Anatomical feasibility of the anterior obturator nerve transfer to restore bowel and bladder function

Total sacrectomies are radical procedures required to treat tumorigenic processes involving the sacrum. The purpose of our anatomical study was to assess the feasibility of a novel nerve transfer involving the anterior obturator nerve to the pudendal and pelvic nerves to the rectum and bladder. Anterior dissection of the obturator nerve was performed in eight hemipelvis cadaver specimens. The common obturator nerve branched into the anterior and posterior at the level of the obturator foramen. The anterior branch then divided into two separate branches (adductor longus and gracilis). The branch to the gracilis was on average longer and also larger than the branch to the adductor longus (8.7 ± 2.1 cm vs. 6.7 ± 2.6 cm in length and 2.6 ± 0.2 mm vs 1.8 ± 0.4 mm in diameter). Each branch of the anterior obturator was long enough to reach the pelvic nerves. The novel transfer of the anterior branch of the obturator nerve to reinnervate the bladder and bowel is anatomically feasible. This represents a promising option with minimal donor site deficit. © 2014 Wiley Periodicals, Inc. Microsurgery 34:459–463, 2014.     

Ultrasound anatomy of the radial nerve in the distal upper arm

BACKGROUND AND OBJECTIVES: We aimed to describe the ultrasound appearance of the radial nerve in the lateral aspect of the distal upper arm. This procedure was done to identify potential novel sites for ultrasound-guided radial-nerve block. METHODS: We scanned the lateral aspect of the distal upper arm in both arms of 50 healthy adult volunteers (equal gender distribution), using a 38 mm, 5 to 10 MHz, linear ultrasound probe (SonoSite MicroMaxx, Hitchen, UK). Three points were defined: A, midway between the anterior process of the acromion and lateral epicondyle of the humerus; B, one third of the distance between A and the lateral epicondyle; C, two thirds of the distance between A and the lateral epicondyle. Subjects' arms were scanned between A and C. We measured the maximal transverse (parallel to skin) and anteroposterior (perpendicular to skin) diameters of the radial nerve and calculated its cross-sectional area. Depth of the radial nerve from the skin surface was measured, and its shape and appearance were noted. RESULTS: At point B, the radial nerve lay in the spiral groove of the humerus, closely associated with the profunda brachii artery and vein. At point C, the nerve had passed through the lateral intermuscular septum and lay between brachioradialis and brachialis muscles. In 99% of arms, the radial nerve was not visible at point A, but became visible between points A and B in 93% of arms. The depth at point B was significantly less than at point C (mean +/- SD: 1.21 +/- 0.35 vs. 1.71 +/- 0.35 cm; P < .001). The measured depth of the nerve was positively correlated (P < .001) with body mass index and with arm circumference, but not with gender. The radial nerve was oval-shaped at both sites, with a cross-sectional area of 3.1 +/- 0.7 mm(2) at point B and 2.9 +/- 0.7 mm(2) at point C. CONCLUSIONS: Points B and C may represent convenient, novel sites for ultrasound-guided radial-nerve block. The nerve is clearly visualized and has not yet divided into superficial and deep branches. Point C may be the optimal site for radial-nerve block because of the smaller risk of vessel puncture. Our observations also demonstrate the ability of ultrasound to identify nerves at sites not clearly defined by surface anatomic landmarks.     

