Surgical anatomy of the radial nerve in the anterior compartment of the arm: relationship with the triceps aponeurosis (original) (raw)
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Journal of Research in Applied and Basic Medical Sciences
Background & Aims: Long course of the radial nerve and its proximity to the humerus makes Radial Nerve (RN) prone to injury in diaphyseal fractures. In an effort to maintain its integrity, soft tissue landmarks can be readily made use of to provide facile nerve identification, as osseous landmarks might get altered in fractures. The aim of this study was to provide an idea of safe zone for securing radial nerve in relation to soft tissue structures and thereby, preventing the concomitant iatrogenic injury. Materials & Methods: 40 Upper limb specimens from 20 cadavers were dissected. The radial nerve was identified proximal to the apex of Tricipital aponeurosis (TA) in posterior arm, at the level of entry into the lateral inter muscular septum and along the lateral border of TA. The mean distance between the radial nerve and aponeurosis was measured at all the three sites to find the safe zone for securing the radial nerve during surgeries. Results: The radial nerve was found proximally from the medial apex of tricipital aponeurosis at a distance of 43.49 ± 6.67 mm (range 30.34-55.72 mm) within the muscle belly of triceps. The minimal permissible distance for the triceps split was 3.03 cm from the medial apex for both right and left arms. The distance of above 15 mm (range from 15.56 to 47.47mm) from the lateral border of tricipital aponeurosis was considered as a safe zone and no branches of the radial nerve were found in this zone. Radial nerve was identified along its course in the range of 15.56 to 47.47 mm from the lateral border of TA and this should be taken into consideration by the operating surgeon. Conclusion: The Tricipital aponeurosis is a useful soft tissue landmark to secure the radial nerve safely throughout its course in the arm. Knowledge of safe and dangerous zones of the radial nerve would help the orthopedic surgeons to avoid the risk of iatrogenic nerve injury, which is not an uncommon phenomenon.
JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2018
Introduction: Identification of the radial nerve and preventing injury to it is crucial, while surgically approaching the humerus from the posterior aspect to treat fractures of the midshaft or the distal third of the bone. Aim: To identify certain anatomic landmarks, using which the radial nerve could be identified during surgical intervention, in order to prevent iatrogenic injury to the nerve. Materials and Methods: Twenty-eight arms belonging to 14 adult cadavers (10 male and 4 female) were used for this study. The distance between the radial nerve on the posterior humerus and the point of confluence of the long and lateral heads of the triceps with the triceps aponeurosis was measured. Statistical analysis using Student's paired t-test was done between the right and left sides. In the distal third of the humerus, the distance of the radial nerve and the lateral border of the triceps aponeurosis at four sites were determined. Results: The mean distance from the point of confluence to the radial nerve along the posterior humerus was 39.7±11.8 mm. The radial nerve passed adjacent to the lateral border of the triceps aponeurosis at a distance of 12-19.5 (±3.27) mm. It was never found to be closer than 4.6±2.54 mm to the aponeurosis. Conclusion: The present study is useful for orthopaedicians while undertaking the surgical management of humeral fractures. The point of confluence and the triceps aponeurosis are two anatomic landmarks that can be used to locate the radial nerve.
The location of the radial nerve (RN) is described with various bony landmarks, but such may be disturbed in the setting of fracture and dislocation of bone. Alternative soft tissue landmarks would be helpful to locate the nerve in such setting. To recognize certain anatomic landmarks to identify, locate and protect RN from any iatrogenic injury during surgical intervention such as open reduction and internal fixation. Forty arms belonging to 20 adult cadavers were used for this study. We measured the distance of RN from the point of confluence of triceps aponeurosis (TA), tip of the acromion and tip of the lateral epicondyle along the long axis of the humerus. These distances were correlated with the upper arm length (UAL). The average UAL was 32.64±0.64 cm. The distance of the RN from the point of confluence of TA (tricepso-radial distance, TRD), tip of acromion (acromion-radial distance) and tip of lateral epicondyle of humerus (condylo-radial distance, CRD) was 3.59±0.16 cm, 14.27±0.59 cm, and 17.14±1.29 cm respectively. No correlation was found with UAL. Statistically, TRD showed the least variability and CRD showed maximum variability. The minimum TRD was found to be 3.00 cm. So this should be considered as the maximum permissible length of the triceps split. The point of confluence of the TA appears to be the most stable and reliable anatomic landmark for localization of the RN during the posterior approach to the humerus.
