Journal List > J Korean Soc Surg Hand > v.20(4) > 1106504

J Korean Soc Surg Hand. 2015 Dec;20(4):204-208. Korean.
Published online December 31, 2015.
Copyright © 2015. The Korean Society for Surgery of the Hand
Extensor Digiti Minimi Triggering Caused by an Anatomical Variation: A Case Report
Youn-Tae Roh,1 Changhoon Jeong,2 Soo-Hwan Kang,2 Jae-Young Lee,2 Sang-Hyun Jeon,2 and Il-Jung Park2
1Department of Orthopaedic Surgery, Uijeongbu Paik Hospital, Uijeongbu, Korea.
2Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Correspondence to: Il-Jung Park. Department of Orthopaedic Surgery, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 327 Sosa-ro, Wonmi-gu, Bucheon 14647, Korea. TEL: +82-32-340-7034, FAX: +82-32-340-2671, Email:
Received August 02, 2015; Accepted August 11, 2015.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Although flexor tendon triggering due to stenosing flexor tenosynovitis is common clinically, extensor triggering is quite rare. Known common causes are impingement between extensor tendon and extensor retinaculum, stenosis of the tendon sheath, and impingement between extensor tendon and osteophyte. We report rare case of triggering in the little finger caused by impingement between extensor digiti minimi and synovial septum.

Keywords: Trigger finger; Extensor digiti minimi; Extensor tendon


Fig. 1
A 22-year-old male student presented a mass and triggering according to the motion of the finger which were palpated on the base of fifth metacarpal bone (black asterisk).
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Fig. 2
In real time ultrasonography, extensor digiti minimi (white arrow) was observed as a single tendon at the base of fifth metacarpal bone (A), but it was divided into two slips as it progressed distally (B).
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Fig. 3
Intra-operative photographs. (A) Duplicated EDM originated distal to the retinaculum. (B,C) Synovial septum (black arrowhead) was present between the radial and ulnar EDM slip. (D) Bifurcated area of EDM tendon (black arrow) was more thickened than surrounding tendon. (E) When the little finger was flexed, impingement between bifurcated area and synovial septum resulted in tightening of the ulnar side EDM slip, with laxity of the radial slip. (F) Two EDM slips were sutured after excision of synovial septum, and then triggering was disappeared. EDM, extensor digiti minimi.
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