Anatomical study of the communicating branches between the medial and lateral plantar nerves

The plantar areas of the foot have specific biomechanical characteristics and play a distinct role in balance and standing. For the forefoot surgeon, knowledge of the variations in the anatomy of communicating branches is important for plantar reconstruction, local injection therapy and an excision of interdigital neuroma. The anatomy of the communicating branches of the plantar nerves between the fourth and third common plantar digital nerves in the foot were studied in 50 adult men cadaveric feet. A communicating branch was present between the third and fourth intermetatarsal spaces nerves in all eight left feet and in six right feet (overall, 28%), and absent in 36 (72%). A communicating branch was found in 14 ft. Ten of the 14 communications were from the lateral to the medial plantar nerve. The length of the communicating branch ranged from 8 to 56 mm (average 16.4 mm) and its diameter was 0.2–0.6 times of the fourth common plantar digital nerve. The angle of the communicating branch with the common plantar digital nerve from which it originated was less than 30° in 11 ft, 30–59° in 27 ft, 60–80° in 8 ft, and more than 80° in 4 ft. Classification of the branch is based on the branching pattern of the communicating branch and explains variations in plantar sensory innervations. We think that the perpendicular coursing communicating branch is at higher risk to be severed during surgery.     

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.     

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.     

The medial and inferior calcaneal nerves: an anatomic study

Summary The existence of chronic heel pain induced by the compression of nerves prompted us to conduct an anatomic study of the innervation of the heel. Fifteen cadaver feet were dissected to investigate the origin, course and branches of the medial calcaneal nerve (MCN) and the inferior calcaneal nerve (ICN). Despite a variable origin (tibial n. (TN) or lateral plantar n. (LPN), the medial calcaneal nerve branches which lay superficial to the abductor hallucis muscle (AH) were quite constant. The medial calcaneal nerve gave branches to the abductor hallucis muscle and innervated the posterior part of the medial face of the heel. It terminated in the superficial heel pad at the inferior part of the heel. In our study, the inferior calcaneal nerve always originated from the lateral plantar nerve. Its relationship to the deep fascia of the abductor hallucis muscle and anterior tubercle of calcaneus may explain the entrapment syndrome of the inferior calcaneal nerve.

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Etude anatomique des nerfs calcanéens médial et inférieur

Résumé L'existence de talalgies chroniques liées à des compressions nerveuses a motivé cette étude de l'innervation du talon. Quinze pieds de cadavres ont été disséqués pour explorer l'origine, le trajet, et les collatérales des nerfs calcanéen médial (NCM) et calcanéen inférieur (NCI). L'origine du NCM était variable : nerf tibial postérieur ou nerf plantaire latéral, la distribution de ses branches, superficielles par rapport au muscle abducteur de l'hallux, étant relativement constante. Elles étaient destinées au muscle abducteur de l'hallux et à la partie postérieure de la face médiale du talon. La portion terminale du nerf calcanéen médial s'épuisait dans le coussin adipeux superficiel du talon à la face inférieure du calcanéus. Le nerf calcanéen inférieur naissait toujours du nerf plantaire latéral. Ses rapports avec le fascia profond du muscle abducteur de l'hallux et le tubercule antérieur du calcanéus accréditent la possibilité d'un syndrome canalaire.

     

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.     

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.

以足底内侧动脉深支内侧支为蒂游离足内侧皮瓣的应用解剖

目的 :为以足底内侧动脉深支的内侧支为蒂足内侧皮瓣设计的改进提供解剖学基础。方法 :在 32侧成人下肢标本及 2只灌注红色乳胶成人新鲜足标本 ,解剖观测了足底内侧动脉深支的内侧支分支分布、吻合、外径及长度 ,皮瓣的静脉和神经分布。结果 :内侧支长 (2 .6± 0 .2 )cm ,外径 (1.0± 0 .1)mm ;伴行静脉 1条占 75 % ,外径 (1.3± 0 .3)mm ,伴行静脉 2条者占 2 5 % ,外径 (0 .9± 0 .2 )mm ;皮瓣供区有隐神经终支和足背内侧皮神经内侧支分布。结论 :①足内侧皮瓣可以是足底内侧动脉深皮内侧支或由跗内侧动脉供血 ;②静脉为动脉伴行静脉和大隐静脉深、浅两套 ;③皮瓣有隐神经终支和足背内侧皮神经内侧支 ;④游离足内侧皮瓣适用于手部创面修复的特殊要求。     

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。     

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.     

