Study of the carrying angle of the human elbow joint in full extension: a morphometric analysis

This study measured the carrying angle of the elbow joint in full extension in 600 students, using the supplementary angle to that between the longitudinal axis of the arm and that of the forearm. The mean carrying angle was 12.88°±5.92: 10.97°±4.27 in men and 15.07°±4.95 in women. The carrying angle changes with skeletal growth and maturity. The angle is always greater on the side of the dominant hand. We confirmed the inverse relationship between the carrying angle and the intertrochanteric diameter. Also, the type of constitution influences the value of the carrying angle, especially in women.     

肘关节矢状面内生物动力模型及其优化解

目的建立肘关节矢状面内的动力学模型,寻求有效方法进行求解。方法利用Matlab的优化工具箱对所建立的模型进行优化求解。结果求解出了肘关节在不同屈伸角速度下,受到不同外力时的关节反力、各肌肉力以及力矩,得出了与文献相一致的结论。结论利用Matlab的优化工具箱可以合理地求解该模型,并且该模型可以用来计算肘关节在受到不同外力时的关节反力、肌肉力以及相应力矩。     

Passive visco-elastic properties of the structures spanning the human elbow joint

Summary The passive elastic torque function and the passive viscous torque function of the muscles and connective tissues spanning the elbow joint have been determined in three adult male subjects. The procedure for estimating the passive elastic torque involved measurement of the torque required to passively move the forearm-hand segment, at a constant angular velocity, throughout a complete range of elbow joint motion. The suspension method (Hatze, 1975) was used to obtain the estimate of passive viscous torque. Both of these torque functions were shown to be nonlinear functions of the angular displacement of the joint. In order to assess whether myotatic reflex activity was contributing to the damping of the segment, and thereby biasing the value of the torque contributed by passive viscous elements, the surface electromyograms of the biceps brachii and brachioradialis muscles were examined while the suspended body segment was oscillated. In one subject there was firm evidence of involuntary muscle activity in the brachioradialis muscle which tended to distort the oscillogram. This activity was enhanced when the subject maintained a voluntary isometric contraction in a remote muscle group (Jendrassik's manoeuvre). Based upon these observations, recommendations have been made for reducing unwanted myotatic reflex activity while using the suspension method to obtain estimates of various biomechanical parameters.On leave from the National Research Institute for Mathematical Sciences, CSIR, Pretoria 0001     

锚钉联合骨道技术重建肘关节尺侧副韧带前束的生物力学研究

目的　探讨肘关节尺侧副韧带（ulnar collateral ligament,UCL）前束在完整、断裂、重建三种状态时的肘外翻稳定性,评价锚钉联合骨道重建技术的有效性。 方法　选用8具新鲜成人尸体上肢制成肘关节骨-韧带模型,均先后模拟成UCL前束完整、断裂及锚钉联合骨道技术重建前束3种状态,测量各状态下肘关节在屈曲0°、30°、60°、90°、120°时的生物力学指标,包括外翻松弛度、肱桡关节接触面积、肱桡关节内压强;根据前束的不同状态分为完整组、断裂组、重建组,每组8具标本,将得出的数据进行统计学分析。 结果　组内比较,各组在屈肘0°时的生物力学指标与其余角度比较,差异具有统计学意义（P＜0.05）;组间比较,各组在0°时的生物力学指标比较,差异无统计学意义（P＞0.05）;组间比较,除0°以外的其余角度,完整组与断裂组、重建组与断裂组的生物力学指标差异有统计学意义（P＜0.05）,完整组与重建组的生物力学指标差异无统计学意义（P＞0.05）。 结论　UCL前束是维持肘关节外翻稳定性的重要结构。肘关节在伸直位时较屈曲位处于相对稳定状态。锚钉联合骨道技术重建UCL前束不仅能恢复肘外翻稳定性,而且还具有与正常肘关节同等优良的生物力学特性。     

The relationship between main elbow flexion skin crease and osseous anatomy of the elbow joint

Background  Studies that investigate the relationships between the main elbow flexion crease and the underlying osseous anatomy are lacking. Methods  The relationship between the flexion skin crease and osseous anatomy of the elbow joint was studied. Markers were placed along the main flexion skin crease of both elbows in 50 healthy volunteers. Measurements were expressed in millimeters of perpendicular distance from each skin crease to the osseous structures of the elbow joint including medial and lateral epicondyles, tip of the olecranon, and radial head. Results  The mean perpendicular distances between the elbow crease from osseous structures were found to be as follows: from medial epicondyle, 6.93 mm; from lateral epicondyle, −0.25 mm; from olecranon, 9.97 mm; and from radial head, −21.97 mm. There was no statistical significant difference between the dominant versus non-dominant hand. Conclusions  The association between the main flexion elbow crease and the bony structures observed in this study seems to support that the elbow crease can be a useful surface anatomy landmark and expected to aid in the placement of surgical incisions.     

