Morphological and functional assessment of the flexor carpi radialis brevis using conventional ultrasound and elastography.

PURPOSE: The flexor carpi radialis brevis (FCRB) is a supernumerary musculotendinous structure of the wrist that has been the focus of some interest in the last decade. While its anatomy is well known, its in vivo function remains unknown as it has never been studied. METHODS: Eleven cases of FCRB underwent a multimodal ultrasound consisting of B-mode, color Doppler and shear wave elastography. RESULTS: A pennate shape was observed in all cases and the mean value of the cross-sectional area was 0.8 cm2 (SD 0.3 cm2). Young's modulus was significantly (p < 0.01) different between the resting position and active flexion or passive extension. CONCLUSION: Our study demonstrates that the FCRB shows biomechanics of a typical skeletal muscle and is voluntarily controlled by flexing the wrist. Absent in other vertebrate taxa, the FCRB probably plays a role in active stability of the wrist in Human.

Flexor carpi radialis brevis: case report of a symptomatic tear.

Anatomical variants of muscle are commonly encountered by surgeons and radiologists. The flexor carpi radialis brevis (FCRB) is an anomalous muscle in the distal forearm with an estimated prevalence of 2-8%. In the literature, there are a few case reports of symptomatic FCRB tenosynovitis without a concomitant tear, and treatment methods described include both conservative and surgical management. We present a case of one patient with radial sided wrist pain and a partial FCRB tear, which to our knowledge is the first case report of a symptomatic FCRB tear. We also review existing literature regarding FCRB anatomy, particularly related to intra-operative dissection and exposure. Identification of an anomalous FCRB on imaging may serve to guide clinicians in their differential diagnosis of radial-sided wrist pain, in which FCRB pathological conditions ought to be included.

Reversed Palmaris Longus Muscle Causing Volar Forearm Pain and Ulnar Nerve Paresthesia.

A case of volar forearm pain associated with ulnar nerve paresthesia caused by a reversed palmaris longus muscle is described. The patient, an otherwise healthy 46-year-old male laborer, presented after a previous unsuccessful forearm fasciotomy for complaints of exercise exacerbated pain affecting the volar forearm associated with paresthesia in the ulnar nerve distribution. A second decompressive fasciotomy was performed revealing an anomalous "reversed" palmaris longus, with the muscle belly located distally. Resection of the anomalous muscle was performed with full relief of pain and sensory symptoms.

Accessory tricuspid valve leaflet and an anomalous muscle bundle in the right ventricular outflow tract in a patient with double-outlet right ventricle: a rare case report.

Double-outlet right ventricle (DORV), a clinically important congenital heart disease, occurs in 1-3% of persons with congenital heart disease. It may occur as an isolated cardiac defect, together with other cardiac lesions, or in association with extracardiac anomalies. Other rare cardiac anomalies include an anomalous muscle bundle (AMB) in the right ventricular outflow tract (RVOT) and an accessory tricuspid valve leaflet. We report a very rare case of concomitant DORV, AMB in the RVOT and accessory tricuspid valve leaflet in a 17-year-old male patient. The patient eventually died from severe decompensated heart failure. To the best of our knowledge, such a case has not been previously reported in the literature.

Presence of anomalous flexor carpi radialis brevis (FCRB) in Madelung's deformity.

An anomalous flexor carpi radialis brevis (FCRB) muscle was present in four of nine patients undergoing surgery for Madelung's deformity. This disproportionately frequent finding suggests an embryologic dysgenesis of forearm formation rather than a developmental tethering of Vicker's ligament.Level of evidence: IV (case series).

Accessory first lumbrical muscle within the carpal tunnel: a case report.

Carpal tunnel syndrome is the most common entrapment neuropathy in the upper extremity. Palmaris longus, flexor digitorum superficialis, and lumbricals have infrequently been reported as causes of nerve compression. During routine Korean cadaver dissection, we incidentally identified an anatomic variant of first lumbrical muscle within the carpal tunnel in both wrists. The aberrant musculature originated from the radial side of the second FDS muscle at distal forearm level, running separately across the wrist beneath the flexor retinaculum. The dissected anomalous muscle was identified as an additional muscle belly of the first lumbrical muscle. Compression of the median nerve at the wrist might rarely be caused by the presence of such a tendon or muscle anomaly found in this study. Surgeons should be aware of possible anatomic variations in the carpal tunnel, and be prepared to modify their surgical plan accordingly.