Anatomic relationship of the cervical nerves to the lateral masses

Eight cervical specimens were transversely sectioned with slices approximately 2 mm to 3 mm in thickness to evaluate the anatomic relationship of the spinal nerves to the lateral masses. Results showed that the spinal nerve either does not appear or, when it does, is situated anteromedially to the superior facet on the cross sections through the upper portion of the superior facet. The anterolateral aspect of the superior facet is free from the spinal nerve. Cross sections through the lower pedicle of the vertebra showed that the spinal nerve rested on the transverse process anterolateral to the lateral mass. The mean distances between the posterior midline of the lateral mass and the posterior border of the spinal nerve measured 15 degrees in the lateral direction were 16.1+/-1.7 mm for C3, 16.5+/-1.8 mm for CA, 16.8+/-1.2 mm for C5, 16.3+/-2.0 mm for C6, and 8.5+/-0.9 mm for C7. This study suggests that the anterolateral corner of the superior facet and the anterior aspect of the lateral mass lateral to the origin of the transverse process would be safer zones for screw exit. Attention should therefore be paid to the screw orientation for the Magerl technique and to the screw length for the Roy-Camille technique. Care should be taken to insert the screw into the C7 lateral mass.     

Radial and axillary nerves. Anatomic considerations for humeral fixation

Because the axillary and radial nerves can be injured during operative exposure and fixation of the humerus, accurate delineation of their location is vital to avoid complications. The authors investigated the relationship of the radial and axillary nerves for radiographically and surgically identifiable bony landmarks. Fifty fresh human cadaveric upper extremities were dissected to identify the nerves as they crossed the lateral intermuscular septum and the humeral surgical neck, respectively. Longitudinal distances between the nerves and the superior aspect of the humeral head, the surgical neck, the superior extent of the olecranon fossa, and the distal aspect of the trochlea were measured with calipers. The average distance from the axillary nerve to the proximal humerus was 6.1 +/- 0.7 cm (range, 4.5-6.9 cm) and 1.7 +/- 0.8 cm (range, 0.7-4.0 cm) from the surgical neck. The radial nerve traversed the lateral intermuscular septum 17 +/- 2.3 cm (range, 13-22 cm) from the proximal humerus, 12 +/- 2.3 cm (range, 7.4-16.6 cm) from the olecranon fossa, and 16 +/- 0.4 cm (range, 9.0-20.5 cm) from the distal humerus, representing the approximate midpoint of the bone. Anteroposterior locking screws placed into the proximal humerus endanger the axillary nerve because it lies directly over the posterior cortex as little as 0.7 cm from the surgical neck. As the radial nerve crosses the lateral intermuscular septum more proximal than generally was thought, it is at risk during implant insertion in the distal half of the humerus. Using measurements calculated from preoperative and intraoperative imaging, the approximate position of the nerve could be determined to better plan fixation method and implant location.     

The radial nerve in the brachium: an anatomic study in human cadavers

PURPOSE: To explore the course of the radial nerve in the brachium and to identify practical anatomic landmarks that can be used to avoid iatrogenic injury during humerus fracture fixation. METHODS: Data were collected from 27 adult cadaveric specimens, including 18 embalmed cadavers and 9 fresh-frozen limbs. Measurements were taken using osseous landmarks to define the relationship of the radial nerve and the posterior and lateral humerus. The extremities were studied further to determine the association of the radial nerve and anatomic landmarks on both longitudinal and cross-sectioned specimens. RESULTS: A 6.3 cm +/- 1.7 segment of radial nerve was found to be in direct contact with the posterior humerus from 17.1 cm +/- 1.6 to 10.9 cm +/- 1.5 proximal to the central aspect of the lateral epicondyle, centered within 0.1 cm +/- 0.2 of the level of the most distal aspect of the deltoid tuberosity. The radial nerve lay in direct contact with the periosteum in all specimens, without evidence of a structural groove in the humerus in any specimen. On entering the anterior compartment, the radial nerve had very little mobility as it was interposed between the obliquely oriented lateral intermuscular septum and the lateral aspect of the humerus. As it extended distally, the nerve coursed anterior to the humerus and became protected by brachialis muscle at the level of the proximal aspect of the lateral metaphyseal flare. CONCLUSIONS: The radial nerve is at risk of injury with fractures of the humerus and with subsequent operative fixation in 2 areas. The first is along the posterior midshaft region for a distance of 6.3 cm +/- 1.7 centered at the distal aspect of the deltoid tuberosity. The second is along the lateral aspect of the humerus in its distal third from 10.9 cm +/- 1.5 proximal to the lateral epicondyle to the level of the proximal aspect of the metaphyseal flare. The deltoid tuberosity is a consistent and practical anatomic landmark that can be used to determine the level of the radial nerve along the posterior aspect of the humerus during operative fixation from an anterior approach.     

