Preserving the superficial branch of the radial nerve during carpometacarpal and metacarpophalangeal joint arthroscopy: an anatomical study

Background  

The superficial branch of the radial nerve (SBRN) is potentially at risk during thumb carpometacarpal (TCM) or thumb metacarpophalangeal (TMP) joint arthroscopy. The aim of this anatomical study was to describe the different branching patterns of the SBRN and to optimize positioning of portals during TCM and TMP arthroscopy.     

Martin-Gruber communicating branch: anatomical and histological study

We dissected 72 upper limbs of fresh cadavers and found 17 cases with a Martin-Gruber communicating branch (23.6%). These were classified into 4 types: type I (n=5, 29.4%): communicating branch between the anterior interosseous and ulnar nn, type II (n=3, 17.6%): Communicating branch between the median and ulnar nn., type III (n=3, 17.6%): Communicating branch between the muscular branches to the flexor digitorum profundus m., type IV (n=6, 35.3%): combination of type I or II and type III. At histologic examination the number and size of the nerve bundles each communicating branch contained proved to be very different. In one case of type II only a single nerve bundle was found. We suggest that the different numbers of nerve bundles innervate different amounts of the intrinsic hand musculature. The communicating branch with a single nerve bundle probably innervated only the first dorsal interosseous muscle.     

Morphometric analysis of metacarpophalangeal and proximal interphalangeal palmar plates

Palmar plates are being used as a source of graft in radial or ulnar collateral ligament reconstruction, pulley reconstruction, and volar plate arthroplasty. The purpose of this study is to determine morphometric and major histological differences of palmar plates in metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints among fingers, and supply sufficient data which would be useful in reconstruction procedures. Ninety-six MCP and 96 PIP palmar plates of 12 well-preserved formalin-fixed cadavers were measured focusing on their length, width, central thickness, and lateral thickness and statistically analyzed using ANOVA. Randomized three male and three female cadavers' specimens were examined histologically after staining with Masson's trichrome. For central thickness of the PIP joint level, there was significant difference among fingers, caused by the middle and little fingers. For lateral thickness of the PIP joint level, there was significant difference which was originated from little fingers. MCP palmar plates were significantly thicker than PIP joint levels for most of the fingers. There were thicker and denser collagen bands in MCP than PIP palmar plates. The relation of size-related parameters was not close with the thickness parameters. The predicted sizes and thicknesses of palmar plates vary according to fingers. The data collected for each finger in this study should be used as a guide in reconstructive procedures that use palmar plates as source of graft.     

Nutrient arteries of the temporomandibular joint: an anatomical and a pathological study

We have identified an artery which is a sub-branch of the inferior alveolar artery, and propose to call it the temporomandibular branch. Mandibular bones of 36 autopsy cases (ages 23-85; 20 males and 16 females) were examined. Contrast media were injected into the inferior alveolar artery, decalcification was conducted, and photographs were taken using soft X-ray equipment (Softex: Nippon Softex, co. CSM type). Then, an examination was conducted concerning sclerosis of these arteries. Next, H.E., Azan, and Pap silver stains were used for microscopic specimens to examine arteriosclerosis of the temporomandibular joint. The artery that sub-branches toward the temporomandibular branch, branches out immediately after the inferior alveolar artery and enters the mandibular foramen, becoming the artery that supplies the temporomandibular joint. This temporomandibular branch travels slightly downward, forward of the inferior alveolar artery, and turns back toward the mandibular base. It advances to the mandibular joint almost directly. The route taken was classified into three types. Toward the head of the mandible, the temporomandibular branch, after passing over the neck of the mandible, divides into two sub-branches, anterior and posterior. In our pathological study of the temporomandibular branch, there were a small number of cases with slight intimal thickening and mild elastosis. As regards sclerotic changes, particularly in cases more than 50 years old. There were very few cases showing intimal changes. Sclerotic changes of the artery supplying the head of the mandible increase with age. The same can be said of the about the constriction rate. These findings correlated with subject age.     

