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Posterior elbow dislocations are the most common type of elbow dislocation and are usually caused by a fall on an outstretched hand. Although the incidence of elbow dislocation complications is rare, the emergency physician is responsible for evaluation and identification of concomitant neurovascular injuries. Failure to identify neurovascular compromise after elbow dislocation or reduction can potentially lead to severe morbidity with limb ischemia, neurologic changes, compartment syndrome, and potential loss of limb. Cyanosis, pallor, pulselessness, and marked pain should suggest vascular injury or compartment syndrome, both requiring immediate intervention. Patients in whom it is not clear if there is vascular injury should undergo further imaging with angiography, considered the gold standard for evaluation of arterial damage. It is important for the emergency physician to maintain a high level of suspicion and evaluate for neurovascular compromise on every patient with elbow dislocation despite the low overall incidence of severe injury., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Musculotendinous variations around the medial epicondyle can contribute to subluxation of the ulnar nerve at the elbow. This article reviews the presenting symptoms, operative findings, and results of surgery for subluxation of the ulnar nerve at the elbow. A retrospective evaluation was performed of 200 elbows managed operatively for medial elbow pathology over a 17-year period between 1990 and 2007. The patient charts were reviewed for chief complaint, radiographic studies, operative reports, and postoperative examination data. Seventeen patients (18 elbows) were treated for a subluxating ulnar nerve. Three patients were women and 14 were men, with a mean age of 27.6 years. Medial elbow pain was the chief complaint in all 17 patients. Seventeen elbows also demonstrated paresthesias in an ulnar nerve distribution. All patients were treated with anterior transposition of the ulnar nerve, and 11 patients (61%) were found to have a muscular anomaly. At a mean follow-up of 17 months, the mean visual analog scale for pain improved from 6.0 to 2.0. There was no functional impairment reported for any patient at final follow-up. Of the 200 elbows surgically treated for medial elbow pathology, 17 patients (8.5%) demonstrated a subluxating ulnar nerve. These patients tend to be young and present with a primary complaint of medial elbow pain. In addition, a subluxating ulnar nerve is often associated with muscular anomalies, which must be addressed concurrently., (Copyright 2010, SLACK Incorporated.)

This article provides a brief review of the normal osseous, ligamentous, muscular, and neurovascular imaging anatomy of the elbow. Special attention is paid to the normal structures that may simulate pathology, as well as anatomical variants that may lead to pathology. This review will help clarify distinctions between normal anatomy and abnormal anatomy, as well as elucidate pathological consequences of a seemingly normal structure., ((c) Thieme Medical Publishers.)

Nerve compression and entrapment syndromes are classic examples of the integrated role of radiologists and clinicians in achieving difficult but accurate diagnoses. The pathology of nerves can only be understood after evaluating the normal architecture and imaging characteristics of nerves. Understanding the correlation of the pathophysiology of nerve compromise with electromyographic findings and imaging findings allows for greater comprehension of a difficult topic. Particularly in the elbow, there are multiple potential areas of nerve entrapment and compression that can be evaluated perhaps best with magnetic resonance imaging., ((c) Thieme Medical Publishers.)

Microsurgical restoration of shoulder abduction with free muscle transfers is one of the most challenging reconstructions. The purpose of this study was to analyze retrospectively the outcomes of free muscle transfer for shoulder abduction. Since 1981, 22 muscles have been transferred for shoulder abduction in posttraumatic brachial plexopathy. Two techniques have been used: a double muscle transfer of adductor longus and gracilis was used for shoulder abduction and elbow flexion, respectively (n = 18), and latissimus dorsi transfer for shoulder abduction (n = 4). For the double muscle transfer, the mean range of motion of shoulder abduction was found postoperatively to be 30 +/- 24 degrees and the mean muscle grade was to be 2.61 +/- 0.76 (P < 0.001). For latissimus transfer, the mean postoperative muscle grade of the transferred muscle was 3.25 +/- 0.73, and the shoulder abduction was 40 +/- 32 degrees. Free muscle transfer can enhance shoulder abduction after inadequate results from primary reconstruction or in late cases. In this study, all patients achieved a stable shoulder, 53% yielded shoulder abduction against gravity, and 9% achieved abduction to the horizontal level.

Research has found an advantage for an external focus of attention in motor control and learning; instructing subjects to focus on the effects of their actions, rather than on body movements, can improve performance during training and retention testing. Previous research has mostly concentrated on movement outcomes, not on the quality of the movement itself. Thus, this study combined surface electromyography (EMG) with motion analysis and outcome measures in a dart throwing task, making this the first study that includes a comprehensive analysis of changes in motor performance as a function of attentional focus. An external focus of attention led to better performance (less absolute error), decreased preparation time between throws, and reduced EMG activity in the triceps brachii. There was also some evidence of increased variability for kinematic measures of the shoulder joint under an external focus relative to an internal focus. These results suggest improved movement economy with an external focus of attention., (Copyright 2010 Elsevier B.V. All rights reserved.)

Feedback control of our limbs must account for the unexpected offset of mechanical perturbations. Here we examine the evoked activity of elbow flexor and extensor muscles to torque pulses lasting 22-152 ms and how torque offset impacts activity in the long-latency (45-100 ms) and voluntary epochs (120-180 ms). For each pulse width, we found a significant attenuation of muscle activity approximately 30 ms after the offset of torque compared with when the torque was sustained. The brief time between the offset of torque and the attenuation of muscle activity implicates group I afferents acting through a spinal pathway, because this route is the only one fast enough and short enough to be responsible. Moreover, elbow muscle activity in the subsequent 20-45 ms following torque-offset was approximately 35% smaller than when the torque was sustained. These results show that a fast spinal process can powerfully attenuate corrective responses of the arm to a torque perturbation.

