The communicating branch of the lateral plantar nerve: A descriptive anatomic study

Since the communicating branch of the lateral plantar nerve has been implicated as a factor in the etiology of Morton's neuroma, a painful perineurofibrosis of a common plantar digital nerve, this project was designed to investigate the anatomy of this communicating branch. Both feet of 40 embalmed human cadavers were dissected to show the frequency of occurrence and anatomical variation of the communicating branch. The communicating branch was present in 66.2% of the feet we studied with no large gender-based differences. Branches occurred bilaterally in 52.5% of cadavers, while 27.5% had branches unilaterally. The occurrence of this branch does not correlate well with the likelihood of development of Morton's neuroma. Differences in diameter of the communicating branch ranged from less than 0.5 mm to as large as the common plantar digital nerves themselves, about 2 mm. The presence or absence of the communicating branch made no qualitative difference in the diameters of the common plantar digital nerves. There were 60.4% of the communicating branches in this study that had a typically-described orientation, arising more proximally in the foot from the fourth common plantar digital nerve, while 39.6% of the branches had a reversed orientation, arising more proximally from the third common plantar digital nerve. These reversed branches had a more oblique orientation when compared to the classic branches. Other anatomical variations were noted, including accessory branches that attached to deeper structures in the foot. These data form a basis for further research into the etiology of Morton's neuroma and improved surgical techniques for correcting this condition. © 1996 Wiley-Liss, Inc.     

Lateromedial and dorsoplantar borders among supplying areas of the nerves innervating the intrinsic muscles of the foot

The branching patterns of nerves supplying the intrinsic muscles of the foot were analyzed as a basis to confirm the muscle layer structure. Thirty‐eight feet of 20 Japanese cadavers were examined in detail in this study. The first dorsal interosseus was innervated by a branch from the deep peroneal nerve as well as a branch of the lateral plantar nerve in 92.1%, the second dorsal interosseus in 10.5% and the third dorsal interosseus in 2.6%. In three specimens, branches from the deep peroneal nerve innervated the oblique head of the adductor hallucis or the lateral head the flexor hallucis brevis. In addition, branches from the medial and lateral plantar nerves and the deep peroneal nerve formed communication loops in three specimens. The first dorsal interosseus, the oblique head of the adductor hallucis and the lateral head of the flexor hallucis and their innervating nerve branches are closely related within the first intermetatarsal space. Since the tibial part of the first interosseus muscle primordium is occupied in the space during development, the variations of innervation patterns and formation of the communicating nerve loops may be explained by various combinations of the part and the other muscle primordia. Anat Rec 255:465–470, 1999. © 1999 Wiley‐Liss, Inc.     

The effects of the communicating branch between medial and lateral plantar nerves on the innervations of the foot lumbrical muscles

Introduction

The communicating branches between the medial (MPN) and lateral (LPN) plantar nerves aren’t frequently observed in relation to the innervation of the foot muscles in previous studies. In this study, the number and localization of the communicating branch on the innervations of foot muscles were evaluated to open a new sight considering the innervations of lumbrical muscles.

Pseudoganglion on the connecting branch between the deep branch of the lateral plantar nerve and medial plantar nerve

The connecting branch between the deep branch of the lateral plantar nerve and medial plantar nerve often has an enlarged site. We investigated these enlarged sites of the connecting branches. We observed the 22 human feet of 20 Japanese cadavers. We investigated the connecting branch macroscopically and histologically. We found the connecting branches between the deep branch of the lateral plantar nerve and medial plantar nerve in 19 feet out of 22 feet. This connecting nerve branch was interposed between the tendon of the flexor hallucis longus and the flexor hallucis brevis, and there enlarged in the anteroposterior direction. After penetration, numbers of fascicles of this connecting branch were increased at the enlarged site. In this region, the connective tissues surrounding the nerve fascicles and vessels were more developed compared with the adjoining sides of this branch. A few fascicles at this enlarged site innervated the first metatarsophalangeal joint capsule. Other nerve fascicles arose from the connecting branch and branched off muscular branches to the flexor hallucis brevis. This branch possibly receives the physical exertion or friction during gait due to its position. Deformity and overload of the foot can cause sensory disorders of the foot, but the anatomical basis for the relationship between the deformity/overload and sensory disorders of the foot is unclear. We discussed that this connecting branch can be a potential cause of pressure neuropathies in the human foot.     

