Applied anatomy of the superficial branch of the radial nerve

Investigation of the dorsal cutaneous nerve injury risk and portal safety related to wrist surgery: an anatomical study

The aim of this study was to define the branching patterns and innervation regions of the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve and to evaluate the distance from 1-2, 3-4, 4-5, midcarpal radial, midcarpal ulnar, dorsal radioulnar joint, 6-radial, 6-ulnar dorsal arthroscopy portals to certain landmarks on the dorsal surface of the hand and wrist. Forty hands and wrists of 20 formalin-fixed intact cadavers without any known pathology, surgical scars or trauma were examined in the Macroscopy Laboratory of Ege University Faculty of Medicine, Department of Anatomy. Arthroscopy portals were placed using a dorsal approach to the wrist in the dissection method. In our study, the distances between the closest branch to the portal of the superficial branch of the radial nerve and the 1-2, 3-4, and midcarpal radial portals were 3.7 ± 2.0, 9.7 ± 3.8, and 8.0 ± 3.4 mm, respectively. And the distances between the closest branch to the portal of the dorsal branch of the ulnar nerve and the 4-5, 6-radial, 6-ulnar, and midcarpal ulnar portals were 18.3 ± 3.8, 7.1 ± 4.4, 2.5 ± 1.8, and 15.4 ± 4.4 mm, respectively. This study demonstrated that the results can guide surgeons in procedures such as the pin fixation of distal radius fractures, where surgeons may not always perform blunt dissection or expose nerves. The findings of the portal replacement would help any surgical procedure on the dorsal wrist be performed with caution.

[Pain around the first ray of the hand: differential diagnoses and treatment]

Pain around the first ray of the hand, particularly in the thumb area, is a frequent clinical problem that can have various causes. This article explores the most important differential diagnoses, including thumb carpometacarpal (CMC-I) osteoarthritis (rhizarthrosis), de Quervain's stenosing tenosynovitis, carpal tunnel syndrome and Wartenberg's syndrome. A detailed medical history, targeted clinical examination and if necessary the use of modern imaging techniques are crucial for making the diagnosis. The therapeutic approaches range from conservative measures to surgical interventions, depending on the severity and underlying cause of the disease. This article provides an overview of current diagnostic and treatment strategies.

Anatomic location of the first dorsal extensor compartment for surgical De-Quervain's tenosynovitis release: A cadaveric study

BACKGROUND

De-Quervain's tenosynovitis is a disorder arising from the compression and irritation of the first dorsal extensor compartment of the wrist. Patients who fail conservative treatment modalities are candidates for surgical release. However, risks with surgery include damage to the superficial radial nerve and an incomplete release due to inadequate dissection. Currently, there is a paucity of literature demonstrating the exact anatomic location of the first dorsal extensor compartment in reference to surface anatomy. Thus, this cadaveric study was performed to determine the exact location of the first extensor compartment and to devise a reliable surgical incision to prevent complications.

AIM

To describe the location of the first dorsal compartment in relation to bony surface landmarks to create replicable surgical incisions.

METHODS

Six cadaveric forearms, including four left and two right forearm specimens were dissected. Dissections were performed by a single fellowship trained upper extremity orthopaedic surgeon. Distance of the first dorsal compartment from landmarks such as Lister's tubercle, the wrist crease, and the radial styloid were calculated. Other variables studied included the presence of the superficial radial nerve overlying the first dorsal compartment, additional compartment sub-sheaths, number of abductor pollicis longus (APL) tendon slips, and the presence of a pseudo-retinaculum.

RESULTS

Distance from the radial most aspect of the wrist crease to the extensor retinaculum was 5.14 mm ± 0.80 mm. The distance from Lister's tubercle to the distal aspect of the extensor retinaculum was 13.37 mm ± 2.94 mm. Lister's tubercle to the start of the first dorsal compartment was 18.43 mm ± 2.01 mm. The radial styloid to the initial aspect of the extensor retinaculum measured 2.98 mm ± 0.99 mm. The retinaculum length longitudinally on average was 26.82 mm ± 3.34 mm. Four cadaveric forearms had separate extensor pollicis brevis compartments. The average number of APL tendon slips was three. A pseudo-retinaculum was present in four cadavers. Two cadavers had a superficial radial nerve that crossed over the first dorsal compartment and retinaculum proximally (7.03 mm and 13.36 mm).

CONCLUSION

An incision that measures 3 mm proximal from the radial styloid, 2 cm radial from Lister's tubercle, and 5 mm proximal from the radial wrist crease will safely place surgeons at the first dorsal compartment.

Clinical anatomy of the lateral antebrachial cutaneous nerve: Is there any safe zone for interventional approach?

INTRODUCTION

The lateral antebrachial cutaneous nerve (LACN) is a somatosensory nerve coursing in the lateral portion of the forearm. The nerve is located in a close proximity to the cephalic vein (CV) all along its course with a danger of being injured during venipuncture. The LACN also overlaps and communicates with the superficial branch of the radial nerve (SBRN) in the distal forearm and hand, making the awareness of their relationship of great importance in the treatment of neuroma. The aim of the study was to observe the relationship of the LACN to surrounding structures as well as its branching pattern and distribution.

MATERIALS AND METHODS

Ninety-three cadaveric forearms embalmed in formaldehyde were dissected. The relationship of the LACN to surrounding structures was noted and photographed, and distances between the structures were measured with a digital caliper. The cross-sectional relationships of the LACN and SBRN to the CV were described using heatmaps.

RESULTS

The emerging point of the LACN was found distally, proximally or at the level of the interepicondylar line (IEL). The LACN branched in 76 cases (81.7 %) into an anterior and posterior branch at mean distance of 47.8 ± 34.2 mm distal to the IEL. The sensory distribution was described according to the relationship of the LACN branches to the medial border of the brachioradialis muscle. The LACN supplying the dorsum of the hand was observed in 39.8 % of cases. The LACN and the SBRN intersected in 86 % of upper limbs with communications noticed in 71 % of forearms. The LACN was stated as the most frequent donor of the communicating branch resulting in neuroma located distal to the communication and being fed from the LACN. The relationship of the LACN and the CV showed that the IEL is the most appropriate place for the venipuncture due to maximal calibers of the CV and deep position of the LACN. The LACN was adjacent to the cubital perforating vein and the radial artery in all cases. The medial border of the brachioradialis muscle was observed less than 1.8 mm from the LACN.