Posttraumatic elbow stiffness in children can be a severe obstacle to accomplishing basic activities of daily living, including dressing, and participating in recreational activities. The etiology of this stiffness is typically extrinsic or instrinsic pathology caused by an earlier supracondylar humerus fracture, elbow dislocation, or elbow fracture-dislocation. Children with functional limitations, typically associated with flexion contractures greater than 30 degrees or less than a functional arc (30 to 130 degrees) can benefit from surgical contracture release, which consistently improves range of motion.

Neuropathic arthropathy (Charcot's arthropathy) is a progressive articular disease associated with a reduced sensorial and protector proprioceptive reflex. Its etiology includes many different conditions such as syringomyelia, traumatic lesion causing medullary deformity, spina bifida, diabetic neuropathy, leprosy neuropathy, neurofibromatosis, amyloid neuropathy, alcohol, and repetitive injection of hydrocortisone into joints, among others. However, the relationship between Charcot's arthropathy and herpetic encephalitis has not yet been described. Herpes encephalitis causes acute and chronic diseases of the peripheral or central nervous system. It can manifest as subacute encephalitis, recurrent meningitis, or myelitis. It can also resemble psychiatric syndromes, diplopia, sensory changes in the face and limbs, personality changes, frontal dysexecutive syndrome, stiff neck, subclinical alterations of the vestibular function, intracranial hypertension, convulsion, hemiparesis, and generally includes motor components, among others. On the other hand, pure peripheral sensory disturbance has not been described. In this article, we report the clinical case of a patient with Charcot's arthropathy secondary to pure peripheral sensory polyneuropathy as a consequence of progressive herpetic encephalitis sequelae. In this article, the authors report the first case of Charcot's arthropathy secondary to herpetic encephalitis.

Neuropathic arthropathy (NA), known as Charcot neuroarthropathy, is a chronic, degenerative arthropathy and is associated with decreased sensory innervation. Numerous causes of this arthropathy have been described. Neuropathic joint, although first described by Charcot in tabes dorsalis in 1868, has subsequently been observed in a variety of conditions including syringomyelia, diabetes mellitus and peripheral nerve disorders. Syringomyelia is characterized by slow progression. The shoulders and elbows are the most frequently involved joints in syringomyelia. Involvement of the hand is a quite rarely seen in the cases of NA caused by syringomyelia. In this article, we reported a case of NA secondary to syringomyelia. The characteristics of this presented case is the presence of Arnold-Chiari malformation accompanying with syringomyelia and involvement of the shoulder, elbow and hand (multiple joint involvement).

Introduction: Intra-articular fractures of the distal humerus frequently require internal fixation. Several approaches have been described, with the posterior approaches being most common. We present a new approach to the distal humerus via the lateral border of the triceps muscle., Patients and Methods: The senior author has used this technique for fixation of intra-articular fractures of the distal humerus in 12 patients., Results: The approach is equally useful for intra- and extra-articular fractures. No cases of postoperative ulna nerve neuropraxia have been encountered. There have been no postoperative wound complications. The exposure has allowed sufficient access to allow anatomically contoured plates to be easily applied to both sides of the distal humerus with confirmation of intra-articular fracture reduction., Conclusions: The approach has the advantages of leaving the muscular bed of the ulna nerve undisturbed, whilst still providing excellent exposure of the distal humerus. The triceps mechanism is not divided or split allowing rapid recovery of extensor function. Additionally, because of the natural carrying angle of the elbow, repositioning of the reflected triceps aponeurosis is easy.

Lateral epicondylitis (LE) or tennis elbow has been the subject of concern during the last 60 years, but the pathogenesis of the LE remains unclear. The LE can be due to the tendinogenic, articular or neurogenic reasons. Numerous theories have been put fourth in the recent past, out of which one of the most popular theories is that the condition results from repeated contraction of the wrist extensor muscles, especially the extensor carpi radialis brevis (ECRB) which may compress the posterior branch of the radial nerve (PBRN) at the elbow during pronation. We studied 72 upper limbs (36 formalin-fixed cadaver) for the origin, nerve supply and the course of PBRN in relation to the ECRB as one of the goal for the present study. The possible presence of an arch of the ECRB around the PBRN was also observed and recorded. The nerve to ECRB was a branch from the radial nerve in 11 cases (15.2%); from the PBRN in 36 cases (50%) and from the superficial branch of the radial nerve in 25 cases (34.7%), respectively. The ECRB had a tendinous arch in 21 cases (29.1%); a muscular arch in 8 (11.1%) cases and the arch was absent in 43 cases (59.7%). When the ECRB had a tendinous or muscular arch around the PBRN, it may compress the same and this condition may worsen during the repeated supination and pronation as observed in tennis and cricket players. The presence of such tendinous or muscular arch should be considered by orthopedicians and neurosurgeons, while releasing the PBRN during LE surgery.

Introduction: We hypothesized that a correlation may exist between the length of the upper limb and the length of the cubital tunnel, which transmits the ulnar nerve from the arm to the forearm. If true, this association might aid in predicting individuals at greater risk of developing ulnar nerve compression at this site., Materials and Methods: A total of 46 cadaveric upper limbs were dissected. The lengths of the upper limb and cubital tunnel were measured and analysis made of any correlation between these two distances., Results: The average length of the cubital tunnel was found to be 2.7 cm (range 1.2-4.7 cm, SD 0.82), and the average length of the upper limb was 62.5 cm (range 51-72 cm, SD 4.33). No significant difference was found with either length of the tunnel between left and right sides or among genders. Neither the ratio of upper limb length to length of the cubital tunnel between genders nor the ratio between left and right sides was found to have a positive correlation., Conclusions: These data suggest that the cubital tunnel length maintains similar proportion to upper limb length among genders and sides and that a correlation between these two distances does not exist.

