Head Of Flexor Pollicis Longus Research Articles

The prevalence and distribution of the variants of Gantzer's muscle: a meta-analysis of cadaveric studies.

The Gantzer’s muscle is often present in the flexor compartment of the forearm. It lies underneath flexor digitorum superficialis and compresses the anterior interosseous nerve. Furthermore, this muscle frequently bestows an accessory muscle of flexor pollicis longus or flexor digitorum profundus, or sometimes together. The current meta-analysis aims to compute the prevalence of subtypes of Gantzer’s muscle. Major electronic databases (PubMed, Scopus, Google Scholar, etc.) were searched for title and abstract. After removing the duplicate citations, the titles/abstracts were shortlisted with the help of inclusion and exclusion criteria. The shortlisted titles/abstracts were downloaded or collected from the library. The data of all subtypes of Gantzer’s muscle were pooled from shortlisted published manuscripts for meta-analysis. The pooled estimate of other anatomical characteristics was also observed. A total of 59 cadaveric studies of sample size 5,903 were evaluated for pooled prevalence of flexor pollicis longus (accessory head). Similarly, the authors evaluated 14 studies of 1,627 upper limbs for flexor digitorum profundus (accessory head). The unit of analysis was per 100 upper limbs. The Pooled prevalence of accessory muscle of flexor pollicis longus and flexor digitorum profundus were 48% (95% CI, 44%–52%) and 17% (95% CI, 13%–21%), respectively. The Gantzer’s muscle is present in 2/3rd of the upper limbs. Accessory head of flexor pollicis longus is almost three times more common than the accessory head of flexor digitorum profundus. A classification of Gantzer’s muscle is needed to reduce the ignorance of these variants.

Incidence and Morphology of Accessory Head of Flexor Pollicis Longus in Telangana, India

Introduction: Flexor Pollicis Longus (FPL) may have accessory slips which arise from lateral or medial border of coronoid process of ulna and medial epicondyle of humerus. The accessory slip of FPL is known as Accessory Head of Flexor Pollicis Longus (AHFPL) or Gantzer’s Muscle. Aim: To study the incidence and morphology of AHFPL and the relationship of AHFPL with Median Nerve (MN) and Anterior Interosseous Nerve (AIN) in Telangana population. Materials and Methods: The present study was an observational study, conducted on 25 cadavers (21 male, 4 female) for a period of 18 months (July 2019-December 2020) in Department of Anatomy, Osmania Medical College, Hyderabad, Telangana, India. The cadavers which were used for dissection by first year MBBS students were included in the present study and the cadavers with scars, deformities and with congenital anomalies were excluded from the present study. Results: In the present study, AHFPL was found in 58% upper limbs. It was bilateral in 40%, unilateral in 18% upper limbs. The shape of AHFPL was fusiform in majority of (86.2%) upper limbs. It originated from the coronoid process of ulna in 62% and from medial epicondyle of humerus in 38% upper limbs, inserted by joining with tendon of FPL. The AHFPL was innervated by AIN in all the cases and this nerve was located posterior to AHFPL in majority of (83%) upper limbs, posterolateral in few (17%) upper limbs. The MN was related anterior to the AHFPL in most of the upper limbs. Conclusion: In the present study, AHFPL was found in 58% upper limbs. Bilateral occurrence (40%) was common than unilateral (18%). The presence of AHFPL can cause AIN syndrome, pronator teres syndrome. The knowledge of AHFPL would be useful for both physicians and surgeons to know the aetiology and management of compression neuropathy/nerve entrapment syndrome.

An unusual variation - Unilateral Gantzer's muscle

The accessory head of flexor pollicis longus (FPL) muscle, also known as the Gantzer's muscle, was first described in 1813. The accessory head of FPL muscle significantly varies between studies in its origin, innervation, and relationships to the anterior interosseous nerve and the median nerve. In a 50-year-old male cadaver, we found an additional muscle belly arising from medial epicondyle and joining with the tendon of FPL muscle. The total length of the accessory muscle was 8 cm and was innervated by the ulnar nerve, which is not mentioned in any of the articles in the literature. It is called as Gantzer's muscle as it is taking origin from medial epicondyle. Due to the significant variations in the origin, insertion, innervation, and relationship to the anterior introsseous nerve, median nerve, ulnar nerve, and ulnar vessels of the accessory head of FPL, dependable anatomical knowledge is essential for diagnosis and treatment of nerve entrapment syndromes and avoiding injury during the surgical procedures.