The tricipital aponeurosis--a reliable soft tissue landmark for humeral plating
Hand surgery : an international journal devoted to hand and upper limb surgery and related research : journal of the Asia-Pacific Federation of Societies for Surgery of the Hand, 2015
This study aims to identify the relationship of the radial nerve as it descends across the humerus with reference to a reliable soft tissue landmark, the tricipital aponeurosis. Following cadaveric dissection of 10 adult humerii, the radial nerve was located as it crossed the lateral midsagittal point of the humeral diaphysis. A horizontal line was then subtended medially from this point to another line subtended vertically from the lateral border of the tricipital aponeurosis. The vertical distance from this intersection to the lateral apex of the aponeurosis was recorded in three positions (full flexion, 90° of flexion and full extension). The location of the radial nerve on the posterior aspect of the humeral diaphysis to the medial apex of the tricipital aponeurosis was also noted. In 90° of flexion the radial nerve at the lateral midsagittal point of the humerus was 0.9 mm proximal to the lateral apex of the tricipital aponeurosis. Flexion and extension of the elbow changed the...
Fracture of distal humerus: MIPO technique with visualization of the radial nerve
Acta Ortopédica Brasileira, 2014
Objectives: To evaluate the outcomes in patients treated for humerus distal third fractures with MIPO technique and visualization of the radial nerve by an accessory approach, in those without radial palsy before surgery. Methods: The patients were treated with MIPO technique. The visualization and isolation of the radial nerve was done by an approach between the brachialis and the brachiorradialis, with an oblique incision, in the lateral side of the arm. MEPS was used to evaluate the elbow function. Results: Seven patients were evaluated with a mean age of 29.8 years old. The average follow up was 29.85 months. The radial neuropraxis after surgery occurred in three patients. The sensorial recovery occurred after 3.16 months on average and also of the motor function, after 5.33 months on average, in all patients. We achieved fracture consolidation in all patients (M=4.22 months). The averages for flexion-extension and prono-supination were 112.85° and 145°, respectively. The MEPS average score was 86.42. There was no case of infection. Conclusion: This approach allowed excluding a radial nerve interposition on site of the fracture and/or under the plate, showing a high level of consolidation of the fracture and a good evolution of the range of movement of the elbow. Level of Evidence IV, Case Series.
Establishing Safe Zones to Avoid Nerve Injury in the Approach to the Humerus in Pediatric Patients
Journal of Bone and Joint Surgery, 2019
Background: The surgical anatomy of upper-extremity peripheral nerves in adults has been well described as "safe zones" or specific distances from osseous landmarks. In pediatrics, relationships between nerves and osseous landmarks remain ambiguous. The goal of our study was to develop a model to accurately predict the location of the radial and axillary nerves in children to avoid iatrogenic injury when approaching the humerus in this population. Methods: We conducted a retrospective review of 116 magnetic resonance imaging (MRI) scans of entire humeri of skeletally immature patients; 53 of these studies met our inclusion criteria. Two independent observers reviewed all scans. Arm length was measured as the distance between the lateral aspect of the acromion and the lateral epicondyle. We then calculated the distances (defined as the percentage of arm length) between the radial nerve and distal osseous landmarks (the medial epicondyle, transepicondylar line, and lateral epicondyle) as well between the axillary nerve and the most lateral aspect of the acromion. Results: The axillary nerve was identified at a distance equaling 18.6% (95% confidence interval [CI], ±0.62%) of arm length inferior to the lateral edge of the acromion. The radial nerve crossed (1) the medial cortex of the posterior part of the humerus at a distance equaling 63.19% (95% CI: ±0.942%) of arm length proximal to the medial epicondyle, (2) the middle of the posterior part of the humerus at a distance equaling 53.9% (95% CI: ±1.08%) of arm length proximal to the transepicondylar line, (3) the lateral cortex of the posterior part of the humerus at a distance equaling 45% (95% CI: ±0.99%) of arm length proximal to the lateral epicondyle, and (4) from the posterior to the anterior compartment at a distance equaling 35.3% (95% CI: ±0.92%) of arm length proximal to the lateral epicondyle. A strong linear relationship between these distances and arm length was observed, with an intraclass correlation coefficient