A rare muscular anomaly in the upper arm--the chondroepitrochlearis muscle with an aberrant type of the muscular arch of axilla.

A rare muscular anomaly was found in the right arm of a 92-year-old man at Nagoya University in 1995. The anomalous muscle had two heads, one ventral and one dorsal. The ventral head was a continuation of the abdominal part of the pectoralis major muscle, and the dorsal head arose from the lateral surface of the latissimus dorsi muscle. The two heads united at the medical surface of the upper third of the arm to form a common tendon, which descended on the medial surface of the upper arm parallel with a long tendon of the coracobrachialis muscle and attached to the medial epicondyle of the humerus. This anomalous muscle was supplied by the most caudal branch of the pectoral ansa (caudal pectoral nerve) and the intercostobrachial nerve (Th2). This pectoral nerve first innervated the ventral head, and next the greater part of the dorsal head. The intercostobrachial nerve (Th2) innervated a small part of the dorsal head. The present anomaly looked quite similar to the case reported by Yokoh as the coexistence of the chondroepitrochlearis and the dorsoepitrochlearis muscles. However, judging from the muscular origin, insertion and innervation, the ventral head was considered to be the chondroepitrochlearis muscle, whereas the dorsal head was not dorsoepitrochlearis muscle but an aberrant type of the muscular arch of axilla.     

The axillopectoral muscle (of Langer) report of three cases

Abstract The axillopectoral muscle, usually called Langer’s axillary arch instead of Langer’s arm arch, is a supernumerary muscle and is the principal anatomic variation of the axilla. Three cases of the muscle were observed originating from latissimus dorsi crossing over the axillary neurovascular bundle and inserting deep to the insertion of pectoralis major or into the coracoid process. Clinicians should be aware of its existence as it can give rise to different pathologies. It should be recognised and excised to expose the axillary artery and vein in patients with trauma and to perform axillary lymphadenectomy or axillary bypass. It should be considered in the differential diagnosis of axillary masses or in a history of intermittent axillary vein obstruction. If the muscle causes problems its excision should be curative.     

Insertion abnormality of bilateral pectoralis minimus

Bilateral insertion abnormality of pectoralis minimus (sterno-costo- coracoidian muscle) muscle was examined. The variant muscle was lying under the pectoralis major muscle and was medial to the pectoralis minor muscle. This muscle started from the first costal cartilage to the manubrium sterni and ended in the upper surface of the shoulder joint on the right side. On the opposite side, it took origin from the second costal cartilage to the manubrium sterni and the second costochondral joint, afterwards became a tendinous structure and divided into two on the coracoid process. The thicker part ended on the upper surface of the articular capsule of the shoulder joint, the thinner part inserted on the lateral third of inferior part of clavicle and fascia of subclavius muscle.     

Case reports on the pectoralis quartus and the pectoralis intermedius muscles

Each one case of the pectoralis quartus and the pectoralis intermedius muscles was found on the left thoracic wall in a 73 year old male and on the right thoracic wall in a 57 year old female respectively. The pectoralis quartus was a thin muscle of triangular shape, the base of which was the origin arising from the left thoracic wall at the level of the 6th rib between the pectoralis major and the latissimus dorsi, being separated from both margins of the muscles. The aberrant muscle ascended left-upwards about 10 cm to insert to the inner surface of the pectoralis major near its lower margin. The muscle was innervated by the most caudal pectoral nerve, passing around the lower margin of the pectoralis minor. The pectoralis quartus is extremely rare in man, and only two cases were reported by Bluntschli (1906) and Frey (1921). From the comparative anatomical point of view, the pectoralis quartus muscle was supposed to be a remnant of the ventral part of the subcutaneous trunci muscle in lower mammals, differing from the ordinary muscular arch of the axilla which was believed to derive from the dorso-cranial part of the muscle. The pectoralis intermedius was located in the deep layer of the right pectoralis major, lying about 2 cm below the lower margin of the pectoralis minor. It arose in the 4th and 5th ribs and extended right-upwards, running almost parallel with the pectoralis minor. The origin of the pectoralis minor shifted cranially to the 2nd and 3rd ribs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coexistence of a pectoralis quartus muscle and an unusual axillary arch: case report and review

A pectoralis quartus muscle and an unusual axillary arch were found on the left side of a female cadaver. The axillary arch was a musculoaponeurotic complex continuous with the iliacal fibers of the latissimus dorsi. The muscular part, together with the tendon of pectoralis major, inserted into the lateral lip of the bicipital groove of the humerus, whereas the aponeurotic part was formed by a fibrous band that extended deep to the pectoralis major to insert into the coracoid process between the attachments of the coracobrachialis and pectoralis minor. The pectoralis quartus originated from the rectus sheath, and joined the inferior medial border of the fibrous band of the axillary arch, at the lateral edge of the pectoralis major. The axillary arch muscle crossed anteriorly the axillary vessels and the brachial plexus. The clinical importance of these muscles is reviewed.     