吻合血管神经第1跖趾关节移植重建肘关节的解剖学基础

目的：为吻合血管神经第1跖趾关节移植重建肘关节提供解剖学基础。法：20侧灌注红色乳胶的成人下肢标本解剖观察第1跖趾关节的血管神经分布及关节的构造，24只足部动脉铸型标本对关节支作对照观察。结果：第1跖趾关节的血供有背胫侧、背腓侧，跖胫侧、踊腓侧和关节后5部分关节支，腓侧关节支多和粗于胫侧，关节支外径0．3～0．5mm。关节支发自第1跖背动脉、腓侧趾背动脉、第1跖底动脉、趾底动脉和横动脉近侧支。关节的神经支与动脉相似，主要发自腓深神经、腓浅神经内侧支、第1趾足底总神经和趾底固有神经。结论：吻合血管神经的第1跖趾关节移植适用于修复重建单纯性肘关节缺损或强直，供区移植骨融合对足的外形功能影响不大。     

Intramuscular nerve distribution pattern of the oblique and transverse heads of the adductor hallucis muscles in the human foot

To understand which layer of the intrinsic muscles of the foot the adductor hallucis muscle belongs to, it is essential to investigate the innervation patterns of this muscle. In the present study, we examined the innervation patterns of the adductor hallucis muscles in 17 feet of 15 Japanese cadavers. We investigated the intramuscular nerve supplies of the adductor hallucis muscles in six feet and performed nerve fiber analysis in three feet. The results indicate that: (i) the oblique head of the adductor hallucis muscle is divided into three compartments (i.e. lateral, dorsal and medial parts) or two compartments (i.e. dorsal and medial parts) based on its intramuscular nerve supplies, but we could not classify the transverse head into any parts; (ii) the communicating twig between the lateral and medial plantar nerves penetrated the oblique head of the adductor hallucis muscle in 13 of 17 feet (76.5%); (iii) the penetrating twig entered between the lateral and dorsal parts of the oblique head, passed between the lateral and medial parts of this muscle and then connected with the medial plantar nerve; and (iv) the majority of the nerve fibers of the penetrating twig derived from the lateral plantar nerve. The present study demonstrated that only the lateral part of the oblique head of the adductor hallucis muscle had a unique innervating pattern different from other parts of this muscle, suggesting that the lateral part of the oblique head has a different origin from other parts of this muscle.     

Lateromedial and dorsoplantar borders among supplying areas of the nerves innervating the intrinsic muscles of the foot.

The branching patterns of nerves supplying the intrinsic muscles of the foot were analyzed as a basis to confirm the muscle layer structure. Thirty-eight feet of 20 Japanese cadavers were examined in detail in this study. The first dorsal interosseus was innervated by a branch from the deep peroneal nerve as well as a branch of the lateral plantar nerve in 92.1%, the second dorsal interosseus in 10. 5% and the third dorsal interosseus in 2.6%. In three specimens, branches from the deep peroneal nerve innervated the oblique head of the adductor hallucis or the lateral head the flexor hallucis brevis. In addition, branches from the medial and lateral plantar nerves and the deep peroneal nerve formed communication loops in three specimens. The first dorsal interosseus, the oblique head of the adductor hallucis and the lateral head of the flexor hallucis and their innervating nerve branches are closely related within the first intermetatarsal space. Since the tibial part of the first interosseus muscle primordium is occupied in the space during development, the variations of innervation patterns and formation of the communicating nerve loops may be explained by various combinations of the part and the other muscle primordia.     