Magnetic resonance imaging of the distribution of local anesthetic during the three-in-one block

The three-in-one technique of simultaneously blocking the femoral, the lateral femoral cutaneous (LFC), and the obturator nerves by a single injection of a local anesthetic was first described in 1973, and it was suggested that the underlying mechanism was one of cephalad spread resulting in a blockade of the lumbar plexus. Today, the technique is widely used in surgery and pain management of the lower limb. Many investigators have, however, reported suboptimal analgesia levels, particularly in the obturator nerve. The purpose of this prospective study was to trace the distribution of a local anesthetic during a three-in-one block by means of magnetic resonance imaging (MRI). Seven patients scheduled for surgery of the lower limb were analyzed with the aid of a primary MRI and then received three-in-one blocks using 30 mL of bupivacaine 0.5% under the guidance of a nerve stimulator. A secondary MRI was performed to determine the distribution pattern of the local anesthetic. It emerged that the local anesthetic blocks the femoral nerve directly, the LFC nerve through lateral spread, and the anterior branch of the obturator nerve by slightly spreading in a medial direction. No involvement of the proximal and posterior portions of the obturator nerve was observed, nor was there any cephalad spread that could have resulted in a lumbar plexus blockade. We therefore conclude that the basis of the three-in-one block is confined to lateral, medial, and caudal spread of the local anesthetic, which effectively blocks the femoral and LFC nerves, as well as the distal anterior branch of the obturator nerve. IMPLICATIONS: We demonstrate by using magnetic resonance imaging that the mechanism of a three-in-one block is one of lateral, caudal, and slight medial spread of a local anesthetic with subsequent blockade of the femoral, the lateral femoral cutaneous, and the anterior branch of the obturator nerves. It does not involve cephalad spread of the local anesthetic with blockade of the lumbar plexus.     

逆行腓肠神经营养血管岛状皮瓣感觉重建的解剖研究

目的研究应用股后皮神经主干重建逆行腓肠神经营养血管岛状皮瓣感觉功能的解剖学依据. 方法 30只成人尸体下肢标本,4%甲醛固定,手术放大镜下解剖股后皮神经主干于小腿后部的分布、分支及其与小隐静脉的关系,记录直径0.1 mm以上的神经分支,测量其长度及直径. 结果在小腿后窝处,股后皮神经主干下行进入浅筋膜,与小隐静脉伴行,70%位于小隐静脉内侧,30%位于小隐静脉外侧.股后皮神经主干全程有营养血管伴行.根据神经的分布范围,将股后皮神经分为3型:Ⅰ型,分布于小腿后部上1/4,占33.3%,神经干于窝中点直径为0.5±0.1 mm;Ⅱ型,分布于小腿后部上1/2,占43.3%,神经主干于窝中点的直径为1.0±0.4 mm,在小腿后部中上段(即:逆行腓肠神经营养血管岛状皮瓣的常用供区)发出分支2.0±0.8支,分支直径0.3±0.2 mm,分支长度3.5±2.7 mm,分支末端与小隐静脉之间的距离为0.8±0.6 mm;Ⅲ型,分布于小腿后部上3/4,占23.3%,神经主干于窝中点的直径为1.2±0.3 mm,在小腿后部中上段发出3.7±1.7支分支,分支直径0.4±0.1 mm,分支长度3.7±2.6 mm,分支末端与小隐静脉之间的距离为0.8±0.4 mm.在小腿后部中上段,未发现腓肠内侧皮神经发出分支进入浅筋膜. 结论通过股后皮神经主干与受区感觉神经分支吻合,股后皮神经(66.6%,Ⅱ型与Ⅲ型)可以用于重建逆行腓肠神经营养血管岛状皮瓣的感觉功能.     