Anatomical Study of Accessory Head of Flexor Pollicis Longus and Its Clinical Significance

Background: Cases of nerve entrapment are commonly seen in medical practice. The flexor pollicis longus muscle of the front of the forearm sometimes may have an accessory head. The accessory head of flexor pollicis longus muscle (AHFPL) may compress the anterior interosseus nerve (AIN) to cause weakness of the deep muscles of the front of the forearm. The aim of the present study is to find the incidence of AHFPL and to identify its structural relationships to the median nerve and AIN. Methods: A total of sixty upper limbs of thirty embalmed cadavers were dissected and studied for the presence of AHFPL. Parameters studied were incidence of AHFPL, whether it is bilateral or unilateral, its origin and insertion, and its relationship with AIN. Results: AHFPL was found in 16 cadavers (53%). In 7 out of the 16 cadavers (43.75%), AHFPL was bilateral and in 9 out of 16 cadavers (56.25%), AHFPL was unilateral. AIN was located below the AHFPL in 14 cadavers and in 2 cadavers, it was passing above the AHFPL. The nerve supply of AHFPL was through AIN in the 16 cadavers. Conclusion: Knowledge of AHFPL and its relations with AIN may help medical professionals in diagnosis and treatment as this anatomical variation can lead to compression neuropathy.

Study of Accessory Head of Flexor Pollicis Longus in South Indian Population

Study of Accessory Head of Flexor Pollicis Longus in South Indian Population

A report on the accessory head of Flexor Pollicis Longus and Variations of Forearm Musculature

Abstract Introduction: Gantzer's muscle has drawn attention from several authors owing to the possibility of interosseous nerve compression. This is a report of an accessory head of flexor pollicis longus (FPL, a variant of Gantzer's muscle) and a review of the variations of all muscles of the forearm. Materials and Methods: An accessory head of FPL was discovered in both the right and left antebrachial regions during a cadaver dissection. The muscle was dissected and photographed. Results: The anatomical variation I report is a slender conical muscle joining the FPL. Its origin merged with fibers of the flexor digitorum superficialis. It inserted into the upper part of the middle third of the forearm by joining the medial tendinous part of the FPL; this join was by means of a short cylindrical tendon. The reported muscle was innervated by the anterior interosseous nerve, which was seen to be present posterolateral to the muscle in both forearms. Conclusion: The described muscle might cause pressure problems to the underlying structures especially the anterior interosseous nerve. Variations must be considered during surgical intervention to avoid unintentional damage to healthy tendons. In addition, accessory tendons can potentially be useful in the repair or replacement of damaged tendons through surgical transfer or transplantation. Variations of muscles, especially accessory muscles, may mimic the behavior of soft tissue tumors and can result in nerve compressions. This collection of variations of the forearm musculature will be useful to surgeons in practice as well as students in dissection labs.

Incidence of accessory head of flexor pollicis longus (Gantzer’s) muscle

Incidence of accessory head of flexor pollicis longus (Gantzer’s) muscle

Clinical Correlations of Accessory Head of Flexor Pollicis Longus with Anterior Interosseous Nerve Syndrome: A Case Report

Clinical Correlations of Accessory Head of Flexor Pollicis Longus with Anterior Interosseous Nerve Syndrome: A Case Report

Persistent median artery of the forearm and palm: a cadaver study into its origin, course, fate and clinical significance.

The median artery is the axis artery of forearm till the 811 week of gestation and thereafter nor- mally regresses, only its proximal part remaining patent as the companion artery of the medi- an nerve in adults. A large, well developed persistent median artery extended to the palm and contributed to its vascular supply in 6 out of 100 upper limbs dissected. Dissection was used to demonstrate the persistent median arteries from their origin to termination. The persistent median artery originated from the ulnar artery in the cubital fossa. It pierced the median nerve, descended anterior t4 the nerve'in a common sheath and passed deep to the flexor retinaculum. An accessory head of flexor pollicis longus, which is a usual finding associated with the persis- tent median artery, was seen in one forearm. The superficial palmar arch was not seen in any specimen with persistent median artery. In all the specimens with persistent median artery, the lateral half of the palm and lateral 2½ digits were supplied by it, whereas the medial half of palm and the medial 2½ digits were supplied by the ulnar artery. The persistent median artery may contribute to median nerve compression neuropathy. The variations in the vascular supply of hand have clinical implications.

