Nerve Of Forearm Research Articles

Communication between radial nerve and medial cutaneous nerve of forearm

Radial nerve is usually a branch of the posterior cord of the brachial plexus. It innervates triceps, anconeous, brachialis, brachioradialis, extensor carpi radialis longus muscles and gives the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm; without exhibiting any communication with the medial cutaneous nerve of forearm or any other nerve. We report communication between the radial nerve and medial cutaneous nerve of forearm on the left side in a 58-year-old male cadaver. The right sided structures were found to be normal. Neurosurgeons should keep such variations in mind while performing the surgeries of axilla and upper arm.

A study of the effects of anomalous innervation on the diagnosis of median or ulnar nerve injury

Objective To study the effects on the diagnosis of median or ulnar nerve injury by the presence of anomalous anastomosis between median and ulnar nerves in the forearm and the palm of the hand, including the anastomosis from median nerve in the forearm to the ulnar nerve (Martin-Gruber anastomosis, MGA), the anastomosis from ulnar nerve in the forearm to the median nerve(reversed Martin-Gruber anastomosis, RMGA), and the anastomosis from median nerve in the palm of the hand to the ulnar nerve (Riche-Cannieu anastomosis, RCA). Methods An 160 cases of median or ulnar nerve injury with the presence of anomalous anastomosis were assigned to three groups: 65 cases of ulnar nerve lesion with MGA, 8 cases of median nerve lesion with RMGA, and 87 cases of median nerve lesion with RCA. The anatomical bases, clinical manifestations, electrophysiological data and diagnosis were discussed. Results In the case of median or ulnar nerve lesion, the function of the muscle which was controlled by the injured nerve can be compensated due to the existence of the anomalous anastomosis. This could result in discrepancy between the clinical symptoms and the degree of nerve lesion and electrophysiological findings. Conclusion Thorough understanding of the characteristics of these three types of anomalous innervation between median and ulnar nerves is crucial to the clinical diagnosis and treatment of median or ulnar nerve injuries, as well as to the correct interpretation of the electrophysiological data. Key words: Electromyography; Median nerve; Ulnar nerve; Anomalous innervation

Less Invasive Plate Osteosynthesis in Humeral Shaft Fractures

Stable internal fixation of the humeral shaft by less invasive percutaneous plate insertion using two separate (proximal and distal) incisions, indirect reduction by closed manipulation and fixation to preserve the soft tissue and blood supply at the fracture zone. Early mobilization of the shoulder and elbow to ensure a good functional outcome. Humeral shaft fractures (classified according to AO classification as: 12-A, B, C). Humeral shaft fractures extending to the proximal or distal shaft, small or deformed medullary canal or open growth plate. Humeral shaft fractures with primary radial nerve palsy. Proximal humeral shaft fractures extending to the humeral head. Distal humeral fractures extending to the elbow joint. Two incisions proximal and distal to the fracture zone are used. A 3-cm proximal incision lies between the lateral border of the proximal part of the biceps and the medial border of the deltoid. Distally, a 3-cm incision is made along the lateral border of the biceps. The interval between biceps and brachialis is identified. The biceps is retracted medially to expose the musculocutaneous nerve. The brachialis muscle has dual innervation, the medial half being innervated by the musculocutaneous nerve and the lateral half by the radial nerve. The brachialis is split longitudinally at its midline. The musculocutaneous nerve is retracted along with the medial half of the brachialis, while the lateral half of the brachialis serves as a cushion to protect the radial nerve. A deep subbrachial tunnel is created from the distal to the proximal incision. The selected plate is tied with a suture to a hole at the tip of the tunneling instrument for pulling the plate back along the prepared track. The plate is aligned in the correct position on the anterior surface of the humerus. Traction is applied and the fracture reduced to restore alignment by image intensifier, followed by plate fixation with at least two bicortical locking screws or three bicortical conventional screws in each fragment. Between January 2003 and January 2006, 23 patients were operated on using the less invasive plate osteosynthesis technique. The minimum follow-up period of 12 months was completed in 20 patients. The mean healing time was 14.6 weeks, defined as three of four cortices having stable bridging callus. In one patient with delayed union, healing was observed after 28 weeks. Functional outcomes were evaluated using the Constant Score and the Hospital for Special Surgery (HSS) Score. 19 patients had good to excellent elbow function with a mean HSS Score of 93.5 points. All patients achieved satisfactory shoulder function with a mean Constant Score of 85.8 points compared to 90.6 on the healthy side. Complications observed were one paresthesia of lateral cutaneous nerve of forearm (no radial nerve injury) and one loosening of the LCP (Locking Compression Plate) screws due to technical error.