Cutaneous Nerves at Risk During the Posterior Midline Approach to the Elbow

The purpose of this study was to investigate the cutaneous nerves at risk during the posterior midline approach to the elbow and proximal ulna. Ten fresh frozen cadaver upper extremities were used for this study. A posterior midline skin incision extending from 10 cm proximal to 15 cm distal to the olecranon tip was created. All superficial nerves were identified and preserved. Nerve diameters were measured, their distance from the olecranon tip assessed, and they were dissected proximally to confirm their nerve of origin. Point of nerve arborization to skin from the midline incision was quantified. An average of one confirmed nerve proximal and five distal to the olecranon tip were identified with an average diameter of 0.9 mm proximal and 1.3 mm distal to the olecranon. The largest nerves were typically located 2 cm proximal (range 7–46 mm) and 45 mm distal (range 9–135 mm) to the olecranon. The branches arborized into the skin an average of 5.2 mm lateral to the incision. All nerves joined the posterior medial antebrachial cutaneous nerve. The branches of the medial antebrachial cutaneous nerve are at risk with a straight posterior midline elbow incision, though the clinical significance of injury to these nerves at this location is unknown.     

Extent of blockade with various approaches to the lumbar plexus

The extent of blockade when four different techniques were used for blocking the lumbar plexus was prospectively evaluated in 80 adult patients. The extent of blockade was measured by testing motor function of all nerves except the lateral and posterior femoral cutaneous nerves, which were evaluated by pinprick response. The posterior approaches of Dekrey at L3 (n = 20) and Chayen at L4-5 (n = 20) proved similarly effective in producing blockade of the femoral, obturator, and lateral femoral cutaneous nerves, as well as the nerves to the psoas muscle. The anterior approach of Winnie (femoral sheath or 3-in-1 block) using paresthesia (n = 20) or peripheral nerve stimulation (n = 20) proved effective in producing blockade of the femoral and lateral femoral cutaneous nerves, but ineffective for obturator nerve blockade. None of the four techniques produced blockade of the sacral plexus. Perhaps our means of assessing blockade (motor) is what produced the difference between our findings and those of others.     

Brachial plexus anatomy

The brachial plexus may be visualized simply as beginning with five nerves and terminating in five nerves. It begins with the anterior rami of C5, C6, C7, C8, and the first thoracic nerve. It terminates with the formation of the musculocutaneous, median, ulnar, axillary, and radial nerves. The intermediate portions are displayed in sets of threes: three trunks are formed, followed by three divisions, then three cords. Each trunk gives rise to two divisions and each cord gives rise to two branches. The lateral cord divides into the musculocutaneous nerve and the lateral branch of the median nerve. The medial cord divides into the medial branch of the median nerve and the ulnar nerve. The posterior cord divides into the axillary and the radial nerves. The anatomy of the brachial plexus can be confusing, especially because of frequent variations in length and caliber of each of its components.     

带肋间神经外侧前支脐旁感觉皮瓣的应用解剖

目的为形成带感觉神经的脐旁游离皮瓣提供解剖学基础。方法在２０具４０侧成人躯干标本上,观测了下位肋间神经外侧前支与腹壁下血管形态、分支及分布规律。结果腹壁下动脉起点外径为（２．３±０．３）ｍｍ,伴行静脉（３．６±０．４）ｍｍ。下位肋间神经外侧前支在腋前线前后１～２ｃｍ相应肋间穿出,神经在锁骨中线附近浅出皮下。第８～１０肋间神经外侧前支浅出皮下在脐上０～７ｃｍ范围内,恰好支配脐旁皮瓣设计的范围。结论可设计以腹壁下血管带第８～１０肋间神经外侧前支的脐旁感觉皮瓣。     