骨间掌侧神经受压综合征的解剖学研究

在32具成人尸体的64侧上肢中解剖了骨间掌侧神经及其发出的肌支共510支,对其分支平面,分支数目,长度及其走行过程中的受压因素进行了观察和测量,旋前圆肌尺骨头的纤维弓,指浅屈肌腱弓,拇长屈肌的异常肌束和骨间掌侧血管的分支血管束是造成骨间掌侧神经受压的主要因素.     

Development and clinical significance of the musculus dorsoepitrochlearis in men

Musculus dorsoepitrochlearis is a typical muscle variation, which, if in full extent, is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi. It passes over the axilla under the axillary fascia crossing the medial side of the brachial plexus and continues as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. Its full extent is rarely developed—the connection into the intermuscular septum being mostly absent. Muscular slips from the musculus latissimus then insert on various structures in the axilla, often on the crest of greater tubercle of humerus or into the musculus pectoralis major (this variation is known as the axillary arch of Langer) or to other neighboring structures (coracoid process, fasciae of muscles). In our observations, 209 patients with traumatic lesions of the brachial plexus underwent surgical procedure. The presence of the musculus dorsoepitrochlearis has been observed. It was found in the form of various slips from the musculus latissimus dorsi in 4 patients. In 3 of those 4 patients, the innervation was derived from the nervus thoracodorsalis. We also presented 2 case reports of patients with clinical symptoms caused by compression of nerves in the axilla by the dorsoepitrochlear strip. Clin. Anat. 22:481–488, 2009. © 2009 Wiley‐Liss, Inc.     

Unusual variation of the inferior attachment of the pectoralis minor muscle

An unusual inferior attachment of pectoralis minor muscle was found on the right side of a male cadaver. The tendinous attachment, originating only from the 5th rib, was detected during the routine practical dissections. There were no other associated features in the thoracic region of this cadaver. We believe that this variation that has not been reported previously in the literature, should be taken into consideration by the surgeons.     

Axillary arch in Bulgarian population: clinical significance of the arches

In order to study the incidence of the axillary arch in the Bulgarian population, we examined the axillary regions of 56 formol-carbol fixed human cadavers and observed two cases with a unilateral axillary arch. In the first case, the variant structure was situated on the right side of a 58-year-old female cadaver. The axillary arch extended from the lateral border of the latissimus dorsi to the posterior layer of the pectoralis major tendon. In the second case, the axillary arch was found on the left side of a 63-year-old male cadaver and had the same attachment points as in the first case. The innervation and blood supply of the arches are discussed. We have also reviewed extensive information concerning the clinical importance of the axillary arch, and for the first time, it was summarized clearly for clinicians. The summary consists of three parts: "diagnosis" of the axillary arch by physical investigation or imaging techniques; the axillary arch and surgical interventions in the region of the axilla; the axillary arch as an entrapment site for the axillary vessels and nerves.     

Pes anserinus: layered supportive structure on the medial side of the knee

The pes anserinus is composed of a combination of tendinous insertions of the sartorius, gracilis and semitendinosus muscles. Precise knowledge of the structures on the medial side of the knee and the relationships between fascia and tendons is critical for diagnosis, surgery, and the development of improved operative procedures of the knee. To obtain precise data on the layered structures associated with the fascia cruris on the medial side of the knee and the fibrous bundles attached to them, we dissected nine legs of five adult cadavers. We observed a superficial longitudinal fibrous bundle on the superficial surface of the sartorius and a deep longitudinal fibrous bundle on the aponeurotic membrane covering the tendon of the gracilis muscle. The distal parts of the tendons of the gracilis and semitendinosus were found to have aponeurotic membranes, and these membranes were fused with the fascia cruris. These two longitudinal fibrous bundles and the aponeurotic membranes from the gracilis and semitendinosus tendons fused with the fascia cruris, and a small tendinous expansion from the semimembranosus muscle fused with the aponeurotic membrane from the semitendinosus tendon and tibial collateral ligament as well as the fascia covering the medial head of the gastrocnemius and fascia cruris. Based on the considerable tension from the sartorius, gracilis, semitendinosus, semimembranosus and gastrocnemius muscles, these bundles, membranes, and muscles may act as a complex tensor fasciae cruris muscle and play a significant role as stabilizers of the medial side of the knee joint in the upright posture.     

