Accessory Flexor Carpi Ulnaris Muscle in Humans: A Rare Anatomical Case with Clinical Considerations.

Anatomical variations of the forearm flexor muscles are occasionally encountered. Though usually observed incidentally during autopsies or imaging studies, they may at times cause concern due to associated clinical symptoms. This report presents a case of unilateral accessory flexor carpi ulnaris (AFCU) muscle observed in a human male cadaver aged 78 years. During routine cadaveric dissection, an anomalous AFCU muscle was observed in the left forearm of a human male cadaver aged 78 years. Standard institutional guidelines pertaining to the use of human cadaver for teaching and research were followed. A thorough literature review about the flexor carpi ulnaris (FCU) through the PubMed, Embase and Google scholar databases was undertaken, using the keywords - accessory flexor carpi ulnaris muscle, aberrant flexor carpi ulnaris muscle and anatomical variation of flexor carpi ulnaris muscle. Relevant gross anatomical findings were recorded and photographed. AFCU was identified on the medial aspect of the distal third of the left forearm. The AFCU was found originating from the ante-brachial fascia and the fascia covering the FCU on the left forearm, forming a small separate belly deep to the main muscle. It terminated as a thin tendon running alongside the hypothenar muscles and attached distally to the base of the proximal phalanx of the little finger. The AFCU was found to be innervated by a branch of the ulnar nerve. Awareness about the rare AFCU muscle is clinically important as a possible cause of ulnar nerve compression but also as a possible graft in reconstruction surgeries.

Superficial branch of the radial nerve passing through the supinator canal, emerging between the extensor digitorum and abductor pollicis longus muscles and consequently supplying the second finger and radial portion of the third finger: a case report and clinical implications.

Awareness of unique path of the superficial branch of the radial nerve and its unusual sensory distribution can help avoid potential diagnostic confusion. We present a unique case encountered during a routine dissection of a Central European male cadaver. An unusual course of the superficial branch of the radial nerve was found in the right forearm, where the superficial branch of the radial nerve originated from the radial nerve distally, within the supinator canal, emerged between the extensor digitorum and abductor pollicis longus muscles and supplied the second and a radial half of the third digit, featuring communications with the lateral antebrachial cutaneous nerve and the dorsal branch of the ulnar nerve. Due to dorsal emerging of the superficial branch of the radial nerve the dorsal aspect of the thumb was innervated by the lateral antebrachial cutaneous nerve. To our best knowledge such variation of the superficial branch of the radial nerve has never been reported before. This variation dramatically changes aetiology and manifestation of possible entrapment syndromes which clinicians should be aware of.

Acceptable range of forearm deformity derived from relation to three-dimensional analysis and clinical impairments.

This study aimed to investigate deformity patterns that cause clinical impairments and determine the acceptable range of deformity in the treatment of forearm diaphyseal fractures. A three-dimensional (3D) deformity analysis based on computed bone models was performed on 39 patients with malunited diaphyseal both-bone forearm fractures to investigate the 3D deformity patterns of the radius and ulna at the fracture location and the relationship between 3D deformity and clinical impairments. Clinical impairments were evaluated using forearm motion deficit. Cutoff values of forearm deformities were calculated by performing receiver operating characteristic analysis using the deformity angle and the limited forearm rotation range of motion (less than 50° of pronation or supination) resulting in activities of daily living (ADL) impairment as variables. The extension, varus, and pronation deformities most commonly occurred in the radius, whereas the extension deformity was commonly observed in the ulna. A positive correlation was observed between pronation deficit and extension deformity of the radius (R = 0.41) and between supination deficit and pronation deformity of the ulna (R = 0.44). In contrast, a negative correlation was observed between pronation deficit and pronation deformity of the radius (R = -0.44) and between pronation deficit and pronation deformity of the ulna (R = -0.51). To minimize ADL impairment, radial extension deformity should be <18.4°, radial rotation deformity <12.8°, and ulnar rotation deformity <16.6°. The deformities in the sagittal and axial planes of the radius and in the axial plane of the ulna were responsible for the limited forearm rotation.