The peroneocuboid joint: morphogenesis and anatomical study

The peroneocuboid joint, between the peroneus longus tendon and the cuboid bone, has not been anatomically well-defined and no embryological study has been published. Furthermore, the ossification of the os peroneum (a sesamoid inside the peroneus longus tendon) and its associated pathology has been considered to be generated by orthostatic and/or mechanical loads. A light microscopy analysis of serially sectioned human embryonic and fetal feet, the analysis of human adult feet by means of standard macroscopic dissection, X-ray and histological techniques have been carried out. The peroneus longus tendon was fully visible until its insertion in the 1st metatarsal bone already at embryonic stage 23 (56–57 days). The peroneocuboid joint cavity appeared at the transition of the embryonic to the fetal period (8–9th week of gestation) and was independent of the proximal synovial sheath. The joint cavity extended from the level of the calcaneocuboid joint all the way to the insertion of the peroneus longus tendon in the 1st metatarsal bone. The frenular ligaments, fixing the peroneus longus tendon to the 5th metatarsal bone or the long calcaneocuboid ligament, developed in the embryonic period. The peroneus longus tendon presented a thickening in the area surrounding the cuboid bone as early as the fetal period. This thickening may be considered the precursor of the os peroneum and was similar in shape and in size relation to the tendon, to the os peroneum observed in adults. To the best of our knowledge, this is the first study to show that the os peroneum, articular facets of the peroneus longus tendon and cuboid bone, the peroneocuboid joint and the frenular ligaments appear during the embryonic/fetal development period and therefore they can not be generated exclusively by orthostatic and mechanical forces or pathological processes.     

The deep belly of the temporalis muscle: an anatomical, histological and MRI study

In order to achieve a better functional and clinical knowledge of a masticatory muscle called the sphenomandibularis that is suspected to be responsible for headaches by compressing the maxillary nerve, bilateral dissections of the infratemporal fossa were performed on ten human cadavers and completed by histological and radiological studies of the same areas. Both macroscopic and microscopic observations obviously showed that the so-called sphenomandibularis muscle corresponds to the deep portion of the temporalis muscle, since there is no epimysial septum between these two structures, which previously have been described as being completely independent from each other. In spite of the close topographic relationship between the deep belly of the temporalis and the lateral pterygoid muscle, as well as their similar innervation pattern, the sphenomandibularis in fact has to be considered functionally as an original but non-isolated positional fascicle of the temporalis muscle itself. Our observations, correlated with MR images, suggest indeed that the deep belly of the temporalis muscle is of functional importance in the masticatory movements, but is not involved by its neurovascular vicinity in the genesis of specific headaches. Its surgical release, however, should be discussed in the case of a temporal myoplasty.     

The cubital tunnel: anatomical study of its distal part

Different levels of ulnar nerve compression have been reported (the medial intermuscular septum, the posterior compartment of the arm, soft tissue or bony abnormalities of the cubital tunnel). In some rare cases, compression can lie in a 10-cm long tunnel, distal to Osborne's ligament, between the humeral head of the ulnar flexor muscle of wrist (FCU) and the medial epicondylar muscles. Only few publications mention this fact as a factor of residual or recurrent symptoms after common surgical procedures. However, a distal pathology of the cubital tunnel has proved to be the only factor of nerve entrapment in our clinical practice. Specific anatomical dissection of this area was carried out to find and classify the anatomical structures that may play a role in ulnar nerve distal compression. Twenty-four embalmed limbs from 13 cadavers were dissected. The purpose of this study was to find anatomical fibrous structures at an average of 10 cm from the medial epicondyle. Anatomical structures were classified into five types: no aponeurosis between the FCU and the medial epicondylar muscles (54.2% of cases), a fibrous band taut between the FCU and the fourth- and fifth-finger ulnar insertions of the flexor digitorum superficialis (FDS) (8.3%), a thin (20.8%) or thick (4.2%) partial aponeurosis between the FCU and the medial epicondylar muscles, and total aponeurosis (12.5%). Anatomical variations of the distal cubital tunnel were divided in five types, but their clinical significance remains unclear.     

