial nerve. It can also be due to anatomic variations, such as a split brachioradialis tendon entrapping the nerve. This case report describes a unique example of a professional baseball player diagnosed with Wartenberg syndrome who was later found to have a split brachioradialis tendon during surgical management. It is an important addition to the field of hand surgery since, to our knowledge, we have not identified such a rare case concerning a professional athlete previously described in the literature.

The posterior interosseous nerve at the proximal forearm: anatomical study and clinical correlation / El nervio interóseo posterior en el antebrazo proximal: estudio anatómico y correlación clínica

SUMMARY: The deep branch of the radial nerve (DBRN) runs through the radial tunnel, which is a muscle-aponeurotic structure that extends from the humeral lateral epicondyle to the distal margin of the supinator muscle (SM). The Posterior Interosseous Nerve (PIN) originates as a direct continuation of the DBRN as it emerges from the SM and supplies most of the muscles of the posterior compartment of the forearm. The PIN can be affected by compressive neuropathies, especially at the "Arcade of Frohse". Its preservation is of special interest in surgical approaches to proximal radius fractures and in compressive syndromes release, for which surgeons must have an adequate anatomical knowledge of its course. This descriptive cross-sectional study evaluated 40 upper limbs of fresh cadavers. The diameters of the DBRN, the length of the radial tunnel, and the distances to the supinator arch, PIN emergence and PIN bifurcation were measured. The deep branch of the radial nerve (DBRN) has a course of 23.8 ± 3.7 mm from its origin to the supinator arch, presenting a diameter of 2.2 ± 0.3 mm at that level. The length of the radial tunnel was 42.2 ± 4 mm. The PIN originated 70.7 ± 3.5 mm distal to the lateral epicondyle. Type I corresponds to the division of the PIN during its journey through the radial tunnel, presenting in 35 % of cases, and Type II corresponds to the division of the PIN distal to its emergence from the radial tunnel presenting in the remaining 65 %. This study enriches the knowledge of the PIN and provides useful reference information on a Latin American mestizo sample. We propose the division pattern of the PIN into two types. Future studies may use this classification not only as a qualitative variable, but also include quantitative morphometric measurements.

El ramo profundo del nervio radial (RPNR) discurre por el túnel radial, que es una estructura músculo- aponeurótica que se extiende desde el epicóndilo lateral del húmero humeral hasta el margen distal del músculo supinador (MS). El nervio interóseo Posterior (NIP) se origina como una continuación directa del RPNR cuando emerge del MS e inerva la mayoría de los músculos del compartimiento posterior del antebrazo. El NIP puede verse afectado por neuropatías compresivas, especialmente en la "Arcada de Frohse". Su conservación es de especial interés en los abordajes quirúrgicos de las fracturas proximales de radio y en la liberación de síndromes compresivos, para lo cual los cirujanos deben tener un adecuado conocimiento anatómico de su curso. Este estudio descriptivo transversal evaluó 40 miembros superiores de cadáveres frescos. Se midieron los diámetros de la RPNR, la longitud del túnel radial y las distancias al arco supinador, la emergencia del NIP y la bifurcación del NIP. El RPNR tenía un recorrido de 23,8 ± 3,7 mm desde su origen hasta el arco supinador, presentando un diámetro de 2,2 ± 0,3 mm a ese nivel. La longitud del túnel radial fue de 42,2 ± 4 mm. El NIP se originó 70,7 ± 3,5 mm distal al epicóndilo lateral. El tipo I corresponde a la división del NIP durante su recorrido por el túnel radial presentándose en el 35 % de los casos, y el tipo II corresponde a la división del NIP distal a su salida del túnel radial presentándose en el 65 % restante. Este estudio enriquece el conocimiento del NIP y proporciona información de referencia útil sobre una muestra de mestizos latinoamericanos. Proponemos el patrón de división del NIP en dos tipos. Futuros estudios pueden utilizar esta clasificación no solo como una variable cualitativa, sino también incluir medidas morfométricas cuantitativas.

Anatomical variations in the sensory innervation of the dorsal surface of the first digit space, a cadaveric study with clinical consequences.