Reliability of the Masada Classification for Forearm Involvement in Patients With Hereditary Multiple Osteochondromas (HMO).

BACKGROUND: Classifications describing forearm lesions in patients with Hereditary Multiple Osteochondromatosis (HMO) have been used to recommend surgical intervention and stratify outcomes; however, there is no consensus on which classification offers greater reliability. The purpose of this study was to determine the reliability of the Masada classification and newer classifications among pediatric hand surgeons. METHODS: One hundred one patients with HMO between June 2014 and October 2019 were enrolled in the Congenital Upper Limb Differences (CoULD) Registry. Of those, 67 patients with 101 forearms were included. Four pediatric hand surgeons from the CoULD study group undertook an online evaluation. Each rater classified radiographs according to the Masada classification. Six weeks later, raters were asked to reclassify images according to the Masada, Gottschalk, and Jo classifications. Rater agreement for these classifications was assessed by estimating Fleiss kappa along with a 95% CI. RESULTS: Interrater agreement for Masada classification after the first reading was poor (κ=0.35; 95% CI=0.30-0.41) across all raters. Interrater agreement across the 4 raters decreased for the Masada classification from the first to the second reading (κ=0.35 vs 0.21; P <0.001). Intrarater agreement for the Masada classification ranged from 0.32 to 0.63 from the first to the second study reading. Gottschalk and Jo classifications yielded significantly better interrater agreement compared with Masada (κ=0.43 vs 0.21; P <0.001). Unclassifiable cases were highest in the Masada classification (34% to 44%) and lower in the Jo (17%) and Gottschalk (14%) classifications. CONCLUSION: Despite wide use, the Masada classification was found to have low reliability when classifying forearm deformities in HMO. Gottschalk offered more options for location, yet lacked deformity description including radial head dislocation. Jo classification offered more locations than Masada and incorporated radial head dislocation in some patterns. Based on the shortcomings in all 3 classification systems, the development of a more inclusive and reliable classification is warranted. LEVEL OF EVIDENCE: Level II; Diagnostic.

Coexistence of two accessory flexor pollicis longus heads or coexistence of two-headed flexor pollicis longus with an unrecognized anatomical structure?

The flexor pollicis longus (FPL) is located in the anterior compartment of the forearm. It is morphologically variable in both point of origin and insertion. An additional head of the FPL can lead to anterior interosseous syndrome. This report presents a morphological variation of the FPL (additional head in proximal attachment and bifurcated tendinous insertion in distal attachment) and an unrecognized structure that has not so far been described in the literature. This structure originates in six heads (attached to the FPL or interosseous membrane) that merge together, and inserts on to the FPL. All the variations noted have clinical significance, ranging from potential nerve compression to prevention of tendon rupture.

Risk scoring tool for forearm skin tears in Japanese older adults: A prospective cohort study.

[Aim] Because painful skin tears frequently occur in older patients, the prevention of skin tears is fundamental to improve their quality of life. However, a risk assessment tool for skin tears has not been established yet in Japan. Therefore, we aimed to propose a risk scoring tool for skin tears in Japanese older adult. [Methods] We conducted a prospective cohort study with 6-month follow-up in two long-term care hospitals in Japan. A total of 257 inpatients were recruited. Patient and skin characteristics were collected at baseline, and the occurrence of forearm skin tears were examined during follow-up. To develop a risk scoring tool, we identified risk factors, and converted their coefficients estimated in the multiple logistic regression analysis into simplified scores. The predictive accuracy of the total score was evaluated. [Results] Of 244 participants, 29 developed forearm skin tears during the follow-up period, a cumulative incidence of 13.5%. Senile purpura, pseudoscar, contracture, and dry skin were identified as risk factors for skin tears. Their weighted scores were 6, 4, 5, and 6, respectively. The area under the receiver operating characteristic curve of the total score was 0.806. At a cut-off score of 12, the sensitivity was 0.86, and the specificity was 0.67. [Conclusion] Our forearm skin tear risk scoring tool showed high accuracy, whereas specificity was low. This tool can contribute to prevent forearm skin tears in Japanese older adults.