Background: Elbow extension is important for the elbow joint, and it is more difficult to restore with microsurgery than elbow flexion. The purpose of this article is to describe the experience of the authors with elbow extension reconstruction in obstetric brachial plexus palsy patients. The outcomes were analyzed in relation to the type of brachial plexus lesion, timing of surgery, and the type of nerve reconstruction., Methods: Fifty-five children with obstetric brachial plexus palsy who underwent nerve reconstruction for elbow extension restoration were studied. The mean follow-up period was 6.4 years (range, 2-22 y). Reinnervation of the triceps muscle was accomplished with indirect neurotization of the posterior cord from intraplexus donors or with direct neurotization from extraplexus donors, such as the contralateral C7 and the intercostal nerves., Results: Thirty-seven (67%) of the 55 cases showed good or excellent results (>or=M3+). The average postoperative muscle grading for the triceps was 3.34+/-0.99 compared with 1.19+/-1.29 preoperatively (P<0.0001). Patients with C5 to C7 palsy achieved significantly stronger elbow extension than those with C5 to T1 palsy. In addition, the timing of surgery significantly influenced the final outcome., Conclusions: Elbow extension is one of big challenges to be restored, especially in obstetric brachial plexus palsy. In early cases (within 6 mo) intraplexus reconstruction of the posterior cord can give excellent results. In later cases, or in cases of multiple avulsions, extraplexus motor donors, which selectively targeted the triceps, can give variable results.

Eccentric exercise has been extensively used as a model to study muscle damage-induced neuromuscular impairment, adopting mainly a bilateral matching task between the reference (unexercised) arm and the indicator (exercised) arm. However, little attention has been given to the muscle proprioceptive function when the exercised arm acts as its own reference. This study investigated muscle proprioception and motor control, with the arm acting both as reference and indicator, following eccentric exercise and compared them with those observed after isometric exercise. Fourteen young male volunteers were equally divided into two groups and performed an eccentric or isometric exercise protocol with the elbow flexors of the non-dominant arm on an isokinetic dynamometer. Both exercise protocols induced significant changes in indicators of muscle damage, that is, muscle soreness, range of motion and maximal isometric force post-exercise (p < 0.05-0.001), and neuromuscular function was similarly affected following both protocols. Perception of force was impaired over the 4-day post-exercise period (p < 0.001), with the applied force being systematically overestimated. Perception of joint position was significantly disturbed (i.e., target angle was underestimated) only at one elbow angle on day 4 post-exercise (p < 0.05). The misjudgements and disturbed motor output observed when the exercised arm acted as its own reference concur with the view that they could be a result of a mismatch between the central motor command and an impaired motor control after muscle damage.

Objectives: To describe the relationship of the major muscular, ligamentous and neurovascular structures in relation to standard medial elbow arthroscopic portals used in dogs, and to evaluate their potential iatrogenic lesions., Design: Anatomical study using 20 canine cadaveric elbows., Methods: Arthroscopic explorations were performed using medial portals. Three 4 mm orthopaedic pins were introduced in place of the arthroscope, egress canula and instrumental portals. Limbs were dissected. Distances between pins and neurovascular structures were measured. Muscle, ligament and cartilage lesions were recorded., Results: Minimal muscular lesions were observed. No ligament injury was evidenced. Superficial iatrogenic cartilage lesions were observed in three joints. The arthroscopic portal was 23.1 mm (range: 16 to 28.5 mm) caudal to the brachial artery, 21.0 mm (13-30.5 mm) caudal to the median nerve, and 4.0 mm (1-7 mm) cranial to the ulnar nerve. The instrumental portal was 16.3 (9-24 mm) caudal to the brachial artery, 13.5 mm (7-24.5 mm) caudal to the median nerve, and 11.8 (8-18 mm) cranial to the ulnar nerve. The egress portal was 21.4 mm (12-37 mm) caudal to the ulnar nerve., Conclusions and Clinical Relevance: The study confirmed the safety of elbow medial arthroscopic portals. Care must be taken when placing the camera portal so as to avoid injury of the ulnar nerve. Should extensive intra-articular procedures be needed, manipulation of instruments should be done cautiously in the cranio-medial compartment of the joint due to the proximity of the median nerve to the capsule.

Purpose: Restoration of elbow flexion is the highest priority for brachial plexus reconstruction, and its reconstructive strategy is well established. The purpose of this article is to report elbow joint position sense (JPS) after double free muscle transfer (DFMT) for complete paralysis of brachial plexus., Methods: Thirteen patients with complete brachial plexus paralysis who were treated with DFMT underwent evaluation of elbow JPS. JPS was measured as the subject's ability to actively reproduce a previously presented position of the elbow joint (target angle). We calculated the difference between target and reproduced angle and defined this as the absolute error (AE). Ten healthy control subjects participated in this study., Results: In control subjects, mean AE measured 4 degrees +/- 1 degree at the target angle of 60 degrees and 4 degrees +/- 2 degrees at 80 degrees. After DFMT, patients' mean AE measured 5 degrees +/- 2 degrees at the target angle of 60 degrees and 5 degrees +/- 3 degrees at 80 degrees. There was no statistical difference between the control and DFMT groups at target angles of 60 degrees and 80 degrees., Conclusions: Patients with complete paralysis of the brachial plexus had evidence of elbow JPS after successful restoration of elbow flexion after DFMT. Although this study provides us with useful information regarding the perception of elbow JPS, further study is necessary to confirm the exact mechanism of perception of elbow JPS., Type of Study/level of Evidence: Therapeutic IV.