阴股沟皮瓣应用解剖学研究

目的明确阴股沟皮瓣的解剖学基础.方法对10具(20侧)成年女尸阴股沟区皮肤进行解剖学研究.结果阴股沟皮瓣存在多重血液供应;其中,闭孔动脉前皮支分布于皮瓣中部,浅出点距会阴正中线(3.0±0.5)cm,距阴道口前缘(1.7±0.4)cm距耻骨下支外侧缘(0.6±0.2)cm,管径(0.8±0.1)mm;阴唇后动脉主要供应大阴唇,并恒定地以本干的形式在大阴唇皮下与阴部外浅动脉形成血管吻合,在阴道口后缘前后各1.5cm的范围内,发出2、3支阴唇后动脉外侧支,外径为(0.7±0.3)mm,分布于阴股沟皮瓣后部;阴部外浅动脉斜形穿过皮瓣上端走向大阴唇,沿途发出柳枝状血管分支分布于皮瓣上端.结论阴股沟皮瓣阴道再造所利用的血管是阴唇后动脉外侧支,而非阴唇后动脉主干;由于闭孔动脉前皮支浅出点位置较高而且固定,以之为蒂形成的皮瓣不适用于阴道再造,而适合于会阴部较小皮肤缺损的修复.     

The anatomy of the posterior interosseous nerve as a graft

Thirty upper limbs from skeletally mature embalmed cadavers were studied to determine the anatomic reliability of the posterior interosseous nerve as a donor nerve graft. The posterior interosseous nerve branches 0.43 +/- 0.52 cm from the distal edge of the superficial head of the supinator and 8 +/- 1.6 cm from the lateral epicondyle form a common leash. There are 6 branches, which are arranged from the ulnar to the radial side at their origin from this leash. The first and second branches supply the extensor digitorum communis, the third branch supplies the extensor carpi ulnaris, the fourth branch supplies the extensor digiti minimi, and the fifth branch arises from the undersurface of the common leash and divides into 2 sub-branches (medial and lateral) 10.1 +/- 3.2 cm distal to the lateral epicondyle and 12.8 +/- 2.2 cm proximal to Lister's tubercle. These 2 sub-branches make an inverted V shape around the extensor pollicis longus. The medial branch supplies the extensor pollicis longus and extensor indicis proprius. The lateral branch supplies the extensor pollicis longus and extensor pollicis brevis and ends at the wrist capsule. At a mean distance of 8.1 +/- 1.2 cm proximal to Lister's tubercle the lateral sub-branch gives off its last muscular branch to the extensor pollicis longus and becomes a pure sensory terminus. As the terminal part of the lateral sub-branch approaches the wrist capsule it expands at a mean distance of 1.9 +/- 0.5 cm proximal to Lister's tubercle. The sixth branch arises from the radial side of the common leash and divides into 3 sub-branches. The first sub-branch supplies the abductor pollicis longus and extensor pollicis brevis, the second supplies the abductor pollicis longus, and the third supplies the superficial head of the supinator. This study showed that the mean length obtainable for harvesting the lateral sub-branch of the fifth branch of the posterior interosseous nerve is 6.2 +/- 0.7 cm, which represents the length of the nerve between the last muscular branch to the extensor pollicis longus to the point at which the nerve expands.     