The innervation of the joints of the foot

The nerve supply of the ankle joint and of the joints of the foot was studied in dissections of fetal and adult feet and in serial sections of fetal feet stained with silver. The ankle joint was supplied by the tibial, sural, deep peroneal, and saphenous nerves, and by the accessory deep peroneal nerve when present. The tarsal joints were supplied on their plantar aspects by the medial or lateral plantar nerves, and on their dorsal aspects chiefly by the deep peroneal nerve. The joint between the lateral and intermediate cuneiform received branches from the intermediate dorsal cutaneous nerve also. The lateral dorsal cutaneous nerve and the accessory deep peroneal nerve when present provided additional branches to the subtalar and calcaneocuboid joints. The tarsometatarsal joints were supplied on their plantar aspects by the medial or lateral plantar nerves. Most of them were supplied on their dorsal aspects by the deep peroneal nerve, but the cuboid-metatarsal joints received their supply from the intermediate dorsal cutaneous nerve. The intermetatarsal joints had a similar but sparser supply. The joint between the fourth and fifth metatarsal received branches from the intermediate dorsal cutaneous nerve. The plantar digital nerves provided the main supply to the metatarsophalangeal joints. The dorsal aspect of the first metatarsophalangeal joint was supplied by the deep peroneal and the medial dorsal cutaneous nerves, of the second metatarsophalangeal joint by the deep peroneal nerve, and of the fourth and fifth metatarsophalangeal joints by the lateral dorsal cutaneous nerve. The interphalangeal joints did not receive articular branches from the dorsal digital nerves, except in the case of the interphalangeal joint of the big toe, which was supplied by the deep peroneal and the medial dorsal cutaneous nerves.     

Ramification pattern of the deep branch of the lateral plantar nerve in the human foot

To understand how the oblique and transverse heads of the adductor hallucis muscle of the human foot are phylogenitically and ontogenetically developed, it is essential to know nerve supplies of these two heads of the muscle. In the present study, we dissected seven feet of five Japanese cadavers in detail to clarify the ramification patterns of the deep branch of the lateral plantar nerve by peeling off its epineurium (the nerve fascicle analysis method). We found that the muscular branch to the oblique head of the adductor hallucis muscle directly separated from nerve fascicles constituting the deep branch of the lateral plantar nerve, whereas the muscular branch to the transverse head arose in common with branches which innervated other intrinsic muscles of the foot, i.e., the 2nd and 3rd lumbrical muscles and the 1st and 2nd dorsal interossei muscles. The present study revealed that two heads of the adductor hallucis muscle, the oblique and transverse, had different innervating patterns, suggesting that two heads of the human adductor hallucis muscle develop from different primordia, and not from common ancestors.     

踝跖部神经显微断层解剖及其临床意义

目的：为不同部位断足再植提供理论基础和有关数据。方法：用体视学方法对６６例成人踝跖部胫神经及其重要分支进行观测。结果：胫神经的平均横径和面积分别为：第１断层５．８ｍｍ，１４．１ｍｍ２，足底内侧神经的平均横径和面积分别为：第１断层４．０ｍｍ，７．２ｍｍ２，第２断层４．１ｍｍ，６．８ｍｍ２；第３断层４．３ｍｍ，６．５ｍｍ２；第４断层３．７ｍｍ，５．４ｍｍ２；第５断层３．１ｍｍ，４．４ｍｍ２；第６断层３．２ｍｍ，４．４ｍｍ２；第７断层２．９ｍｍ，４．７ｍｍ２。足底外侧神经的平均横径和面积分别为：第１断层３．０ｍｍ，４．８ｍｍ２；第２断层３．１ｍｍ，４．５ｍｍ２；第３断层３．５ｍｍ，４．７ｍｍ２；第４断层４．０ｍｍ，４．４ｍｍ２；第５断层４．５ｍｍ，４．６ｍｍ２。结论：提出了“三段”断足分型法。不同断层平面断足再植吻接神经时要首选吻接主干，但断层１１和１２应根据足部感觉功能需要首选吻接胫侧神经。     

Interfascicular septum of the calcaneal tunnel and its relationship with the plantar nerves: A cadaveric study