A Muscle Variant of the Lateral Neck Region: The Cleido-Vertebral Muscle.

Introduction: Anatomical variations of the neck muscles have previously been reported, involving in particular the omohyoid and sternothyroid muscles. We herein report a novel variant neck muscle found during a routine surgical procedure. Case Report: A 63-year-old women underwent a pelvi-mandibulectomy with bilateral neck dissection for a squamous cell carcinoma of the floor of mouth pT3N1. On the right neck dissection, the present peculiar muscle was discovered. It was located in the lateral region of the neck, deeply to the sternocleidomastoid muscle and caudally to the hyoid bone. It took origin from the sixth cervical vertebrae's transverse process and attached caudally to the middle third of the clavicular bone, after having passed superficially to the omohyoid muscle's intermediate tendon. Conclusions: Neck muscles are important during head and neck surgery due to their significance as surgical landmarks and their relationship with noble vessels. Being aware of possible variant that can alter classical anatomical reference points is important to prevent iatrogenic trauma.

Bakody's Test Positive Thoracic Outlet Syndrome Caused by Anomalous Muscle: A Case Report.

Anomalous muscle causes thoracic outlet syndrome (TOS). A 40-year-old man presented with numbness of the left upper extremity, similar to cervical spondylotic radiculopathy. He presented with a positive Bakody's test. However, magnetic resonance imaging showed no significant changes in the cervical spine and revealed an anomalous muscle adjacent to the left brachial plexus. We diagnosed the muscle as the cause of TOS and performed a resection, which resulted in symptomatic improvement.

Symptomatic bifid insertion of the Flexor Carpi Radialis Brevis.

A 35 year-old right-handed female presented with persistent wrist pain lasting two years. Imaging disclosed an accessory tendon-shaped structure, identified as a Flexor Carpi Radialis Brevis, strangling the Flexor Carpi Radialis tendon at the wrist during effort. Surgical exploration found the insertion of the Flexor Carpi Radialis Brevis to be bifid. Resection of the stenosing branch and the fibrotic tendon sheath restored strength in the right wrist and painless symmetrical motion compared to the left wrist ten weeks postoperatively.

Flexor carpi radialis brevis muscle, a rare anomalous muscle of the forearm; a case report and literature review.

The flexor carpi radialis brevis (FCRB) is a rare abnormal muscle of the distal forearm or wrist. Its incidence varies in different reports, which oscillating between 2-8%. This paper reports a case of FCRB found in the anatomy of the forearm. The abnormal muscle, which started from the facies volaris distal radii, occupies the terminus of pronator quadratus, and was observed with dysplasia in the pronator quadratus. We also reviewed the literature on FCRB anatomy, especially the surgical exposure of distal radius fractures and the clinical symptoms caused by FCRB. Knowledge of the anomalous muscles of the forearm and wrist can highly improve clinician's understanding of the disease during surgery and imaging examination, and reduce unnecessary trauma caused by misdiagnosis.

Flexor Carpi Radialis Brevis Resection for Treatment of a Distal Radius Fracture: A Case Report.

The flexor carpi radialis brevis (FCRB) is an anomalous muscle of the forearm that is only present in 3.5 to 8.6% of the population. In the case of volar plating of distal radius fractures, the FCRB inhibits proper fracture exposure and thus hinders proper reduction. A 78-year-old female presented with right distal radius fracture which necessitated internal fixation. Following mobilization and retraction of the flexor carpi radialis tendon, an anomalous muscle belly was identified as the FCRB. With continued difficulty in exposure and fracture site reduction, resection of the FCRB was performed. The patient was able to return to her activities of daily living without pain and demonstrated no appreciable functional deficit. This case report demonstrates a distal radius fracture where FCRB resection was used, resulting in no detrimental clinical outcomes.

Clinical Application of Anomalous Muscles for Tendon Transfer in the Upper Limb: A Systematic Review of the Literature.