English

BACKGROUND: Accessory head of Flexor pollicis longus in the forearm is one of the factors for causing anterior interosseous nerve syndrome. The objectives were to study the incidence, morphology of accessory head of flexor pollicis longus and its relation with median nerve and anterior interosseous nerve. METHODS: The present study was observational and descriptive type. A total of 60 upper limbs from 30 cadavers were dissected in the Department of Anatomy. The accessory head of flexor pollicis longus muscle was identified and its relation with median and anterior interosseous nerve was observed. The shape, origin and insertion of accessory head of flexor pollicis longus were noted. The length and width of the muscle belly and tendon were measured with digital vernier caliper. The findings were compared with that of previous studies. RESULTS: The accessory head of flexor pollicis longus was present in 13(43.3%) cadavers. The shape of muscle was fusiform in 84.61% and slender in 19.38%.Commonest site of origin was coronoid process of ulna (53.33%)., from the medial epicondyle 33.33% and 6.66% each form tendon of brachialis and deep head of pronator teres respectively. The average length and width of muscle belly were 93.48 ± 1.76mm and 7.03 ± 1.43 respectively. The tendon length and width were 20 ± 8.09mm and 0.55 ± 0.23mm. The median nerve was running anteriorly and the anterior interosseous nerve laterally to the muscle belly in all the cases. CONCLUSION: The presence of accessory head of flexor pollicis longus can be an important factor in anterior interosseous nerve syndrome, pronator teres syndrome. The results obtained in the present study would be useful for both physicians and surgeons to know the cause and therefore an appropriate management of the clinical syndromes.

Sindrome compressiva del nervo mediano al muscolo pronatore rotondo

The pronator teres syndrome is a rare compression neuropathy of the median nerve. In the antecubital region the nerve lies between the two heads of the pronator teres muscle. Many structures compress the nerve at this level: Struther’s ligament, bicipital aponeurosis, pronator teres, flexor digitorum superficialis, the accessory head of flexor pollicis longus and vascular structures. The distinctive physical findings are tenderness of the proximal part of pronator teres, worsened by resisted pronation of the forearm and flexion of the elbow, and numbness involving the middle and index fingers and the thumb. Electrodiagnostic studies can be very helpful but entirely normal findings cannot exclude the diagnosis. Patients with pronator syndrome should be managed first with nonoperative treatment. Patients who do not respond to such therapy are candidate to surgical decompression and neurolysis of the median nerve.

Aberrant deep flexor muscles of the forearm associated with the accessory origin of first lumbrical muscle

Objective To find out variations in the deep forearm flexors that are associated with anomalous origin of the first lumbrical muscle. Introduction Muscular anomalies of the upper extremity could cause peripheral nerve disorders. Although variations in the attachments of lumbrical muscles have been commonly studied, muscle with an additional origin in the proximal aspect of the forearm from the deep flexors is not much discussed. Methods Fifty-three formalin-fixed upper limbs were dissected to assess the aberrant origin of the first lumbrical from the deep forearm flexors. The measurement, shape, origin, insertion and innervation of aberrant deep forearm flexors were noted and photographed. Results In two (3.77%) out of 53 upper limbs unilateral aberrant deep forearm flexors were found giving accessory anomalous origin to the first lumbrical muscle. In 11 cases (20.75%) the presence of accessory head of flexor pollicis longus was seen, and found co-existing with the aberrant deep forearm flexor in one (1.89%) limb. Discussion The clinical implication of these muscular anomalies, such as aberrant origins and hypertrophy of the first lumbrical, in nerve entrapments, especially in the aetiology of carpal tunnel syndrome, is considered. The awareness and identification of the muscular variations of the antebrachial and carpal regions will facilitate safe surgery of cases of median nerve entrapment syndromes.