Movements of the elbow and shoulder during pronation of the forearm

It is known that medial and lateral movements of the lower end of the ulna occur during pronation and supination of the forearm, but there is little clear evidence as to where these movements originate. Twenty normal subjects pronated their forearm about either an undefined, lateral, or medial axis. Measurements were made from paired photographs taken at increments of 45° during the movement. Abduction of the ulna always occurred but its magnitude did not vary significantly with differing axes of pronation. During pronation about an undefined axis the abduction at the elbow produced a lateral movement of the ulna which was usually appropriate for the axis of pronation in use. Medial or lateral rotation of the humerus was used to increase or decrease the amount of lateral movement of the lower end of the ulna to suit the requirements of pronation about a medial or lateral axis.     

Intra-articular compressive stress of the elbow joint in extension: an experimental study using Fuji films

The use of Fuji films is simple but their manipulation and result interpretation seem to be difficult in the framework of medical research. The reliability and reproducibility of Fuji films have been proved by many previous studies. This study was undertaken to know precisely the articular zones of the elbow and to determine the compressive stress these areas undergo during different activities, in order to assess the importance of different articular contact areas. These data indicate the need for better-adapted elbow prosthesis and can be eventually used to design more durable prosthesis for the elbow. The compressive stress on the radial head was less than 25% in extension. The stress on the radial head varied from the neutral position (23% of the stress), to full pronation (11% of the stress) and to full supination (6% of the stress). The Humero-ulnar compartment had the maximum impact. Coronoid process seemed to be a fundamental element of the elbow joint in extension (60% of total compressive stress). The Medial humero-ulnar compartment was less stressed than the lateral compartment. The radial head does not seem to play a major role in the stability of the elbow in extension if the ulnar collateral ligament exists. The ulnar collateral ligament is essential to the elbow joint stability. The lifespan of a non-constrained prosthesis would depend on the existence of the couple: radial head/ulnar collateral ligament; the absence of radial head could compromise the humero-ulnar stability. This work paved the way for the designing of new non-constrained elbow prosthesis with the reconstruction of the radial head.     

Time-varying stiffness of human elbow joint during cyclic voluntary movement

Summary The objective of this study was to determine the extent to which subjects modulate their elbow joint mechanical properties during ongoing arm movement. Small pseudo-random force disturbances were applied to the wrist with an airjet actuator while subjects executed large (1 rad) elbow joint movements. Using a lumped parameter model of the muscle, tendom and proprioceptive feedback dynamics, a time-varying system identification technique was developed to analyze the phasic changes in the elbow joint's mechanical response. The mechanical properties were found to be time-varying, and well approximated by a quasi-linear second-order model. The stiffness of the arm was found to drop during movement. The arm was always underdamped, with the damping ratio changing during movement. Inertia estimates were constant and consistent with previous measurements. Overall, the moving arm was found to be very compliant, with a peak stiffness value less than the lowest value measured during posture, and a natural frequency of less than 3 Hz. Changing the speed of movement, or the load from gravity, changed the stiffness measured, but not in strict proportion to the change in net muscle torque.     

Characteristics and outcome of 27 elbow periprosthetic joint infections: results from a 14-year cohort study of 358 elbow prostheses

Elbow arthroplasty is increasingly performed in patients with rheumatic and post-traumatic arthritis. Data on elbow periprosthetic joint infection (PJI) are limited. We investigated the characteristics and outcome of elbow PJI in a 14-year cohort of total elbow arthroplasties in a single centre. Elbow prosthesis, which were implanted between 1994 and 2007 at Schulthess Clinic in Zurich, were retrospectively screened for infection. PJI was defined as periprosthetic purulence, the presence of sinus tract or microbial growth. A Kaplan–Meier survival method and Cox proportional hazard analysis were performed. Of 358 elbow prostheses, PJI was identified in 27 (7.5%). The median patient age (range) was 61 (39–82) years; 63% were females. Seventeen patients (63%) had a rheumatic disorder and ten (37%) had osteoarthritis. Debridement and implant retention was performed in 78%, followed by exchange or removal of the prosthesis (15%) or no surgery (7%). The relapse-free survival (95% CI) was 79% (63–95%) after 1 year and 65% (45–85%) after 2 years. The outcome after 2 years was significantly better when patients were treated according to the algorithm compared to patients who were not (100% vs. 33%, p <0.05). In 21 patients treated with debridement and retention, the cure rate was also higher when the algorithm was followed (100% vs. 11%, p <0.05). The findings of the present study suggest that the treatment algorithm developed for hip and knee PJI can be applied to elbow PJI. With proper patient selection and antimicrobial therapy, debridement and retention of the elbow prosthesis is associated with good treatment outcome.     