Vascularization of the Median Nerve in the Distal Forearm and its Clinical Significance: Level 2 Evidence

Vascularization of the Median Nerve in the Distal Forearm and its Clinical Significance: Level 2 Evidence

Documenting the Density of Innervation in a Sensate Radial Forearm Flap Based on the Lateral Antebrachial Cutaneous Nerve

Sir: A left radial forearm innervated flap was elevated for a hemitongue reconstruction but was not needed. The flap, still attached by its vascular pedicle and the lateral antebrachial cutaneous nerve, was returned to the forearm. One month later, we subjected it to sensory testing to see whether (1) the flap retained normal and evenly distributed sensation (demonstrating its suitability as a sensate flap) and (2) the division of overlapping contributions from the superficial radial sensory nerve and the medial antebrachial cutaneous nerve reduced the flap's sensory acuity. The flap measured 10 × 6 cm. It lay to the radial side of the distal forearm, with its lateral border overlying the cephalic vein and its medial third lying medial to the midline of the forearm. By its position, overlapping sensory contributions from the medial antebrachial cutaneous nerve and the DRCN would be expected.1–4 A mirror image of the flap was drawn on the opposite (right) forearm. Each was divided into longitudinal and transverse thirds (Fig. 1) and tested for pain (sharp/dull), temperature (hot/cold), light pressure (Semmes-Weinstein monofilament 10-g, 5.07 strand), and static and moving two-point discrimination.Fig. 1.: Postoperative day 30: the left innervated radial forearm flap is healing satisfactorily. Its image has been marked on the contralateral (right) forearm as a control. Each is divided into nine mirror-image zones.Light pressure, vibration, hot, and cold sensation were present equally in all nine segments of both the flap and control. One-centimeter static two-point discrimination was present in all nine segments of both flap and control. Eight-millimeter static two-point discrimination was equally variable bilaterally (Fig. 2).Fig. 2.: Eight-millimeter static two-point discrimination (+, present; 0, absent).Six-millimeter moving two-point discrimination was present in all nine segments of both flap and control groups. Five-millimeter moving two-point discrimination was equally variable bilaterally (Fig. 3). Sharp-dull discrimination was present bilaterally in all segments except the flap's zone 9.Fig. 3.: Five-millimeter two-point moving discrimination (+, present; 0, absent). Six and 8 mm were present in all zones.The lateral antebrachial cutaneous nerve is the dominant sensory nerve of the lateral forearm, with overlap from the medial antebrachial cutaneous nerve and superficial radial sensory nerve.1–4 The tiny area of sensory loss when the superficial radial sensory nerve is cut suggests a fairly extensive overlap. Because this forearm flap was designed to capture the primary territory of the lateral antebrachial cutaneous nerve and include the cephalic vein, it was centered on a line running between the radial artery and the cephalic vein in the distal forearm.1 Boutros et al. stated that although the lateral antebrachial cutaneous nerve is the dominant sensory nerve of the forearm, 40 percent of the flap is unrepresented by the nerve.4 However, the flap reported by Boutros et al. had its skin paddle extending from the brachioradialis laterally to the flexor carpi ulnaris medially. Boutros et al. stated that for ideal sensation, all three sensory nerves of the forearm should be raised and anastomosed to the lingual nerve stump.4 This is unnecessary: the lateral antebrachial cutaneous nerve flap clearly carries normal sensation. Furthermore, overlapping sensory contributions from the medial antebrachial cutaneous nerve and the superficial radial sensory nerve do not summate in providing normal sensation: the flap is adequately innervated by the lateral antebrachial cutaneous nerve alone. Because the removal of nerves supplying overlapping territory results in no diminution of sensation, we must conclude that this redundancy may have some survival advantages, and that the neurons carrying sensation from overlapping areas by means of different nerves simply project onto the same relay cells in the dorsal column nuclei.1 J. Brian Boyd, M.D. Sarah Sung Kim, B.S. Joachim Granzow, M.D. Tom Liu, M.D. Division of Plastic and Reconstructive Surgery Harbor–University of California, Los Angeles Medical Center David Geffen School of Medicine at University of California, Los Angeles Los Angeles, Calif.

