人腕关节动力肌腱的力臂值及意义探讨

目的：测量人腕关节主要动力肌腱在腕运动过程中的力臂的大小。方法：运用７只新鲜成人尸体上肢标本,将运动腕关节的肌腱和旋转电压计相连,在腕关节分别从屈曲至伸直,桡偏至尺偏过程中,用计算机同时记录腕动力肌腱滑动距离和腕运动角度,根据腱滑动距离和腕运动角度计算出肌腱平均力臂和力臂变化。结果：桡侧腕长伸肌腱的腕桡偏力臂最大,桡侧腕短伸肌腱的伸腕力臂最大,尺侧腕伸肌腱和腕尺偏力臂最大,而伸腕力臂很小,桡侧、尺     

腕掌侧双通道改良手术入路治疗桡尺骨远端骨折的解剖学基础

目的　报道腕掌侧双通道入路治疗桡尺骨远端骨折的应用解剖学基础。 方法 10侧新鲜成人尸体上肢标本,于腕掌侧在桡侧腕屈肌腱与掌长肌腱之间做纵行切口,进入皮下后向桡侧、尺侧绕过腕管内结构,通过双通道入路来观测桡骨、尺骨远端的暴露情况。 结果 在腕横纹上方3.0 cm水平,桡侧通路牵拉最大横向暴露距离为(3.0±0.29) cm,尺侧通路牵拉最大横向暴露距离为(2.3±0.26) cm,桡侧通路暴露桡骨远端尺侧半效果欠佳,而尺侧通路可以有效暴露桡骨远端尺侧半及尺骨远端。 结论 腕掌侧双通道改良手术入路治疗桡尺骨远端骨折具有可行性,暴露效果良好,值得在临床上推广。     

The influence of wrist thickness on amplitudes of sensory nerve action potentials

Normal values of sensory nerve action potential (SNAP) amplitudes vary widely. There are many factors which can influence the amplitude of the SNAP, such as the type of recording techniques, temperature, distance between recording electrodes, skin impedance, etc. In this study, we investigated the correlation between wrist thickness (palmar to dorsum diameter) and amplitudes of the SNAP of median and ulnar nerves of 20 healthy subjects. Ring electrodes were placed on the second and the fifth fingers and a surface block electrode was placed at the wrist between the flexor carpi radialis and the palmaris longus tendon and just radial to the flexor carpi ulnaris tendon, for testing the median and ulnar nerves, respectively. Both orthodromic and antidromic techniques were used. Depending on the technique, either ring or surface block electrodes could be the stimulating or the recording electrodes. By supramaximal intensity stimulation, the amplitude of the SNAP was measured from peak to peak. The results revealed that SNAP amplitudes and wrist thickness are reversely correlated, with statistical significance (p < or = 0.005) by using the antidromic technique. The influence of wrist thickness on SNAP amplitudes should be recognized when performing an electrodiagnostic study to determine axonal degeneration by using the SNAP amplitude parameter.     

An unusual termination of the ulnar nerve in the palm.

During the dissection of the left forearm and hand of a 57-year old male cadaver fixed in 10% formalin, it has been noted that the medial proper palmar digital nerve to the little finger arose from the dorsal branch of the ulnar nerve, instead of the superficial branch of the same nerve. The dorsal branch, given off by the ulnar nerve in the forearm, coursed distally and dorsally deep to the flexor carpi ulnaris muscle. Some 2 cm proximal to the pisiform, it pierced the deep fascia on the posteromedial side of the muscle to become superficial. At this point, one of the three branches given off travelled distally on the palmar-ulnar side of the hand to the skin of the little finger. There were connections between this branch and the branches of the superficial branch of the ulnar nerve which innervated the skin of the hypothenar eminence. Further, another branch of the superficial branch of the ulnar nerve passed under the fibrous arch of the flexor digiti minimi brevis muscle origin and the opponens digiti minimi muscle to re-unite with its parent nerve.     

