Sonoanatomy of the deep branch of the ulnar nerve

Abstract

Introduction This study evaluated the sonoanatomy of the deep motor branch of the ulnar nerve (DBUN) using high‐resolution ultrasonography (HRUS). Methods In 60 wrists of 30 healthy adults, the gross course, cross‐sectional area (CSA), and diameter of the DBUN were observed by HRUS (frequency band 3–16 MHz). Its course was assessed by using the distance from anatomical landmarks and depth from the skin. Results The DBUN was found in all subjects with HRUS, and it branched off from the ulnar nerve before reaching the hamate bone. At the hook‐of‐hamate level, the mean DBUN CSA was 1.5 ± 0.2 mm2, and the mean diameter was 1.5 ± 0.2 mm. The mean distance from the hamate hook to the DBUN was 5.4 ± 1.0 mm, and the mean depth from the skin was 8.6 ± 1.6 mm. Discussion Sonoanatomy of the DBUN obtained from HRUS may be useful in detecting or preventing DBUN lesions.

Study of the Median and Ulnar Nervous Branks to Kaplan’s Line

“…They used the KCL and the line accompanying the ulnar margin of the ring finger as a reference for the access route, to avoid damage to the DBUN. Choi and Yoon 13 evaluated the DBUN in 60 wrists of 30 healthy adult patients using high-resolution ultrasonography. The course of the RMNU was evaluated using the hamate annulus and skin depth as reference.…”

Sonographic normal values for the cross-sectional area of the ulnar nerve: a systematic review and meta-analysis

“…Only one study, including extremes of BMI (mean BMI of 35.2 kg/ m 2 ), had noticeably higher CSA values, supporting the hypothesis that BMI may influence the CSA value. One of the included studies compared CSA values of the ulnar nerve between subgroups based on BMI (< 25 kg/m 2 versus ≥ 25 kg/m 2 ) and found no difference at the wrist and in the hand [14]. However, included participants all had a BMI below 30.0 kg/m 2 and do not represent extremes of BMI.…”

“…CSA values of branches of the ulnar nerve (i.e. deep branch of the ulnar nerve, superficial branch of the ulnar nerve, dorsal ulnar cutaneous nerve and palmar ulnar cutaneous nerve) in the hand were described in only four studies and are shown in Table C.2 (Online Supplementary File C) [11][12][13][14].…”

Ultrasound of the Ulnar Nerve: A Pictorial Review

“…Since the shape is similar along its course, diameter may also be used rather than CSA. 17,55,56 Reported values for the DBUN are summarized in Table 1.…”

“…DBUN normal measurements have not been greatly reported in the literature and are based on small series of healthy individuals. Since the shape is similar along its course, diameter may also be used rather than CSA 17,55,56 …”