Symptomatic flexor carpi radialis brevis: case report

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.

A Rare Anatomical Finding of Undescribed Accessory Palmaris Longus in the Distal Forearm: A Case Report

Upper limb muscle anomalies and their clinical implications have been described frequently in the literature reviews. In this article, we are presenting a case of aberrant forearm muscle that had not been described before, and could be considered as a palmaris longus muscle variation. A 24-year-old man presented to the emergency department, Hamad General Hospital, Doha, Qatar, with right forearm laceration with multiple cut structures for which he was admitted for exploration and repair. Intraoperatively, flexor digitorum superficialis of the third, fourth, and fifth digits, flexor carpi radialis, and palmaris longus were injured' and all of them were repaired. We noticed an aberrant muscle-which was also injured-that originated from the distal third of the radius on its medial aspect to insert into the palmar fascia; pulling this muscle's tendon resulted in tightening of palmar fascia' same as the palmaris longus. Along with the importance of deep knowledge of typical human anatomy, hand surgeons must be aware that an aberration from normal anatomy might be anticipated, to provide the best care to our patients.

The prevalence and distribution of the flexor carpi radialis brevis muscle in the Turkish population

The flexor carpi radialis brevis (FCRB) is a very rare anomalous muscle that is usually asymptomatic but may cause various pathologies, such as radial-sided wrist pain. The aim of this study was to determine the prevalence of FCRB in the Turkish population, its location, and sex differences. Forearm, wrist, and hand magnetic resonance images of 849 individuals aged 18–65 years were retrospectively evaluated in this study. The survey found an FCRB prevalence of 4%, with a prevalence of 3.6% among women and of 4.7% among men. However, the difference between the sexes was not statistically significant (p = 0.629). The origin of all 34 FCRBs identified was the distal third of the anterior aspect of the radius; the insertion site of 28 was the second metacarpal bone, whereas that of the remaining 6 was the os trapezium. In conclusion, the data of this study report the prevalence of FCRB for the first time in the Turkish population, which will contribute to radiological and surgical evaluations in the region and help in early and accurate diagnosis of various pathological conditions that may be caused by FCRB.

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.

Surgical Exposure Technique for Volar Locking Plate Fixation of Distal Radius Fractures in Patients with Flexor Carpi Radialis Brevis Muscle Anomaly

The flexor carpi radialis brevis (FCRB) muscle, considered a rare anomaly, is not well known among orthopedic surgeons. The indications for volar locking plates to treat distal radius fractures have recently expanded, and, as a result, encounters with the FCRB are becoming more common. However, few studies have described how to retract an FCRB. Here, we describe seven of 264 patients with FCRB who underwent surgery for distal radius fractures. In one case, the retracted FCRB interfered with the internal fixation. The presented cases demonstrate that the radial retraction of an FCRB with a large muscle belly enables favorable exposure of the distal radius.

Multifactorial Wrist Pain Treated with Tenotomy of Anomalous Flexor Carpi Radialis Brevis: A Case Report

CASE

We present a case of a 33-year-old left hand-dominant/right hand-involved active duty Navy sailor woman with volar radial wrist pain. She underwent scaphoid cyst excision and bone grafting as well as tenotomy. Intraoperatively, she was noted to have a flexor carpi radialis brevis (FCRB) tendon that was transected. After surgery, her 1-year outcomes demonstrated range of motion improved equivalent with her contralateral side, her visual analogue scale (VAS) pain score had decreased to 1, and her QuickDASH and Patient-Rated Wrist Evaluation improved.

CONCLUSIONS

Our case represents 1-year outcome after surgical release of a FCRB. Our patient's pain and functional scores exceeded the minimal clinically important difference.

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.

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.

Flexor carpi radialis brevis: a rare accessory muscle presenting as an intersection syndrome of the wrist

The flexor carpi radialis brevis (FCRB) is a rare accessory muscle of the forearm and wrist. It is typically asymptomatic, but has been discovered either incidentally during cadaveric studies or at the time of surgery in patients with distal forearm injury. Rarely, the FCRB muscle is associated with pain. We report a patient with wrist pain related to intersection between the tendon of the FCRB muscle and the tendon of the flexor carpi radialis (FCR) muscle, with an associated longitudinal split tear of the FCR tendon, documented by magnetic resonance imaging (MRI). To our knowledge, this is only the second report in the English literature of this intersection syndrome.

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.