The percutaneous placement of lateral distal humeral pins risks injury to the radial nerve. We aimed to provide a reliable and safe parameter for the insertion of lateral distal humeral pins. A secondary aim of this study was to investigate the effect of pin/screw placement in the intended zone of fixation at the lateral distal humerus. We dissected 70 fresh cadaveric upper limbs and the radial nerve was identified and its course followed into the anterior compartment. The point where the radial nerve crosses humerus in mid lateral plane was identified and the distance between this point and lateral epicondyle was measured, as was the maximum trans-epicondylar distance, along with the olecranon fossa height. Statistical analysis was performed using the Pearson correlation coefficient. The average trans-epicondylar distance was measured at 62 +/- 6 mm (range 52-78 mm), and the average lateral radial nerve height was 102 +/- 10 mm (range 75-129 mm). The ratio of the lateral nerve height to the trans-epicondylar distance was an average of 1.7 +/- 0.2 (range 1.4-2.0). The Pearson correlation coefficient between the lateral nerve height and the trans-epicondylar distance was r = 0.95. A relative dimension, the trans-epicondylar distance is both reliable and easily accessible to the operating surgeon. The absolute safe zone for pin entry into the lateral distal humerus is that area lying within the caudad 70% of a line, equivalent in length to the patient's own trans-epicondylar distance, when projected proximally from the lateral epicondyle.

Reaching to visual targets engages the nervous system in a series of transformations between sensory information and motor commands. That which remains to be determined is the extent to which the processes that mediate sensorimotor adaptation to novel environments engage neural circuits that represent the required movement in joint-based or muscle-based coordinate systems. We sought to establish the contribution of these alternative representations to the process of visuomotor adaptation. To do so we applied a visuomotor rotation during a center-out isometric torque production task that involved flexion/extension and supination/pronation at the elbow-joint complex. In separate sessions, distinct half-quadrant rotations (i.e., 45 degrees ) were applied such that adaptation could be achieved either by only rescaling the individual joint torques (i.e., the visual target and torque target remained in the same quadrant) or by additionally requiring torque reversal at a contributing joint (i.e., the visual target and torque target were in different quadrants). Analysis of the time course of directional errors revealed that the degree of adaptation was lower (by approximately 20%) when reversals in the direction of joint torques were required. It has been established previously that in this task space, a transition between supination and pronation requires the engagement of a different set of muscle synergists, whereas in a transition between flexion and extension no such change is required. The additional observation that the initial level of adaptation was lower and the subsequent aftereffects were smaller, for trials that involved a pronation-supination transition than for those that involved a flexion-extension transition, supports the conclusion that the process of adaptation engaged, at least in part, neural circuits that represent the required motor output in a muscle-based coordinate system.

Background: This study attempts to confirm that the Disabilities of Arm, Shoulder and Hand (DASH) Outcome Measure self-administered questionnaire is valid specifically for ulnar neuropathy at the elbow. Validity of the Levine-Katz questionnaire for ulnar neuropathology compared with DASH was also studied., Materials and Methods: Forty-eight patients with isolated ulnar nerve surgery completed a 6-month evaluation. Patients were assigned a clinical stage. The DASH and Levine-Katz questionnaires were administered, and pinch and grip strength were measured preoperatively and postoperatively. Levine-Katz questionnaires were correlated with DASH to establish criterion validity. Construct validity was tested by determining a relationship between scores and clinical stages and by comparing scores preoperatively and postoperatively., Results: There was a high correlation between DASH scores and symptom severity and functional status. Although correlations were significant between DASH and biomechanical measures, correlation coefficients were lower. Postoperatively, all measures improved significantly., Conclusion: This study confirms that scores on the DASH questionnaire reflect the clinical staging of ulnar neuropathy at the elbow.

The loss of independent joint control in the paretic upper limb is a cardinal sign of movement disorders following stroke. However, the underlying neural mechanisms for such a loss following stroke are still largely unknown. In order to investigate the possible contribution of altered sensorimotor cortical activity to the loss of independent joint control, we measured electroencephalographic (EEG) and torque signals during the generation of static shoulder/elbow torques. We found significant increases in the overlap of shoulder and elbow joint representations at the cortical level in stroke subjects as compared to control subjects. Linear regression results demonstrated significant associations between the cortical overlap of joint representations and the degree of the loss of independent joint control. Therefore, we conclude that an increased overlap of cortical representations for shoulder and elbow contributes to the expression of the loss of independent shoulder/elbow control of the paretic upper limb in chronic hemiparetic stroke survivors.

This prospective study was performed to evaluate and compare the morphological changes and dynamics of the ulnar nerve after percutaneous cross-pinning with Kirshner wire (group 1; 13, mean age 8.3 years, 10 male and three female children) and only lateral pinning (group 2; eight, mean age 7.6 years, six male and two female children) of displaced unilateral supracondylar fractures in children's elbows using ultrasonography in comparison with the contralateral healthy elbows. Postoperative evaluation revealed that ulnar nerve movement was reduced and the major axis diameter of elbow flexion and ulnar nerve was larger (P<0.05) than the major axis diameter in the elbow extension in group 1 than group 2. We think that the treatment of the displaced supracondylar fracture of the humerus in children with only a lateral Kirshner wire would be safer and more convenient.

Background: Partial joint denervation is the concept of preservation of joint function and relief of joint pain by interrupting the neural pathways that transmit the pain message from the joint to the brain. When traditional, nonoperative, musculoskeletal approaches fail, the surgical approach may require joint fusion or replacement arthroplasty. The purpose of this article is to extend these concepts from the wrist to the elbow and shoulder., Methods: For each joint, research required (1) anatomical dissection to identify innervation of the specific joint, (2) identification of route through which to administer local anesthetic based on new anatomical knowledge, (3) demonstration that pain relief is possible by injection of local anesthetic in patients who have failed traditional musculoskeletal treatments for that joint, (4) creation of surgical approach(es) to resect involved nerve(s), and (5) documentation of success of this approach with an appropriate patient population., Results: The results obtained for partial joint denervation of the wrist can be applied successfully to the elbow and shoulder. If anesthetic block of joint innervation results in greater than or equal to a five-point reduction in visual analogue scale score, 90 percent of the patients can expect good to excellent pain relief from partial joint denervation., Conclusions: Partial joint denervation offers an outpatient, ambulatory operative approach that is joint sparing and rehabilitation free. For plastic surgery, this concept opens new areas for patient care, permitting relief of pain and restoration of function to joints even proximal to the wrist, permitting plastic surgeons to bring this hope to our orthopedic and pain management colleagues.