INTRODUCTION: Radial nerve palsy is a classical complication of a humeral shaft fracture. In clinical practice, motor palsy of the radial nerve is sometimes observed without an abnormality felt in the sensory territory. HYPOTHESIS: We hypothesised that this dissociation between sensory and motor involvement is related to anatomical variations of the sensory innervation of the dorsal surface of the first digit space, thus, we decided to study the nature and frequency of these variations. MATERIAL AND METHOD: A cadaveric study was conducted on 24 upper limbs to analyse the truncal origin of the sensory branches innervating the dorsal surface of the first digit space. RESULTS: The sensory branch of the radial nerve (SBRN) participated in the innervation of the dorsal surface of the first digit space in 22 limbs, an anatomical variation was present in 2 cases with a mixed innervation by the SBRN and the lateral cutaneous nerve of forearm (LCNF) in 1 case and singular innervation by LCNF, with no SBRN involvement, in 1 case. Communications between SBRN and LCNF were found in 7 cases. DISCUSSION: Pure motor radial damage, without a sensory deficit of the dorsal surface of the first digit space, does not preclude a complete traumatic injury of the radial nerve. The sensory innervation of this region can be relayed by a branch of the LCNF. LEVEL OF EVIDENCE: IV; cadaveric study.

EPIDEMIOLOGICAL STUDY OF SURGICALLY TREATED HUMERAL SHAFT FRACTURES - A 10-YEAR REVIEW.

Most epidemiological studies do not exclusively address fractures treated surgically but include those with conservative treatment. In Brazil, few epidemiological studies address fractures prevalence undergoing surgical treatment. Objective: To assess the prevalence, demographics, and associated injuries of surgically treated humeral shaft fractures. Methods: A retrospective study between 2009 and 2019 with patients undergoing osteosynthesis of humeral shaft fracture. Categorical variables were assessed using Fisher's chi-square or exact test, and non-categorical variables were assessed using the unpaired t-test. A significance level of 5% was adopted. Results: A total of 115 patients were evaluated. Mean age was 37.9 ± 15.6 years, with a male predominance (66.9%) due to car accidents. The most prevalent fracture type was 12 A3. Open fracture prevalence was 11.3%. Radial nerve damage prevalence was 33% and low-energy trauma was twice as likely. Conclusion: Surgically treated humeral shaft fractures were more prevalent in men, young, and related to high-energy trauma, with a transverse line pattern. Fractures secondary to low-energy trauma had a greater association with radial nerve injury. Level of Evidence III, Epidemiological, Retrospective Study.

A maior parcela dos estudos epidemiológicos não aborda exclusivamente as fraturas tratadas cirurgicamente, mas engloba as de tratamento conservador. No Brasil existem poucos estudos epidemiológicos que versam sobre a prevalência das fraturas submetidas ao tratamento cirúrgico. Objetivo: Avaliar a prevalência, os dados demográficos e as lesões associadas das fraturas da diáfise do úmero tratadas cirurgicamente. Métodos: Estudo retrospectivo conduzido entre 2009 e 2019, com pacientes submetidos a osteossíntese de fratura diafisária do úmero. As variáveis categóricas foram testadas pelo teste qui-quadrado ou teste exato de Fisher, enquanto as não categóricas foram medidas pelo teste t não pareado. Adotou-se nível de significância de 5%. Resultados: Foram avaliados 115 pacientes. A média de idade foi de 37,9 ± 15,6 anos, com uma predominância de pacientes do sexo masculino (66,9%) devido a acidentes automobilísticos. A fratura tipo 12 A3 foi a mais prevalente. A prevalência de fratura exposta foi de 11,3%. A lesão nervo radial ocorreu em 33%, principalmente em traumas de baixa energia. Conclusão: As fraturas diafisárias do úmero tratadas cirurgicamente foram mais prevalentes em homens jovens e relacionadas a traumas de alta energia, com padrão de traço transverso. Fraturas secundárias e traumas de baixa energia tiveram maior associação com lesão do nervo radial. Nível de Evidência III, Estudo Epidemiológico, Retrospectivo.

Functional Outcome Of Extra-Articular Distal Humerus Fracture Fixation Using A Lateral Column Locking Compression Plate.

Background: : A host of different methodologies have been implemented in the management of distal humerus fractures, including conservative measures and surgical fixation with a variety of plates. This study was conducted to evaluate the functional outcome of open reduction and internal fixation of extra articular distal humerus fractures with distal humerus locking compression plate. Methods: This is a retrospective cohort study of patients with close extra articular distal humerus fractures who underwent open reduction and internal fixation with a distal humerus locking compression plate at Ghurki Trust Teaching Hospital from July 2017 to December 2019. Various demographic indicators were used for data analysis and radiological union was assessed in serial follow-ups. Functional outcome was evaluated using the Mayo Performance Elbow Score at the final follow-up. Results: Thirty-one patients presented with extra-articular fracture of humerus (N=31) with average age 33.5±9.90 years. The average follow-up period was 13.8 months. Radiological union was achieved in 14.8 weeks (range 12-20 weeks). Out of 31 patients, 28 had excellent results with mean Mayo Elbow Performance Score of 94.8. Two patients (6.5%) had radial nerve palsy post-operatively. Conclusion: This study shows that open reduction and internal fixation of extra-articular distal humerus fractures with distal humerus locking compression plates allows for stable fixation, good functional outcome, and low complication rates.