The relationship between the plantar nerves and internal fascial structure of the calcaneal tunnel is clinically important to alleviate pain of the sole. The study aimed to investigate the three‐dimensional (3D) anatomy of the calcaneal tunnel and its internal fascial septal structure by using microcomputed tomography (mCT) with a phosphotungstic acid preparation, histologic examination, and ultrasound‐guided simulation. Twenty‐one fixed cadavers and three fresh‐frozen cadavers (13 men and 11 women, mean age 82.1 years at death) were used in this study. The 3D images of the calcaneal tunnel harvested by mCT were analyzed in detail. Modified Masson trichrome staining and serial sectional dissection after ultrasound‐guided injection were conducted to verify the 3D anatomy. Within the calcaneal tunnel, the interfascicular septum (IFS) commenced proximal to the malleolar‐calcaneal line and distal to the bifurcation of the tibial nerve into the plantar nerves. The medial and lateral plantar nerves were separated by the IFS, which divided the calcaneal tunnel into two compartments. The plantar nerves were ramified into two or three branches within each compartment. The IFS terminated around the talocalcaneonavicular joint, and the plantar nerves traveled into the sole. Clinical manipulation of the plantar nerves should be performed in consideration of the fact that they are clearly separated by the IFS. Clin. Anat. 32:877–882, 2019. © 2019 Wiley Periodicals, Inc.     

Sural-tibial nerve communications in humans

We investigated the occurrence of a communication between the sural and tibial nerves in 49 legs of 28 Japanese cadavers. In front of the calcanean tendon, we found the communication in 7 legs (14.3%) or in 5 cadavers (18.9%). The sural nerve gave rise to a number of medial and lateral branches, including the lateral calcanean branch at the lateral side of the ankle. The communicating branch with the tibial nerve arose from the first medial branch and pierced the deep fascia of the leg. In 4 cases, the U-shaped communication was formed between the sural and tibial nerves, and in 3 cases, the Y-shaped communication. Electrophysiologi-cal evidence of an anomalous motor function of the sural nerve has been reported recently. We consider that the U-shaped communication between the sural and tibial nerves gives a morphological basis to the motor function of the sural nerve.     

Anatomic variations of the median nerve within the carpal tunnel

Two hundred seventy-five consecutive carpal tunnel releases were reviewed to identify anomalies of median nerve anatomy. High division of the median nerve was observed in nine cases; in two of these the nerve divided proximally and then rejoined distally as a “closed loop.” In 42 cases the motor branch passed through the flexor retinaculum. Multiple motor branches were present in 13 cases. The palmar cutaneous branch passed through the flexor retinaculum in seven cases. In three cases, the distal communicating sensory ramus between the medial and ulnar nerves arose proximal to the superficial arch. Median nerve anomalies within the region of the carpal tunnel are common. Knowledge of such anomalies is important to avoid iatrogenic injury.     

The deep plantar arch in humans constitution and topography

Abstract The integrity of the various structures within the feet depends on their blood supply. Lesions of the feet often require revascularization, which if successful avoids the need for amputation. To provide greater anatomical detail to aid vascular surgery and imaging, the anatomy and constitution of the deep plantar arch was studied in 50 adult cadaveric feet. The arteries of the foot were injected with red neoprene latex and dissected under magnification. The deep plantar arch, present in all feet, was the result of anastomosis between the deep plantar artery and the deep branch of the lateral plantar artery. The deep plantar artery was predominant in 72% of specimens (Type I arches) and the lateral plantar artery in 22% (Type II), with the contribution being equal in 6% (Type III). The medial plantar artery contributed to the medial segment of the deep plantar arch by its deep branch in 12% of specimens. The distance between the deep plantar arch and each interdigital commissure was generally constant, averaging 29% of total foot length. The deep plantar arch was located in the middle third of the foot in all specimens, being in the distal part of this third in 90%. The deep plantar arch is, therefore formed mainly by the deep plantar artery, a branch of the dorsal artery of foot its location can be estimated if foot length is known.     