Biomechanical modelling of the human sacroiliac joint

From a mechanical point of view, the human pelvis can be considered as a stable, complex three link structure. This three-link closed-chain system explains why there is so little motion in the sacroiliac joint. Based on the minimum total potential energy principle, a quasi-static model of the human pelvis with its three joints is developed. In the model, the articular cartilage linings of the joint surfaces are considered as thin layers with a geometric non-linear behaviour. They lie between two rigid curved surfaces that are represented by small three-node elements. Accessory ligaments and capsules are represented by a number of non-linear springs. A primary model is developed based on a female cadaver. According to the primary model, the translation of the sacroiliac joint in the direction of force is about 0·5 mm in the lateral direction, about 1·8 mm in the antero-posterior direction, and about 1·5 mm in the superior or inferior direction, when a load of 1000 N is applied to the sacrum. When a load of 50 N m⁻¹ is applied to the sacrum, the rotation in the load direction is about 1·6° in axial rotation, about 1·0° in flexion or extension and about 1·1° in lateral bending.     

Simultaneous dislocation of the radial head and distal radio-ulnar joint. A case report

Isolated dislocation of the distal radio-ulnar joint and isolated dislocation of the radial head in adults are not common injuries. A simultaneous dislocation of the radial head and distal radio-ulnar joint with no other injury seems to be extremely rare since only one report was found in the English literature. A similar case, but with some differences in presentation and treatment is reported.     

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。     

人工腰椎间盘置换术后上位关节突关节内应力变化的研究

目的　研究人工腰椎间盘置换术对上位相邻节段关节突关节内应力（FS）的影响,并与腰椎融合术进行比较,为人工腰椎间盘的临床应用提供理论依据。 方法　选取6具新鲜成人尸体的腰骶段（L2~S1）标本,将每具标本依次制作成L4/5椎间盘完整（对照组）、L4/5椎间盘置换和L4/5椎间融合模型,并依次进行生物力学实验,将压力传感器置入L3/4关节突关节,以400 N的恒定轴向载荷,±7.5 Nm的力矩模拟生理状态下轴向、后伸和左右侧弯4种运动,分别测量3种模型在各种运动下L3/4关节突关节内压力。 结果　在模拟生理载荷的各种运动下,人工椎间盘置换组与椎间盘完整组相比较,上位关节突关节内压力差异无统计学意义（P＞0.05）,而腰椎间融合组相对于椎间盘完整组和人工椎间盘置换组,上位关节突关节内压力均显著增加,差异具有统计学意义（P＜0.05）。 结论 人工腰椎间盘置换术后,上位相邻节段关节突关节内压力与正常腰椎相比无明显改变,而腰椎间融合术后,上位相邻节段关节突关节内压力则显著增加。     

Variations in the normal anatomy of the collateral ligaments of the human elbow joint

The variations which occur in the medial and lateral ligament complexes of the elbow were investigated. These occurred frequently with the standard appearances occurring in no more than half the specimens on the medial side and one quarter of those on the lateral side. Surgeons who regularly perform elbow arthroplasty must be aware of these considerations, especially with the introduction of unconstrained prostheses which rely upon the ligament complex for their postoperative stability.     

肘关节“恐怖三联征”的治疗――附10例报告

目的探讨肘关节"恐怖三联征"的治疗方法和疗效。方法 10例患者手术治疗9例,其中1例行人工桡骨头置换,并修复肘关节前关节囊及肘内、外侧副韧带;8例内固定,术后予长臂石膏或铰链式支架外固定制动2～3周,早期开始屈伸康复训练。闭合复位保守治疗1例。结果 10例患者均获随访,随访时间3～40月,平均22.5个月。手术组切口均一期愈合。术后8～12周骨折达临床愈合,平均9.2周。肘关节平均屈伸范围为110°±28°,前臂平均旋转活动范围为109°±25°,1例有创伤性关节炎。按照肘关节HHS评分标准评定标准进行评价:优5例、良2例、可1例、差2例(含保守治疗1例),总优良率为70%。结论对于肘关节"恐怖三联征",应积极手术治疗,重建或恢复骨的结构,坚强内固定,修复关节周围支持结构,早期功能锻炼,能有效恢复关节功能,减少骨折并发症。     