of >0.9 across all measurements. Conclusions: The positions of the radial and axillary nerves maintain linear relationships with arm lengths in growing children. The locations of these nerves in relation to palpable osseous landmarks are predictable. Clinical Relevance: Knowing the locations of upper-extremity peripheral nerves as a proportion of arm length in skeletally immature patients may help to avoid iatrogenic injuries during surgical approaches to the humerus. A confident surgeon has an intimate understanding of applied anatomy and an excellent knowledge of anatomic relationships. Avoiding iatrogenic injury is critically important. Hence, various publications have described "safe zones" and reference distances from anatomic landmarks 1. These points of reference help surgeons anticipate the positions of critical structures such as nerves before they are encountered, thereby reducing the chance of iatrogenic injury 2-4. The surgical anatomy of peripheral nerves in the upper extremity has been well described in adults 5. Fleming et al. described the "one-third, two-thirds rule" to reliably identify the radial nerve as it crosses from the posterior to the anterior compartment of the upper arm 6. Uhl et al. established the 13-cm rule to avoid iatrogenic radial nerve injury when approaching the humerus posteriorly 7. Cetik et al. elucidated a "safe zone" for the axillary nerve when approaching the proximal part of the humerus through a deltoid-split approach 8. These rules simplify complex anatomy and can be easily committed to memory to avoid iatrogenic nerve injury and increase patient safety 9 .
Radial Nerve Injuries Associated With Humeral Fractures
The Journal of Hand Surgery, 2006
A radial nerve injury associated with a humeral shaft fracture is an important injury pattern among trauma patients. It is the most common peripheral nerve injury associated with this fracture. Although treatment for this injury pattern is a controversial subject among upperextremity surgeons, certain principles of management need to be applied in all cases. As our understanding of the pathoanatomy of the humerus and surrounding neurovascular structures has evolved, surgeons have adapted their strategies to improve outcome and avoid long-term morbidity. The principles of management and the clinical outcomes of various treatment strategies, defined in the literature, are reviewed in this article.
Early surgical exploration of radial nerve injury associated with fracture shaft humerus
Microsurgery, 2008
The series included 36 patients, predominantly male, mean age 30.3 years. The most common cause of injury was motor car accident in 20 patients. Postreduction radial nerve injury occurred in nine cases. Open fracture humerus with radial nerve injury in seven cases. The fractures were situated in the middle or distal third of the humeral shaft. Most were transverse fractures. Twelve patients had surgery on the day of injury and the other 24 at a mean of 8 days later (3-14). Narrow dynamic compression plate was generally used for fixation. Exploration of the radial nerve demonstrated compression at the lateral intermuscular septum in 19 cases, entrapment in the fracture site in nine cases, and loss of its continuity in eight cases. Neurolysis was required in 20 cases, epineurorrhaphy in nine cases, interfascicular nerve grafts in five, and first-intention tendon transfer in two. Results of nerve surgery were assessed with the MRC (Medical Research Council) at a mean follow-up of 8.2 years. Outcome was rated good to excellent in 28 patients, fair in 1, and poor (failure) in 3. Firstintention tendon transfers were performed in 2 patients and 2 patients were lost to follow-up. Mean delay to recovery was 7 months after neurolysis and nerve repair and 15 months after nerve grafts. The fracture was united in all cases. The mean time of union was 5 months. V
JSES international, 2022
Background: The surgical anatomy of upper-extremity peripheral nerves in adults has been well described as "safe zones" or specific distances from osseous landmarks. In pediatrics, relationships between nerves and osseous landmarks remain ambiguous. The goal of our study was to develop a model to accurately predict the location of the radial and axillary nerves in children to avoid iatrogenic injury when approaching the humerus in this population. Methods: We conducted a retrospective review of 116 magnetic resonance imaging (MRI) scans of entire humeri of skeletally immature patients; 53 of these studies met our inclusion criteria. Two independent observers reviewed all scans. Arm length was measured as the distance between the lateral aspect of the acromion and the lateral epicondyle. We then calculated the distances (defined as the percentage of arm length) between the radial nerve and distal osseous landmarks (the medial epicondyle, transepicondylar line, and lateral epicondyle) as well between the axillary nerve and the most lateral aspect of the acromion. Results: The axillary nerve was identified at a distance equaling 18.6% (95% confidence interval [CI], ±0.62%) of arm length inferior to the lateral edge of the acromion. The radial nerve crossed (1) the medial cortex of the posterior part of the humerus at a distance equaling 63.19% (95% CI: ±0.942%) of arm length proximal to the medial epicondyle, (2) the middle of the posterior part of the humerus at a distance equaling 53.9% (95% CI: ±1.08%) of arm length proximal to the transepicondylar line, (3) the lateral cortex of the posterior part of the humerus at a distance equaling 45% (95% CI: ±0.99%) of arm length proximal to the lateral epicondyle, and (4) from the posterior to the anterior compartment at a distance equaling 35.3% (95% CI: ±0.92%) of arm length proximal to the lateral epicondyle. A strong linear relationship between these distances and arm length was observed, with an intraclass correlation coefficient of >0.9 across all measurements. Conclusions: The positions of the radial and axillary nerves maintain linear relationships with arm lengths in growing children. The locations of these nerves in relation to palpable osseous landmarks are predictable. Clinical Relevance: Knowing the locations of upper-extremity peripheral nerves as a proportion of arm length in skeletally immature patients may help to avoid iatrogenic injuries during surgical approaches to the humerus. A confident surgeon has an intimate understanding of applied anatomy and an excellent knowledge of anatomic relationships. Avoiding iatrogenic injury is critically important. Hence, various publications have described "safe zones" and reference distances from anatomic landmarks 1. These points of reference help surgeons anticipate the positions of critical structures such as nerves before they are encountered, thereby reducing the chance of iatrogenic injury 2-4. The surgical anatomy of peripheral nerves in the upper extremity has been well described in adults 5. Fleming et al. described the "one-third, two-thirds rule" to reliably identify the radial nerve as it crosses from the posterior to the anterior compartment of the upper arm 6. Uhl et al. established the 13-cm rule to avoid iatrogenic radial nerve injury when approaching the humerus posteriorly 7. Cetik et al. elucidated a "safe zone" for the axillary nerve when approaching the proximal part of the humerus through a deltoid-split approach 8. These rules simplify complex anatomy and can be easily committed to memory to avoid iatrogenic nerve injury and increase patient safety 9 .
A Method to Localize The Radial Nerve Using the ‘Apex Of Triceps Aponeurosis’ as a Landmark
Clinical Orthopaedics and Related Research®, 2011
Background The relationship of the radial nerve is described with various osseous landmarks, but such relationships may be disturbed in the setting of humerus shaft fractures. Alternative landmarks would be helpful to more consistently and reliably allow the surgeon to locate the radial nerve during the posterior approach to the arm. Questions/purposes We investigated the relationship of the radial nerve with the apex of triceps aponeurosis, and describe a technique to locate the nerve. Materials and Methods We performed dissections of 10 cadavers and gathered surgical details of 60 patients (30 patients and 30 control patients) during the posterior approach of the humerus. We measured the distance of the radial nerve from the apex of the triceps aponeurosis along the long axis of the humerus in cadaveric dissections and patients. This distance was correlated with the height and arm length. For all patients, we recorded time until first observation of the radial nerve, blood loss, and postoperative radial nerve function. Results The mean distance of the radial nerve from the apex of the triceps aponeurosis was 2.5 cm, which correlated with the patients' height and arm length. The mean time until the first observation of the radial nerve from beginning the skin incision was 6 minutes, as compared with 16 minutes in the control group. Mean blood loss was 188 mL and 237 mL, respectively. With the numbers available, we observed no difference in the incidence of patients with postoperative nerve palsy: none in the study group and three in the control group. Conclusion The apex of the triceps aponeurosis appears to be a useful anatomic landmark for localization of the radial nerve during the posterior approach to the humerus. Each author certifies that he has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that the work and all investigations were conducted in conformity with ethical principles of research. An approval from Institutional Review Board was granted.