Objective: To determine, with more precision than in previous investigations, if the innervation zone (IZ) for the biceps brachii can move with increases in isometric torque, and if so, whether or not that movement is influenced by differences in joint angle., Methods: Twenty-three participants (mean age=21.7 years) performed isometric contractions of the forearm flexors at 20, 40, 60, 80, and 100% of their maximal voluntary contraction (MVC) at three separate elbow joint angles (90, 120, and 150 degrees ). During each contraction, 16 channels of bipolar surface electromyographic (EMG) signals were recorded from the biceps brachii using a linear electrode array. For each joint angle, movement of the IZ with increases in torque was identified by a change in the EMG channel that was over the IZ., Results: For each joint angle, the IZ shifted proximally (2.3 channels) with increases in torque from 20 to 100% MVC. With an interelectrode distance of 2.5mm, this 2.3-channel shift reflects a 4.5-7.0mm movement of the IZ., Conclusion: The IZ shifts proximally 4.5-7.0mm with increases in isometric torque, independent of joint angle., Significance: These findings suggested that if isometric contractions are performed at different torque levels, the electrodes should be placed at least 7mm from the IZ.

Despite the prevalence of hyperactive stretch reflexes in the paretic limbs of individuals with chronic hemiparetic stroke, the fundamental pathophysiological mechanisms responsible for their expression remain poorly understood. This study tests whether the manifestation of hyperactive stretch reflexes following stroke is related to the development of persistent inward currents (PICs) leading to hyperexcitability of motoneurons innervating the paretic limbs. Because repetitive volleys of 1a afferent feedback can elicit PICs, this investigation assessed motoneuronal excitability by evoking the tonic vibration reflex (TVR) of the biceps muscle in 10 awake individuals with chronic hemiparetic stroke and measuring the joint torque and electromyographic (EMG) responses of the upper limbs. Elbow joint torque and the EMG activity of biceps, brachioradialis, and the long and lateral heads of triceps brachii were recorded during 8 s of 112-Hz biceps vibration (evoking the TVR) and for 5 s after cessation of stimulation. Repeated-measures ANOVA tests revealed significantly (P

We describe the first reported case of an intraneural ganglion cyst, an ulnar ("cubital") intraneural cyst, which, on literature review, dated to 1810. For over 80 years, its original brief description by Beauchêne was wrongly attributed to Duchenne, effectively making the reference and specimen inaccessible to scrutiny. Fortunately, the intact cyst had been safely housed in the Musée Dupuytren, Paris, France, thus permitting its examination. Although originally described as a "serous" cyst, our present understanding of the anatomy of the ulnar nerve and of peripheral nerve pathology allowed us to reinterpret it as a mucin-filled, elbow-level, ulnar intraneural ganglion cyst. In addition to its description as a fusiform cystic enlargement of the nerve, we documented similar enlargement of a lumen-bearing branch, the articular branch at the level of the elbow. Based on our assessment of the specimen and with a modern perspective, we concluded that the origin of the cyst was from the postero-medial aspect of the elbow joint and that its fluid content, having dissected through a capsular defect, followed the path of the articular branch into the parent ulnar nerve. The purpose of this report is to clarify historical misconceptions regarding the pathogenesis of this controversial entity., ((c) 2008 Wiley-Liss, Inc.)

Summary: Reconstruction of elbow function in severe or late brachial plexus injuries represents a challenge to the reconstructive microsurgeons. The current sophisticated techniques of nerve reconstruction in combination with secondary local or free functional muscle transfers, may offer satisfactory outcome. Latissimus dorsi can be transferred as a pedicled or free muscle to restore elbow function. We present our experience with elbow reanimation in late cases of brachial plexus paralysis utilising latissimus dorsi muscle transfer. From 1998 to 2006 we operated 103 patients with brachial plexus paralysis. Amongst these patients, 21 were late cases and underwent latissimus dorsi muscle transfer for elbow reanimation. Ten patients had free latissimus dorsi transfer for elbow flexion. Free latissimus dorsi muscle was neurotised either directly via three intercostals in three patients or with a nerve transfer procedure using the contralateral seventh cervical nerve root in seven patients. Care was taken to maintain the proper tension to the muscle, which must hold the elbow in static flexion of about 120 degrees at the end of the procedure. Powerful elbow flexion (M4-M4+) or extension (M4) was obtained after the first 3 months in all patients who had an ipsilateral pedicled latissimus dorsi transfer. In the group of free muscle transfers, elbow flexion was seen after 6-8 months. After the initiation of muscle contraction, eight of the patients regained elbow flexion of M3-M4+. Latissimus dorsi muscle transfer is a reliable method for elbow reanimation. Appropriate postoperative management is also an important factor to obtain better outcome.