新型镍钛记忆合金掌指关节假体的生物力学研究

目的 探讨新型镍钛（Ni-Ti）记忆合金掌指关节假体的轴向压缩刚度特征,为该假体的临床应用提供生物力学依据。方法 选用10侧完整成人新鲜手标本,按数字表法随机分为假体组和对照组,每组5侧。假体组分别在第2~5掌指关节置入新型Ni-Ti记忆合金掌指关节假体,对照组标本只做切开及缝合处理。假体组和对照组手标本分别解剖游离出第2~5掌指关节,分别以伸直位、屈曲30°、屈曲60°固定于BOSE材料试验机上,分别在载荷为50、100、150、200、250、300、350 N时记录标本的轴向压缩位移,计算垂直和屈曲载荷状态下的轴向压缩刚度。所有标本实验后使用X线机透视,观察有无骨折,有无假体松动、断裂等情况。在假体组和对照组的组内和组间,分别比较第2~5指掌指关节在伸直位和屈曲30°、60°位时轴向压缩刚度。结果 所有标本实验后X线机透视检查显示,无明显骨折,假体无松动、断裂等情况。假体组和对照组第2~5掌指关节的轴向压缩刚度均随着掌指关节屈曲角度的增大而逐渐减小。假体组与对照组比较,第2~5指掌指关节伸直位时轴向压缩刚度差异均无统计学意义（P值均>0.05）;屈曲30°、60°时假体组轴向压缩刚度均大于对照组,差异均有统计学意义（P值均<0.05）。假体组和对照组组内比较,在伸直位和屈曲30°、60°位时,不同掌指关节间轴向压缩刚度差异均无统计学意义（P值均>0.05）。结论 新型Ni-Ti记忆合金掌指关节假体轴向压缩刚度符合正常掌指关节的生物力学特征。置入该假体后,不同掌指关节在不同屈曲角度下均具有良好的稳定性。     

Assessing macroscopic and microscopic indicators of osteoarthritis in the distal interphalangeal joints: a cadaveric study

Osteoarthritis is manifested both by macroscopically visible lesions and by specific histological indicators. Although traditional views of the disease process invoke physical abrasion of joint surfaces, recent studies indicate that tissue-level changes may precede grossly visible lesions of articular cartilage. This study investigates the association between gross and histological indicators of osteoarthritis at the manual interphalangeal joints, and examines a sequence of events that may lead to the onset of cartilage degeneration. Interphalangeal joints from the hands of nine cadavers were dissected, of which 52 joints were collected and further evaluated. Gross degradation of the proximal articular surface was graded on a scale of 0-3 (with 0 representing normal cartilage with no visible lesions). Osteoarthritic lesions were found in 86% of specimens and showed no preferential occurrence between males and females or right and left hands. Histological analysis indicated that known microscopic indicators of osteoarthritis always occur in Grade 1-3 specimens, but can also be recognized in some macroscopically normal specimens. Many macroscopically normal specimens exhibited chondrocyte clustering (28.6%) and/or tide mark irregularities (57%), indicating that these features are most likely the earliest to develop in the progression of osteoarthritis. It is possible that the initiating etiology is thickening of the subchondral bone, but this was not directly observed. Results indicate significant thinning of the cartilage as macroscopic degradation progresses. Our study supports, with slight modification, a previously proposed cascade of histological changes that may ultimately lead to the physical destruction of articular cartilage.     

The iliosacral joint in lizards: an osteological and histological analysis

The development of the iliosacral joint (ISJ) in tetrapods represented a crucial step in the evolution of terrestrial locomotion. This structure is responsible for transferring forces between the vertebral column and appendicular skeleton, thus supporting the bodyweight on land. However, most research dealing with the water-to-land transition and biomechanical studies in general has focused exclusively on the articulation between the pelvic girdle and femur. Our knowledge about the contact between the pelvic girdle and vertebral column (i.e. the ISJ) at a tissue level is restricted so far to human anatomy, with little to no information available on other tetrapods. This lack of data limits our understanding of the development and evolution of such a key structure, and thus on the pattern and processes of the evolution of terrestrial locomotion. Therefore, we investigated the macro- and microanatomy of the ISJ in limb-bearing squamates that, similar to most non-mammalian, non-avian tetrapods, possess only two sacral ribs articulating with the posterior process of the ilium. Using a combination of osteology, micro-computed tomography and histology, we collected data on the ISJ apparatus of numerous specimens, sampling different taxa and different ontogenetic stages. Osteologically, we recorded consistent variability in all three processes of the ilium (preacetabular, supracetabular and posterior) and sacral ribs that correlate with posture and locomotion. The presence of a cavity between the ilium and sacral ribs, abundant articular cartilage and fibrocartilage, and a surrounding membrane of dense fibrous connective tissue allowed us to define this contact as a synovial joint. By comparison, the two sacral ribs are connected to each other mostly by dense fibrous tissue, with some cartilage found more distally along the margins of the two ribs, defining this joint as a combination of a syndesmosis and synchondrosis. Considering the intermediary position of the ISJ between the axial and appendicular skeletons, the shape of the articular surfaces of the sacral ribs and ilium, and the characteristics of the muscles associated with this structure, we argue that the mobility of the ISJ is primarily driven by the movements of the hindlimb during locomotion. We hypothesize that limited torsion of the ilium at the ISJ happens when the hip is abducted, and the joint is likely able to absorb the compressional and extensional forces related to the protraction and retraction of the femur. The mix of fibres and cartilage between the two sacral ribs instead serves primarily as a shock absorber, with the potential for limited vertical translation during locomotion.     