肘前入路钢板内固定联合Kocher入路桡骨头置换治疗肘关节恐怖三联征

目的探讨采用肘关节前方入路微型钢板内固定联合外侧Kocher入路桡骨头置换治疗肘关节恐怖三联征的临床疗效。方法回顾性分析从2015年6月至2017年6月我科收治和采用肘关节前方入路微型钢板内固定联合外侧Kocher入路桡骨头置换治疗肘关节恐怖三联征的8例病例资料。其中男7例,女1例;年龄20～47岁,平均28.3岁;患者均为单侧损伤,右侧损伤5例,左侧3例。尺骨冠状突骨折按Regan-Morrey分型:Ⅰ型1例,Ⅱ型5例,Ⅲ型2例;桡骨头骨折按Mason分型:Ⅲ型5例,Ⅳ型3例。均采用肘关节前方入路微型钢板内固定联合外侧Kocher入路桡骨头置换治疗,记录手术时间、术中出血量,观察切口愈合、骨折愈合情况及术后并发症情况,应用Mayo肘关节功能评分标准(MEPS)评定肘关节功能。结果本组获随访10～23个月,平均15.7个月,所有8例患者切口均一期愈合,骨折均获得临床愈合。未见神经、血管损伤及肘关节骨化性肌炎等并发症。根据患者肘关节的运动功能、稳定性、疼痛和日常活动等情况采用Mayo肘关节功能评分标准(MEPS)评估手术疗效:优3例,良4例,中1例,优良率87.5%。结论采用肘关节前方入路微型钢板内固定联合外侧Kocher入路桡骨头置换治疗肘关节恐怖三联征,具有术中显露充分、固定可靠及手术时间短等优势,临床疗效满意。     

Functional anatomy of the lateral collateral ligament complex of the elbow

Postero-lateral instability of the elbow joint is a rare clinical condition, commonly related to a disruption of the lateral collateral ligament complex of the elbow. Twenty elbow joint specimens were studied in order to describe the morphologic characteristics of this complex, and to determine the role of its different components in the stability of the elbow. After a morphologic and morphometric investigation, serial divisions of the medial bundle of the lateral collateral ligament were performed, with or without section of the annular ligament and the anterior bundle of the lateral collateral ligament. The anterior and medial bundles of the lateral collateral ligament had close relationships with the annular ligament and a common proximal course. Isolated section of the medial bundle of the lateral collateral ligament induced only minor laxity of the elbow joint. Combined divisions of the medial and the anterior bundles at their humeral insertion, or the medial bundle and the annular ligament at their ulnar insertion resulted in a reproducible subluxation of the ulno-humeral joint. Thus, postero-lateral rotatory stability of the elbow joint is largely maintained by the lateral collateral ligament complex, composed of three elements: the anterior and medial bundles of the lateral collateral ligament, and the annular ligament. In clinical practice, chronic postero-lateral instability is best treated by a ligamentous reconstruction, that must take into account all these anatomic considerations. We report here a new technique of ligamentoplasty using the fascia of the extensor carpi ulnaris muscle.     

儿童肘部尺神经前置术的应用解剖

目的为临床儿童尺神经前置术提供解剖学基础。方法 10具(共20肘)福尔马林固定的6~8岁儿童尸体上肢标本,解剖尺神经沟、尺神经行径伴行血管以及尺神经前置后解剖关系。结果尺神经主要接受尺侧上副动脉血供,前臂尺神经的血供则主要由尺动脉提供,尺侧上副动脉、尺侧下副动脉及尺侧返动脉后支血管的大部分行程与尺神经紧贴伴行,在尺神经前置越过肱骨内上髁时,不会造成伴行血管过度牵拉而对尺神经血供造成影响。尺神经前置后滑动性好,有良好的组织床,同时又能解除屈肘对尺神经牵拉。结论研究结果显示:尺神经前置术不会影响神经血供,具有可行性,前置时需切断上臂内侧肌间隔,皮下前置滑动性好。     

Development of the human elbow joint

Many studies have been published on the development of the human elbow joint, but authors disagree on its morphogenetic timetable. Most discrepancies center on the cavitation of the elbow joint (including the humeroradial, humeroulnar, and superior radioulnar joints), and the organization of the tunnel of the ulnar nerve. We summarize our observations on the development of the elbow joint in 49 serially sectioned human embryonic (n = 28) and fetal (n = 21) upper limbs. During week 12, ossification begins in the epiphyses of the elements comprising the elbow joint. At the end of the embryonic period, the shallow groove between the posterior aspect of the medial epicondyle and the olecranon process, begins to be visible. The elbow joint cavity appears in O'Rahilly stage 21 (51 days) at the level of the humeroulnar and humeroradial interzones. Formation of the cavity begins at the medialmost portion of the humeroradial interzone and the lateralmost portion of the humeroulnar interzone. The annular ligament begins to develop in O'Rahilly stage 21 (51 days), and the superior radioulnar joint cavity appears between this ligament and the lateral aspect of the head of the radius during O'Rahilly stage 23 (56 days). We established the morphogenetic timetable of the human elbow joint.