CONCLUSION

The study provides morphological data on the LACN distribution, branching pattern and relationship to surrounding structures in a context of clinical use in different spheres of medicine. The branching pattern of the LACN appears to be more constant compared to data provided by previous authors. We emphasized the meaning of cross-sectional relationship of the LACN to the CV to avoid venipuncture outside the cubital fossa if possible. The posterior branch of the LACN was predicted as appropriate donor of the graft for a digital nerve. The LACN appeared to be in a close proximity within the whole length of the brachioradialis muscle what the orthopedic surgeons must be concerned of. The meaning of the donor-nerve of the communicating branch in neuroma treatment was also introduced.

Role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of peripheral nerves in the upper extremity

Upper extremity entrapment neuropathies are common conditions in which peripheral nerves are prone to injury at specific anatomical locations, particularly superficial regions or within fibro-osseous tunnels, resulting in pain and potential disability. Although neuropathy is primarily diagnosed clinically by physical examination and electrophysiology, imaging evaluation with ultrasound and magnetic resonance neurography are valuable complementary non-invasive and accurate tools for evaluation and can help define the site and cause of nerve dysfunction which ultimately leads to precise and timely treatment. Ultrasound, which has higher spatial resolution, can quickly and comfortably characterize the peripheral nerves in real time and can evaluate for denervation related muscle atrophy. Magnetic resonance imaging on the other hand provides excellent contrast resolution between the nerves and adjacent tissues, also between pathologic and normal segments of peripheral nerves. It can also assess the degree of muscle denervation and atrophy. As a prerequisite for nerve imaging, radiologists and sonographers should have a thorough knowledge of anatomy of the peripheral nerves and their superficial and deep branches, including variant anatomy, and the motor and sensory territories innervated by each nerve. The purpose of this illustrative article is to review the common neuropathy and nerve entrapment syndromes in the upper extremities focusing on ultrasound and magnetic resonance neurography imaging.

Comparison of pain levels of traditional radial, distal radial, and transfemoral coronary catheterization

OBJECTIVE

The aim of our study was to compare the traditional radial artery, distal radial artery, and transfemoral artery, which are vascular access sites for coronary angiography, in terms of pain level using the visual analog scale.

METHODS

Between April 2021 and May 2022, consecutive patients from three centers were included in our study. A total of 540 patients, 180 from each of the traditional radial artery, distal radial artery , and transfemoral artery groups, were included. The visual analog scale was applied to the patients as soon as they were taken to bed.

RESULTS

When the visual analog scale was compared between the groups, it was found to be significantly different (transfemoral artery: 2.7±1.6, traditional radial artery: 3.9±1.9, and distal radial artery: 4.9±2.1, respectively, p<0.001). When the patients were classified as mild, moderate, and severe based on the visual analog scale score, a significant difference was found between the groups in terms of body mass index, process time, access time, and number of punctures (p<0.001). Based on the receiver operating characteristic analysis, body mass index>29.8 kg/m2 predicted severe pain with 72.5% sensitivity and 73.2% specificity [(area under the curve: 0.770, 95%CI: 0.724-0.815, p<0.0001)].

CONCLUSION

In our study, we found that the femoral approach caused less access site pain and a high body mass index predicts severe pain.

An unreported innervation of the coracobrachialis longus by the radial nerve: a potential pitfall for clinicians

PURPOSE

The aim of the presented case is to describe an unprecedented innervation of the coracobrachialis longus muscle by the radial nerve.

METHODS

An 82-year-old body donor at death was subjected to a routine anatomical dissection for teaching and research purposes at the Department of Anatomical Dissection and Donation in Lodz, Poland.

RESULTS

We have found an additional branch of the radial nerve, which departed from it just below its beginning. Its initial section ran alongside the radial nerve in the axilla, then headed medially accompanying superior ulnar collateral artery. Then, it reaches the coracobrachialis longus muscle and is the only one to innervate it.

CONCLUSIONS

The brachial plexus (BP) is very variable and well understood. Nevertheless, we must remember that there may still be variations in its structure, which may involve problems at every stage of diagnosis and treatment of diseases associated with its structures. Their knowledge is extremely important.

The communication patterns between the lateral antebrachial cutaneous nerve and the superficial branch of the radial nerve

INTRODUCTION

The superficial branch of the radial nerve (SBRN) and the lateral antebrachial cutaneous nerve (LACN) are sensory nerves coursing within the forearm in a close relationship. This high degree of overlap and eventual communication between the nerves is of great surgical importance. The aim of our study is to identify the communication pattern and overlap of the nerves, to localize the position of this communication in relation to a bony landmark, and to specify the most common communication patterns.

MATERIALS

and methods: One hundred and two adult formalin-fixed cadaveric forearms from 51 cadavers of Central European origin were meticulously dissected. The SBRN, as well as the LACN, were identified. The morphometric parameters concerning these nerves, as well as their branches and connections, were measured with a digital caliper.

RESULTS

We have described the primary (PCB) and secondary communications (SCB) between the SBRN and the LACN and their overlap patterns. One hundred and nine PCBs were found in 75 (73.53%) forearms of 44 (86.27%) cadavers and fourteen SCBs in eleven hands (10.78%) of eight cadavers (15.69%). Anatomical and surgical classifications were created. Anatomically, the PCBs were classified in three different ways concerning: (1) the role of the branch of the SBRN within the connection; (2) the position of the communicating branch to the SBRN; and (3) the position of the LACN branch involved in the communication to the cephalic vein (CV). The mean length and width of the PCBs were 17.12mm (ranged from 2.33-82.96mm) and 0.73mm (ranged from 0.14-2.01mm), respectively. The PCB was located proximally to the styloid process of the radius at an average distance of 29.91mm (ranged from 4.15-97.61mm). Surgical classification is based on the localization of the PCBs to a triangular zone of the SBRN branching. The most frequent branch of the SBRN involved in the communication was the third (66.97%). Due to the frequency and position of the PCB with the third branch of the SBRN, the danger zone was predicted. According to the overlap between the SBRN and the LACN, we have divided 102 forearms into four types: (1) no overlap; (2) present overlap; (3) pseudo-overlap; and (4) both present and pseudo-overlap. Type 4 was the most common.

CONCLUSION

The patterns of communicating branch arrangements appeared to be not just a rare phenomenon or variation, but rather a common situation highlighting clinical importance. Due to the close relationship and connection of these nerves, there is a high probability of simultaneous lesion.

Radial nerve compression: anatomical perspective and clinical consequences

The radial nerve is the biggest branch of the posterior cord of the brachial plexus and one of its five terminal branches. Entrapment of the radial nerve at the elbow is the third most common compressive neuropathy of the upper limb after carpal tunnel and cubital tunnel syndromes. Because the incidence is relatively low and many agents can compress it along its whole course, entrapment of the radial nerve or its branches can pose a considerable clinical challenge. Several of these agents are related to normal or variant anatomy. The most common of the compressive neuropathies related to the radial nerve is the posterior interosseus nerve syndrome. Appropriate treatment requires familiarity with the anatomical traits influencing the presenting symptoms and the related prognoses. The aim of this study is to describe the compressive neuropathies of the radial nerve, emphasizing the anatomical perspective and highlighting the traps awaiting physicians evaluating these entrapments.