Electrical stimulation of the brachioradialis branch of the radial nerve has been shown to inhibit the discharge of voluntarily activated motor units in biceps brachii during weak contractions with the elbow flexor muscles. The purpose of the present study was to characterise the inhibitory reflex by comparing its strength in the short and long heads of the biceps brachii and examining the influence of forearm position on the strength of the reflex. Spike-triggered stimulation was used to assess the influence of radial nerve stimulation on the discharge of single motor units in the biceps brachii of 15 subjects. Stimulation of the radial nerve prolonged the interspike interval (P < 0.001) of motor units in the long (n = 31, 4.8 +/- 5.6 ms) and short heads (n = 26, 8.1 +/- 12.3 ms) of biceps brachii with no difference between the two heads (P = 0.11). The strength of inhibition varied with forearm position for motor units in both heads (n = 18, P < 0.05). The amount of inhibition was greatest in pronation (7.9 +/- 8.9 ms), intermediate in neutral (5.8 +/- 7.1 ms), and least in supination (2.8 +/- 3.4 ms). These findings indicate that the inhibition evoked by afferent feedback from brachioradialis to low-threshold motor units (mean force 3-5% MVC) in biceps brachii varied with forearm posture yet was similar for the two heads of biceps brachii. This reflex pathway provides a mechanism to adjust the activation of biceps brachii with changes in forearm position, and represents a spinal basis for a muscle synergy in humans.

The authors examined the relationship between movement velocity and distance and the associated muscle activation patterns in 18 individuals with focal hand dystonia (FHD) compared with a control group of 18 individuals with no known neuromuscular condition. Participants performed targeted voluntary wrist and elbow flexion movements as fast as possible across 5 movement distances. Individuals with FHD were slower than controls across all distances, and this difference was accentuated for longer movements. Muscle activation patterns were triphasic in the majority of individuals with FHD, and muscle activation scaled with distance in a similar manner to controls. Cocontraction did not explain movement slowing in individuals with dystonia, but there was a trend toward underactivation of the 1st agonist burst in the dystonic group. The authors concluded that slowness is a consistent feature of voluntary movement in FHD and is present even in the absence of dystonic posturing. Underactivation of the 1st agonist burst appears to be the most likely reason to explain slowing.

Individuals with C5/C6 spinal cord injury (SCI) have a number of paralyzed muscles in their upper extremities that can be electrically activated in a coordinated manner to restore function. The selection of a practical subset of paralyzed muscles for stimulation depends on the specific condition of the individual, the functions targeted for restoration, and surgical considerations. This paper presents a musculoskeletal model-based approach for optimizing the muscle set used for functional electrical stimulation (FES) of the shoulder and elbow in this population. Experimentally recorded kinematics from able-bodied subjects served as inputs to a musculoskeletal model of the shoulder and elbow, which was modified to reflect the reduced muscle force capacities of an individual with C5 SCI but also the potential of using FES to activate paralyzed muscles. A large number of inverse dynamic simulations mimicking typical activities of daily living were performed that included 1) muscles with retained voluntary control and 2) many different combinations of stimulated paralyzed muscles. These results indicate that a muscle set consisting of the serratus anterior, infraspinatus and triceps would enable the greatest range of relevant movements. This set will become the initial target in a C5SCI neuroprosthesis to restore shoulder and elbow function.

The double free-muscle transfer technique achieved a dramatic revolution in the treatment of total paralysis of the brachial plexus by providing universal prehensile function, although several requirements such as successful free-muscle transfers, stability of the proximal joints and prolonged postoperative rehabilitation are necessary for the success of this procedure. To obtain the best outcome of double free-muscle transfer, it is imperative to understand the key factors, viz. selection of the donor muscle, meticulous microsurgical technique, importance of proximal joint stability, selection of the kind of grip and postoperative rehabilitation. Double free-muscle transfer is not a simple microsurgical muscle transfer for finger movement, but a universal reconstructive procedure for total paralysis of the upper limb.

Objective: The purpose of this study was to identify factors confounding high-resolution ultrasonographic measurements of the ulnar nerve to test their influence when discriminating between limbs affected and unaffected by ulnar nerve entrapment (UNE) at the elbow., Methods: High-resolution ultrasonographic measurements of ulnar nerve dimensions at the elbow were compared between 2 groups of subjects: symptomatic and asymptomatic for UNE. Rank analysis of covariance regression tests were performed to determine whether significant differences existed between the 2 groups. The changing coefficient method (using rank analysis of covariance tests) was used to test for potential confounding effects of age, weight, height, body mass index, sex, limb sidedness, limb handedness, and nerve mobility. These tests were repeated for each measurement while controlling for the identified confounders. Exact 2-tailed Wilcoxon signed rank tests were performed to test for significant differences between measurements of the diameter of the ulnar nerve with the elbow in full extension and full flexion., Results: Age, weight, body mass index, sex, and elbow position were shown to have confounding influences on high-resolution ultrasonographic measurements of the ulnar nerve. No confounding effect was apparent for limb sidedness or dominance. Cross-sectional area and long-axis diameter measurements demonstrated significant differences between nerves with and without UNE after controlling for confounders., Conclusions: Two cross-sectional measurements (area and maximum cross-sectional diameter) of the ulnar nerve, made at the level of the medial epicondyle, were found to be robust discriminators between nerves with and without UNE. In the absence of normative reference values of the ulnar nerve, the contralateral limb may be used as the comparative control.

Purpose: Peripheral articular denervation has been proposed as an alternative treatment for degenerative arthritis. It shows particular promise in the elbow because the joint is non-weight bearing and easily exposed. Accurate knowledge of peripheral neuroanatomy is required for future denervation surgeries, yet very few studies focus on the articular branches of the ulnar, median, and radial nerves that provide elbow capsule innervation., Methods: Twenty-three upper limbs from skeletally mature fresh-frozen cadavers were used for dissection of the ulnar, median, and radial nerves. The presence, number, location, and diameter of articular branches to the elbow capsule were recorded., Results: The ulnar nerve typically supplied 1 to 2 large branches to the elbow capsule (range, 0-4). In the 3 specimens with a greater number, a thinner diameter was noted (<1 mm compared with 1.2 mm). The median nerve contributed an average of 1.3 branches (range, 0-4) and showed an inverse ratio with the ulnar nerve contribution. The posterior interosseous nerve contributed a range of 0 to 4 branches, arising at 5 mm to 2 mm after bifurcation of the radial nerve., Conclusions: Most previous upper-extremity nerve studies have failed to fully characterize the contributions of all 3 major nerves to capsular innervation. We have thoroughly documented the articular branching patterns of all 3 major nerves and show that all 3 may contribute branches to the capsule.