Ipsilateral Radial Neuropathy after COVID-19 mRNA Vaccination in an Immunocompetent Young Man.

The global coronavirus disease 2019 (COVID-19) pandemic spurred an urgent need for vaccination and herd immunity. Recently, mRNA vaccines for COVID-19 have been used widely despite reports of several adverse events. Most adverse effects are mild, although a few are associated with neurological complications. Unfortunately, there is a scarcity of information on peripheral nerve complications after COVID-19 mRNA vaccination. We report the case of an immunocompetent young male patient who suffered from ipsilateral wrist drop with multiple lymphadenopathy in the cervical and axillary region after Pfizer-BioNTech vaccination. He experienced unilateral wrist drop, which significantly improved with corticosteroid treatment. Based on knowledge of this adverse effect, careful surveillance and increased awareness are needed for early diagnosis. To the best of our knowledge, this is the first reported case in the English literature of radial neuropathy resulting in wrist drop in a recently vaccinated and young immunocompetent patient.

Epidemiological study of surgically treated humeral shaft fractures - a 10-year review / Estudo epidemiológico das fraturas diafisárias do úmero tratadas cirurgicamente - uma revisão de 10 anos

ABSTRACT Most epidemiological studies do not exclusively address fractures treated surgically but include those with conservative treatment. In Brazil, few epidemiological studies address fractures prevalence undergoing surgical treatment. Objective: To assess the prevalence, demographics, and associated injuries of surgically treated humeral shaft fractures. Methods: A retrospective study between 2009 and 2019 with patients undergoing osteosynthesis of humeral shaft fracture. Categorical variables were assessed using Fisher's chi-square or exact test, and non-categorical variables were assessed using the unpaired t-test. A significance level of 5% was adopted. Results: A total of 115 patients were evaluated. Mean age was 37.9 ± 15.6 years, with a male predominance (66.9%) due to car accidents. The most prevalent fracture type was 12 A3. Open fracture prevalence was 11.3%. Radial nerve damage prevalence was 33% and low-energy trauma was twice as likely. Conclusion: Surgically treated humeral shaft fractures were more prevalent in men, young, and related to high-energy trauma, with a transverse line pattern. Fractures secondary to low-energy trauma had a greater association with radial nerve injury. Level of Evidence III, Epidemiological, Retrospective Study.

RESUMO A maior parcela dos estudos epidemiológicos não aborda exclusivamente as fraturas tratadas cirurgicamente, mas engloba as de tratamento conservador. No Brasil existem poucos estudos epidemiológicos que versam sobre a prevalência das fraturas submetidas ao tratamento cirúrgico. Objetivo: Avaliar a prevalência, os dados demográficos e as lesões associadas das fraturas da diáfise do úmero tratadas cirurgicamente. Métodos: Estudo retrospectivo conduzido entre 2009 e 2019, com pacientes submetidos a osteossíntese de fratura diafisária do úmero. As variáveis categóricas foram testadas pelo teste qui-quadrado ou teste exato de Fisher, enquanto as não categóricas foram medidas pelo teste t não pareado. Adotou-se nível de significância de 5%. Resultados: Foram avaliados 115 pacientes. A média de idade foi de 37,9 ± 15,6 anos, com uma predominância de pacientes do sexo masculino (66,9%) devido a acidentes automobilísticos. A fratura tipo 12 A3 foi a mais prevalente. A prevalência de fratura exposta foi de 11,3%. A lesão nervo radial ocorreu em 33%, principalmente em traumas de baixa energia. Conclusão: As fraturas diafisárias do úmero tratadas cirurgicamente foram mais prevalentes em homens jovens e relacionadas a traumas de alta energia, com padrão de traço transverso. Fraturas secundárias e traumas de baixa energia tiveram maior associação com lesão do nervo radial. Nível de Evidência III, Estudo Epidemiológico, Retrospectivo.

Silas Weir Mitchell, MD, LLD, FRC: Neurological Evaluation and Rehabilitation of the Injured Upper Extremity.