Anatomical Assessment of Cephalic Vein and Superficial Branch of Radial Nerve Using High-Resolution Ultrasound Imaging

Introduction  The superficial branch of the radial nerve (SBRN) has a risk of nerve injury during cephalic vein (CV) cannulation. Due to the lack of imaging study regarding SBRN and CV relationship, we analyzed the anatomical relationship between the SBRN and the CV using ultrasound (US) imaging. Materials and Methods  In total, 82 upper limbs of 41 healthy volunteers were analyzed. The SBRN and CV were identified at the following three points in the elbow extension and pronation position: at the radial styloid process (point 1), 5 cm proximal to point 1 (point 2), and 10 cm proximal to point 1 (point 3). Results  The distance between the SBRN and CV was 1.1 ± 1.0 mm at point 1, 1.3 ± 1.3 mm at point 2, and 2.1 ± 1.6 mm at point 3. The depth of the SBRN from the surface of the skin was 2.7 ± 0.9 mm at point 1, 3.5 ± 1.1 mm at point 2, and 5.5 ± 1.9 mm at point 3. The percentage of the SBRN that ran beneath the CV was 17.5%, 53.5%, and 92.4% at points 1, 2, and 3, respectively. Conclusion  Ultrasonography can reveal the anatomical relationship between the SBRN and CV.

Percutaneous Release of the First Extensor Tendon Compartment in De Quervain's Disease by Acupotomy with US-Guidance: A Cadaveric Study

Background

De Quervain's disease is a painful stenosing tenosynovitis of the first dorsal compartment of the hand affecting the tendons of the abductor pollicis longus and extensor pollicis brevis. This study aimed to evaluate the safety and efficacy of percutaneous first extensor compartment releases performed on embalmed cadaveric models by acupotomy operation with or without US guidance.

Methods

Percutaneous release was performed with an acupotomy on 59 wrists of cadavers; 23 wrists were operated with US guidance, and 39 wrists were operated without US guidance. Each arm was dissected and assessed regarding the amount of release as well as the extent of neurovascular and tendon injury. Anatomical structures were also observed in this study.

Results

Twenty cases (87%) were successfully released with ultrasound-assisted techniques, and 27 cases (75%) were successfully released with blind techniques. No neurovascular injury occurred in any arm, regardless of technique. No significant tendon injury was seen in any arm. Although minor surface scratches were visualized in 11 cases, they occurred in 3 cases (13.04%) with ultrasound assistance and in 8 cases (22.22%) with blind techniques. There was no statistically significant difference between the two groups in the measurement of the distance from the incision marks to the blood vessels and nerves. A fibrous septum and bony protrusions were found in the first dorsal compartment, which may be anatomical factors affecting the success of treatment.

Conclusion

Both traditional and US-guided percutaneous release by acupotomy of the first extensor tendon compartment can be performed for all wrists. US-guided techniques can improve the success rate and reduce damage during acupotomy operations.

An Analysis of the Structures at Risk from Percutaneous Pinning of Distal Radius Fractures and a Comparison of Two Pinning Techniques: A Cadaveric Study

Background: A stab incision and blunt dissection prior to wire placement are believed to decrease the risk of injury to underlying structures during percutaneous pinning of distal radius fractures (DRF). However, only a few studies have compared stab incision and blunt dissection to direct wire placement. The aim of this cadaveric study is to analyse the structures at risk during percutaneous pinning of DRF and compare the two methods of wire placement.

Methods: A total of 10 cadavers (20 upper limbs) were divided into two groups of five each. Five 2.0 mm Kirschner (K)-wires were inserted into the distal radius under fluoroscopic control in a standard fashion to simulate percutaneous pinning of DRF. In group 1, the K-wires were inserted directly, whereas in group 2, the wires were inserted after making a stab incision and blunt dissection to reach the bone. Each cadaveric limb was then dissected carefully to measure the distance of the K-wires from the branches of the superficial radial nerve (SRN), the cephalic vein and the first dorsal compartment and to determine the structures injured (pierced or in close contact) by the K-wires.

Results: Out of the 100 K-wires placed, 18 wires were in close contact or pierced an underlying structure. These included 11 wires injuring tendons, six wires injuring branches of the SRN and one wire injuring the cephalic vein. Direct wire placement (group 1) resulted in injury to eight structures (44.4%) while stab incision and blunt dissection prior to wire placement (group 2) resulted in injury to 10 structures (55.5%). This difference was not statistically significant.

Conclusions: Percutaneous pinning of DRF is associated with a high risk of injury to the extensor tendons and branches of the SRN. This risk is not reduced by making a stab incision and blunt dissection prior to K-wire placement.

A preliminary analysis of a prospective multicenter randomized controlled study of the efficacy and safety on traditional and distal radial access in interventional cardiology

Background: Despite the obvious advantages of transradial access and its widespread use, there are technical problems that force interventional surgeons to improve the methods of endovascular interventions. Aims: to analyze the effectiveness and safety of distal and traditional radial access for endovascular interventions. Methods: The study included 282 patients who underwent an endovascular intervention with distal radial access (DRA, 139 patients) or traditional radial access (TRA, 143 patients). The study is registered at www.clinicaltrials.gov, NCT04211584. Results: The median diameter of the radial artery in its proximal part, i.e. at the site of TRA, was 2.5 mm [Q1; Q3: 2.27; 2.8], in the DRA group the median was 2.28 mm [Q1; Q3: 2.06; 3.56], p 0.0001. We noted statistically significant differences in the duration of puncture (p=0.0215), but not in the duration of the introducer insertion, catheterization of the coronary artery, fluoroscopy, the total time of intervention, the dose of ionizing radiation. In total, 28 complications developed (9.9% of 282): 14 in each of the groups in one year after the intervention. Two (0.7% of 282) patients developed bleeding [1 (0.7% of 139) DRA, 1 (0.7% of 143) TRA], 5 (1.8% of 282) radial artery dissection [2 (1.4% of 139) DRA, 3 (2.1% of 143) TRA], 9 (3.2% of 282) puncture failure [7 (5% of 139) DRA, 2 (1.4% of 143) TRA], 4 (1.4% of 282) radial artery perforation [2 (1.4% of 139) DRA, 2 (1.4% of 143) TRA], 7 (2.5% of 282) hematoma more than 5 cm [2 (1.4% of 139) DRA, 5 (3.5% of 143) TRA], 1 (0.4% of 282) radial artery thrombosis [(0.7% of 143) TRA]. The risk of complications did not depend on the type of access. Conclusions: Distal and traditional radial access do not differ in their efficiency and safety. At the same time, we noted a certain tendency to a longer puncture of the radial artery with distal radial access compared to the traditional one, which is due to the smaller diameter of the radial artery.