Novel surgical approach to the carpal tunnel: cadaveric feasibility study

Carpal tunnel syndrome is the most common entrapment neuropathy dealt with by the clinician. Multiple techniques have been used to surgically treat this pathological condition and all of these approach the carpal tunnel from the palmar surface of the hand or wrist. We have developed a novel endoscopic approach to the carpal tunnel utilizing a dorsal approach that necessitates a good appreciation of the anatomy of this region. This approach was carried out in 10 hands. Through a single dorsal incision we were able to transect the flexor retinaculum in all specimens without obvious damage to neural or vascular tissues. The microscissors used in our study were found to be too delicate for transection of the flexor retinaculum thus another cutting tool should be considered. Our dorsal approach with visualization of the internal aspect of the flexor retinaculum may obviate many of the complications that are seen with the current techniques used to surgically treat carpal tunnel syndrome such as injury to the median nerve and its branches. Clinical trials are now necessary with prospective randomized studies that will determine which techniques are most efficacious and minimize complications most effectively.     

Anterior tibial artery and its actual projection on the lateral aspect of the tibia: a cadaveric study

The anterior tibial artery (ATA) is at risk of injury during high tibial osteotomy, Ilizarov wire placement, pin placement in external fixation, or proximal locking screw insertion, as the artery is not visualized intraoperatively. The ATA is anchored to the oval foramen of the interosseous membrane on the proximal tibia by the deep fascia and recurrent genicular vascular branches. Segment 1 (from the bifurcation of the popliteal artery to the level of the interosseous foramen) and the proximal part of segment 2 (from the interosseous foramen to the level where the artery crosses the anterior border of the tibia) may be damaged when pin, wire or screw placement is directed posterolaterally at that level. Distally, a straight mediolateral pin or Ilizarov wires may lacerate the artery. Segment 2 of the ATA descends against the interosseous membrane in its proximal part, which is projected on the posterior third of the tibia relative to the sagittal plane; in its middle part, it runs close to the lateral cortex of the tibia, it is projected on the middle third of the tibia; in its distal part it runs gradually towards the anterior third of the tibia and contacts with the anterior third of the tibial cortical surface. This information may help reduce risk of injury to the ATA during high tibial osteotomy, external fixation and pin placement or insertion of locking screws.     

踝管内胫后神经松解有关的应用解剖

目的：为踝管内胫后神经松解治疗踝管综合征,跟痛症等提供解剖学基础,方法：在15例成人尸体标本,对胫后神经在踝管内的分支部位及其走行进行了解剖观察研究,测量了胫后神经的滑动距离,结果：胫后神经多在内踝水平下3cm内分出足底内,外侧神经支配足底部皮肤感觉及内在肌,少部分在内踝上分支,从胫神经主干内踝上1厘米内发出1－2支神经（跟内侧支）在皮下或深筋膜下行走达足跟脂肪垫内及跟骨内,沿途呈树枝状分支,被动活动关节时,踝管内胫神经可滑动8．2mm(5.0-12.5mm,),结论：踝管内胫神经松解应充分 解胫神经的主干及主要分支,足跟分支卡压可能与足跟痛有关,故对顽固性足跟痛患者可考虑封闭,松解或切断有关神经支。     