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.

Manufacture and clinical application of the forearm pronation's assistant tableware in the severely burned.

INTRODUCTION: Even after reconstructive surgery, it is still difficult for patients with severe burns to achieve independent eating activity. In this project, we customized the forearm pronation's assistant tableware to assist in improvement with eating activities. METHODS: From January 2017 to December 2018, 28 patients with severe burns including the hands were recruited. For the patient's independent eating activities, we customized forearm pronation's tableware (forks and spoons). We compared modified Barthel index (MBI) and Visual analogue scale (VAS) of satisfaction under three conditions: no auxiliary tableware, ADL universal cuff, or forearm pronation tableware; to compare the duration and the weight of food spilled during lunch when the patients wore the ADL universal cuff or the forearm pronation's tableware. Differences in MBI (rank data) were tested by the Friedman test, differences in VAS (normal distribution) were tested with One-way ANOVA (Bonferroni), differences in the duration and the weight (normal distribution data) were tested by paired sample t test. RESULTS: After wearing the forearm pronation's assistant tableware, MBI VAS both increased more than when the patients did not wear the auxiliary tableware (all p＜0.05). When the subjects wore forearm pronation tableware, the duration of lunch significantly decreased and the quality of eating activity significantly improved compared to the ADL universal cuff in eating activity (all p＜0.05). CONCLUSION: After wearing the forearm pronation's assistant tableware, the patients with severe burns completely or almost completely accomplished independent eating, the duration was decreased, and during eating activity the quality and the satisfaction were improved. CLINICAL TRIAL REGISTRATION: Chinese Clinical trial registry, ChiCTR1800019963.

Bilateral anatomical variations in the extensor compartment of forearm and hand.

An unusual variation of the extensor muscles was found during the routine dissection of the posterior compartment of the forearm. The left forearm presented an extensor medii proprius muscle, the tendon of which had an unusual trajectory. It passed through the second extensor compartment between the tendons of the extensor carpi radialis longus and extensor carpi radialis brevis muscles. The right forearm presented two muscles for the index finger: one, the extensor indicis et medius communis, the tendon of which was split into three tendons, one radial and one ulnar for the index finger and a rudimentary tendon for the middle finger; the second muscle for the index finger had an unusual origin, common with the extensor carpi radialis brevis, and its tendon ran superficially to the tendon of the extensor indicis et medius communis muscle. Knowledge goes tendon variations can be significant not only for clinicians to misdiagnose a debilitating wrist extensor pain syndrome but also for surgeons to avoid iatrogenic injuries in hand surgery.

Gradual ulnar lengthening in Masada type I/IIb deformity in patients with hereditary multiple osteochondromas: a retrospective study with a mean follow-up of 4.2 years.

BACKGROUND: Gradual ulnar lengthening is the most commonly used procedure in the treatment of Masada type I/II deformity in patients with hereditary multiple osteochondromas. However, the treatment remains controversial for the recurrence of deformity in growing children. This study aims to evaluate the clinical and radiological outcomes of ulnar gradual lengthening in our clinic. METHODS: We retrospectively reviewed patients who underwent ulnar lengthening by distraction osteogenesis from June 2008 to October 2017. The carrying angle (CA) and range of motion (ROM) of the forearm and elbow were clinically assessed, and the radial articular angle (RAA) and ulnar shortening (US) were radiologically assessed before lengthening, 2 months after external frame removal, and at the last follow-up. RESULTS: The current study included 15 patients (17 forearms) with a mean age of 9.4 ± 2.3 years at the index surgery. The mean follow-up period was 4.2 ± 2.4 years. There were 9 patients (10 forearms) with Masada type I deformity and 6 patients (7 forearms) with Masada type IIb deformity. The mean amount of ulnar lengthening was 4.2 ± 1.2 cm. The mean RAA improved from 37 ± 8 to 30 ± 7° initially (p = 0.005) and relapsed to 34 ± 8° at the last follow-up (p = 0.255). There was a minimal deterioration of US yet significant improvement at the last follow-up compared to pre-op (p < 0.001). At the last follow-up, the mean forearm pronation and elbow flexion increased significantly (p < 0.001 and p = 0.013, respectively), and the mean carrying angle also improved significantly (p < 0.001). No patient with type IIb deformity achieved a concentric radial head reduction. CONCLUSIONS: Gradual ulnar lengthening significantly reduces cosmetic deformity and improves function in patients with Masada type I/IIb deformity. Our results supported early ulnar lengthening for patients with a tendency of dislocation of the radial head.