A split and conjoined median nerve in the forearm

We observed a variation of the median nerve that split into two divisions in the proximal forearm and conjoined into a single cord in the distal forearm before entering the carpal tunnel. The medial division was larger than the lateral division. An aberrant muscular slip from the flexor digitorum superficialis ran over the medial division of the split median nerve. The muscular slip over the medial division might have caused an entrapment syndrome of this nerve due to several muscular and cutaneous branches originating from the medial division. This variation of the median nerve has not been reported to our knowledge and may affect diagnosis and treatment of any neuropathy of the median nerve.

Morphological study of the communication between the musculocutaneous and median nerves

We investigated the incidence of each pattern of the communications between the musculocutaneous and median nerves and discussed its morphological significance. The communications between both nerves were seen in 188 (41.5%) of 453 specimens. They were classified into five regular patterns according to their directions and formations. The incidence of the communication was significantly higher in those with excessive heads of biceps brachii than in those without them (p < 0.05). As a result, we established a classification of the regular pattern of the communications and revealed that the musculocutaneous and median nerves had the possibility of forming plexuses in the humeral area. The musculocutaneous nerves are regarded as the bundles that arise from the median nerve with the lateral cutaneous nerve of forearm and the branches to the biceps brachii and brachialis muscles.

Anomalous Palmar Cutaneous Branch of the Median Nerve in the Distal Forearm: Case Report

Variations exist in the anatomy of the palmar cutaneous branch of the median nerve about the wrist. We report an anatomic variation in the course of the palmar cutaneous branch of the median nerve identified in a 17-year-old girl undergoing surgery for a scaphoid nonunion. Instead of coursing ulnar to the flexor carpi radialis tendon, deep to the antebrachial fascia between the tendons of the flexor carpi radialis and palmaris longus, the palmar cutaneous branch of the median nerve was noted to cross volar to the distal aspect of the flexor carpi radialis to lie on its radial aspect. Knowledge of the anatomic variant described in this report should encourage surgeons to dissect carefully as they expose the flexor carpi radialis during the exposure of the distal radius or scaphoid.

Corticosteroid Injection for Carpal Tunnel Syndrome

N i T ticos ured b not c rnat ysio after v s h rand onths d up s uct ticos and s lini -week f ID a res and o ct t the s ded c t of c es w (inc el) w d s ysio mHE PATIENT 44-year-old right-handed man, a surgeon, has sy oms of numbness and tingling in his right th ndex, and middle fingers, and the radial half of hi nger, when operating and when driving a car. Sy oms are similar but less severe on the left sid escribes being awakened from sleep several time ight and having to shake his hand and wrist olding them dependant in order for the paresthesia ubside. He has tried intermittent neutral wrist sp pplication, as well as unscheduled nonsteroidal a nflammatory drugs (NSAIDs) without appreciable i rovement in his symptoms. On examination, it ound that he has diminished cervical spine rang otion, but he has no lower motor neuron signs pper extremity or upper motor neuron signs in ower extremity. He has a positive Tinel’s sign ove edian nerve at the carpal tunnel on the right a egative Tinel’s sign on the left. He has bila halen’s sign and negative symptom reproduction ompression or percussion of the median nerve in roximal forearm. His static 2-point discrimination m throughout, and he has normal palmar abduc trength on both sides. He has no visible muscle ng or fasciculations. He asks whether or not a co teroid injection would be helpful in terms of resolu f symptoms.

Additional Muscle Slip of Flexor Carpi Ulnaris Associated with Anomalous Ulnar Nerve and Ulnar Artery in the Distal Forearm

Durante una diseccion de rutina en clases para estudiantes de Medicina, se observo una anomalia del musculo flexor ulnar del carpo asociado con una variacion del nervio y arteria ulnar, en la parte distal del antebrazo. Un vientre adicional derivado de la parte inferior del musculo flexor ulnar del carpo cruzaba el nervio ulnar y vasos ulnares, nervio mediano y terminaba en una amplia aponeurosis la cual cruzaba los tendones del musculo flexor superficial de los dedos y se fusionaba con la fascia profunda y el retinaculo flexor. El nervio ulnar y la arteria ulnar se dividian en sus ramas terminales, en la parte inferior del antebrazo. Sin embargo, la distribucion de las ramas terminales tanto del nervio ulnar como de la arteria ulnar eran normales. La comprension de estos inusuales hallazgos pueden ser clinicamente relevantes para describir el compartimiento anterior del antebrazo.