An online catalog of muscle variants: Student perceptions of a new opportunity for self-directed learning

OBJECTIVE:

Muscle variants are common findings in dissection laboratories. These anomalous structures can be relevant in the diagnosis and management of certain conditions and therefore could be incorporated into anatomy curricula at chiropractic colleges. We aimed to create an online resource of muscle variants to facilitate student self-directed learning within this area of study.

METHODS:

At the time of their discovery during routine educational dissection, muscle variants included in the catalog were documented and subsequent case reports written. All content created for this resource, including photographs and videos, was hosted on the institution's learning management system. Students enrolled in our doctor of chiropractic program were invited to view the catalog and encouraged to leave feedback by completing an online survey.

RESULTS:

Student responses to Likert-style survey questions generally indicated high levels of satisfaction regarding the utility and features of the catalog. Open-ended and Likert-style survey questions were used to help guide the future directions of this developing resource. Concurrent anatomy students were not more likely to contribute to the catalog compared to students who had previously completed the university's anatomy course series ( p = .75, 2-tailed Fisher exact test).

CONCLUSION:

An online supplement to graduate-level gross anatomy courses can aid in the instruction of muscle variants by providing an opportunity for student self-directed learning. This resource will be updated continually and will be expanded on to include neurovascular and visceral variants. Student participation will be sought in developing future content to be included in this catalog.

Anomalous Forearm Muscles and Their Clinical Relevance

Despite their relatively low prevalence in the population, anomalous muscles of the forearm may be encountered by nearly all hand and wrist surgeons over the course of their careers. We discuss 6 of the more common anomalous muscles encountered by hand surgeons: the aberrant palmaris longus, anconeus epitrochlearis, palmaris profundus, flexor carpi radialis brevis, accessory head of the flexor pollicis longus, and the anomalous radial wrist extensors. We describe the epidemiology, anatomy, presentation, diagnosis, and treatment of patients presenting with an anomalous muscle. Each muscle often has multiple variations or subtypes. The presence of most anomalous muscles is difficult to diagnose based on patient history and examination alone, given that symptoms may overlap with more common pathologies. Definitive diagnosis typically requires soft tissue imaging or surgical exploration. When an anomalous muscle is present and symptomatic, it often requires surgical excision for symptom resolution.

Flexor carpi radialis brevis muscle: A case report and its prevalence in patients with carpal tunnel syndrome

BACKGROUND

During the surgery for a distal radius fracture, we encountered a large anomalous muscle lying across the distal radius. The muscle was identified as a flexor carpi radialis brevis muscle (FCRB), based on its location, function, and innervation. This experience led us to clarify its prevalence in living subjects and alert surgeons of its presence.

METHODS

We reviewed wrist MRI scans of 515 hands of 379 patients with carpal tunnel syndrome (CTS). The prevalence of the FCRB was calculated. The cross sectional area (CSA) of the FCRB was compared with that of the hypothenar muscles. Signal intensity and fat infiltration of the FCRB were assessed using semiquantitative methods. The anterior compartment ratio (CSA of the anterior compartment of the forearm was divided by CSA of the forearm. CSA of the FCRB was excluded for measurement) was compared between patients with and without FCRB.

RESULTS

We found seven hands of six patients (1.6%) with a FCRB. All of these tendons were inserted into the second metacarpal base. CSA of FCRB was smaller than that of the hypothenar muscles. Semiquantitative assessment revealed normal signal intensities of the FCRB compared with those of other muscles. The anterior compartment ratio was smaller in patients with FCRB than without FCRB. None of the FCRB in our series demonstrated any sign of tendinitis on MRI. Furthermore, the postoperative clinical course for those patients was uneventful.

CONCLUSIONS

Prevalence of FCRB in patients with CTS was 1.6%. FCRB should function as a wrist flexor. Its strength varied according to the individuals but was not greater than that of the hypothenar muscles. It is still unclear if the FCRB could cause the development of CTS. However, it was found that the FCRB could be a mass which occupies and narrows the anterior compartment.

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.

Flexor carpi radialis brevis: an unusual anomalous muscle of the wrist

During imaging studies or surgical procedures, anomalous forearm and wrist muscles are occasionally encountered. Among them, the flexor carpi radialis brevis is very rare. Because the trend is growing toward treating distal radius fractures with volar plating, the flexor carpi radialis brevis is worth knowing. Here, we report two cases with a review of the literature.