Ultrasound of the Radial Nerve: A Pictorial Review

This pictorial review focuses on the ultrasound (US) appearance of the normal and pathological radial nerve (RN) and its branches and provides tips with which to locate them and avoid misinterpretation of normal findings. A wide range of our pathological cases are reviewed and presented to help in familiarizing the reader with common and uncommon clinical scenarios that affect the RN and its main branches.

Ultrasound Measurements of the First Extensor Compartment: Determining the Transection Limits for Ultra-minimally Invasive Release of De Quervain Tenosynovitis

Background: De Quervain syndrome is the second most common compressive tendinopathy. Although the length of the first extensor compartment (FEC) has been studied previously, there is no documented reported comparison study of short-axis and long-axis sonographic measurements. The thread technique, or Guo Technique, has been applied to carpal tunnel syndrome, trigger finger, and superficial peroneal compressive neuropathy. To perform this procedure, it is critically important to accurately identify the boundaries for transection. Methods: Twenty-one fresh frozen cadaver upper extremities were examined under ultrasound to determine the length of the extensor retinaculum (ER) over the FEC. Using the sonographic landmarks, the ERs were measured in short axis and long axis over their proximal to distal margins and from the distal margins to the distal edges of the radial styloids. These sonographic measurements were then compared with gross anatomical measurements. Results: The short-axis sonographic measurement of the ER on average was 22.53 mm (95% confidence interval [CI] = 20.79-24.05 mm). The long-axis sonographic measurement of the ER on average was 15.65 mm (95% CI = 13.70-17.78 mm). The average length of the ER by gross anatomical dissection was 22.40 mm (95% CI = 21.15-23.51 mm). Conclusions: The short axis is not significantly different from the gross anatomical measurement; however, the long axis is significantly lower than the gross anatomical measurement. The results support the idea that the short axis is more accurate than the long axis.

Structures Endangered During Minimally Invasive Plate Osteosynthesis of the Upper Extremity

Minimally invasive plate osteosynthesis is a surgical technique that is becoming increasingly common because radiographic images and implant technologies advance in capabilities. It is imperative for surgeons to enhance their understanding of the surgical anatomy related to new approaches for fracture fixation. While performing minimally invasive plate osteosynthesis, there is a danger of injuring structures in the common percutaneous and submuscular pathways. We describe the critical anatomical structures in these pathways and tips for injury avoidance when operating on the clavicle, scapula, humerus, and wrist.

Feasibility of Distal Radial Access for Coronary Angiography and Percutaneous Coronary Intervention: A Single Center Experience

OBJECTIVE

Asymptomatic radial artery occlusion remains the most common complication in transradial coronary interventional procedure. To prevent radial artery occlusion, distal transradial access (dTRA) has been suggested recently. In this article, we aim to describe our experience and to assess feasibility and safety of this new access site for routine coronary angiography (CAG) and percutaneous coronary intervention (PCI).

METHODS

We retrospective analyzed 1,063 consecutive patients who were assigned to undergo CAG or procedural PCI through dTRA between 1 January 2018 and 31 December 2019 at Affiliated Zhongshan Hospital of Dalian University. The size of radial sheath used was 5 or 6 French. The sheath was removed at procedure termination, and hemostasis was obtained by compression bandage with gauze. The success rate of dTRA access defined by successful radial artery cannulation on the first dTRA side attempted, the cause of access failure, the hemostasis duration, the incidence of post-catheterization radial artery occlusion, and the other access-related complications including hematoma of forearm and thumb numbness were assessed.

RESULTS

Radial artery cannulation via dTRA was successful in 953 of 1,063 patients with a success rate of 89.7%. Mean age of successful cases was 64.6 ± 11.2 years (26-94 years) with 339 (35.6%) women. A total of 363 (38.1%) cases were PCI. Among them, 95 cases (10%) underwent urgent PCI, including primary PCI in 64 patients with ST-segment elevation myocardial infarction and immediate PCI (<2 h from hospital admission) in 31 patients with very high-risk non-ST-segment elevation acute coronary syndrome. A total of 269 (28.2%) cases were via left dTRA. The 6 French sheath was used in 602 (63.2%) cases. Hemostasis was obtained within 2 h in 853 (89.5%) patients. There were 110 (10.3%) procedural failures: 59 (5.6%) cases of artery puncture failure, 49 (4.9%) cases of guide wire insertion failure, and 2 (0.2%) cases of sheath insertion failure. Complications potentially related to distal radial access included radial artery occlusion at the access site (13 cases, 1.4%), forearm radial artery occlusion (4 cases, 0.4%), hematoma of forearm (5 cases, 0.5%), and transient thumb numbness (2 cases, 0.2%).

CONCLUSION

dTRA is a feasible and safe access and can be used as a rational alternative to traditional radial access for routine coronary interventional procedure.

Anatomical characterization of acupoint large intestine 4

Large intestine 4 (LI4) is a major acupoint used in various treatments in acupuncture and Traditional Chinese Medicine. There are structures associated within the region of LI4 that have three-dimensional anatomical relationship that needs further characterization. The aims of this study were: (a) to observe the anatomical variation of structures around LI4; (b) to observe specific overlap of structures around LI4. A 1256 mm² area was dissected in 25 cadaveric hands around LI4. Nondissected areas were marked with pins as reference points. Dissections were photographed with a fixed camera. Subsequently, images were imported to Adobe Photoshop 2020 and analyzed. Descriptive statistics and graphs were compiled using Graphpad Prism 2020. The tributaries of the dorsal venous plexus (22.3%), branches of superficial radial nerve (18.9%), first dorsal interosseous muscle (52.4%), arterial branches in the first interosseous space (10.2%), and deep ulnar nerve (4.0%) were observed in the area of LI4. One branch of the superficial radial nerve passed through LI4. The deep ulnar nerve was found in the bulk of the first dorsal interosseous muscle. Several structures observed intersected at LI4. The superficial radial nerve interweaved with the dorsal venous plexus superficially. The deep ulnar nerve passed anterior to the second palmar metacarpal artery before entering into the first dorsal interosseous muscle. These results provide anatomical evidence and variation into the vascular contributions at LI4.

Trapeziectomy and Abductor Pollicis Longus Suspensionplasty Combined with Extensor Pollicis Brevis Tenodesis for Management of Thumb Basal Joint Osteoarthritis and Metacarpophalangeal Hyperextension

Metacarpal joint hyperextension is common cause of postoperative dissatisfaction after trapeziectomy in the management of basal thumb osteoarthritis. The senior author uses this technique to address this biomechanical problem at the time of trapeziectomy.