Posteromedial dislocation of the elbow in a child with lateral condyle fracture: Case report with review of literature

Dislocation of the elbow is a rare injury in children with a reported incidence of 3-6 percent of all elbow injuries1,2,3. Posteromedial dislocation is reported to be even rarer with only three reports so far. The dislocations are associated with various associated fractures, the medial epicondyle fracture being the commonest. There are reports of lateral condyle fracture associated with posteromedial dislocation1,2,3. Our case was associated with fracture of both bones of the distal forearm and radial nerve palsy which has not been reported previously. The child with posteromedial dislocation with lateral condyle fracture was treated with open reduction of the lateral condyle. The patient had excellent recovery of elbow function. A case of posteromedial dislocation of the elbow with associated lateral condyle fracture and both bones distal forearm fracture are reported due to its rarity. Keywords : Dislocation of elbow, Lateral condyle fracture, forearm fracture Nigerian Journal of Orthopaedics and Trauma Vol. 7 (1) 2008 pp. 29-30

Accessory brachialis muscle: A case report

Variations of arm flexors are not uncommon with the exception of brachialis muscle. The role of brachialis is critical as it is the primary flexor of the elbow joint. Variations of brachialis are rare in literature. We present a case of an accessory-brachialis muscle (AcBr), found during routine cadaveric dissection. The AcBr originated from the lateral aspect of the brachialis muscle and lateral intermuscular septum. During its course towards the elbow, it crossed over the radial nerve and the distal tendon splits into two. The medial slip ran over the ulnar artery and merged with the deep fascia covering the pronator teres muscle, whereas lateral slip was inserted to the fascia covering the supinator. In the ipsilateral arm, an additional lateral cutaneous nerve of forearm (LCNF) was found coursing over the brachialis muscle medial to the LCNF. Clinical consideration of the present variations has been discussed. The present variation should be considered in the etiology of radial-tunnel syndrome (RTS).

Late treatment and functional reconstruction for injuries of forearm nerves and tendons

目的 总结前臂掌侧神经、肌腱损伤的晚期治疗与手功能重建的方法 及疗效.方法 对56例前臂掌侧神经、肌腱损伤术后的晚期患者,采用肌腱、神经松解,蚓状肌和拇对掌功能重建等方法 进行修复.结果 术后56例获得3～10个月(平均6个月)的随访,其中肌腱松解优良率为90%,蚓状肌功能重建优良率为88%,拇对掌功能重建优良率为90%.结论 前臂掌侧血管、神经、肌腱损伤术后,依据不同的情况采用不同的方法 进行重建,可以取得满意的临床效果。

5. The real role of forearm mixed nerve conduction study for the assessment of retrograde axonal atrophy in carpal tunnel syndrome

5. The real role of forearm mixed nerve conduction study for the assessment of retrograde axonal atrophy in carpal tunnel syndrome

Effect of Low Dose Electrocautery Usage during Radial Artery Harvesting on the Neurological Outcome of the Forearm: A Neuroelectrophysiological Study

The present study aimed to investigate whether electrocautery caused any thermal injury to the forearm nerves or not. We compared the neurological outcome of two different radial artery harvesting techniques through neuroelectrophysiological studies. Preoperative values and postoperative conduction changes after one month were compared in two groups of patients. Each of the groups consisted of 20 patients. Radial arteries were harvested using scissors in Group 1 and with a low dose diathermy technique in Group 2. The mean amplitude of sensory action potentials of radial nerves was significantly reduced postoperatively at the end of the first month in both groups (P = 0.01, P = 0.001). But there were no significant differences between groups with respect to the sensory action potentials of ulnar and median nerves postoperatively. There were no significant differences between groups with respect to radial, ulnar and median nerve motor conduction recordings. Low dose electrocautery does not cause excessive nerve injury compared with the scissors technique in radial artery harvesting. Electrocautery may be used safely for RA harvesting in the forearm.

Application of nerve action potential (NAP) of ulnar nerve in the forearm in diagonosis of mild cubital tunnel syndrome

目的 寻求诊断肘管综合征的最敏感的电生理指标.方法 2005年10月-2006年3月,对32例轻度肘管综合征的患者进行系统的电生理检测,并对数据进行分析.结果 32例中肘段尺神经运动传导速度(MNCV)减低阳性率占50%,小指-腕感觉传导速度(SNCV)减慢及感觉电位波幅(AMP)降低的阳性率占40.6%,前臂尺神经干动作电位(NAP)波幅降低的阳性率占87.5%,肘段尺神经短段微移测定(SSCT)异常占59.4%,肌电图检测(EMG)阳性率占3.1%.结论 前臂段(腕-肘)的尺神经NAP波幅较健侧下降＞50%,是诊断早期肘管综合征较敏感的电生理指标之一。