Effects of using the posterior or anterior approaches to the lumbar plexus on the minimum effective anesthetic concentration (MEAC) of mepivacaine required to block the femoral nerve: a prospective, randomized, up-and-down study

BACKGROUND AND OBJECTIVES: To evaluate if psoas compartment block requires a larger concentration of mepivacaine to block the femoral nerve than does an anterior 3-in-1 femoral nerve block. METHODS: Forty eight patients undergoing anterior cruciate ligament repair were randomly allocated to receive an anterior 3-in-1 femoral block (femoral group, n = 24) or a posterior psoas compartment block (psoas group, n = 24) with 30 mL of mepivacaine. The concentration of the injected solution was varied for consecutive patients using an up-and-down staircase method (initial concentration: 1%; up-and-down steps: 0.1%). RESULTS: The minimum effective anesthetic concentration of mepivacaine blocking the femoral nerve in 50% of cases (ED(50)) was 1.06% +/- 0.31% (95% confidence interval [CI], 0.45%-1.68%) in the femoral group and 1.03% +/- 0.21% (95% CI, 0.6%-1.45%) in the psoas group (P = .83). The lateral femoral cutaneous and obturator nerves were blocked in 4 (16%) and 5 (20%) femoral group patients as compared with 20 (83%) and 19 (80%) psoas group patients (P = .005 and P = .0005, respectively). Intraoperative analgesic supplementation was required by 15 (60%) and 5 (20%) patients in the femoral and psoas groups, respectively (P = .01). CONCLUSIONS: Using a posterior psoas compartment approach to the lumbar plexus does not increase the minimum effective anesthetic concentration of mepivacaine required to block the femoral nerve as compared with the anterior 3-in-1 approach, and provides better quality of intraoperative anesthesia due to the more reliable block of the lateral femoral cutaneous and obturator nerves.     

Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results

Because both the saphenous nerve and in part the obturator nerve are traversing the adductor canal of the thigh, we hypothesised that repeated administration of a local anaesthetic (LA) into this aponeurotic space could be a useful option for post-operative analgesia after knee replacement surgery. A systematic search of the literature pertinent to the blockade of the saphenous and/or obturator nerves for pain relief after knee surgery was conducted. Further, pain and opioid requirements were evaluated in eight patients receiving a continuous blockade of the saphenous and obturator nerve (adductor-canal-blockade) after total knee arthroplasty (TKA). Finally, we performed cross-sectional MR scans of the adductor canal after injection of ropivacaine 30ml in one patient. The systematic literature search revealed only one controlled study, where selective blockade of the saphenous nerve was investigated for the purpose of clinical pain relief after knee arthroscopy. We located no studies reporting on saphenous and/or obturator nerve block for pain relief after TKA. Preliminary findings in eight patients demonstrated that a continuous adductor-canal-blockade for 48h after TKA was associated with low mean pain scores at rest and low mean requirements for supplemental morphine. MR scans in one patient demonstrated that 30ml of LA filled the adductor canal, including the distal part, where the posterior branch of the obturator nerve joins the vessels and the saphenous nerve. Continuous adductor-canal-blockade may be a valuable adjunct for post-operative analgesia after major knee surgery. These preliminary results should be confirmed in randomised, controlled trials.     

新型微创前置肱骨中下段解剖锁定钢板的设计及相关解剖研究

目的 探讨应用自行研制的3.5 mm新型前置肱骨中下段解剖锁定钢板微创治疗肱骨干中下段骨折的可行性和安全性.方法 新鲜冷冻成人上肢6具,分别于上臂前侧远近端做3 cm皮肤切口,通过肌下隧道插入钢板,经切口打入螺钉固定.原位解剖重要神经结构,观察其与钢板的关系,测量桡神经在不同位置与钢板外侧缘、钢板最远端内侧与正中神经、螺钉头部与桡神经沟处桡神经的距离.结果 新增前置肱骨中下段解剖锁定钢板远端的绝大部分被肱肌覆盖,其与桡神经、肌皮神经及正中神经之间隔有肱肌肌腹,钢板与桡神经之间分别在穿经外侧肌间隔以及冠状窝水平的距离平均分别为14.53 mm和8.38 mm,桡神经穿经外侧肌间隔至冠状窝上缘连线中点处的平均距离为8.39 mm;屈肘80°和伸肘0°位时钢板最远端内侧与正中神经的距离平均分别为11.89 mm和l0.53mm,由近向远的第3枚螺钉头部与桡神经沟近侧缘的距离平均为5.90 mm.结论 采用自行研制的新型前置解剖锁定钢板微创固定肱骨干中下段骨折理论上是可行且安全的.

