Saudi Journal of Anaesthesia

ORIGINAL ARTICLE
Year
: 2007  |  Volume : 1  |  Issue : 2  |  Page : 53--56

Sonoanatomy of the ulnar nerve in the distal forearm


A Thallaj1, A El-Dawlatly2, A Turkistani3, O Zoraigi4, M Shraf Al-Deen5,  
1 Consultant Anesthetist, King Khalid University Hospital, Riyadh, Saudi Arabia
2 Professor of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia
3 Associate Professor, Chairman Department of Anesthesia, College of Medicine, King Saud University., Saudi Arabia
4 Resident in Anesthesia, King Khalid University Hospital., Saudi Arabia
5 Registrar in Anesthesia, King Khalid University Hospital., Saudi Arabia

Correspondence Address:
A Thallaj
Riyadh 11471, P.O.Box 7805
Saudi Arabia




How to cite this article:
Thallaj A, El-Dawlatly A, Turkistani A, Zoraigi O, Al-Deen M S. Sonoanatomy of the ulnar nerve in the distal forearm.Saudi J Anaesth 2007;1:53-56


How to cite this URL:
Thallaj A, El-Dawlatly A, Turkistani A, Zoraigi O, Al-Deen M S. Sonoanatomy of the ulnar nerve in the distal forearm. Saudi J Anaesth [serial online] 2007 [cited 2022 Jan 23 ];1:53-56
Available from: https://www.saudija.org/text.asp?2007/1/2/53/51861


Full Text

 Background



THE PRACTICE OF ULTRASOUND guided regional anesthesia requires excellent knowledge of the related clinical anatomy. In the distal forearm, the ulnar nerve gives off a dorsal cutaneous branch which supplies sensation to the dorsomedial hand and digits [1] . Ulnar verve block in the distal forearm with conventional technique may spare the dorsal branch and result in incomplete block [2],[3] . Ultrasound represents a unique modality for visualizing peripheral nerves, because of its ability to scan the nerve over a long distance, and it has been used to visualize and to guide ulnar nerve block in the distal forearm [4],[5],[6] . We aimed to describe the sonographic appearance of the ulnar nerve division in the distal forearm, test the reliability of ultrasound to depict the dorsal cutaneous branch and to examine the relationship of the ulnar nerve division point and other palpable bony landmarks.

 Methods



After institutional approval and informed consent, 100 male and female volunteers (equal gender distribution) were recruited from king khalid university hospital staff. Exclusion criteria include injury or deformity to the upper extremity. Initially, volunteers had their anthropometric data recorded, including age, gender, height and weight. Using high frequency (5-13MHz) linear transducer (LOGIQ e, GE), we scanned the medial aspect of the left distal forearm. A transverse view of the ulnar nerve, the division point and the dorsal cutaneous branch were obtained. The skin over the division point (D point) was marked in agreement between two anesthetists [Figure 1]. Two measurements were taken to map out the ulnar nerve division point [Figure 2]. A line was drawn from the ulnar styloid process to the olecranon and this distance was recorded as (OS), and the distance between the division point and the ulnar styloid process was recorded as (DS).

 Results



All subjects completed the study. Demographics of the sample can be summarized as follows [Figure 3]: Age (mean+/- SD; male: 32.9+/- 8.9, female: 39.3+/­10yr; p [7] ) have found that the dorsal branch originated at an average distance of 5.5 cm proximal to the ulnar head. In our study, we measured the distance between the ulnar nerve division point and the ulnar styloid process (the average length of the ulnar styloid process is 4.2 mm [8] ), our sonographic estimates of the DS distance (~ 5.9 cm) confirmed the previous anatomical findings. We found also that the DS distance has no correlation with other measured variables. In conclusion, high-end ultrasound machines with high frequency broad band transducers can reliably visualize the ulnar nerve division point and the dorsal cutaneous branch in the distal forearm.

References

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