Numerous anomalous muscles of the forearm and hand have been reported in the literature. The majority were encountered in cadaver dissections and some were incidentally detected during tendon transfer surgery. Because of the limited number of motors available for transfer, it may be advantageous if an anomalous muscle with favorable anatomy can function as a potential donor in a suitable clinical environment. Although several authors have illustrated various anomalies and their functional significance, the reports of actual utilization of such muscles as donors for tendon reconstructions are sparse. The aim of the study is to conduct a systematic review of the clinical applications of anomalous muscles in the upper extremity. After a thorough search of PubMed, Web of Science, Scopus, and Cochrane Library databases, only three out of 106 studies were found to be relevant. Two of them discussed the anomalous radial wrist extensor tendon transfer for thumb flexion. The third study described the usage of anomalous flexor carpi ulnaris (FCU) for thumb opposition and index finger flexion, and also proposed a classification. This is the first systematic review of the clinical application of anomalous muscles as donors in the upper extremity tendon transfer surgical procedures. Knowledge of the above classification helps in intraoperative evaluation of the type of the anomaly and the possible consideration of anomalous muscle as a source of transplant material in an appropriate clinical setting.

Prevalence and Clinical Manifestations of the Anconeus Epitrochlearis and Cubital Tunnel Syndrome.

Background: The true prevalence of the anconeus epitrochlearis (AE) and the natural history of cubital tunnel syndrome associated with this anomalous muscle are unknown. The purpose of this study was to evaluate the prevalence of AE and to characterize the preoperative and postoperative features of cubital tunnel syndrome caused by compression from an AE. Methods: All elbow magnetic resonance imaging (MRI) scans and all patients undergoing cubital tunnel surgery during a 20-year period were identified and retrospectively reviewed for the presence of an AE. All patients with an AE identified intra-operatively were matched to patients with no AE identified at surgery based on age, sex, concomitant procedures, and year of surgery. Preoperative and postoperative physical exam findings, electrodiagnostic study results, time to improvement, and reoperations were compared between the groups. Results: A total of 199 patients had an elbow MRI, and 27 (13.6%) patients were noted to have an AE present. Average time to improvement after surgical release was 23.0 days for patients with an AE and 33.2 days for patients with no AE. Twenty-seven patients with an AE noted improvement at the first postoperative visit (68%) compared to 15 patients without an AE (33%). No patients with an AE underwent reoperation for recurrent symptoms (0%) compared with four patients (10%) without an AE. Conclusions: The prevalence of AE in our study is 13.6%. These patients experience quicker and more reliable symptom improvement after surgical release than those without the anomalous muscle.

Prevalence of Flexor Carpi Radialis Brevis in Chinese Patients with Volar Wrist Plating Performed for Distal Radius Fracture.

Background: Volar locking plates were increasing popular as treatment of distal radius fractures. Various distal forearm anatomical variants were encountered during surgery. Flexor carpi radialis brevis (FCRB) was one of the most common and relevant anatomical variants because of its close proximity to fracture site. Methods: This is a retrospective single-centre study. In a 3.5-year period from March 2015 to August 2018, 133 patients who suffered from distal radius fracture requiring volar wrist plating were identified. Operation records and clinical photos were reviewed. All patients were followed up for at least 1 year. Any complications were recorded. Results: 9 patients with FCRB variant were identified. The prevalence was 6.8%. Hypoplastic pronator quadratus were found in 5 cases out of the 9 cases. None of these cases had any neurovascular injuries. No complications were noted during follow-up at 1 year. Conclusions: In Chinese population with volar locking plate done for distal radius fracture, the prevalence of flexor carpi radialis brevis was 6.8%. Surgeons should be aware of the possibility of FCRB variant.

A Transverse Carpal Muscle Causing Carpal Tunnel Syndrome.

Accessory and atypical muscles of the upper limb are common, whereas symptomatic variations presenting with carpal tunnel syndrome (CTS) are rare. A rare unilateral accessory transverse carpal muscle located palmar to the transverse carpal ligament is described. The accessory muscle, associated with CTS clinical manifestations in a 38-year-old Greek male worker, can be quite problematic during CTS operation. The current case emphasizes the importance of meticulous knowledge of the variable anatomy of the carpal tunnel (CT) area, since the accessory muscles may be accompanied by ectopic motor branches and a high risk of iatrogenic injury. Recognition and careful evaluation of accessory muscles may enhance a surgeon's ability to carry out a safer and successful CT approach.