[Anatomical landmarks for peripheral neural blocks of the forearm and the wrist: A cadaveric study]

BACKGROUND

There are no data ensuring a standardized landmark-based-technique for blocking sensitive nerves of the forearm.

PURPOSE

To identify locations were with use of good palpable bony landmarks and lines between them sensitive nerve blocks on the forearm can be done with great success.

MATERIAL AND METHODS

Dissection of the superficial branch of the radial nerve (SBRN), the dorsal branch of the ulnar nerve (DBUN), the lateral, medial and dorsal antebrachial cutaneous nerve (LACN, MACN, and DACN) as well as the palmar branch of the median nerve (PBMN) was performed on five upper limbs of five different Caucasian cadavers. With respect to radius and ulnar styloid, Lister's tubercle, and the medial and lateral epicondyle of the humerus as well as connecting lines between these bony landmarks locations were defined, where the mentioned nerves can be found and blocked.

RESULTS

The six nerves can be safely blocked at the following sites: the SBRN 85 mm proximal to Lister's tubercle on a line drawn between the latter and the medial humeral epicondyle; the LACN 38 mm and the dorsal one 32 mm ulnar from the lateral epicondyle; the MACN 14 mm radial to the medial epicondyle; the DBUN 27 mm proximal to the ulnar styloid in direction to the lateral epicondyle; the PBMN 45 mm proximal to the radial styloid following a line between the latter and the medial epicondyle and 21 mm ulnarwards perpendicular to this line.

CONCLUSION

Using superficial good palpable landmarks at the wrist and elbow as well as connecting lines between them the SBRN, DBUN, PBMN, LACN, MACN, and DACN can easily be located.

Can Ultrasonography Be Useful in Planning Surgery for De Quervain Tenosynovitis?: A Prospective Study With Emphasis on Detection of the Superficial Radial Nerve and Dominant Pathologic Tendon

OBJECTIVES

We performed preoperative ultrasonography (US) to detect the anatomic course of the superficial radial nerve (SRN) and dominant pathologic tendon of the first extensor compartment in de Quervain tenosynovitis.

METHODS

We prospectively studied 27 patients (29 wrists) with de Quervain tenosynovitis who underwent surgical release of the first extensor compartment. Preoperatively, US was performed to evaluate the presence of the dominant pathologic tendon and the septum in the subcompartment, number of SRNs in the area of the surgical incision, and anatomic running course of the SRN. These variables were also checked intraoperatively. Cohen κ statistics were calculated to investigate agreement between US and surgical field findings.

RESULTS

There were 7 men and 20 women (mean age, 47.8 years; range, 26-67 years). For the dominant pathologic tendon, there were 2 cases (6.9%) of an abductor pollicis longus, 11 cases (37.9%) of an extensor pollicis brevis, and 16 cases (55.2 %) of a nondominant tendon (κ = 0.94). For the subcompartment, there were 10 cases (34.5%) without a septum, 8 (27.6%) with an incomplete septum, and 11 (37.9%) with a complete septum (κ = 0.95). Most SRNs crossed over the first extensor compartment (κ = 0.78).

CONCLUSIONS

Preoperative US can be useful in detecting the anatomic running course of the SRN and dominant pathologic tendon before surgery for de Quervain tenosynovitis. Classifying the anatomic course of the SRN could be essential to planning surgery, and it could be helpful to prevent injury of the SRN during surgery.

Reconstruction of Finger Pulp Defects With an Innervated Distally-Based Neurovascular Flap

PURPOSE

Finger pulp resurfacing is a challenging reconstructive problem. This article introduces sensory reconstruction of finger pulp defects using an innervated distally-based neurovascular flap raised from the dorsum of the thumb.

METHODS

From May 2015 to May 2017, the innervated distally-based neurovascular flap was used in 36 patients. The mean age at surgery was 37 years (range, 18-61 years). All patients were assessed using the total active motion (TAM) scoring system of the American Society for Surgery of the Hand. The sensitivity of the flap was tested using static 2-point discrimination.

RESULTS

Full flap survival was achieved in 35 cases. Partial necrosis at the distal margin of the flap was observed in 1 case. At the final follow-up (mean, 20 months; range, 18-23 months), the mean TAM of the thumb was 206° (range, 188°-238°), including 8 excellent and 28 good results. The mean TAM of fingers was 266° (range, 251°-282°), including 4 excellent and 32 good results. The mean value of static 2-point discrimination was 5 mm (range, 4-7 mm) in the flap, including 31 excellent and 5 good results.

CONCLUSIONS

The innervated distally-based neurovascular flap raised from the dorsum of the thumb is a reliable alternative for sensory reconstruction of finger pulp defects.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Distal radial artery access in the anatomical snuffbox for coronary angiography and intervention: A single center experience

BACKGROUND

To explore the feasibility and safety of coronary angiography (CAG) and percutaneous coronary intervention (PCI) via the distal radial artery in the anatomical snuffbox.

METHODS

Ninety two patients who underwent CAG or PCI through distal radial artery access at The Second Affiliated Hospital of Zhejiang Chinese Medical University from September 2017 to March 2018 were included in our study. We collected baseline characteristics, number, and duration of arterial punctures, procedural success rate, postoperative compression time, the numerical rating scale (NRS) scores at 3 hours after procedure, complications, hospitalization duration.

RESULTS

The mean age was 69 ± 11years (44-92 years), and there were 57 males (62.0%). The diameter of the right distal radial artery and the more proximal right radial artery were 0.171 ± 0.05 cm, 0.213 ± 0.06 cm, respectively. On average, the number of puncture attempts was 1.52 ± 0.81, access time was 2.3 ± 1.78 minutes (0.33 - 8.72 minutes), access success was 95.7%, the postoperative compression time was 3.41 ± 0.76 hours (2-6 hours), the NRS scores at 3 hours was 1.53 ± 0.72 (1-4), and the mean hospitalization duration was 7.13 ± 4.02 days. Four patients underwent left distal radial artery access and 88 patients underwent right distal radial artery access. There were 3 local hematomas after procedure and 2 patients had vasospasm. There were no cases of major bleeding, arteriovenous fistula, radial artery occlusion, or hand numbness.

CONCLUSION

Cardiac catheterization through the distal radial artery in the snuffbox is safe and feasible. The right distal radial artery access can be routinely carried out.