Pulley anatomy for the radial side of the wrist.

This is the first presentation in the literature of a radial tendon flexor pulley in the distal forearm adjacent to the flexor carpi radialis. The clinical significance is that in performing wrist tendon arthroplasty, this structure and, in close proximity, the sensory branch of the median nerve may be encountered. Whether cutting the pulley of the flexor carpi radialis is clinically significant in changing wrist biomechanics is unknown.     

Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles

The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler''s staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm²), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm²). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18–0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler''s technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the ‘design’ of their functional capability. In addition to improving our understanding of muscle anatomy and function, elucidation of forearm neuromuscular compartments architecture may ultimately provide information useful for selection of muscle subdivisions used in tendon transfer.     

Innervation of the medial epicondylar muscles: an anatomic study in 50 cases

The median nerve is classically distributed to the medial epicondylar muscles by two branches (superior and inferior) for the pronator teres muscle, a common trunk for the flexor carpi radialis and palmaris longus muscles, and a branch for the flexor digitorum superficialis muscle. The 50 dissections were made by two workers on 30 upper limbs of formolized cadavers and 20 limbs from fresh-frozen cadavers. The innervation of the pronator teres m. was classical in only 26% of cases, and the “normal” pattern for the flexor carpi radialis and palmaris longus mm. was found in only 40% of cases. The innervation of the flexor digitorum superficialis m. was the least subject to variations, a single branch being observed in 68% of cases. We found a solitary medio-ulnar anastomosis of Martin-Gruber to the flexor carpi ulnaris muscle. This study confirmed the great variability of the branches of the median nerve at the elbow, and the importance of identifying them in surgical procedures for transposition of the medial epicondyle.     

An unusual topographic relationship between high origin of superficial ulnar artery and bitendinous palmaris longus

Anatomical Science International - The ulnar artery usually arises from the brachial artery at the cubital fossa. It descends beneath the flexor carpi ulnaris in the forearm and then terminates at...     

An immunohistochemical study of the extracellular matrix of entheses associated with the human pisiform bone

The immunohistochemical labelling patterns of the extracellular matrix at the insertion of the flexor carpi ulnaris tendon and the entheses at both ends of the pisometacarpal and pisohamate ligaments were compared in order to relate the molecular composition of the attachment sites to their mechanical environment. Tissue was obtained from elderly dissecting room cadavers and labelled with a panel of monoclonal antibodies directed against collagens, glycosaminoglycans, proteoglycans and matrix proteins. All entheses were fibrocartilaginous and labelled positively for molecules typically associated with articular cartilage (type II collagen, chondroitin 6 sulphate, aggrecan and link protein). Labelling for type II collagen was most conspicuous at the attachment of the flexor carpi ulnaris tendon. In the ligaments, type II collagen labelling was always greater at the pisiform end. Matrilin 1 was universally present at all five entheses examined and fibromodulin labelling was most intense around the tidemark. Fibromodulin may thus be involved in anchorage and/or the control of mineralization at the hard-soft tissue interface of entheses. The greater prominence of fibrocartilage at the pisiform enthesis of the flexor carpi ulnaris tendon than at any ligament attachment may relate to the marked change in the tendon insertional angle that occurs with wrist movements. We also suggest that the more fibrocartilaginous character of the proximal compared with the distal ends of the ligaments relates to the fact that the pisiform is anchored in position and is thus at the centre of rotation of any movement of ligaments attached to it.     