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.

Complete Removal of the Epitrochleoanconeus Muscles in Patients with Cubital Tunnel Syndrome: Results From a Small Prospective Case Series.

BACKGROUND: Sometimes during surgery for cubital syndrome an anomalous muscle called the epitrochleoanconeus is encountered. Different surgical strategies on how to decompress the ulnar nerve in the presence of this muscle have been proposed, including transection of the muscle, resection, or subcutaneous transposition of the ulnar nerve. Because of the low incidence, there is no consensus on what type of surgical treatment can best be performed. In the present study, we prospectively followed a small series of patients, in which the muscle was resected. METHODS: Five patients who presented to our clinic with cubital tunnel syndrome in the presence of an epitrochleoanconeus muscle were followed prospectively. Two patients had bilateral epitrochleoanconeus muscles, 1 patient had recurrent symptoms after previous myotomy. Clinical outcome after resection of the muscle was graded using the Likert scale. In addition, histopathologic analysis was performed on the resected muscles, including ATPase histochemistry. RESULTS: Six of 7 cases had complete relief of symptoms (Likert 1) 6 weeks after excision of the epitrochleoanconeus muscle, including the case with recurrent symptoms after previous myotomy. Histopathologic analysis of the muscles showed grouped muscle fiber atrophy and type grouping in all cases, both signs of denervation that confirm the compressive pathophysiology of cubital tunnel syndrome in these patients. CONCLUSIONS: The results of this small prospective case series show that excision of the epitrochleoanconeus muscle in patients with cubital tunnel syndrome frequently leads to complete recovery. Further support for this surgical strategy was found from histopathologic analysis of the resected muscles.

Anomalous Lateral Rectus Muscle Band in a Case of Duane Retraction Syndrome.

Anomalous orbital structures are suspected in restrictive strabismus with features of severe globe retractions, overshoots, or synergistic movements. We report a case of suspected Duane syndrome that was found to have an anomalous band beneath the lateral rectus muscle. Such abnormal structures are rare, but it is important to identify and manage them to optimize outcomes.

Anatomic Variations of the Flexor Carpi Radialis Brevis: A Report of Five Cases.

The flexor carpi radialis brevis (FCRB) is a rare, anomalous musculotendinous structure of the wrist. Here, we report five cases of FCRB in a consecutive series of 123 distal radius fractures that were repaired by using volar locking plates.

Excision of anomalous muscle bundles as an important addition to extended septal myectomy for treatment of left ventricular outflow tract obstruction.

OBJECTIVE: This study aims to report our preliminary experience and anatomic findings in the surgical treatment and postoperative management of hypertrophic obstructive cardiomyopathy. METHODS: This study included 277 patients with hypertrophic obstructive cardiomyopathy (168 [60.65%] were male), with a median age of 47 years (interquartile range, 35-54 years), who underwent surgical myectomy performed by 1 surgeon in Fuwai Hospital between May 2010 and April 2015. The median follow-up was 14 months (interquartile range, 7-24 months). RESULTS: A total of 127 patients (45.85%) underwent concomitant procedures, and 2 patients (0.72%) died in the early perioperative days. The left ventricular outflow gradient decreased from 78 mm Hg (interquartile range, 61-100 mm Hg) to 11 mm Hg (interquartile range, 8-15 mm Hg) when discharged (P < .001). Of the 228 patients with well-documented anatomic description, more than 80% had various intraventricular anomalies. The cumulative survival was 99.28% (95% confidence interval, 97.15-99.82) at 1 year and 96.98% (95% confidence interval, 92.56-98.79) at 5 years. Of the surviving 272 patients, 268 (98.53%) were categorized with functional class I and II of the New York Heart Association classification at the latest evaluation. CONCLUSIONS: Anomalous muscle bundles are common in hypertrophic obstructive cardiomyopathy, and they may lead to middle-apical obstruction. Surgical myectomy provides excellent clinical outcomes with low risk for sufficient relief of obstruction and radical correction of intraventricular anomalies in patients with hypertrophic obstructive cardiomyopathy.