Operative fixation is indicated for most type-II and III supracondylar humeral fractures in order to prevent malunion. Medial comminution is a subtle finding that, if treated nonoperatively, is likely to lead to unacceptable varus malunion. Angiography is not indicated for a pulseless limb, as it delays fracture reduction, which usually corrects the vascular problem. A high index of suspicion is necessary to avoid missing an impending compartment syndrome, especially when there is a concomitant forearm fracture or when there is a median nerve injury, which may mask symptoms of compartment syndrome. Lateral entry pins have been shown, in biomechanical and clinical studies, to be as stable as cross pinning if they are well spaced at the fracture line, and they are not associated with the risk of iatrogenic ulnar nerve injury.

The intention of this prospective study was to evaluate the role of the musculocutaneous and radial nerves in elbow flexion and forearm supination. The study included 29 patients having loco-regional anaesthesia for minor hand surgery. Elbow flexion and forearm supination forces were evaluated before and after an isolated musculocutaneous nerve block in one group and an isolated radial nerve block in another group. The results showed that the biceps tendon is responsible for 47% of the forearm supination force and the combination of brachioradialis and the supinator for 64% of this force. It showed also that the musculocutaneous and radial nerves contribute by 42% and 27.5%, respectively, to the flexion force of the elbow. These results are intended to help surgeons in decision making when treating chronic biceps tendon rupture, in repair of traumatic brachial plexus neuropathy and in using tendon transfers, such as the Steindler transfer, around the elbow.

In Erb (C5-C6) type of palsy due to traumatic brachial plexus injury, function is dependent upon the ability of the arm to maneuver and stabilize the hand for action. Complete loss of power of elbow flexion after brachial plexus injuries is a severe disability. If there is control of the shoulder, elbow flexion is of major importance. Various types of procedures have been described to recover or reanimate elbow flexion for chronic or failed upper type paralysis, including free muscle transfer, unipolar and bipolar pedicled muscle transfer, and various tendon transfers. In this article, we describe the surgical technique of bipolar pectoralis major transfer and our experience with this type of transfer, wherein we prefer to transfer all components of the pectoralis major muscle including the sternocostal and clavicular origins and humeral insertion without a fascial graft by the inclusion of a strip of the rectus abdominis fascia along with the flap.

Paralysis of elbow flexion or extension leads to major impairment of upper extremity function. Surgical reconstruction can be achieved using several procedures. If the time interval since the nerve injury is short, anatomic reconstruction by means of nerve suture or nerve transplantation should be attempted. Alternatively, nerve transposition is possible. If more than 12-18 months have elapsed, reinnervation of arm muscles can no longer be expected. In this case, muscle transposition is helpful. Restoring flexion is predominantly required following brachial plexus injury, when the function of the biceps, brachioradialis and brachialis muscles are lost. As donor muscles the latissimus dorsi, pectoralis major and triceps brachii can be used, alternatively a transfer of the flexor-pronator muscles of the forearm is possible. Latissimus dorsi transfer to reconstruct elbow flexion is also indicated in defects of the anterior upper arm muscle compartiment due to trauma, ischemia, or tumor. Patients with proximal radial nerve lesions may benefit from latissimus transfer to reachieve elbow flexion extension. In tetraplegic patients, elbow extension is restored mainly by transfer of the posterior deltoid muscle extended with a tendon graft, or by means of a biceps-to-triceps transfer.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant nerve disease usually caused by 1,5 Mb deletion on chromosome 17p11.2.2-p12, the region where the PMP-22 gene is located. The patients with HNPP usually have relapsing and remitting entrapment neuropathies due to compression. We present a 14-year-old male who had acute onset, right-sided ulnar nerve entrapment at the elbow. He had electrophysiological findings of bilateral ulnar nerve entrapments (more severe at the right side) at the elbow and bilateral median nerve entrapment at the wrist. Genetic tests of the patient demonstrated deletions in the 17p11.2 region. The patient underwent decompressive surgery for ulnar nerve entrapment at the elbow and completely recovered two months after the event. Although HNPP is extremely rare, it should be taken into consideration in young adults with entrapment neuropathies.

Placing K-wires obliquely through the anterior ulnar cortex is a common modification of traditional olecranon tension-band wiring. Wire tip protrusion, however, risks injury to adjacent neurovascular structures and may impede forearm rotation. This study examines the proximity of neurovascular structures to the anterior proximal ulnar cortex. The anatomy of 47 adult elbows was examined through magnetic resonance imaging. A radiologist measured the spatial relationship of 6 neurovascular structures to a mid-sagittal reference point 1.5 cm distal to the coronoid on the anterior surface of the ulna. Distance and angular measurements were made in the transverse plane of the reference point. Within a reasonable arc of K-wire placement, the ulnar artery and median nerve were at greatest risk yet were still beyond 10 mm from the anterior ulnar cortex. To avoid iatrogenic neurovascular injury during tension-band wiring of the olecranon, protrusion of wire tips beyond the anterior ulnar cortex should be no more than 1 cm at a distance of 1.5 cm distal to the coronoid.