Anomalous flexor digiti minimi brevis in Guyon's canal

In an adult male cadaver, the flexor digiti minimi brevis, a muscle of the hypothenar eminence, was found to arise from the superficial transverse septum (between the superficially placed flexor carpi ulnaris, palmaris longus, and flexor carpi radialis muscles, and the deeply placed flexor digitorum superficialis muscle) in the distal fourth of the flexor aspect of the left forearm. The muscle exhibited two strata of muscle fibers at its origin. The superficial stratum was a thin layer of transversely running fibers confined to the forearm, which has not been previously reported. The deep stratum, a thick layer of longitudinally running fibers, formed the bulk of the muscle. It traversed Guyon's canal superficial to the ulnar nerve and vessels to reach the hypothenar eminence. Its course through Guyon's canal could be a cause for ulnar tunnel syndrome. The ulnar nerve trunk innervated not only the anomalous flexor digiti minimi brevis muscle, but also abductor digiti minimi and palmaris brevis. This may be due to the common phylogeny of these three muscles from the same muscle mass.     

内窥镜下微创治疗肘管综合征的相关解剖学研究

目的　为内窥镜下进行肘管尺神经减压并前移术提供临床应用解剖基础。 方法　10例新鲜尸体标本、20例临床病例传统手术中尺神经在臂部、前臂游离长度,尺神经第1肌支距离肱骨内上髁的距离、尺神经前移距离。在4例新鲜尸体标本上模拟手术。 结果　此术式尺神经前臂、臂部游离距离为（3.90±0.145）cm（3.64~4.23 cm）、（4.21±0.18）cm（3.80~4.53 cm）,前移距离（1.49±0.05）cm（1.39~1.57 cm）,尺神经第1肌支距离肱骨内上髁距离（2.18±0.38）cm（1.13~2.72cm）。此术式入路点、轴线、层面：肱骨内上髁与尺骨鹰嘴间长约2 cm纵行切口;肱骨内上髁与尺骨鹰嘴之间中点与豌豆骨连线上约7cm长的轴线,肱骨内上髁与尺骨鹰嘴之间中点与肱二头肌内侧肌间隔中点连线上长8cm的轴线;奥本斯韧带、前臂尺侧腕屈肌之间纤维弓形组织表面,臂部深筋膜表面。模拟手术成功。 结论　研究证实此术式可行,达预期效果。     

Synaptic connections from large afferents of wrist flexor and extensor muscles to synergistic motoneurones in man

 Short-latency excitatory Ia reflex connections were determined between pairs of human wrist flexor and extensor muscles. Spindle Ia afferents were stimulated by either tendon tap or electrical stimulation. The activity of voluntarily activated single motor units was recorded intramuscularly from pairs of wrist flexor or extensor muscles. Cross-correlation between stimuli and the discharge of the motor units provided a measure of the homonymous or heteronymous excitatory input to a motoneurone. Homonymous motoneurone facilitation was generally stronger than that of the heteronymous motoneurones. The principal wrist flexors, flexor carpi radialis (FCR) and flexor carpi ulnaris (FCU), were tightly connected through a bidirectional short-latency reflex pathway. In contrast, the extensor carpi ulnaris (ECU) and the extensor carpi radialis (ECR) did not have similar connections. ECU motoneurones received no short-latency excitatory Ia input from the ECR. ECR motoneurones did receive excitatory Ia input from ECU Ia afferents; however, its latency was delayed by several milliseconds compared with other heteronymous Ia excitatory effects observed. The wrist and finger extensors were linked through heteronymous Ia excitatory reflexes. The reflex connections observed in humans are largely similar to those observed in the cat, with the exception of heteronymous effects from the ECU to the ECR and from the extensor digitorum communis (EDC) to the ECU, which are present only in humans. The differences in the reflex organization of the wrist flexors versus the extensors probably reflects the importance of grasping. Received: 19 August 1996 / Accepted: 6 March 1997     

The proximal origins of the flexor–pronator muscles and their role in the dynamic stabilization of the elbow joint: an anatomical study

Purpose

The purpose of this study was to anatomically investigate the proximal origin of flexor–pronator muscles (FPMs) and clarify their contribution to dynamic stabilization of the elbow joint during valgus stress.