Abstract：

Objective To verify the feasibility and safety of a self-designed anatomical anterior locking plate for minimally invasive treatment of mid-distal humeral fractures. Methods Six fresh-frozen cadaveric specimens of upper extremity were used for the present anatomic study.A 3 cm incision was made on the anterior side of the arm between the deltoid muscle and biceps muscle and another 3 cm incision was made along the lateral side of biceps muscle proximal to the cubital crease to expose the anterior cortex.The plate was inserted from the distal incision proximally and positioned on the anterior side of the humeral shaft.The biceps muscle and brachialis were dissected to expose the radial,musculocutaneous and median nerves in situ.Relationships between the plate and nerves were observed.The distances between the lateral border of the plate and the radial nerve were measured where the nerve pierced the lateral intermuscular septum and at the point above the coronoid fossa and at the middle of the above 2 points.The distances between the distal end of the plate and the median nerve were measured when the elbow was in 80° flexion and full extension.The distance between the head of the third proximal screw and the spiral groove was also measured. Results Most part of the plate was covered by the brachial muscle.There was no direct contract between the plate and the radial,musculocutaneous and median nerves,all separated by the muscle belly of the brachialis.The average distances between the lateral border of the plate and the radial nerve where the nerve pierced the lateral intermuscular septum and at the superior edge of the coronoid fossa and at the middle of the 2 points were 14.53 mm (range,13.1 to 17.1 mm),8.38 mm (range,4.2 to 11.3 mm) and 8.39 mm (range,0 to 13.9 mm) respectively.The average minimum distances between the medial border of the distal end of the plate and the median nerve when the elbow was in 80° flexion and full extension was 11.89 mm (range 9.6 to 15.5 mm) and 10.53 mm (range 9.0 to 12.1 mm) respectively.The average distance between the head of the third proximal screw and the spiral groove was 5.90 mm (range,4.2 to 7.1 mm). Conclusions Our novel anatomical anterior locking plate is theoretically safe for the minimally invasive treatment of mid-distal humeral fractures.     

Posterior interosseous nerve terminal branches

Thirty upper limbs from skeletally mature embalmed cadavers were studied to define the most common pattern of the terminal branches of the posterior interosseous nerve. At 0.43 +/- 0.52 cm from the distal edge of the superficial head of the supinator and 8 +/- 1.6 cm from the lateral epicondyle, the posterior interosseous nerve branches, forming a common leash. There were six branches, which were arranged from the ulnar to the radial side at their origin from the common leash. The first and second branches supplied the extensor digitorum communis, the third branch supplied the extensor carpi ulnaris, the fourth branch supplied the extensor digiti minimi, and the fifth branch arose from the undersurface of the common leash and divided into two branches (medial and lateral) at 10.1 +/- 3.2 cm distal to the lateral epicondyle and 12.8 +/- 2.2 cm proximal to Lister's tubercle. The medial branch supplied the extensor pollicis longus and extensor indicis proprius. The lateral branch supplied the extensor pollicis longus and extensor pollicis brevis and ended at the wrist capsule. The sixth branch arose from the radial side of the common leash and divided into three branches. The first branch supplied the abductor pollicis longus and extensor pollicis brevis. The second branch supplied the abductor pollicis longus. The third branch supplied the superficial head of the supinator. The authors of this study describe the most efficient way to identify the six branches and how to avoid the risk of damaging them during surgical exposure.     