改良跖趾关节游离移植重建掌指关节的显微解剖及临床应用

目的：为带血供改良跖趾关节全关节及半关节移植修复掌指关节的应用提供解剖学基础,总结该改良关节置换不同术式的临床应用经验。方法：解剖观测30侧经动脉内灌注红乳胶成尸下肢标本,对第2跖趾关节的解剖结构及血供关系进行显微解剖学测量。在解剖学研究的基础上,临床应用吻合血管的改良全关节及半关节重建修复掌指关节14例,其中全关节8例,半关节6例。术后均进行早期系统的康复训练。结果：第2跖趾关节的血供丰富,血管、神经位置恒定。临床应用14例,其中12例于术后5个月～3年2个月得到随访,第2掌指关节均获得较良好的功能恢复,带关节囊半关节移植效果最佳,全关节移植次之。结论：改良的第2跖趾关节游离移植重建第2掌指关节的不同术式,能有效地恢复第2掌指关节的功能。熟悉关节的解剖特点、改良的手术方案、神经关节支的修复及全面的关节结构功能重建是手术的关键。     

Innervation patterns of the inferior glenohumeral ligament: anatomical and biomechanical relevance

Although the Inferior Glenohumeral Ligament (IGHL) has a well known mechanical and proprioceptive relevance in shoulder stability, the interrelation of the ligament's anatomical disposition/innervation has not actually been described previously. The purpose of the study was to determine the IGHL innervation patterns and relate them to dislocation. Forty-five embalmed and 16 fresh-frozen human cadaveric shoulders were studied. Masson's Trichrome staining detailed the intraligamentous nerve fiber arrangements. The effect on the articular nerves of an anteroinferior dislocation of the shoulder joint and the position of 60 degrees abduction and 45 degrees external rotation was studied dynamically. The axillary nerve provided IGHL innervation in 95.08% of the cases. We saw two distinct innervation patterns originating from the axillary nerve. In Type 1, one or two collaterals diverged later from the main trunk to enter the ligament. Type 2 showed innervation to the ligament provided by the posterior branch for three to four neural branches. In both cases, these branches enter the ligament near the glenoid rim and at the 7 o'clock position (right shoulder). The radial nerve (Type 3 innervation pattern) provided IGHL innervation in 3.28% of the cases. Microscopic analysis revealed wavy intraligamentous neural branches. The articular branches relaxed and separated from the capsule at the apprehension position and stayed intact after dislocation. These results showed a special predisposition to avoid possible denervation and suggested that the neural arch probably remains unaffected after most dislocations. Knowledge of the neural anatomy of the shoulder will clearly help in avoiding its injury in surgical procedures.     

Physical, biochemical and cellular comparison of synovial fluid from the distal interphalangeal joint and distal sesamoid bursa in normal and abnormal hooves of cattle

A common area of lameness in cattle is the digital region, especially the distal sesamoid bursa (DSB) and distal interphalangeal joint (DIPJ). Physical, biochemical and cellular evaluations of the synovial fluid of the DSB and DIPJ were compared in normal and abnormal hooves in cattle. Synovial fluid from the DIPJ and DSB from 22 normal (11 hind limb and 11 forelimb) and 27 abnormal (16 hind limb and 11 forelimb) hooves of both sexes of Holstein cows were collected. Clinical observation of animal gait before slaughtering, grass evaluation and radiographic examination of the hoof was the basis for allocation to either the normal or abnormal group. Physical characteristics which were evaluated included the quality of mucin clot, gross appearance and viscosity. Total nucleated cell counts, differential cell counts, protein and glucose concentrations and the activities of AST, ALT, LDH and ALP were measured by validated standard methods. The mucin clot quality was graded as predominantly good (86%) in normal samples, as opposed to moderate (68.5%) in the abnormal samples. The viscosity of the majority of normal specimens (81.6%) was good, and more than 70% of the abnormal specimens had a moderate grade. Total nucleated cell counts of the synovial fluid from the normal group were 59.45?±?4.25 and 55.93?±?3.89?cells/μl (mean ± SD) in DSB and DIPJ, respectively, compared with 92.18?±?4.76 and 93.06?±?4.75?cells/μl in the abnormal group. The glucose concentration of normal synovial fluid from the DSB and DIPJ were 34.25?±?0.71 and 32.55?±?0.52?mg/dl, respectively, and showed no significant difference between these two samples. The results reveal that the enzyme activity of the abnormal synovial fluid from the DSB and DIPJ significantly increased. Also, there were no significant differences between the mean concentrations of total protein in the normal and abnormal synovial fluid specimens. Despite the non-significant differences of some cellular and biochemical parameters of synovial fluid between the DSB and the DIPJ, the differences of these variables in normal and abnormal hooves may be beneficial for the diagnosis of healthy and abnormal synovial fluid.     