A case of double Gantzer's muscle and its possible role in nerve entrapment

Department of Anatomy and Biology, Osaka Medical College, Takatsuki, Osaka, JapanAnomalous variants are essential for teaching bothanatomists and surgeons. Muscle anomalies of theupper extremity are recognized causes of periph-eral nerve disorder (Jones et al., 1997; Pai et al.,2008). Gantzer’s muscle (GM) or accessory head offlexor pollicis longus (FPL) has been implicated inKiloh-Nevin (i.e., ‘‘anterior interosseous’’ nerve)syndrome (Rask, 1979; Oh et al., 2000; Mahakka-nukrauh et al., 2004; Pai et al., 2008). Moreover,both GM and fibrous arch of flexor digitorum sub-limes (FDS) are considered as possible anatomicalfactors for median nerve (MN) entrapment neurop-athy (Lee and LaStayo, 2004; Bilecenoglu et al.,2005). Two GMs (Fig. 1) were detected in the rightforearm of an old Japanese male cadaver duringpractical anatomy course for undergraduate medi-cal students at Osaka medical college. Thesemuscles were present at two different anatomicalplanes. One of them, the deep GM (DGM), waslarger, voluminous in shape, and originated fromthe medial epicondyle of humerus and inserted intothe ulnar side of FPL muscle at the junctionbetween proximal and middle thirds of forearm.The second one or superficial GM (SGM) wassmaller and fusiform in shape and arose from theundersurface of humeroulnar head of FDS muscleand terminated distally into the FPL close and lat-eral to insertion of DGM. The MN passed superficialto the deep head of pronator teres (PT) musclewhere it gave the anterior interosseous nerve(AIN) just distal to the lower border of the crossedmuscle. The AIN arose from the lateral side of MNand both nerves coursed distally between twomyo-fibro-tendinous layers; the fibrous arch of FDSand SGM superficially and the DGM deeply. It hasbeen reported that the arcuate ligament of Fearnand Goodfellow is the fibrous tissue that blends to-gether from the PT and FDS muscles and can catchboth the AIN and MN in some patients sufferingMN compressive neuropathy (Rask, 1979). In ourcase, the origin of AIN from the radial side of MNwas reported by Ashworth et al. (1997). The AINdescended radial to the DGM, gave branches toboth SGM and FPL, sank deep to the tendon ofSGM and then passed deep to FPL where it reap-peared again medial to the latter muscle on theinterossous membrane. The manner of proximaland distal attachments, the shape as well as theinnervation of GMs, have been reported by others(Oh et al., 2000; Mahakkanukrauh et al., 2004;Pai et al., 2008). It seems that both MN and AINwere caught in intermuscular tunnel roofed by theSGM and FDS and floored by the DGM. The pres-ence of both DGM and SGM in addition to fibrousarch of FDS may be involved in MN and AIN com-pressive neuropathy. Moreover, the presence oftwo GMs may result in restricted movement of FPLand subsequent pain in lower forearm as reportedby others (Ryu and Watson, 1987; Pai et al.,2008). On the other hand, the GMs may be impor-tant in local transfers for restoring function in mul-tiple nerve palsies (Pai et al., 2008). The accessoryheads of the flexor muscles have been described inprimates and other mammals (pigs, foxes, andmarmots) as a muscle belly that connects themedial epicondyle origin of the FDS with the moreor less differentiated deep flexors muscle. Theflexor muscles of the forearm that develop fromthe flexor mass divide into two layers, superficialand deep. The FDS, FPL, and flexor digitorum pro-fundus originate from the deep layer. The existenceof accessory muscles connecting the flexor musclescould be explained by the incomplete cleavage ofthe deep layer of the flexor mass during develop-ment (Jones et al., 1997). This is the first report inthe literature regarding the presence of two GMsarising from different proximal attachments at two

Anatomic study and clinical analysis of anterior interosseous nerve compression syndrome

Objective To investigate the anatomic factors that cause anterior interosseous nerve entrapment and analyze the clinical results of decompression. Methods Twelve fresh cadaver upper limb specimens were dissected. The anatomic characteristics of the anterior interosseous nerve and the possible compression factors along its course were observed. Fifteen cases of anterior interosseous nerve compression syndrome were treated between May 1997 and December 2007. One underwent conservative treatment and 14 had surgical decompression of the anterior interosseous nerve. The tendinous structures that compressed the nerve were resected. In 7 cases the vessels that run across the nerve were ligated. Postoperative fo].low up time ranged from 6 months to 4 years. Results Anatomic studies in the dissected 12 specimens showed 91.7% occurrence ( 11specimens) of tendinous structures of the deep head of pronator teres. The anterinor interosseous nerve was almost always sandwiched between the two heads of pronator teres. The tendinous arch of flexor digitorurn superficialis of the index and middle fingers occurred in 41.7% (5 specimens). Accessory head of flexor pollicis longus occurred in 58.3% (7 specimens). The incidence of abnormal vessels across the median nerve and the anterior interosseous nerve was 66.7% (8 specimens). The 7 cases treated with additional ligation of the abnormal vessels running across the anterior interosseous nerve had better results than those treated only with nerve decompression and resection of the tendinous or fibrous structures. Conclusion Anterior interoaseous nerve compression syndrome is the result of multiple factors. All the structures that can cause entrapment of the nerve on its anatomic course should he released in order to achieve satisfactory results. Key words: Nerve compression syndromes; Anatomy, regional; Anterior interosseous nerve

The accessory heads of flexor pollicis longus and flexor digitorum profundus: Incidence and morphology