The best vein to be accessed based on descriptive study of dorsal metacarpal vein

It is well known that the most common sites for venous access are the superficial veins of the upper limb, particularly dorsal metacarpal veins and median cubital vein. Although dorsal metacarpal veins are the first choice for venous cannulation, there is scarce information about their anatomic variation. Hence, detailed anatomical information about these veins will improve the anatomic knowledge of the health care providers. Subsequently, this study was designed to study the dorsal metacarpal veins and to determine the most prominent dorsal metacarpal vein. A cross sectional study of 402 subjects (804 hands), was prepared to study the superficial veins on the dorsum of the hand among Jordanian students and staff of one of the major governmental medical colleges in Jordan, by using infrared illumination system. The obtained data was analyzed according to sex, sidedness, and handedness. Six locations of the most prominent dorsal metacarpal veins were identified. There was a significant relation between both females and males and the most prominent dorsal metacarpal vein (P=0.01). For the first time this study identified the most common location of the most prominent dorsal metacarpal vein in the fourth intermetacarpal space.

An Extensile Approach to the Radial Aspect of the Carpus: "The Link Incision"

The structures on the radial side of the wrist and thumb base can be approached by a longitudinal incision on the radial side of the wrist. However, longer longitudinal scars can be cosmetically unacceptable and can result in a scar contracture. It is preferable to curve longer incisions along the Langer's skin lines to achieve better scar characteristics. Curving the incision also enables an extensile approach and provides easy access to the thumb base, radial carpus, and radial wrist joint. We describe our approach as a "Link" between the most common approaches that surgeons are familiar with; the dorsoulnar approach to the thumb metacarpophalangeal joint for ulnar collateral ligament repair and the flexor carpi radialis approach for distal radial fracture fixation. The zone between these two incisions is not as frequently approached. Our incision connects these two well established incisions and we have described a step by step approach to this unfamiliar area. This "Link zone" overlies the thumb trapeziometacarpal joint, scaphotrapeziotrapezoid joint, and the radial styloid. It contains superficial branches of the radial nerve, first extensor compartment tendons, and the deep branch of radial artery in the anatomic snuff box. The "Link incision" is an extensile approach in both the proximal and distal directions.

Fragment-Specific Fixation in Distal Radius Fractures

PURPOSE OF REVIEW

Fragment-specific fixation can be a useful tool in treating distal radius fractures. In order to best utilize these techniques, surgeons require an understanding of the normal anatomy, fracture patterns, approaches, and fixation strategies.

RECENT FINDINGS

Fragment-specific fixation may be appropriate for certain fracture patterns particularly when monoblock plating techniques are not sufficient. Radial styloid, volar rim, dorsal wall, dorsal-ulnar corner, and impacted intraarticular fragments may be secured with implants designed specifically for each individual fragment. Although more technically demanding, advantages include accurate articular reconstruction, minimal hardware irritation, and reliable functional outcomes.

A review of main anatomical and sonographic features of subcutaneous nerve injuries related to orthopedic surgery

Lesion to subcutaneous nerves is a well-known risk of orthopedic surgery and a significant cause of postoperative pain and dissatisfaction in patients. High-resolution ultrasound can be used to visualize the vast majority of small subcutaneous nerves of the upper and lower limbs. Ultrasound detects nerve abnormalities such as focal hypoechoic thickening, stump neuroma, and scar encasement, and provides information not only about the peripheral nerve itself but also about its relationship to adjacent anatomical structures. The purpose of this review is to provide an overview of the anatomy of the main subcutaneous nerves damaged during orthopedic surgery, recall at-risk procedures, and offer useful anatomic landmarks to help the sonographer identify and follow the nerves when an iatrogenic lesion is suspected.

Neurophysiological study of the radial nerve variant in the innervation of the dorsomedial surface of the hand

INTRODUCTION

Sensory innervation of the dorsomedial surface of the hand usually depends on the dorsal ulnar nerve (DUN). Innervation in this area by the superficial radial nerve (SRN) has been described as a normal variant.

METHODS

We studied 358 patients using nerve conduction of the DUN and SRN with dorsomedial recording. Each hand was classified into usual innervation (only DUN response), mixed variant (response of both nerves), or complete variant (only SRN response).

RESULTS

Mixed innervation was found in 14.2% of hands and complete innervation was found in 6.8% of hands, mostly unilaterally. No statistically significant differences were observed in age, sex, or clinical suspicion between usual and variant innervation. The potential amplitude after SRN stimulation was greater in the complete variant.

DISCUSSION

It is important to know the characteristics of this variant in order to avoid diagnostic errors and to prevent iatrogenic lesions in surgery performed on the dorsum of the wrist. Muscle Nerve 58: 732-735, 2018.

“In Situ Vascular Nerve Graft” for Restoration of Intrinsic Hand Function: An Anatomical Study

Background: In combined high median and ulnar nerve injury, transfer of the posterior interosseous nerve branches to the motor branch of the ulnar nerve (MUN) is previously described in order to restore intrinsic hand function. In this operation a segment of sural nerve graft is required to close the gap between the donor and recipient nerves. However the thenar muscles are not innervated by this nerve transfer. The aim of the present study was to evaluate whether the superficial radial nerve (SRN) can be used as an “in situ vascular nerve graft” to connect the donor nerves to the MUN and the motor branch of median nerve (MMN) at the same time in order to address all denervated intrinsic and thenar muscles.

Methods: Twenty fresh male cadavers were dissected in order to evaluate the feasibility of this modification of technique. The size of nerve branches, the number of axons and the tension at repair site were evaluated.

Results: This nerve transfer was technically feasible in all specimens. There was no significant size mismatch between the donor and recipient nerves

Conclusions: The possible advantages of this modification include innervation of both median and ulnar nerve innervated intrinsic muscles, preservation of vascularity of the nerve graft which might accelerate the nerve regeneration, avoidance of leg incision and therefore the possibility of performing surgery under regional instead of general anesthesia. Briefly, this novel technique is a viable option which can be used instead of conventional nerve graft in some brachial plexus or combined high median and ulnar nerve injuries when restoration of intrinsic hand function by transfer of posterior interosseous nerve branches is attempted.

Superficial branch of the radial nerve injury: A case for conscious perioperative arterial cannulation

We present a case of an injury to the superficial branch of the radial nerve following unconscious radial artery cannulation in a 57-year-old gentleman for revision of lumbar spinal fusion. Nerve damage is a rare complication of this commonly used technique; whilst usually self-limiting, it can lead to a significant under-reported burden of morbidity on our patients. We discuss current norms of practice, questioning the safety of unconscious arterial cannulation, and suggest that, where possible, it should be performed in the conscious patient to minimise the risk of this rare complication.

Coronary angiography using the left distal radial approach - An alternative site to conventional radial coronary angiography

Objective:

To share our experience with the left distal radial approach for transradial coronary angiography and interventions. By performing the radial puncture in the fossa radialis or the so called anatomical “Snuffbox” we aimed to present the feasibility and complications of this new technique.