Hodgkin's disease: an immunohistochemical and histological study

The distribution of immunoglobulin (Ig) in Hodgkin's tissue has been demonstrated in paraffin and cryostat sections by the unlabelled antibody peroxidase-antiperoxidase (PAP) method and the two-stage fluorescein isothiocyanate (FITC)-based technique. The morphology and histogenesis of the Reed-Sternberg (RS) and Hodgkin (HD) cells has been studied with the metalophil method of Marshall (1948) and this revealed a population of dendritic histiocytes which corresponded in number, sizes and distribution to the RS and HD cells in adjacent sections stained by haematoxylin and eosin. The largest RS cells, however, appeared to be non-dendritic. A notable feature of Hodgkin's tissue was the tendency for the dendritic cells to form "nodules", in combination with a population of small lymphocytes. The PAP technique reveals Ig in the form of mu and delta heavy chains, as well as kappa and lambda light chains, in close association with and probably on the surface of a high proportion of these lymphocytes, suggesting that they are immature B cells. Similar reactions were given by the mantle of lymphocytes of surviving normal lymphoid follicles, and metalophil dendritic histiocytes were also demonstrated within the mantle and subjacent part of the germinal centre. Numerous immunocytes containing Ig were present in all lesions; in the majority of cases, more cells contained gamma than alpha or mu heavy chains, although in these cases alpha-positive cells outnumbered those containing gamma or mu heavy chains. In two-thirds of the cases, one-third of the RS cells contained cytoplasmic immunoglobulin. This was exclusively gamma heavy, although both light chains were present. In about half the cases a minority of the HD cells contained gamma chain. The results suggest that HD and RS cells are dendritic histiocytes of the type normally found in the lymphoid follicles and that their tendency to form nodules in assoication with B lymphocytes is a manifestatin of this origin. It is suggested that the presence of Ig most probably results from absorption of antigen-antibody complexes on the cell surface.     

The phrenico-esophageal ligament: an anatomical study

The phrenico-esophageal ligament (PEL), which is claimed by some to be an important anti-reflux barrier, has been accepted as an important structure by some surgeons dealing with the surgical treatment of hiatal hernias. However, the characteristics of its anatomical structure and the physiological importance of this ligament is still a subject of discussion. The aim of this study was to define this anatomic structure and to point out the clinical importance of the PEL. This study has been carried out on samples taken from 2 fresh and 12 fixed cadavers. The PEL was observed to be derived from the transversalis and endothoracic fascia attaching the esophagus to the diaphragmatic crura at the region of the esophageal hiatus. While the transversalis fascia covered the inferior surface of the diaphragm, it was observed to divide into upper and lower leaflets when it approached the esophageal hiatus. The endothoracic fascia turned superiorly at the level of esophageal hiatus and attached on to the esophagus by uniting with the upper leaflet of the transversalis fascia in 11 of the specimens. In three of the specimens, it attached on the esophagus at a higher level than the transversalis fascia. The histologic sections of our study revealed that the PEL is formed by collagen and elastic fibers composed of fibroblasts and blood vessels. Since the PEL is a strong structure that firmly attached to the esophageal wall and surrounded the upper part of the distal esophagus like a skirt, it is reasonable that it may play an important role in the gastroesophageal sphincteric mechanism. Histological evidence for decrease in collagen fibers with age and the loose arrangement of the elastic fibers due to this decrement might decrease the resistance and the elasticity of the PEL. This situation may explain the predisposition to hiatal hernias seen with increased in age.