Anatomic relations of the median nerve to the ulnar insertion of the brachialis muscle: safety issues and implications for medial approaches to the elbow joint (original) (raw)
Related papers
A Rare Case of Lateral Displacement of Median Nerve in a Dislocated Elbow and its Management
2022
O’Driscoll proposed mechanism of Posterolateral Rotatory Instability of elbow involves axial loading with flexion at the elbow. The Ulno-humeral joint undergoes external rotation due to eccentrically loaded triceps, while the humerus (whole-body) Nerve injury following dislocation or fracture-dislocation of the elbow is rare [1, 2], it commonly occurs in the pediatric age group, yet it can occur rarely in adults. The most commonly involved is the ulnar nerve followed by the median nerve with an incidence of 3% [3]. Anatomically median nerve lies medial to the brachial artery, deep to bicipital aponeurosis, and anterior to brachialis muscle at the level of the elbow. Hackel et al. [4, 5] showed that the median nerve lies close to the trochlea in extension (4.8 mm in full extension and 8.4 mm in 90° flexion) and it is located above the medial quarter of the trochlea (5.9 mm from the medial border of trochlea). As the median nerve lies medially in the elbow in relation to the distal hu...
Surgical anatomy of the radial nerve at the elbow
Surgical and Radiologic Anatomy, 2009
An anatomical study of the brachial portion of the radial nerve with surgical implications is proposed. Thirty specimens of arm from 20 fresh cadavers (11 male, 9 female) were used to examine the topographical relations of the radial nerve with reference to the following anatomical landmarks: acromion angle, medial and lateral epicondyles, point of division between the lateral and long heads of the triceps brachii, lateral intermuscular septum, site of division of the radial nerve into its superWcial and posterior interosseous branches and entry and exit point of the posterior interosseous branch into the supinator muscle. The mean distances between the acromion angle and the medial and lateral levels of crossing the posterior aspect of the humerus were 109 ( §11) and 157 ( §11) mm, respectively.
Clinical Anatomy, 2009
The percutaneous placement of lateral distal humeral pins risks injury to the radial nerve. We aimed to provide a reliable and safe parameter for the insertion of lateral distal humeral pins. A secondary aim of this study was to investigate the effect of pin/screw placement in the intended zone of fixation at the lateral distal humerus. We dissected 70 fresh cadaveric upper limbs and the radial nerve was identified and its course followed into the anterior compartment. The point where the radial nerve crosses humerus in mid lateral plane was identified and the distance between this point and lateral epicondyle was measured, as was the maximum trans-epicondylar distance, along with the olecranon fossa height. Statistical analysis was performed using the Pearson correlation coefficient. The average trans-epicondylar distance was measured at 62 ± 6 mm (range 52–78 mm), and the average lateral radial nerve height was 102 ± 10 mm (range 75–129 mm). The ratio of the lateral nerve height to the trans-epicondylar distance was an average of 1.7 ± 0.2 (range 1.4–2.0). The Pearson correlation coefficient between the lateral nerve height and the trans-epicondylar distance was r = 0.95. A relative dimension, the trans-epicondylar distance is both reliable and easily accessible to the operating surgeon. The absolute safe zone for pin entry into the lateral distal humerus is that area lying within the caudad 70% of a line, equivalent in length to the patient's own trans-epicondylar distance, when projected proximally from the lateral epicondyle. Clin. Anat. 22:684–688, 2009. © 2009 Wiley-Liss, Inc.
Cutaneous nerves at risk during the posterior midline approach to the elbow
Hand (New York, N.Y.), 2010
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 ner...
JAAOS: Global Research and Reviews, 2019
Introduction: The purpose of this study was to investigate whether a safe zone rule could be applied to prevent iatrogenic injuries to the radial nerve (RN); and determine whether there is a relationship between the diameter of the radial head and capitellum and the distance of the posterior interosseous nerve (PIN) to the radiocapitellar joint. Methods: Ten fresh-frozen cadaveric specimens were used to measure the distances between the RN and the lateral epicondyle; the PIN and the radiocapitellar joint; the lateral epicondyle and the PIN as it crossed the ulnohumeral joint; the diameter of the radial head; the width of the capitellum; and the fingerbreadths of the specimens. Results: Four fingerbreadths determined a safe zone between the lateral epicondyle and the RN proximally at the point at which it pierced the intermuscular septum and the mid-lateral portion of the humeral shaft. Two fingerbreadths provided a safe zone for the PIN from the radiocapitellar joint to the midpoint of the axis of the radius only with the forearm in pronation. Conclusion: A four-finger rule, two-finger rule, and radial head diameter or capitellum size may predict a safe zone for the RN and PIN except for the segment of the nerve where it crosses the anterior cortex of either the humerus or radius.
Anatomical study of Variations of Median Nerve and Musculocutaneous Nerve in the Arm
2020
Background: The variations related to the median nerve and musculocutaneous nerve are relatively less common. The variations may have potential clinical implications especially during surgeries and nerve blocks. Materials and Method: The routine dissection of 50 adult cadavers including 42 males and 8 females in the Department of Anatomy during undergraduate training was carried out to detect the variations in the structure, formation and relation of Median nerve and musculocutaneous nerve. Results and Findings: There was a variation observed in the formation of median nerve in three adult cadavers. In three male cadaver, there was unilateral variation in the formation of the median nerve by more than two roots . However, in each of these cadavers the distribution of the median nerve was normal in arm, forearm and palm. There was normal pattern of formation, relation and course of Median nerve in rest of the cadavers. Absence of musculocutaneous nerve, and nerve not piercing coracob...
Journal of Plastic Surgery and Hand Surgery, 2024
Introduction: Median nerve injuries occur in approximately 3% of pediatric elbow fracture dislocations. These rare injuries can be difficult to diagnose, and the results are poor in delay cases. Surgical timing is one of the most important prognostic factors. We aimed to present three patients with median nerve palsy who were referred to our clinic late, and according to these cases, we emphasized the expected time frame for exploration based on our anatomical cadaver study. Materials and Methods: Between 2008 and 2010, three patients were referred to our clinic because of median nerve paralysis after a treated elbow dislocation. The mean interval between injury and referral was 15 (min: 13-max: 18) months, and the mean age of the patients was 15 (13-18) years. Neurolysis was performed in two patients, and for the third patent, after neurolysis, axonal continuity was observed to be disrupted so sural nerve grafting was performed with four cables. Tendon transfers were performed in all patients. A total number of 20 upper extremities of 10 cadavers were dissected. Due to its proximal innervation and ease of assessment, the muscle innervation of the flexor pollicis longus (FPL) was planned to be evaluated. The distance from the medial epicondyle is calculated in the cadaver study where the nerve injury is found. Results: The mean length from the medial epicondyle to the motor innervation of FPL was calculated in each specimen and found to be 101.99 millimeters (mm) (range: 87.5-134.2). The mean longest innervation of FPL was 110.83 mm from (range 87.5-148.1) the medial epicondyle calculated by including each specimens longest nerve length. Knowing that the healing time of a nerve lesion is 1 mm per day, we calculated that the recovery of FPL would take approximately 4 months. Conclusion: When nerve healing is expected to be 1 mm a day in axonotmesis type injury, after the median nerve palsy following elbow dislocation, thumb flexion should be achieved in the following 4 months generally if the nerve was not entrapped in the joint. This cadaver-based study objectively defined how long to wait for the innervation of the FPL in median nerve injuries in elbow fracture dislocations.