Appreciating the history of Hand Surgery is part of what most of us enjoy about our profession. Most of us know that Silas Weir Mitchell, MD, coined the terms "Causalgia" and "Phantom Limb," yet few of us know that our present-day evaluation of the sensory and motor function of the hand and some of our rehabilitation methods for motor palsy were introduced by Mitchell as he worked, scholarly, in Turner's Lane Hospital, the first hospital devoted to nerve injuries, to understand Civil War gunshot wounds related to musket ball. Mitchell's contributions to neurosensory and motor evaluation were reviewed by reading his historical publications. Mitchell's described cervical sympathetic injury Horner's Syndrome), sensory recovery preceding motor recovery after proximal nerve injury, that more sensory information can be perceived by applying greater pressure, importance of passive joint movement to prevent contracture, value of electrical stimulation after motor palsy, value of rest to facilitate healing, ability of 1- and 2-point sensory testing to evaluate sensibility, value of testing temperature to understand neuropathology, importance of experimental peripheral nerve surgery to clinical care, recorded muscle strength by manual evaluation, staged degree of nerve injury, described Saturday night and crutch palsy, and first described Hoffmann-Tinel sign. Mitchell made signifiant and seminal observations, that have largely gone unrecognized and that we use today in care of the injured upper extremity.

Radial tunnel syndrome in psoriatic enthesitis: Complication or coincidence?

Radial tunnel syndrome (RTS) is a rare condition resulting from posterior interosseous nerve (a branch of radial nerve) compression, within the radial tunnel. Lateral epicondylitis as a possible aetiology for RTS has been previously described. Here we report a 64-year-old female, with history of scalp psoriasis, who presented with pain over the lateral aspect of the left elbow and proximal forearm for one year, and decreased sensation over the lateral aspect of distal left forearm including the hand for 20 days. Examination revealed enthesitis at left lateral epicondyle, which was confirmed on magnetic resonance imaging. Touch and pain sensations were reduced over the left thumb, index finger, lateral aspect of the hand and distal forearm, and forearm pain was exaggerated with restricted extension of the wrist and third finger. Rheumatoid factor, anti-nuclear and anti-neutrophil cytoplasmic antibody were negative, and nerve conduction study were normal. A diagnosis of RTS as a possible complication of psoriatic enthesitis was suggested, and patient showed good response to non-steroidal anti-inflammatory drugs.

Analyzing the functional effects of dynamic and static splints after radial nerve injury.

The radial nerve is a commonly injured upper extremity peripheral nerve. The inability to extend the wrist results in a loss of hand function and dexterity that affects patients' ability to perform their activities of daily living. There is no strong evidence to support a particular splint design for improving dexterity. This cohort study compared whether a static or dynamic splint can improve hand dexterity when assessed with the 9-hole peg test (9-HPT) after radial nerve injury. Thirty-four subjects with radial nerve palsy participated in the study. The test was repeated three times for each subject, first without the splint, and then while wearing the control static wrist splint, and finally while wearing the dynamic splint. The 9-HPT was used as the outcome measure. The 9-HPT times were 36.4±4.8seconds without a wrist splint and improved when using the static and the dynamic splints to 33.5±4.5seconds (P<0.01) and 25.7±3.5seconds (P<0.01) respectively. The use of a dynamic splint after radial nerve palsy can provide the patient with greater manual dexterity when compared to using no splint or a static splint.

Radial motor nerve conduction studies in the upper arm.

INTRODUCTION: The main goal of this study was to determine the contribution of the anterior forearm muscles to the compound muscle action potential (CMAP) recorded from the extensor digitorum (ED) after proximal stimulation. METHODS: Twenty-one healthy volunteers and 114 patients with compressive and traumatic radial neuropathies were examined. Stimulation was carried out at six different points: distal third of the upper arm; Erb's point; axilla; medial upper arm; antecubital fossa; and ulnar groove. RESULTS: In the control group, Erb's CMAP area was significantly greater than the distal CMAP area. In compressive neuropathy, there was conduction block, but no change in conduction velocity. There were no differences in Erb's CMAP latencies between the control group and the neuropathies group. DISCUSSION: CMAPs recorded over the ED with stimulation at the brachial plexus represent the sum of the motor unit action potentials of the posterior and anterior forearm muscles.

Anatomical Study of Radial Tunnel and its Clinical Implications in Compressive Syndromes.