Methods

52 elbows from 26 donated formalin-fixed cadavers were examined. The pronator teres muscle (PT), flexor carpi radialis muscle (FCR), palmaris longus muscle (PL), flexor digitorum superficialis muscle (FDS), and flexor carpi ulnaris muscle (FCU) were identified, and their proximal origin and relationship to the anterior bundle of the medial ulna collateral ligament (AOL) were macroscopically and histologically investigated.

Results

The PT, FCR, PL, and FDS converged and formed a common tendon at their proximal origin (the anterior common tendon: ACT). The ACT was attached to the medial epicondyle and the joint capsule, just anterior and parallel to the AOL. The histological morphology of the ACT was quite similar to that of the AOL. The ulnar head of the PT was observed in 48 of 52 elbows (92.3 %), just behind the humeral head of PT. It mainly originated from the anterior edge of the sublime tubercle, while the upper part of ulnar head transitioned directly into the thickened joint capsule just anterior to the AOL.

Conclusion

The proximal attachment of the FPMs had a characteristic morphology. According to our results, the ACT and PT might assist the AOL by sharing static and dynamic traction forces applied to the medial elbow joint.     

Anatomy of the ulnar nerve at the elbow: Potential relationship of acute ulnar neuropathy to gender differences

Men develop perioperative ulnar neuropathies more frequently than women. To determine the role of anatomical gender differences in the development of these neuropathies, we performed several studies of the anatomy of the ulnar nerve, cubital tunnel, and elbow region. These studies included detailed dissection of male and female embalmed and unembalmed cadavers, ultrasound measurements of the tissue layers at the elbow, and measurement of various dimensions of the coronoid process of the ulna in multiple skeletal sets. No gross anatomical differences were found between genders regarding the course of the ulnar nerve through the upper limb. However, there was a strikingly larger (2–19 times greater) fat content on the medial aspect of the elbow in women compared to men, and the tubercle of the coronoid process was approximately 1.5 times larger in men (P ≤ .002, rank sum test). Our finding suggest that the tubercle of the coronoid process is a likely area for external compression-induced ischemia of the ulnar nerve because the nerve and its arterial supply (the posterior ulnar recurrent artery) are covered at the tubercle only by skin, subcutaneous fat, and a very thin aponeurosis of the flexor carpi ulnaris. Importantly, this tubercle is larger and the nerve and blood vessels passing by it are less protected by subcutaneous fat in men than in women. These two anatomical differences between men and women may contribute to the increased frequency of perioperative ulnar neuropathy induced by external pressure at the medial aspect of the elbow in men. Clin. Anat. 11:372–378, 1998. © 1998 Wiley-Liss, Inc.     

Muscle variations and abnormal branching and course of the ulnar nerve in the forearm and hand

During dissection of the right forearm of a 27-year-old female cadaver, variations in the form and insertion of the palmaris longus muscle were observed. The tendon of the palmaris longus muscle, which demonstrated a centrally placed belly, split into two tendons: one inserted into the palmar aponeurosis and the other into the proximal part of the flexor retinaculum. Additionally, we found an accessory muscle extending between the flexor retinaculum and the tendon of the abductor digiti minimi muscle. This accessory muscle was located deep to the ulnar artery but superficial to the superficial and deep branches of the ulnar nerve at the wrist. Finally, an aberrant branch of the ulnar nerve was identified in the forearm; it traveled distally alongside the ulnar artery and in the palm demonstrated communications with common palmar digital nerves from the ulnar and the median nerves. No variations were observed in the contralateral upper limb.     