Older age and multi-joint external fixator are two risk factors of complications in ulnar lengthening in children with hereditary multiple exostosis.

OBJECTIVES: Hereditary multiple exostosis (HME) often involves forearm deformities. The aim of this study was to present the clinical results of 37 children who underwent ulnar lengthening with two different types of unilateral external fixators and to investigate the risk factors of complications. METHODS: We evaluated 37 children with forearm deformities caused by HME treated in our hospital from January 2008 to July 2019. The surgical procedures included resection of exostosis, osteotomy of the ulna, and gradual lengthening of the ulna with a unilateral external fixator. According to the type of fixator they received, the children were divided into two groups: group A received monorail fixators and group B received multi-joint fixators. Radiographic and functional parameters were assessed. Complications were recorded. RESULTS: All patients were followed-up for an average of 4.6 years (3.0 to 6.5). In both group A and group B, the ulna shortening (US), radial articular angle (RAA), carpal slip (CS), elbow flexion, forearm pronation, supination, and Mayo Elbow Performance Score (MEPS) values improved significantly from preoperatively to postoperatively (p < 0.05). However, the ulnar deviation was observed in 4 cases in group B and no cases in group A. According to logistic regression, the difference was only related to age (p < 0.05) and the type of external fixator (p < 0.05). CONCLUSIONS: Ulnar lengthening with unilateral external fixation is a safe and effective procedure for the treatment of HME. Regarding complications, deviation of the ulna axis was more likely to occur in older children with multi-joint external fixators.

Unusual presentation of acute compartment syndrome of the forearm and hand.

A 49-year-old man was referred to orthopaedics with an acute onset of left forearm and hand swelling, widespread blisters and erythema after lying face down on the floor for an unknown period of time. He also presented with left wrist stiffness due to pain and clawing of the fingers and glove-type loss of sensation in the whole hand. Any attempt to straighten the fingers or extend the wrist exacerbated the pain. Symptoms deteriorated rapidly. Compartment syndrome was diagnosed and surgical fasciotomies of his left forearm and left hand were performed following multidisciplinary urgent discussions between plastic surgeons, microbiologists, anaesthetists and orthopaedic surgeons. The left forearm and left hand underwent extensive decompression and subsequent skin grafting and had good healing despite the initial skin presentation. The patient has made a satisfactory recovery and has required extensive hand physiotherapy and social care.

Discondrosteosis de Léri-Weill. Presentación de una familia afectada / Léri-Weill dyschondrosteosis. Presentation of an affected family

RESUMEN Fundamentación: La discondrosteosis de Léri-Weill, displasia ósea de origen genético que afecta la región mesomélica con acortamiento de las extremidades, provoca talla baja con extremidades cortas con deformidad de Madelung; esta enfermedad muestra un patrón de herencia autosómico dominante con alta penetrancia. Objetivo: Describir las deformidades de esta discondrosteosis de baja frecuencia con expresividad variable, que se presentó de la misma forma en todos los afectados de esta familia. Presentación de caso: Se reportó una familia con enfermos en tres generaciones con deformidad de Madelung de ambas muñecas y baja estatura de origen mesomélico, que se mantiene seguimiento en consultas de Genética Clínica y Ortopedia. Conclusiones: El examen físico y radiológico imprescindibles para llegar al diagnóstico clínico. El método clínico y la valoración multidisciplinaria resultaron de gran valor para definir esta enfermedad y poder brindar un adecuado asesoramiento genético a esta familia.