Median to radial nerve transfer for treatment of radial nerve palsy

The purpose of this study is to report a surgical technique of nerve transfer to restore radial nerve function after a complete palsy due to a proximal injury to the radial nerve. The authors report the case of a patient who underwent direct nerve transfer of redundant or expendable motor branches of the median nerve in the proximal forearm to the extensor carpi radialis brevis and the posterior interosseous branches of the radial nerve. Assessment included degree of recovery of wrist and finger extension, and median nerve function including pinch and grip strength. Clinical evidence of reinnervation was noted at 6 months postoperatively. The follow-up period was 18 months. Recovery of finger and wrist extension was almost complete with Grade 4/5 strength. Pinch and grip strength were improved postoperatively. No motor or sensory deficits related to the median nerve were noted, and the patient is very satisfied with her degree of functional restoration. Transfer of redundant synergistic motor branches of the median nerve can successfully reinnervate the finger and wrist extensor muscles to restore radial nerve function. This median to radial nerve transfer offers an alternative to nerve repair, graft, or tendon transfer for the treatment of radial nerve palsy.

Anatomic characteristics of a fascia and its bands overlying the ulnar nerve in the proximal forearm: a cadaver study

This study describes the characteristics of a fascia overlying the ulnar nerve for 10 cm distal to the midpoint of the retrocondylar groove. A total of 28 cadaver upper extremities were dissected. The ulnar nerve between the flexor carpi ulnaris and flexor digitorum profundus was traced distally underneath a thin fascia. The length of the fascia was measured and examined for the presence of segmental fascial thickenings, referred to as 'Bands'. Two types of fascia were found. In Type I, three Bands were identified within the fascia and the mean length of the fascia was 5.6 cm. In Type II, four Bands were identified and the mean length of the fascia was 7.7 cm. The presence of Bands within the fascia overlying the ulnar nerve in the proximal forearm may require release at the time of decompression, or anterior transposition, of the ulnar nerve at the cubital tunnel.

The effect of transcutaneous electrical nerve stimulation on local and distal cutaneous blood flow following a prolonged heat stimulus in healthy subjects

The aim of this study was to investigate the effects of transcutaneous electrical nerve stimulation (TENS) on blood flow and skin temperature following an elevation of baseline blood flow using infrared preheating. A randomized controlled approach was used whereby 66 healthy human subjects (33 male, 33 female) were allocated to one of three intervention groups (n=22 per group, equal male and female): Control, Low frequency TENS (4 Hz/200 micros), or High frequency TENS (110 Hz/200 micros). TENS was applied just below motor threshold over the median nerve of the right forearm for 15 min immediately following an infrared preheating. Cutaneous blood flow and skin temperature were recorded at 3-min intervals from the forearm and fingertips during TENS and for 15 min following TENS. Analysis of data revealed no significant differences between High and Low frequency TENS for cutaneous blood flow or skin temperature at the forearm. A small and short lived increase in cutaneous blood flow at the index finger was observed on TENS groups compared with control when TENS was switched off. TENS reduced skin temperature when compared to control during the first 9 min of the 15-min stimulation period at the middle finger but not at the index finger. It was concluded that the effects of high and low frequency TENS when applied below motor threshold produced changes in blood flow and skin temperature that were transient and small.

Anatomical Course of the Superficial Branch of the Radial Nerve and Clinical Significance for Surgical Approaches in the Distal Forearm.

10 embalmed cadaver forearms and wrists were dissected to determine the anatomical course of the superficial branch of the radial nerve in the distal forearm. The superficial radial nerve bifurcated in two branches at a mean of 54,7 mm proximal to the radial styloid. From the styloid process of the radius, the mean distance to the closest dorsal branch of the superficial radial nerve was 3,5 mm and the mean distance to the closest volar branch was 9,8 mm. The mean distance between the closest branch of the superficial radial nerve and Lister?s tubercle was 16,4 mm. The crossing point between the nerve and the cephalic vein was located at a mean of 54,3 mm proximal to the styloid process. At the level of styloid process the mean distance between the closest dorsal branch of the superficial radial nerve and the first dorsal compartment was 15,2 mm and between the closest volar branch and the first dorsal compartment 4,4 mm. Detailed knowledge of anatomic characteristics of the superficial branch of the radial nerve may help prevent injury during operations and treat traumatic lesions of the nerve. Because of great variations in the course of the superficial radial nerve we could not define an absolute safe zone for surgical procedures on the distal forearm. Iatrogenic lesions of the superficial radial nerve are described complications of percutaneous procedures. Therefore open surgical approaches are recommended.