健侧颈_7神经根移位直接修复对侧臂丛神经下干的动物实验模型

目的 建立健侧颈,神经根移位经颈前皮下直接缝合患侧下干的实验动物模型.方法 清洁级雄性SD大鼠20只,以右侧为健侧,左侧为患侧,将健侧的颈_7神经根前、后股经颈前皮下隧道直接与患侧的颈_8、胸_1神经根缝合.通过测量健侧颈7神经根至前后股远端的最大长度与前后股的直径和、颈,神经根前后股远端跨过(或未达到)颈前中线的长度、颈_8胸_1神经根近端跨过(或未达到)颈前中线的长度、颈_8胸_1神经根的直径和与缝合口的神经通过率来综合评价建立该模型的可行性.结果 健侧颈,神经根至前后股远端的最大长度平均为8.15mm,颈_7神经根前后股远端未达到颈前中线的长度平均为2.74mm,前后股的直径和平均为924.64μm,颈_8胸_1神经根近端跨过颈前中线的长度平均为3.88mm,颈_8胸_1神经根的直径和平均为1 296.38μm,上述二者可在颈前皮下直接缝合.缝合口的神经通过率平均为70.53%.结论 大鼠健侧颈,神经根移位经颈前皮下可直接与患侧下干缝合,术后有再生神经纤维通过.该模型有效、重复性好,为研究健侧颈,神经根经颈前皮下直接缝合对侧下干提供理想的动物模型.     

The anatomic features of the sural nerve with an emphasis on its clinical importance

BACKGROUND: The sural nerve is formed by the union of the medial and lateral cutaneous nerves of the leg that originate from the tibial and common peroneal nerves. Operative procedures and traumatic injuries to the popliteal fossa, leg, ankle and foot place the sural nerve and its branches at risk. The aim of this study was to describe the course, variations and some clinically significant relations of the sural nerve. METHODS: The sural nerve was dissected in 30 lower limbs (leg-ankle-foot) of 15 cadavers. The specimens were measured, drawn and photographed. RESULTS: In 18 specimens (60%) the sural nerve originated from the union of the medial and lateral cutaneous nerves of the leg in the upper two-thirds of the leg (classic type). The union of the medial and lateral cutaneous branches was in the distal third of the leg in three specimens (10%). The lateral cutaneous nerve was absent in five (16.7%), and the medial cutaneous nerve was absent in 2 (6.7%) specimens. In two specimens (6.7%) the nerves had separate courses. The mean distance between the most prominent part of the lateral malleolus and the sural nerve was 12.76 +/- 8.79 mm. The mean distance between the tip of the lateral malleolus and sural nerve was 13.15 +/- 6.88 mm. The most common distribution of the sural nerve in the foot was to the lateral side of the fifth toe (60%), followed by the lateral two and a half toes (26.7%). CONCLUSIONS: These described variations and measurements should be helpful for planning operative approaches that minimize the risk of sural nerve injury.     

The lumbosacral nerves in relation to dorsal S1 screw placement and their locations on plain radiographs

Seven adult cadaver lumbopelvises were harvested to study the anatomic relationship of the L4 and L5 nerves to S1 dorsal screw placement and the location of the L4, L5, and S1 nerves on plain radiographs. The mean lateral angle of S1 screw trajectory toward the L4 nerve was 31+/-8 degrees, and the mean screw trajectory length was 53+/-8 mm. The mean lateral angle of the screw trajectory toward the L5 nerve was 21+/-8 degrees, and the mean screw trajectory length was 38+/-4 mm. On both inlet and outlet radiographs, the lateral angle of the nerves increased from L4 to S1. The L4 nerve coursed over the middle third of the superior ala in the inlet view and the middle third of the lateral mass in the outlet view. The L5 nerve coursed over the inner third of the superior ala and inner third of the lateral mass. On the lateral view, the mean distances from the sacral promontory to the L4, L5, and S1 nerves along the anterior border of the sacrum were 4+/-7 mm, 12+/-5 mm, and 28+/-8 mm, respectively. This study suggests that S1 sacral screws be directed between 30 degrees and 40 degrees lateral to avoid compromising the lumbosacral trunk and sacroiliac joint.