Axillopectoral muscle (Langer's muscle)

In a routine dissection of the axillary fossa, a muscle originating from the coracoid process of the scapula and extending to the long head of triceps brachii muscle was observed. The mentioned muscle was adhering to both the triceps brachii muscle and the tendinous part of the latissimus dorsi muscle. This anatomical variation is referred to as axillary arch (Langer's muscle or axillopectoral muscle). The muscle mass was measured 9.6 cm in length and 1.4 cm in width. The accessory muscle can be a reason of an axillary mass and can exert pressure on the neighboring neurovascular bundle or lymph routes; thus, exposing a wide range of symptoms. Therefore, variations of this area should be kept in mind in surgical interventions.     

Identification of two accessory muscle bundles with anomalous insertions in the flexor side of the right forearm

During dissection practice held at Kyorin University School of Medicine in 2004, two anomalous muscles were observed on the Rt-forearm-flexor-side of an 83-year-old man. The results of this investigation are reported. One accessory muscle originated from the tendinous insertion of the biceps brachii and medial epicondyle. After passing through the deep layer of the pronator teres, it became tendinous, passing towards the trapezium and second metacarpal base. Its two origins fused superficial to the ulnar artery distal to the cubital fossa, and it merged with the deep region of the pronator teres. More distally, the accessory muscle formed a belly before again becoming tendinous and bifurcated, one branch attaching to the trapezium and the other fusing with the belly of the second accessory muscle. These findings suggested that this accessory muscle was similar to Gantzer's muscle. The other accessory muscle arose distal to the origin of the flexor pollicis longus and inserted onto the second metacarpal base. In addition, from the distal side of its origin, a small muscle bundle was formed and became tendinous. It fused with the insertion tendon of the first accessory muscle to the trapezium. The second accessory muscle was thought to be deep radial carpal flexor.     

肘部及前臂上段正中神经卡压综合征的临床解剖学研究

目的 探讨肘部正中神经卡压综合征的解剖学基础。方法 解剖观察５０侧上肢标本,结果 肱二头肌腱膜与正中神经的关系有非覆盖４０例（８０％）,部分覆盖型６侧（１２％）和完全覆盖型４侧（８％）。旋前圆肌纤维桥斜过正中神经前方３２侧（６４％）。旋前圆肌肱骨头肌内有腱束８例（成人,占１８．６％）,尺骨头汪岙较厚筋膜４７侧（９４％）。指浅屈肌起始结构有联合腱弓型４４侧（８８％）,纤维情怀２侧型（４％）和腱束型（     

Insertion of the pectoralis major into the shoulder joint capsule

The pectoralis major muscle is subject to various morphologies. One presumably very rare variation is insertion of this muscle into the shoulder joint. During the routine dissection of the right upper extremity of an adult male cadaver a distinct separate tendinous insertion into the shoulder joint capsule was identified. This vertical tendon (7 mm×6 cm) traveled just lateral to the long head of the biceps brachii muscle and terminated into the fibrous aspect of the joint capsule without penetrating it. Mechanical traction on the humeral attachment of the pectoralis major resulted in anteroinferior displacement of the shoulder joint capsule. The possible embryologic origin of this variation is discussed. Clinicians may wish to consider potential attachment of the pectoralis major into the capsule of the shoulder joint in diagnosing pathology of this region.     

骨间前神经综合征的局部解剖学研究

目的 搪塞骨间前神经综合征的解剖学基础。方法 解剖４８例（左右各２４侧）成人防固定标本。结果 骨间前神经主干邻近腱性结构有旋前圆肌纤维桥（５８．３％），尺骨头浅面腱膜（９３．７％），联合腱板（８３．３％）和指浅屈肌纤维弓（９１．２％），横过骨间前神经的拇长岂副头（６６．７％），及少 尺侧血管、小束肌肉或纤维结构。７７％骨间前神经干走在桡骨颈前方结论 骨间的神经主干邻近的腱性结构及距离桡骨颈近可能是     

