A Method to Localize The Radial Nerve Using the ‘Apex Of Triceps Aponeurosis’ as a Landmark

Abstract

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 MethodsWe 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. IntroductionOwing to an increase in high-energy trauma cases, the incidence of fractures of the humerus diaphysis is increasing. Operative treatment of humeral fractures, especially the distal third region, chronic osteomyelitis of the distal third of the humerus requiring sequestrectomy and radial nerve palsy requiring exploration, usually requires a posterior approach to the humerus. This approach causes iatrogenic radial nerve injury in 0% to 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.

Treatment of Humeral Shaft Fractures

“…A study that was performed on cadavers and sixty patients measured the distance of the radial nerve from this apex. Those results indicate that the distance of the radial nerve was consistently about 2.5 cm from the apex of the triceps aponeurosis 54 .…”

The Tricipital Aponeurosis — A Reliable Soft Tissue Landmark for Humeral Plating

“…In 2011, Arora et al examined the position of the nerve in relation to the apex of the aponeurosis in both the cadaveric and the operative setting. 35 It was noted that the nerve could reliably be located 25 mm proximal to the apex of the aponeurosis. This correlates with and supports our finding of the nerve positioned 21.8 mm from this point (referred to as the medial apex of the aponeurosis).…”

Causes of Secondary Radial Nerve Palsy and Results of Treatment

“…The radial nerve arises from the ventral branches of the nervi spinalis C7–Th1. It then creates the posterior cord of the brachial plexus [ 8 ]. Together with the accompanying vessels, it then proceeds from the medial side to the side of the posterior surface of the humerus in the groove of the radial nerve, and on the border of the middle and distal 1/3 of the humeral shaft turns to the side-arm front surface [ 9 ].…”

“…[ 10 ]. Other studies have indicated a higher course for the radial nerve, from the proximal humerus (53% of the humeral length) at 12.0±2.3 cm (range, 7.4–16.6 cm) and from the olecranon fossa (36% of the humeral length) at 16.0±0.4 cm (range, 9.0–20.5 cm) [ 8 , 12 ].…”

“…The large anatomical variability in the course of the nerve, which increases the risk of damage to the radial nerve, affects both the surgical access and type of stabilization. This is why many different surgical approaches, including anterior, anterolateral, lateral, posterior, and modified approaches, have been used to expose the humerus and to complete fixation [ 8 ].…”