An accessory head of the extensor indicis: a rare case report
Issued Date
2024-01-01
Resource Type
ISSN
09301038
eISSN
12798517
Scopus ID
2-s2.0-85197532750
Journal Title
Surgical and Radiologic Anatomy
Rights Holder(s)
SCOPUS
Bibliographic Citation
Surgical and Radiologic Anatomy (2024)
Suggested Citation
Suwannakhan A., Yurasakpong L., Taradolpisut N., Somrit M., Chaiyamoon A., Georgiev G.P., Iwanaga J., Tubbs R.S. An accessory head of the extensor indicis: a rare case report. Surgical and Radiologic Anatomy (2024). doi:10.1007/s00276-024-03433-7 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/99642
Title
An accessory head of the extensor indicis: a rare case report
Corresponding Author(s)
Other Contributor(s)
Abstract
Purpose: A deep knowledge of the variations of the posterior forearm musculature is crucial for assessing and diagnosing conditions in this region. Extensor indicis (EI) is one of the muscles in this region, which exhibits diverse anatomical variations. This report documents an extremely unusual form of the EI with an accessory head on the dorsum of the hand. Methods: During routine dissection, an extremely rare presentation of the EI was found in the left forearm of a 94-year-old female cadaver. Results: This unusual EI consisted of two muscle bellies. The traditional belly originated from the distal two-thirds of the ulna. The muscle became tendinous around the carpal area, distal to the extensor retinaculum. The tendon was subsequently joined by an accessory muscle belly originating from the distal radioulnar ligament. The EI tendon inserted onto the dorsal expansion of the index finger, ulnar to that of the extensor digitorum. The posterior interosseous nerve innervated the muscle. Conclusion: Herein, we report an extremely rare form of the EI. To our knowledge, EI with an accessory head has only been reported rarely over the past 200 years. Moreover, our report appears to be the first case with photographic details of this anatomical variation. Clinicians should be aware of this variation for proper diagnosis and treatment.