Methods:

Left distal radial artery was used as an access site in 54 patients admitted to our clinic for coronary angiography and intervention between May 25^th and October 20^th 2017. All of them had pulse in their left distal radial artery. In the laboratory, they had their left arm gently flexed at the shoulder so that the hand was placed over their right groin. The operator stood on the right side of the patient and performed coronary angiography and interventions. During the hospital stay, demographic features and complications were recorded.

Results:

Mean age of patients was 59.3 years and 80% were male. We used Judkins 6 French catheters for the procedures. Seventeen patients admitted with acute coronary syndrome. They all underwent successful left distal transradial coronary angiography and intervention. Primary angioplasty was performed in 10 patients. In total, 20 patients had coronary intervention. Left anterior descending artery was the artery requiring most intervention (11 patients). Two patients experienced brachial spasm requiring crossover to right femoral artery. There were no cases of radial artery occlusion, hematoma, or hand numbness. The radial sheath was removed at procedure termination. Hemostasis was achieved with manual compression.

Conclusion:

Left distal radial approach is safe and feasible as a new technique for coronary angiography and interventions.

Clinical anatomy of the cephalic vein for safe performance of venipuncture

Background

The aims of this study were to elucidate why the cephalic vein provides a reliable cannulation site from a morphological viewpoint and identify an effective landmark for avoiding injury to the superficial branch of the radial nerve (SBRN), allowing for safe venipuncture of the cephalic vein.

Findings

We examined 32 forearms and wrists from 18 cadavers. The cephalic vein was a constant structure containing a branch communicating with a collateral vein of the deep palmar arch via the first dorsal interossei muscle. The metacarpal vein from the medial two digits flowed into the cephalic vein. The venous confluence formed 5.8 ± 1.2 cm proximal to the radial styloid process. The SBRN passed 0.4 ± 0.3 cm volar to the venous confluence. The distance between the venous confluence and subcutaneous emergence of the SBRN was 2.6 ± 1.0 cm.

Conclusions

These observations suggest that the cephalic vein is a constant structure that serves as a drainage vein of the hand and provides a reliable cannulation site in the forearm. The venous confluence may serve as a novel landmark to predict the running course of the SBRN.

Evaluation of collimated polarized light imaging for real-time intraoperative selective nerve identification in the human hand

Intraoperative peripheral nerve lesions are common complications due to misidentification and limitations of surgical nerve identification. This study validates a real-time non-invasive intraoperative method of nerve identification. Long working distance collimated polarized light imaging (CPLi) was used to identify peripheral radial nerve branches in a human cadaver hand by their nerve specific anisotropic optical reflection. Seven ex situ and six in situ samples were examined for nerves, resulting after histological validation, in a 100% positive correct score (CPLi) versus 77% (surgeon). Nerves were visible during a clinical in vivo observation using CPLi. Therefore CPLi is a promising technique for intraoperative nerve identification.

Aberrant course of superficial radial nerve in the forearm: an anatomical variation and its clinical implications

The superficial radial nerve (SRN) is the terminal pure sensory branch of the radial nerve supplying dorsal aspects of the proximal portion of the lateral three and a half digits including the lateral two-thirds of the dorsum of the hand. It transits from its submuscular position to a subcutaneous position by passing between the brachioradialis and extensor carpi radialis longus tendons around 7 to 9 cm proximal to the radial styloid. We present a case where this nerve instead of its normal forearm course, pierced the brachioradialis tendon to become subcutaneous.

Radial nerve palsy

As a result of its proximity to the humeral shaft, as well as its long and tortuous course, the radial nerve is the most frequently injured major nerve in the upper limb, with its close proximity to the bone making it vulnerable when fractures occur.Injury is most frequently sustained during humeral fracture and gunshot injuries, but iatrogenic injuries are not unusual following surgical treatment of various other pathologies.Treatment is usually non-operative, but surgery is sometimes necessary, using a variety of often imaginative procedures. Because radial nerve injuries are the least debilitating of the upper limb nerve injuries, results are usually satisfactory.Conservative treatment certainly has a role, and one of the most important aspects of this treatment is to maintain a full passive range of motion in all the affected joints.Surgical treatment is indicated in cases when nerve transection is obvious, as in open injuries or when there is no clinical improvement after a period of conservative treatment. Different techniques are used including direct suture or nerve grafting, vascularised nerve grafts, direct nerve transfer, tendon transfer, functional muscle transfer or the promising, newer treatment of biological therapy. Cite this article: Bumbasirevic M, Palibrk T, Lesic A, Atkinson HDE. Radial nerve palsy. EFORT Open Rev 2016;1:286-294. DOI: 10.1302/2058-5241.1.000028.

Does infrared visualization improve selection of venipuncture sites for indwelling needle at the forearm in second-year nursing students?

OBJECTIVES

To evaluate the effectiveness of a vein visualization display system using near-infrared light ("Vein Display") for the safe and proper selection of venipuncture sites for indwelling needle placement in the forearm.

METHODS

Ten second year nursing students were recruited to apply an indwelling needle line with and without Vein Display. Another ten participants were recruited from various faculty to serve as patients. The quality of the venipuncture procedure at various selected sites was evaluated according to a scale developed by the authors. Time, scores and patterns of puncture-site selection were compared with respect to three different methods: [1] attempt 1 (tourniquet only), [2] attempt 2 (Vein Display only) and [3] attempt 3 (both). To validate the effectiveness of Vein Display, 52 trials were conducted in total.

RESULTS

We found that venipuncture site selection time was significantly improved with the Vein Display, particularly in the case of difficult to administer venipuncture sites. Overall, we found no significant difference with respect to venipuncture quality, as determined by our scale.

CONCLUSION

These results suggest that equipment such as the Vein Display can contribute immensely to the improvement of practical skills, such as venipuncture, especially in the context of elderly patients.

Superficial radial sensory neuropathy: Medial and lateral branch injury

INTRODUCTION

Superficial radial sensory nerve (SRN) injury may involve the main nerve or its distal medial or lateral branch. We investigated the utility of SRN conduction studies on the medial and lateral branches in patients with suspected SRN injury.

METHODS

Fifteen patients with symptoms of SRN neuropathy were studied. Their clinical and electrophysiological findings were assessed according to sensory symptom areas. Three active recording electrode positions were used: snuff box (position A); medial branch (position B); and lateral branch (position C).

RESULTS

In 7 patients with medial area symptoms, abnormal findings were seen in position B (100%) and position A (71%). In 3 patients with medial and lateral area symptoms, abnormal findings were seen in all positions. In 5 patients with lateral symptoms, abnormal findings were seen in position C only.

CONCLUSIONS

Nerve conduction studies for each branch of the SRN are useful in patients with suspected SRN neuropathy.