Studies on plasticity in motor function have shown that motor learning generalizes, such that movements in novel situations are affected by previous training. It has been shown that the pattern of generalization for visuomotor rotation learning changes when training movements are made to a wide distribution of directions. Here we have found that for dynamics learning, the shape of the generalization gradient is not similarly modifiable by the extent of training within the workspace. Subjects learned to control a robotic device during training and we measured how subsequent movements in a reference direction were affected. Our results show that as the angular separation between training and test directions increased, the extent of generalization was reduced. When training involved multiple targets throughout the workspace, the extent of generalization was no greater than following training to the nearest target alone. Thus a wide range of experience compensating for a dynamics perturbation provided no greater benefit than localized training. Instead, generalization was complete when training involved targets that bounded the reference direction. This suggests that broad generalization of dynamics learning to movements in novel directions depends on interpolation between instances of localized learning.

Psychophysical studies have reported an overestimation of limb position in the direction of movement during the early part of active movements. The main hypothesis tested in this study is that the overestimation results from a process of forward prediction of limb state driven by an efference copy of the outgoing motor command. This hypothesis predicts that position overestimation should decrease or disappear during passive movements, for which there should be no efference copy. Seven subjects were asked to remember and to report the perceived angle of their elbow joint at different times during active and passive movements. They showed a highly velocity-dependent overestimation of the elbow joint angle near the beginning of the movement in both active and passive trials. Toward the end of the movement, subjects showed a relatively velocity-independent underestimation of their elbow angle in all trials. Contrary to the prediction of the efference copy hypothesis, the amplitude and the velocity-dependent slope of the elbow angle overestimation were both greater during the early part of passive movements than active movements. This indicates that psychophysical evidence of early overestimation of arm position on its own is not a sufficient proof of forward prediction based on an efference copy, at least under the conditions of this study. Decreased errors during active movements suggest that an efference copy can improve the accuracy of state estimation during active movements. Error patterns seem to parallel the likely level of sensorimotor noise, suggesting a probabilistic mechanism for position estimation.

Nerve and tendon gliding exercises are advocated in the conservative and postoperative management of carpal tunnel syndrome (CTS). However, traditionally advocated exercises elongate the nerve bedding substantially, which may induce a potentially deleterious strain in the median nerve with the risk of symptom exacerbation in some patients and reduced benefits from nerve gliding. This study aimed to evaluate various nerve gliding exercises, including novel techniques that aim to slide the nerve through the carpal tunnel while minimizing strain ("sliding techniques"). With these sliding techniques, it is assumed that an increase in nerve strain due to nerve bed elongation at one joint (e.g., wrist extension) is simultaneously counterbalanced by a decrease in nerve bed length at an adjacent joint (e.g., elbow flexion). Excursion and strain in the median nerve at the wrist were measured with a digital calliper and miniature strain gauge in six human cadavers during six mobilization techniques. The sliding technique resulted in an excursion of 12.4 mm, which was 30% larger than any other technique (p

The present study examined neural activity in the shoulder/elbow region of primary motor cortex (M1) during a whole-limb postural task. By selectively imposing torques at the shoulder, elbow, or both joints we addressed how neurons represent changes in torque at a single joint, multiple joints, and their interrelation. We observed that similar proportions of neurons reflected changes in torque at the shoulder, elbow, and both joints and these neurons were highly intermingled across the cortical surface. Most torque-related neurons were reciprocally excited and inhibited (relative to their unloaded baseline activity) by opposing flexor and extensor torques at a single joint. Although coexcitation/coinhibition was occasionally observed at a single joint, it was rarely observed at both joints. A second analysis assessed the relationship between single-joint and multijoint activity. In contrast to our previous observations, we found that neither linear nor vector summation of single-joint activities could capture the breadth of neural responses to multijoint torques. Finally, we studied the neurons' directional tuning across all the torque conditions, i.e., in joint-torque space. Our population of M1 neurons exhibited a strong bimodal distribution of preferred-torque directions (PTDs) that was biased toward shoulder-extensor/elbow-flexor (whole-limb flexor) and shoulder-flexor/elbow-extensor (whole-limb extensor) torques. Notably, we recently observed a similar bimodal distribution of PTDs in a sample of proximal arm muscles. This observation illustrates the intimate relationship between M1 and the motor periphery.

In C5, C6, or C5-to-C7 root injuries, many surgical procedures have been proposed to restore active elbow flexion. Nerve grafts or nerve transfers are the main techniques being carried out. The transfer of ulnar nerve fascicles to the biceps branch of the musculocutaneous nerve is currently proposed to restore active elbow flexion. Recovery of biceps muscle function is generally sufficient to obtain elbow flexion. However, the strength of elbow flexion is sometimes weak because the brachialis muscle is not reinnervated. Therefore, the transfer of 1 fascicle of the median nerve to the brachialis branch of the musculocutaneous nerve may be proposed to improve strength of the elbow flexion. We describe the technique of this double transfer to restore elbow flexion. The results concerning 5 patients are presented.

Background: Muscle pathology of the arm and forearm in brachial plexus birth injury (BPBI) with elbow flexion contracture has not been evaluated with MRI., Objective: To determine whether limited range of motion of the elbow in BPBI is correlated with specific patterns of muscular pathology., Materials and Methods: For 15 BPBI patients, total active motion (TAM) of the elbow (extension-flexion) and the forearm (pronation-supination) were measured. MRI of the elbow joints and musculature allowed assessment of elbow congruency. Fatty infiltration and size reduction of the muscles were graded semiquantitatively., Results: Mean TAM of the elbow was 113 degrees (50 degrees-140 degrees) and that of the forearm 91 degrees (10 degrees-165 degrees). The greater the size reduction of the brachioradialis muscle, the more diminished was elbow TAM. The more extensive the BPBI and muscle pathology of the pronator teres muscle, the more limited was the TAM of the forearm. Pathology of the supinator and brachialis muscles was evident in every patient., Conclusion: Extensive BPBI may result in marked limitation of TAM. Elbow flexion contracture seems to be caused mainly by brachialis muscle pathology. Prosupination of the forearm is better preserved when the pronator teres is not severely affected. MRI can reliably show the extent of muscle pathology in BPBI.