第1跖骨颈部跖侧动脉分布及吻合的临床解剖研究

目的:研究足底第1跖骨颈部附近的动脉吻合特点,为临床涉及该部位动脉的手术提供解剖学依据。方法:随机选取12侧成人足标本,动脉乳胶灌注,制作血管显微解剖标本,对第1跖骨颈部跖侧的动脉分布及吻合进行观察。结果:在第1跖骨颈部跖侧,由第1跖底动脉向胫侧和腓侧分为两支,两者与第1跖底动脉主干呈‘Y'型分布。两个支在长屈肌腱下,分别向胫侧和腓侧分为上行支和下行支,两侧的上行支和下行支分别与各自的发起动脉又各自形成一个‘Y'型。以上三者相互联系形成立体型的"3Y吻合"。第1跖骨中远1/3交界附近,还有第1跖骨胫侧动脉自第1跖底动脉发出,该动脉也分为上行支和下行支,形成第4个"Y",考虑到该处则共形成"4Y吻合"。结论:第1跖骨颈部跖侧的动脉吻合的参与血管较多,结构较复杂,本文中作者引入"3Y吻合或4Y吻合",能够较形象地描述该处的动脉结构特点。     

Anatomical variations of the plantar fascia's origin with respect to age and sex—an MRI based study

The plantar fascia (PF) plays a significant role in ankle movement and anatomical variations of this structure may significantly alter the biomechanical properties of the foot and lower extremity. The aim of this study was to evaluate the changes of the PF's origin point on the calcaneus (CB), and whether these changes are dependent on age and sex. Two independent observers evaluated two hundred and two foot and ankle MRIs and the following measurements was performed: (A) horizontal length of the AT insertion into the posterior aspect of the CB, (B) horizontal length of the CB and (C) horizontal distance from the most anterior point of the CB to the most posterior part of the PF. Statistical analysis was performed with the results obtained to evaluate both sex and age differences. Based on our results, we observed that: (1) changes of the PF's origin point on the CB is independent of age and sex and (2) the continuity between the PF and AT decreases during aging as a result from changes in the AT's insertion point into the CB. This study concludes that the PF's origin point does not change with respect to age or sex, but the continuity between the PF and AT decreases during aging. Knowledge regarding the biomechanical influences caused by changes in the relationship between the AT and PF may be important in terms of treatment and prophylaxis of both PF and AT pathologies. Clin. Anat. 32:597–602, 2019. © 2019 Wiley Periodicals, Inc.     

Ulnar nerve innervation of the medial head of the triceps brachii muscle: A cadaveric study

Although the ulnar nerve is closely associated with the triceps brachii muscle, the literature does not normally describe it as supplying this muscle. However, recent research has examined the ulnar nerve in the upper arm and identified branches supplying the medial head of the triceps brachii muscle. This study aims to expand upon this research by describing the course and incidence of these branches in a larger sample size. We examined 50 specimens in 25 cadavers. Ulnar innervation of the medial head of the triceps brachii was identified in 14 specimens (28%). The mean distance of the ulnar nerve branch midpoint was 26% along a line between the surgical neck and an epicondyle line, with a range of 11–39%. Innervation of the triceps brachii muscle by the ulnar nerve has important clinical and surgical implications. Clin. Anat. 26:1028–1030, 2013. © 2013 Wiley Periodicals, Inc.     

颈鼓神经的解剖学观察及临床意义

目的　为鼓室神经切除术提供颈鼓神经的解剖学资料。方法　在手术显微镜下对 15 1例尸头及 10 0块颞骨颈鼓小管上、下口的位置、颈鼓神经的交通情况进行了观察。结果　颈鼓小管下口多起自颈动脉管升部后壁 ,上口多位于鼓室隐窝前壁及鼓室内的咽鼓管口处。颈鼓神经与咽鼓管下支交通者占 6 5 5 6 % ,与鼓室神经干相交通者占 2 9 14 %。结论　与鼓室神经相交通的颈鼓神经有可能被误认为鼓室神经双干的前干 ,在行鼓室神经切除术时应予切断     