Kiloh-Nevin syndrome caused by compressive neuropathy of the anterior interosseous nerve in the forearm is believed to occur because of its compression by the accessory head of flexor pollicis longus (FPLah). Gantzer described two accessory muscles, the more frequent is the FPLah and the less frequently observed is the flexor digitorum profundus accessory head (FDPah). Many studies have reported the prevalence, origin, insertion, nerve supply, and relations of these accessory muscles, most of them focusing on the FPLah. This study was designed to investigate the prevalence, morphology, relation to median and anterior interosseous nerve, and also the coexistence of both the accessory heads. A total of 126 upper limbs of the embalmed cadavers were examined in this study. Fifty-eight limbs (46.03%) showed the presence of the FPLah and 18 limbs (14.28%) had the FDPah. The most common origin of both the accessory muscle bellies was from the under surface of the flexor digitorum superficialis. The FPLah inserted into the FPL muscle at varying levels with 80% inserting into the proximal third of FPL, whereas the FDPah in all cases ended near the level of the wrist joining with one or more tendons of the FDP. Clinical implication of the variation is discussed.

Anatomical study of the accessory head of the flexor pollicis longus and the anterior interosseous nerve in Asians.

Anterior interosseous nerve palsy is known to occur uncommonly due to the compression of the nerve by the accessory head of flexor pollicis longus (AHFPL). This study was conducted to investigate the prevalence and origin of the AHFPL and the topographical relationship between the AHFPL and the anterior interosseous nerve in Asians. The AHFPL was present in 48 of 72 arms examined (66.7%), a majority of which originated from the coronoid process. The anterior interosseous nerve was observed to arise from both the medial and posterior aspects of the median nerve. The topographical relationship between the anterior interosseous nerve and the AHFPL was classified into three types depending on if the anterior interosseous nerve crossed the muscular part, or the tendinous part of the AHFPL, or coursed lateral to the AHFPL. The case in which the anterior interosseous nerve crossed the muscular part of the AHFPL occurred most frequently in the current study. The types in which the anterior interosseous nerve may be compressed were also discussed.

Gantzer's muscle: An anatomical study of the accessory head of the flexor pollicis longus muscle

The relationship of Gantzer's muscle (the accessory head of flexor pollicis longus; FPL) to the median nerve and its anterior interosseous branch is debated. In an anatomical study of 25 limbs, the incidence, origin, insertion, nerve supply and relations of Gantzer's muscle have been documented. The muscle was found in 13 of the 25 (52%) limbs and was supplied by the anterior interosseous nerve. It arose from the medial humeral epicondyle in 85% and had a dual origin from the epicondyle and coronoid process in the rest. Its insertion was to the ulnar part of FPL and its tendon. Gantzer's muscle always lay posterior to both the median and anterior interosseous nerves. Anatomical variations in which Gantzer's muscle may contribute to median nerve compression in pronator syndrome are discussed.

Musculoaponeurotic Variations along the Course of the Median Nerve in the Proximal Forearm

31 cadaver arms have been dissected to study the variations in the anatomy of the muscles and fibrous arches which might cause compression of the median nerve in the forearm. Pronator teres always had a superficial head and usually a deep head. Flexor digitorum superficialis varied greatly in its site of origin. The median nerve might be crossed by two, one or no fibro-aponeurotic arches. Gantzer's muscle, an accessory head of flexor pollicis longus, was present in 45% of cadavers. No ligament of Struthers was found. Possible sites and causes of nerve compression are discussed.

Musculoaponeurotic variations along the course of the median nerve in the proximal forearm

31 cadaver arms have been dissected to study the variations in the anatomy of the muscles and fibrous arches which might cause compression of the median nerve in the forearm. Pronator teres always had a superficial head and usually a deep head. Flexor digitorum superficialis varied greatly in its site of origin. The median nerve might be crossed by two, one or no fibro-aponeurotic arches. Gantzer's muscle, an accessory head of flexor pollicis longus, was present in 45% of cadavers. No ligament of Struthers was found. Possible sites and causes of nerve compression are discussed.

Musculoaponeurotic variations along the course of the median nerve in the proximal forearm.

31 cadaver arms have been dissected to study the variations in the anatomy of the muscles and fibrous arches which might cause compression of the median nerve in the forearm. Pronator teres always had a superficial head and usually a deep head. Flexor digitorum superficialis varied greatly in its site of origin. The median nerve might be crossed by two, one or no fibro-aponeurotic arches. Gantzer's muscle, an accessory head of flexor pollicis longus, was present in 45% of cadavers. No ligament of Struthers was found. Possible sites and causes of nerve compression are discussed.