Objective The purpose of the present study was to analyze the structures in the radial tunnel that can cause posterior interosseous nerve entrapment. Methods A total of 30 members of 15 adult cadavers prepared by intra-arterial injection of a 10% solution of glycerol and formalin were dissected. All were male, belonging to the laboratory of anatomy of this institution. Results The branch for the supinator muscle originated from the posterior interosseous nerve in all limbs. We identified the Frohse arcade with a well-developed fibrous constitution in 22 of the 30 dissected limbs (73%) and of muscular constitution in 8 (27%). The distal margin of the supinator muscle presented fibrous consistency in 7 of the 30 limbs (23.5%) and muscular appearance in 23 (76.5%). In the proximal margin of the extensor carpi radialis brevis muscle, we identified the fibrous arch in 18 limbs (60%); in 9 (30%) we noticed the arcade of muscular constitution; in 3 (10%) there was only the radial insertion, so that it did not form the arcade. Conclusion The Frohse arcade and the arcade formed by the origins of the extensor carpi radialis brevis are normal anatomical structures in adult cadavers. However, from the clinical point of view, these structures have the potential to cause entrapment of the posterior interosseous nerve.

Anatomical Study of Radial Tunnel and its Clinical Implications in Compressive Syndromes / Estudo anatômico do túnel radial e suas implicações nas síndromes compressivas

Abstract Objective The purpose of the present study was to analyze the structures in the radial tunnel that can cause posterior interosseous nerve entrapment. Methods A total of 30 members of 15 adult cadavers prepared by intra-arterial injection of a 10% solution of glycerol and formalin were dissected. All were male, belonging to the laboratory of anatomy of this institution. Results The branch for the supinator muscle originated from the posterior interosseous nerve in all limbs. We identified the Frohse arcade with a well-developed fibrous constitution in 22 of the 30 dissected limbs (73%) and of muscular constitution in 8 (27%). The distal margin of the supinator muscle presented fibrous consistency in 7 of the 30 limbs (23.5%) and muscular appearance in 23 (76.5%). In the proximal margin of the extensor carpi radialis brevis muscle, we identified the fibrous arch in 18 limbs (60%); in 9 (30%) we noticed the arcade of muscular constitution; in 3 (10%) there was only the radial insertion, so that it did not form the arcade. Conclusion The Frohse arcade and the arcade formed by the origins of the extensor carpi radialis brevis are normal anatomical structures in adult cadavers. However, from the clinical point of view, these structures have the potential to cause entrapment of the posterior interosseous nerve.

Resumo Objetivo O objetivo do presente estudo foi analisar as estruturas contidas no túnel radial que podem causar neuropatia compressiva do nervo interósseo posterior. Métodos Foram dissecados 30 membros de 15 cadáveres adultos, preparados por injeção intra-arterial de uma solução de glicerina e formol a 10%. Todos do sexo masculino, pertencentes ao laboratório de anatomia desta instituição. Resultados O ramo para o músculo supinador originou-se do nervo interósseo posterior em todos os membros. Identificamos a arcada de Frohse com uma constituição fibrosa bem desenvolvida em 22 dos 30 membros dissecados (73%) e de constituição muscular em 8 (23%) A margem distal do músculo supinador apresentou consistência fibrosa em 7 dos 30 membros (23,5%) e uma aparência muscular em 23 (76,5%). Na margem proximal do músculo extensor radial curto do carpo, identificamos a arcada fibrosa em 18 membros (60%); em 9 (30%), notamos a arcada de constituição muscular; e em três (10%) havia apenas a inserção radial, de maneira que não formava a arcada. Conclusão A arcada de Frohse e a arcada formada pelas origens do músculo extensor radial curto do carpo são estruturas anatômicas normais em cadáveres adultos. No entanto, sob o ponto de vista clínico, essas estruturas têm potencial para causar a compressão do nervo interósseo posterior.

Incidence and operations of median, ulnar and radial entrapment neuropathies in Finland: a nationwide register study.

The aim of this study was to investigate the incidence rates and operations for carpal tunnel syndrome and ulnar and radial neuropathies in specialist care in Finland. Patients diagnosed with entrapment neuropathies of the upper extremity were identified from the Care Register for Health Care, 2007-2016. There were 81,911 cases in 54,095,070 person-years. The total crude incidence rates per 100,000 person-years among women and men were 197 and 105 for carpal tunnel syndrome, 26 and 36 for ulnar neuropathies, and 5.7 and 8.5 for radial neuropathies, respectively. Of these, carpal tunnel syndrome was operated on in 63% of women and 61% of men, ulnar neuropathy in 43% of women and 47% of men, and radial neuropathy in 11% of women and 8% of men. Incidence of carpal tunnel syndrome and ulnar neuropathies increased up to late middle age, while radial neuropathies were less common. Level of evidence: III.