Anatomical study of the supraorbital and supratrochlear nerves: A new classification and application to understanding some migraine headaches

The frontal nerve is the largest branch of the ophthalmic nerve. This nerve gives rise to two terminal branches, the supraorbital (SON) and supratrochlear nerves (STN). To the best of our knowledge, there are no reports describing the detailed proximal course of these nerves while inside the orbit. Therefore, the goal of this study was to clarify the anatomy of the SON and STN inside and at their exit from the orbit. Twenty sides from ten fresh-frozen cadavers were used in this study. Intra and extra orbital dissections were performed to observe the course of the SON and STN. Additionally, measurements of the nerves were made at these locations. The course of the SON and STN inside the orbit was classified into three groups depending on the STN branching pattern from the SON. The group without any branch from the SON and STN inside the orbit was the most common. The exit points of these nerves were via the supraorbital notch, foramen, or neither a notch nor foramen. A distinct fibrous band was consistently found tethering the nerve except in specimens with nerves traversing a bony foramen. The mean diameters of the SON and STN were 1.3 ± 0.2 and 0.7 ± 0.1 mm, respectively. The results of this study further our knowledge of the course and morphology of the SON and STN and might be useful for better understanding and potentially treating some forms of migraine headache due to SON or STN compression/entrapment. Clin. Anat. 33:332–337, 2020. © 2019 Wiley Periodicals, Inc.     

肋间臂神经的解剖及其临床意义

目的：为乳癌腋清扫术中保留肋间臂神经(ICBN)提供解剖学基础。方法：对25具成人尸体的50侧腋区进行了解剖，对肋间臂神经及上下相邻皮神经的走行、分支、支配、粗细等情况进行解剖观察。结果：ICBN可分为缺如型、单干型、单干分支型、双干型及3干型；84％的臂内侧皮神经与ICBN上支、上干相交通；34％的第3肋间神经外侧皮支可发支支配腋窝底；3侧第1肋间神经外侧皮支主干进入上臂内侧。结论：肋间臂神经为第2肋间神经外侧皮支的分支，通常为上支或上干，与臂内侧皮神经联合构成，可有第3或第1肋间神经的外侧皮支参与。其损伤可造成乳房切除术后疼痛综合征，乳癌腋清扫术中经胸小肌后方或经腋静脉下方能顺利找到该神经并加以保护。     

Similarities and dissimilarities of the blood supplies of the human sciatic,tibial, and common peroneal nerves

The aim was to investigate the arterial supply of the sciatic, tibial, and common peroneal nerves. Thirty‐six lower limbs of 18 human fetuses were studied. The fetuses had been fixed in buffered formalin and the blood vessels injected with barium sulfate. Fetal age ranged from 12 to 28 weeks of gestation. Microdissection of the fetal lower extremities was done under ×5 magnifying lenses. The sciatic nerves of 10 lower extremities were dissected and excised and radiographs taken. The extraneural arterial chain of the sciatic nerve was composed of 2–6 arterial branches of the inferior gluteal artery, the medial circumflex femoral artery, the perforating arteries, and the popliteal artery. The extraneural arterial chain of tibial nerve was composed of 2–5 arteries, which were branches of the popliteal, the peroneal, and the posterior tibial arteries. Radiographs showed the presence of complete intraneural arterial chains in the sciatic and tibial nerves, formed from anastomosing vessels. Dissection showed that, in 97.2% of the specimens, the common peroneal nerve was supplied only by one popliteal artery branch, the presence of which was confirmed radiologically. The sciatic and tibial nerves are supplied by numerous arterial branches of different origins, which provide for collateral circulation. In contrast, the common peroneal nerve is most frequently supplied only by one elongated longitudinal blood vessel, a branch of the popliteal artery. Such a vascular arrangement may make the common peroneal nerve less resistant to stretching and compression. Clin. Anat. 26:875–882, 2013. © 2012 Wiley Periodicals, Inc.