Surgical anatomy of the pectoral nerves and the pectoral musculature

The pectoral nerves (PNs) may be selectively injured through various traumatic mechanisms such as direct trauma, hypertrophic muscle compression, and iatrogenic injuries (breast surgery and axillary node dissection, pectoralis major muscle transfers). The PN may be surgically recovered through nerve transfers. They may also be used as donors to the musculocutaneous, axillary, long thoracic, and spinal accessory nerves and for reinnervation of myocutaneous free flaps. Thus, in this article, we reviewed the surgical anatomy of PN. A meta-analysis of the available literature showed that the lateral pectoral nerve (LPN) arises most frequently with two branches from the anterior divisions of the upper and middle trunks (33.8%) or as a single root from the lateral cord (23.4%). The medial pectoral nerve (MPN) usually arises from the medial cord (49.3%), anterior division of the lower trunk (43.8%), or lower trunk (4.7%). The two PN are usually connected immediately distal to the thoracoacromial artery by the so-called ansa pectoralis. The MPN may also show communications with the intercostobrachial nerve. In 50%-100% of cases, it may pass, at least with some branches, through the pectoralis minor muscle. The LPN supplies the upper portions of the pectoralis major muscle; the MPN innervates the lower parts of the pectoralis major and the pectoralis minor muscle. Among the accessory muscles of the pectoral girdle, the LPN may also innervate the tensor semivaginae articulationis humero-scapularis, pectoralis minimus, sternoclavicularis, axillary arch, sternalis, and infraclavicularis muscles; the MPN may innervate the pectoralis quartus, chondrofascialis, axillary arch, chondroepitrochlearis, and sternalis muscles.     

An axillary arch

An axillary (axillopectoral) muscle (arch) was observed extending between the upper border of the latissimus dorsi and the lower border of the pectoralis major muscles in a 48-year-old male cadaver during our dissections. In the same cadaver, the pectoralis major muscle has entirely inserted into the most distal part of the tendon of deltoideus. © 1996 Wiley-Liss, Inc.     

Axillary arch (of Langer): A large-scale dissection and simulation study based on unembalmed cadavers of body donors

Connective or muscular tissue crossing the axilla is named axillary arch (of Langer). It is known to complicate axillary surgery and to compress nerves and vessels transiting from the axilla to the arm. Our study aims at systematically researching the frequency, insertions, tissue composition and dimension of axillary arches in a large cohort of individuals with regard to gender and bilaterality. In addition, it aims at evaluating the ability of axillary arches to cause compression of the axillary neurovascular bundle. Four hundred axillae from 200 unembalmed and previously unharmed cadavers were investigated by careful anatomical dissection. Identified axillary arches were examined for tissue composition and insertion. Length, width and thickness were measured. The relation of the axillary arch and the neurovascular axillary bundle was recorded after passive arm movements. Twenty-seven axillae of 18 cadavers featured axillary arches. Macroscopically, 15 solely comprised muscular tissue, six connective tissue and six both. Their average length was 79.56 mm, width 7.44 mm and thickness 2.30 mm. One to three distinct insertions were observed. After passive abduction and external rotation of the arm, 17 arches (63%) touched the neurovascular axillary bundle. According to our results, 9% of the Central European population feature an axillary arch. Approximately 50% of it bilaterally. A total of 40.74% of the arches have a thickness of 3 mm or more and 63% bear the potential of touching or compressing the neuromuscular axillary bundle upon arm movement.     

Anatomical study on 2 cases of the congenital partial defect of pectoralis major and minor muscles

2 cases of the defect of pectoralis major muscle observed in male cadavers allocated for routine dissection were investigated anatomically, especially on the nerve supply for the defected muscles. In both cases, one on the left and the other on the right side, pectoralis major muscle was defected, the clavicular portion and a small part of sternocostal portion only persisting. Meanwhile, the ipsilateral pectoralis minor muscle was defected in the first case to be a string-like muscle band and was missing in the second case substituted by a membrane which seemed not to be the degenerated same muscle. Both the lateral and medial pectoral nerves supplied the pectoral muscles in the first case. One of rami of the medial pectoral nerve was distributed unusually to the most lateral part of the persisted sternocostal portion. Only the lateral pectoral nerve existed in the second case. In both cases nerves derived from 2 caudal segments, C8 and Th1, were lacking or poor. However, it was suggested that the defect of the muscles was not due to the nonparticipation of these nerves but due to the failure of caudal growth of the pectoral premuscle mass in a five-week embryo (Lewis 1901).