肌皮神经的解剖及其临床意义

目的 对肌皮神经位置及分支进行观测,为临床肌皮神经损伤与神经移位修复提供解剖学基础.方法 对15具成人防腐尸体的双侧上肢进行解剖观察,并测量肌皮神经的起点、长度、分支及交通支等.结果 肌皮神经主干长(50.07 ± 46.08)mm,起始点左右径(3.21 ± 1.17)mm,前后径(1.97 ± 1.16)mm,起点...     

Branching patterns of the facial nerve and its communication with the auriculotemporal nerve

This study examines the anatomic relationships and variability of the facial nerve trunk and its branches, with emphasis on the intraparotid connections between the divisions. Microdissections were performed on 30 Korean half-heads, and the facial nerve trunks and branches were exposed. The average depth of the stylomastoid foramen from the skin surface was 21.0±3.1 mm, and the distance between the stylomastoid foramen and the bifurcation of the temporofacial (upper) and cervicofacial (lower) divisions was 13.0±2.8 mm. In 26 of 30 dissections (86.7%), the facial nerve trunk bifurcated into two main divisions, and a trifurcation pattern was seen in the other four cases (13.3%). According to the origin of the buccal branches, we classified the branching patterns of the facial nerve into four categories. In type I (13.8% of cases), the buccal branches arose from the two main divisions of the trunk but not from other branches of the facial nerve. In type II (44.8% of cases), the buccal branches arising from the two main divisions were interconnected with the zygomatic branch. In type III (17.3% of cases), the marginal mandibular branch sent nerve twigs to the buccal branch, which originated from the upper and lower divisions. In type IV (17.3% of cases), the nerve twigs from the zygomatic and marginal mandibular branches merged to the buccal branch arising from the two main divisions. Communications between the facial and auriculotemporal nerve branches, which are known as communicating auriculotemporal nerves, were observed in 28 of the 30 cases (93.3%). Familiarity with these common variations in the facial anatomy provides useful information for the surgeon in careful dissection, preservation of the facial nerve, and complete removal of the tumors in parotidectomies.     

A rare anatomical variation of the Berrettini anastomosis and third common palmar digital branch of the median nerve

Variations in the origin and distribution of Berrettini anastomosis between the digital branches of the ulnar and median nerves exist and are well described in the literature. During regular dissections by medical students, we encountered a rare variation in the left hand of an approximately 50-year-old male cadaver. Berrettini anastomosis connecting the third common palmar digital branch of the median nerve with the fourth common palmar and proper palmar digital branches of the ulnar nerve presented a plexiform nature. This communicating branch and the third common palmar digital branch of the median nerve were perforated by the superficial palmar arch. Further, the superficial palmar arch was incomplete, and it was solely formed by the superficial branch of the ulnar artery. The unusual relationship of Berrettini anastomosis with the superficial palmar arch is very rare, and knowledge about such a variation is important when performing carpal tunnel release, flexor tendon surgery, and Dupuytren’s fasciectomy and when dealing with arterial repairs and vascular graft applications in the hand.     

Anatomic study of the deep plantar arch

A thorough knowledge of the topography and relations of the plantar arteries is necessary for further advances in arterial reconstruction in the foot. Such reconstruction often avoids amputation in cases of arterial trauma in industrial and automobile accidents, as well as in patients with diabetes and severe ischemia of the lower limbs. Although several studies have addressed the anatomy of the arteries of the foot, there is a shortage of recent studies on surgical vascular anatomy. The deep plantar arch was studied in 50 adult cadaveric feet. It was present in all feet and formed from the anastomosis between the deep plantar artery and the deep branch of the lateral plantar artery. The deep plantar artery was predominant in 48% of the specimens (Type I arches) and the deep branch of the lateral plantar artery in 38% (Type II) with the contribution of each being approximately equal in 14% (Type III). The location of the deep plantar arch can be estimated. The distance between the deep plantar arch and each interdigital commissure was relatively consistent between the subjects, averaging 29% of total foot length. The deep plantar arch was located in the middle third of the foot in all specimens, being in the middle II part of this third in 62%. The mean external diameter of the deep branch of lateral plantar artery was 1.7 mm +/- 0.4 mm. The mean external diameter of the deep plantar artery was also 1.7 mm +/- 0.4 mm. We observed a complete superficial plantar arch in only one specimen (2%). Our findings should assist vascular surgeons in estimating the location of the deep plantar arch from the patient's foot length and in providing other data.     