ABSTRACT Background: Léri-Weill dyschondrosteosis, bone dysplasia of genetic origin that affects the mesomelic region with shortening of the extremities, causes short stature with short extremities with Madelung deformity.This disease shows an autosomal dominant inheritance pattern with high penetrance. Objective: To describe the deformities of this low frequency dyschondrosteosis with variable expressivity which was presented in the same way in all those affected in this family. Case presentation: A family with sick members was reported in three generations with Madelung deformity of both wrists and short stature of mesomelic origin which is followed up in consultations of Clinical Genetics and Orthopedics. Conclusion: The essential physical and radiological examination to reach the clinical diagnosis. The clinical method and the multidisciplinary assessment were of great value to define this disease and to be able to provide adequate genetic counseling to this family.

Discondrosteosis de Léri-Weill. Presentación de una familia afectada / Léri-Weill dyschondrosteosis. Presentation of an affected family

RESUMEN Fundamentación: La discondrosteosis de Léri-Weill, displasia ósea de origen genético que afecta la región mesomélica con acortamiento de las extremidades, provoca talla baja con extremidades cortas con deformidad de Madelung; esta enfermedad muestra un patrón de herencia autosómico dominante con alta penetrancia. Objetivo: Describir las deformidades de esta discondrosteosis de baja frecuencia con expresividad variable, que se presentó de la misma forma en todos los afectados de esta familia. Presentación de caso: Se reportó una familia con enfermos en tres generaciones con deformidad de Madelung de ambas muñecas y baja estatura de origen mesomélico, que se mantiene seguimiento en consultas de Genética Clínica y Ortopedia. Conclusiones: El examen físico y radiológico imprescindibles para llegar al diagnóstico clínico. El método clínico y la valoración multidisciplinaria resultaron de gran valor para definir esta enfermedad y poder brindar un adecuado asesoramiento genético a esta familia.

ABSTRACT Background: Léri-Weill dyschondrosteosis, bone dysplasia of genetic origin that affects the mesomelic region with shortening of the extremities, causes short stature with short extremities with Madelung deformity.This disease shows an autosomal dominant inheritance pattern with high penetrance. Objective: To describe the deformities of this low frequency dyschondrosteosis with variable expressivity which was presented in the same way in all those affected in this family. Case presentation: A family with sick members was reported in three generations with Madelung deformity of both wrists and short stature of mesomelic origin which is followed up in consultations of Clinical Genetics and Orthopedics. Conclusion: The essential physical and radiological examination to reach the clinical diagnosis. The clinical method and the multidisciplinary assessment were of great value to define this disease and to be able to provide adequate genetic counseling to this family.

Clinical application of individualized 3D-printed navigation template to children with cubitus varus deformity.

BACKGROUND: Cubitus varus deformity is a common sequela of elbow fractures in children. Cubitus varus deformity treatment is tending toward 3D correction, which is challenging for orthopedic surgeons. This study aims to explore whether individualized 3D-printed navigation templates can assist with accurate and effective corrective treatment of children with cubitus varus deformity. METHODS: Thirty-five patients were treated for cubitus varus deformity from June 2015 to April 2017, including 21 boys and 14 girls, aged 4.6-13.2 years (average, 7.5 years). Of these cases, 17 deformities were on the left side and 18 were on the right side. All were treated with wedge osteotomy of the lateral distal humerus. 3D-printed navigation templates were used in 16 cases, while traditional surgery was used in 19 cases. All patients underwent computed tomography scans before surgery. Computer software was used to analyze the measurements and design and print individualized navigation templates. The navigation templates were matched, and surgery was initially simulated. Intraoperative individualized navigation templates were used to assist with accurate osteotomy and Kirschner wire fixation. Operation times were recorded in all cases, the carrying angles before and after surgery were assessed by computer, and postoperative elbow joint function was evaluated using Bellemore criteria. All measurement data were presented as means ± SD, and Student's t test was used to examine differences between groups. All count data between both groups were compared using the chi-square test or Fisher's exact test analysis. RESULTS: All individualized navigation templates matched well with the corresponding anatomical markers and were consistent with preoperative planning, simulated surgery, and intraoperative procedures. Average operation times from clear exposure to fixed Kirschner wire were 11.69 min (9.6-13.5 min) for the individualized navigation template group and 22.89 min (17.7-26.8 min) for the traditional operation group (p < 0.001). Average differences in postoperation carrying angles between affected and healthy sides were 1.13° (0-2.0°) and 4.21° (0-7.5°), respectively (p < 0.001). Follow-up 6-12 months postoperation showed that elbow function did not differ significantly between groups using the Bellemore criteria (p > 0.05). CONCLUSIONS: Individualized navigation templates simplify procedures, reduce operation time, and improve accuracy when used in orthopedic surgery to treat children with cubitus varus deformity.