An Anatomical Study to Demonstrate the Proximity of Kirschner Wires to Structures at Risk in Percutaneous Pinning of Distal Radius Fractures

Distal radius fractures are often treated using percutaneous Kirschner wires (K-wires). The sensory nerves in this area, extensor tendons, radial artery and cephalic vein are at risk of injury in this procedure. We undertook a cadaveric investigation to identify probability of damage to these 'at risk' structures by measuring their distances in relation to standard K-wire sites. Nine upper limbs from six formalin-preserved cadavers were studied. Four K-wires were placed percutaneously simulating fixation of a distal radius fracture. Careful dissection was done preserving the original position of neurovascular and tendinous structures. Distances to relevant soft-tissue structures from each K-wire were measured using an electronic digital caliper. Distance of superficial nerves from radial styloid and Lister's tubercle was measured to determine their 'safe distance' from these fixed landmarks. None of the superficial nerves were injured by a K-wire. Cephalic vein had been pierced on 4 occasions (4/18) and extensor tendons on 3 occasions (3/18). Wilcoxon signed-rank test was used to compare distance of the superficial nerves from radial styloid and Lister tubercle, and the latter was found to be the safer option. This study highlights the inherent danger in percutaneous K-wire fixation of wrist fractures. Limited size of the area, where K-wires can be positioned, and anatomic variations of neurovascular structures pose obstacles in developing guidelines for reducing risk of injury. We advocate use of mini-open approach and guiding devices to avert complications of inadvertent impalement and damage to these structures.

Is there a safe zone to avoid superficial radial nerve injury with Kirschner wire fixation in the treatment of distal radius? A cadaveric study

AIM OF THE STUDY

To determine the relation of the superficial radial nerve to bony land-marks and to identify a safe zone for K-wire pinning in the distal radius.

METHOD

The superficial radial nerve was dissected in sixteen upper extremities of preserved cadavers.

RESULTS

We found that the superficial radial nerve emerged from under brachioradialis at a mean distance of 8.45 (±1.22) cm proximal to the radial styloid. The mean distance from the first major branching point of the superficial radial nerve to the radial styloid were 4.8 ± 0.4 cm. All branches of the superficial radial nerve were found to lie in the radial half of an isosceles triangle formed by the radial styloid, Lister's tubercle and the exit point of the superficial radial nerve. There is an elliptical area just proximal to the Lister's tubercle. This area is not crossed by any tendons or nerve. It is bounded by the extensor carpiradialis brevis, extensor pollicis longus.

CONCLUSION

Pinning through the radial styloid is unsafe as the branches of the superficial radial nerve passé close to it. The ulnar half of the isosceles triangle is safe regarding the nerve. The elliptical zone just proximal to the Lister's tubercle is safe regarding the tendons and nerve.

Ultrasonographic reference values for assessing normal radial nerve ultrasonography in the normal population

High-resolution ultrasound has been used recently to characterize median and ulnar nerves, but is seldom used to characterize radial nerves. The radial nerve is more frequently involved in entrapment syndromes than the ulnar and median nerves. However, the reference standard for normal radial nerves has not been established. Thus, this study measured the cross-sectional areas of radial nerves of 200 healthy male or female volunteers, aged 18 to 75, using high-resolution ultrasound. The results showed that mean cross-sectional areas of radial nerves at 4 cm upon the lateral epicondyle of the humerus and mid-humerus (midpoint between the elbow crease and axilla) were 5.14 ± 1.24 and 5.08 ± 1.23 mm², respectively. The age and the dominant side did not affect the results, but the above-mentioned cross-sectional areas were larger in males (5.31 ± 1.25 and 5.19 ± 1.23 mm²) than in females (4.93 ± 1.21 and 4.93 ± 1.23 mm², respectively). In addition, the cross-sectional areas of radial nerves were positively correlated with height and weight (r = 0.38, 0.36, respectively, both P < 0.05). These data provide basic clinical data for the use of high-resolution ultrasound for the future diagnosis, treatment, and prognostic evaluation of peripheral neuropathies.

Anatomical and ultrasound correlation of the superficial branch of the radial nerve

INTRODUCTION

This anatomical study evaluates the role and correlation of ultrasound (US) with anatomy in depicting the superficial branch of the radial nerve (SBRN) and to evaluate the feasibility of US guided perineural infiltration as a potential therapeutic option in Wartenberg syndrome.

METHODS

Twenty-one arms from 11 non-embalmed cadavers were examined with US. Under US guidance perineural injection with ink was performed proximal to the site where the SBRN perforates the forearm fascia. The distribution of ink around the nerve was evaluated with dissection.

RESULTS

US allowed the distinction of the SBRN segments and their relation to the fascia. In all cases, the subfascial segment was stained. In only 57% the subfascially applied ink also reached the subcutaneous compartment.

CONCLUSIONS

With US it is possible to examine and differentiate all segments of the SBRN. US guidance can be used for perineural injection of all relevant segments.

Exposures of the humerus for fracture fixation

The care of humeral shaft fractures is undergoing a transition to more aggressive treatment methods with more frequent operative fixation. The upper arm has an extensive network of nerves, arteries, and veins that must be protected during any operative exposure. The ultimate goal of fixation of a humerus fracture is rigid stabilization to allow early range of motion, protection of the neurovascular structures, and preservation of the triceps mechanism posteriorly and the anterior elbow flexor muscles.

The relationship of the superficial radial nerve and its branch to the thumb to the first extensor compartment

PURPOSE

The superficial radial nerve and its branches are vulnerable during surgery for de Quervain tenovaginitis. We studied the proximity of the nerve branches to the first extensor compartment.

METHODS

We dissected 20 forearms of 11 cadavers and measured the branching point of the superficial radial nerve relative to the radial styloid. We defined the midline of the first extensor compartment and measured distances of nerves adjacent to it.

RESULTS

The superficial radial nerve gave the lateral dorsal digital branch to the thumb at 50 ± 13 mm (minimum, 26 mm; maximum, 72 mm) proximal to the radial styloid. Average distances of the lateral dorsal digital branch to the thumb to the midline of first extensor compartment from proximal to distal were 2, 2, and 2 mm, respectively. In 8 forearms, the lateral dorsal digital branch to the thumb passed directly over the first extensor compartment along its entire length. We found that as the superficial radial nerve diverged from the first extensor compartment, its lateral dorsal digital branch to the thumb coursed parallel and in close relation to it.

CONCLUSIONS

Anatomic knowledge of the course of the superficial radial nerve and its branches is important during open release for avoiding nerve injury.

CLINICAL RELEVANCE

The close relation of the superficial radial nerve and its lateral dorsal digital branch to the thumb with the first extensor compartment may guide surgeons during surgery for de Quervain tenovaginitis.