Donor, recipient and nerve grafts in brachial plexus reconstruction: anatomical and technical features for facilitating the exposure

Forty three cadavers of adult and five patients were included in our study. Accessory, suprascapular, musculocutaneous and sural nerves were dissected. These widely used nerves in brachial plexus reconstruction have varying anatomy and still have no standard approach for surgery. Dissection of the accessory nerve in the upper part of the posterior neck triangle was quite complicated took a relatively long time and the nerve could easily be injured. It was found that these shortcomings could be diminished starting dissection of this nerve in the lower part of the posterior neck triangle near the anterior border of trapezius muscle 2 cm (0–3.5) above the clavicle. Accessory nerve entered inner surface of this muscle 3 cm (1–4) from this edge. The proximal portion of the suprascapular nerve was not difficult to identify if post-traumatic scarring is absent. Alternative approach was starting dissection from the junction of C5 and C6 into superior trunk. The suprascapular nerve diverged distally from this junction at 2 cm (0–2.5). The proximal portion of the musculocutaneous nerve was identified by cutting clavicle or tendon of major pectoral muscle. Quicker and less traumatic exposure of this nerve was starting dissection in the bed between biceps and coracobrachialis muscles. The first branches of the musculocutaneous nerve to the biceps brachii muscle took onset 4 cm (3.5–6) distally from the lower margin of the tendon of major pectoral muscle. First branch to the brachial muscle originated from the musculocutaneous nerve distally from the same tendon at 9.4 cm (6.1–10.5). Two main but controversial principles exist in sural nerve graft dissection: time saving and less traumatic approach. Long nerve graft is necessary during brachial plexus reconstruction when many interposition grafts are needed. Technique of multiple (4–7) transverse skin incisions let us to get sural nerve with both branches as long as 66 cm (average 47 cm). Total length of this nerve mainly depended on branching level, which was found to be 27.5 cm (9–35) measuring proximally from the lateral ankle.     

Biometric study of the relationships between palmar neurovascular structures, the flexor retinaculum and the distal wrist crease

During surgical exposure of the carpal tunnel it is possible to injure the neurovascular structures closely related to the flexor retinaculum, such as the superficial palmar arch and the communicating branch between the ulnar and median nerves. Because of the importance of these structures and with the purpose of increasing knowledge of anatomical details concerning to their location, a biometric study was performed on the retinaculum and the communicating branch, and between the communicating branch and the distal wrist crease, as well as between the retinaculum and the superficial palmar arch. We dissected 56 hands from 28 Brazilian formalin‐preserved cadavers of both sexes (24 male) at the Federal University of São Paulo–Escola Paulista de Medicina, Brazil. The communicating branch was observed in 96.4% of cases and the superficial palmar arch in 78.6%. The communicating branch was found between the common palmar digital nerve of the 4th interosseous space (from the ulnar nerve) to the homonymous nerve of the 3rd interosseous space (from the median nerve). In males, the distance between the distal wrist crease and the site where the communicating branch originates from the ulnar component had an average of 33.9±5.5 mm on the right side and 30.2±8.2 mm on the left. The distance between the distal wrist crease and the junction of the communicating branch with the common palmar digital nerve of the 3rd interosseous space was 43.6±6.9 mm on the right and 40.2±6.2 mm on the left side. Conversely, in 14.8% of cases (1 female), the communicating branch was observed to emerge from the common palmar digital nerve of the 3rd interosseous space. The distance between the retinaculum and the superficial palmar arch in the axial line of the 4th metacarpal bone was on average 7.3±4.3 mm on the right and 8.3±3.5 mm on the left side. At the same level, the distance between the retinaculum and the communicating branch was 6.2±3.7 mm on the right side and 5.1±2.8 mm on the left. These results can be used as a reference during surgical procedures in the palmar region.