Absence of flexor digitorum profundus muscle and variation of flexor digitorum superficialis muscle in a little finger: two case reports.

PURPOSE: Knowledge of rare variants of the FDP is of high clinical importance for physicians examining patients for tendon lacerations and especially for hand surgeons operating tendon injuries. METHODS: During routine dissection at our Department of Anatomy both cases were observed. RESULTS: Variations of flexor digitorum superficialis and flexor digitorum profundus muscles of the little finger were observed in two cadavers. In both cases, the flexor digitorum profundus muscle for the little finger was absent. Moreover, in the first case, the flexor digitorum superficialis muscle for the little finger was hypoplastic and in the second case it featured variable insertion. CONCLUSION: There were found only four cases in previous literature describing absent flexor digitorum profundus tendon without any muscle attachment to the base of the distal phalanx. Furthermore, all previously described cases were observed in living patients. To our best knowledge, a case report in cadaver has yet not been reported and is of high importance for hand surgeons examining the hand for tendon injuries.

Complete extensor digitorum profundus complex: a deep hand extensor muscle to the medial four digits.

PURPOSE: Anatomical variants in the posterior compartment of forearm and hand are not uncommon. Physicians should be aware of variations in this region for correct diagnosis and treatment of diseased hands. METHODS: During a routine dissection at our department, an extremely rare case of deep hand extensor muscle was discovered. RESULTS: A complete extensor digitorum profundus complex was found in the fourth extensor compartment in addition to the extensor indicis proprius. The complex consisted of two muscle bellies originating from the lateral aspect of distal ulna and the adjacent interosseous membrane. The first belly resembled the conventional extensor indicis proprius. The second belly gave off two tendon slips: one inserted to the index and middle fingers and the other formed aponeurosis before inserting to the ring and little fingers. CONCLUSION: To our knowledge, a complete extensor digitorum profundus complex which inserts to all medial four digits has never been reported in humans. Awareness of variations in this region is critical for surgeons operating in the forearm and hand. The present case also provides insights into the evolutionary and developmental origin of these structures.

Bilateral reversed palmaris longus muscle: a case report and systematic literature review.

PURPOSE: We present a case of a bilateral reversed palmaris longus muscle and a systematic review of the literature on this anatomical variation. METHODS: Routine dissection of a 90-year-old male cadaver revealed a rare bilateral reversed palmaris longus. This was documented photographically, and length and relation to anatomical landmarks were recorded. This finding stimulated a systematic review of the literature on the reversed palmaris longus variation, from which measurements were collated and statistical analysis performed to determine the prevalence, average length, relationship to side and sex, and to discuss its clinical and evolutionary implications. RESULTS: The average length of the muscle belly and tendon of reversed palmaris longus was 135 mm and 126 mm, respectively. Statistical analysis revealed no disparity in presentation due to sex and side; however, bilateral reversed palmaris longus has only been reported in males. A high proportion (70.8%) of reversed palmaris longus were discovered in the right upper limb compared to the left. CONCLUSION: Variations in palmaris longus are purported to be as a result of phylogenetic regression. Clinically, patients with this variant may present with pain or swelling of the distal forearm, often as a result of intense physical exertion related to occupation or sport. Clinicians should be aware of this muscle variant as its presence could lead to confusion during tendon allograft harvesting procedures in reconstructive and tendon grafting surgery.