吻合血管的尺神经转位治疗截瘫

目的：重建胸段脊髓横断致伤完全性截瘫患者的部分周围神经功能。方法：在４例截瘫病人将一侧的尺神经自腕部切断,以骨间前神经旋前方肌支吻接远端尺神经深支,取一桡神经浅支的分支与尺神经浅支吻接,自皮下隧分段游离尺神经至腋窝起始处,分离过程中保护尺侧上副血管。于皮下将尺神经及其尺侧上副血管引人侧胸壁隧道。显露胸背动,静脉,将尺侧上副血管与其行端端吻合。在臂部分离出阴部神经、股后皮神经和坐骨神经,用带筋膜蒂股     

Anomalies of the flexor carpi ulnaris: Clinical case report and cadaveric study

Flexor carpi ulnaris (FCU) is an ever‐present muscle of the anterior flexor compartment of the forearm. Variations of FCU are uncommon, with additional slips or heads of muscles described, and only one reported case of an accessory muscle. We describe a unique clinical case report in which an accessory FCU was identified and describe the findings of 5,000 cadaveric dissections of the forearm, performed as part of an ongoing institutional study of anatomical variations. An aberrant accessory forearm flexor muscle was identified incidentally at the wrist during surgery for an anterior interosseous to ulnar nerve transfer for management of ulnar nerve palsy. This muscle was seen running superficial to the ulnar nerve and radial to the FCU proper, arising from the common flexor origin and inserting at the triquetral carpal bone. This was therefore suitably acknowledged as an “accessory FCU”. The anomaly was identified as bilateral using ultrasound imaging, and was found to be anomalously innervated by the median nerve with nerve conduction studies. A subsequent review of 5,000 cadaveric dissections of the forearm did not identify any such variations related to FCU, despite identifying a range of variations of the other forearm flexor musculature. While the scarcity of this anomaly is thus highlighted, consideration of an accessory FCU, and its aberrant innervation is important in a range of surgical approaches. Clin. Anat. 23:427–430, 2010. © 2010 Wiley‐Liss, Inc.     

Pattern of projections of group I afferents from elbow muscles to motoneurones supplying wrist muscles in man

Summary The pattern of projections of low threshold afferents from triceps and biceps brachii muscles onto motoneurones innervating muscles acting at the wrist was assessed by a reflex and a poststimulus time histogram (psth) technique. Activation of low-threshold afferents originating from elbow flexors or extensors resulted in an early, short-lasting inhibition of wrist flexor motoneurones (flexor carpi radialis, flexor carpi ulnaris). An inhibition was also found in the extensor carpi radialis (ECR) motoneurones after stimulation of low-threshold afferents from triceps. Evidence is presented that Ia fibres contribute to these effects. The inhibitory effects were found in all subjects, but they were constant in only 57% of the reflex experimental sessions and in 25% of the explored motor units. Stimulation of biceps low-threshold afferents was always ineffective on ECR motoneurones. No early facilitation was ever seen in motor nuclei innervating wrist muscles following stimulation of low threshold afferents from biceps and triceps. The pattern of transjoint projections of group I afferents from proximal to distal muscles and from distal to proximal ones (Cavallari and Katz 1989) is discussed in relation to that described in the cat forelimb.     

桡侧腕屈肌腱瓣转位修复下桡尺关节脱位的应用解剖和临床研究

目的：从解剖学角度研究桡侧腕屈肌腱瓣转位修复下桡尺关节脱位的机理。方法：对30侧成人上肢标本的桡侧腕屈肌腱分段进行形态学测量,并进行力学测试。为36例下桡尺关节脱位患者,设计以桡侧腕屈肌腱部分腱瓣转位修复下桡尺关节。结果：桡侧腕屈肌腱性部分长（14．3±1．1）cm,肌腱的上、中、下段宽分别为（9．1±1．4）mm、（5．5±0．9）mm和（4．0±0．4）mm,肌腱的上、中、下段厚分别为（2．4±0．6）mm、（2．2±0．4）mm和（2．6±0．5）mm。36例患者术后随访5—10a,平均6．5a。其中优23例,腕关节酸痛基本消失,旋转70°-120°,X线片示正常;良12例,腕关节轻度酸痛,旋转度数改善,X线片示正常;差1例,腕关节仍有酸痛,旋转度数无明显改善,X线片示正常。优良率97．2％。结论：桡侧腕屈肌腱部分转位有足够的长度和强度以修复下桡尺关节脱位,临床应用效果良好。