Reciprocal accessory tendons of the extensor carpi radialis longus and brevis with an interlacing pattern: A cadaveric cross-sectional observational study.

D Srivani; T Pranathi; N Kavya; K Prathiba; GN Charitha

doi:10.51168/ne6g4n70

Autori

D Srivani Assistant Professor, Department of Anatomy, SVIMS-SPMC(W), Tirupati, Andhra Pradesh, India.
T Pranathi Postgraduate, Department of Anatomy, SVIMS- SPMC (W), Tirupathi,
N Kavya Assistant Professor, Department of Anatomy, SVIMS-SPMC(W), Tirupati, Andhra Pradesh, India.
K Prathiba Professor & HOD, Department of Anatomy, SVIMS-SPMC(W), Tirupati, Andhra Pradesh, India.
GN Charitha Associate Professor, Department of Anatomy, SVIMS-SPMC(W), Tirupati, Andhra Pradesh, India.

DOI:

https://doi.org/10.51168/ne6g4n70

Cuvinte cheie:

anatomical variation, cadaveric dissection, extensor carpi radialis brevis, extensor carpi radialis longus, tendon transfer, wrist extensor

Rezumat

Background

Anatomical variations of the radial wrist extensors include accessory muscle bellies, supernumerary tendons, intertendinous connections, and anomalous distal attachments. A configuration in which accessory tendons arise from both the extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB), interlace, and continue distally beside the opposite primary tendon is uncommon.

Objectives: To document the gross morphology, frequency within the dissected sample, and potential clinical relevance of reciprocal accessory ECRL and ECRB tendons identified during routine cadaveric dissection.

Methods

This descriptive cross-sectional cadaveric study examined 20 formalin-embalmed upper limbs in the Department of Anatomy. A standardized dissection sequence exposed the lateral forearm and second dorsal extensor compartment. The origin, course, crossing relationship, and distal continuation of the primary and accessory tendons were recorded and photographed. All available limbs were assessed to reduce selective inclusion, and findings were summarized using counts, percentages, and structured morphological descriptors.

Results

One of the 20 upper limbs (5.0%) showed simultaneous accessory tendons of the ECRL and ECRB. The accessory ECRL tendon coursed medially toward the ECRB, whereas the accessory ECRB tendon crossed superficially through the ECRL region. The slips interlaced. Distally, the accessory ECRL tendon continued alongside the primary ECRB tendon, while the accessory ECRB tendon continued alongside the primary ECRL tendon. The remaining 19 limbs (95.0%) did not show this reciprocal configuration.

Conclusion

The observed arrangement expands the documented spectrum of radial wrist extensor anatomy. Recognition of reciprocal accessory tendons is relevant during dorsal wrist ultrasonography, magnetic resonance imaging, tendon harvesting, reconstructive tendon transfer, and operative exposure of the second extensor compartment.

Recommendations

Surgeons and radiologists should trace unexpected radial wrist extensor slips carefully to avoid misidentification and inadvertent injury during clinical procedures.

Referințe

1. Greenbaum B, Itamura J, Vangsness CT, Tibone J, Atkinson R. Extensor carpi radialis brevis: an anatomical analysis of its origin. J Bone Joint Surg Br. 1999;81(5):926-929. doi:10.1302/0301-620X.81B5.9566.

2. Khullar M, Kalsey G, Laxmi V, Khullar S. Variations in the nerve supply to the extensor carpi radialis brevis. J Clin Diagn Res. 2012;6(1):13-16. doi:10.7860/JCDR/2012/.1879.

3. Lee JC, Healy JC. Normal sonographic anatomy of the wrist and hand. Radiographics. 2005;25(6):1577-1590. doi:10.1148/rg.256055028.

4. Wood VE. The extensor carpi radialis intermedius tendon. J Hand Surg Am. 1988;13(2):242-245. doi:10.1016/S0363-5023(88)80058-3.

5. Albright JA, Linburg RM. Common variations of the radial wrist extensors. J Hand Surg Am. 1978;3(2):134-138. doi:10.1016/S0363-5023(78)80060-4.

6. Yoshida Y. Anatomical studies on the extensor carpi radialis longus and brevis muscles in Japanese. Okajimas Folia Anat Jpn. 1994;71(2-3):127-135. doi:10.2535/ofaj1936.71.2-3_127.

7. Claassen H, Wree A. Multiple variations in the region of mm. extensores carpi radialis longus and brevis. Ann Anat. 2002;184(5):489-491. doi:10.1016/S0940-9602(02)80084-X.

8. Hong MKY, Hong MKH. An uncommon form of the rare extensor carpi radialis accessorius. Ann Anat. 2005;187(1):89-92. doi:10.1016/j.aanat.2004.08.001.

9. Nayak SR, Madhan Kumar SJ, Krishnamurthy A, Prabhu LV, Ranade AV, Rai R, et al. An additional radial wrist extensor and its clinical significance. Ann Anat. 2007;189(3):283-286. doi:10.1016/j.aanat.2006.10.005.

10. Nayak SR, Krishnamurthy A, Prabhu LV, Rai R, Ranade AV, Madhyastha S. Anatomical variation of radial wrist extensor muscles: a study in cadavers. Clinics (Sao Paulo). 2008;63(1):85-90. doi:10.1590/S1807-59322008000100015.

11. West CT, Ricketts D, Brassett C. An anatomical study of additional radial wrist extensors including a unique extensor carpi radialis accessorius. Folia Morphol (Warsz). 2017;76(4):742-747. doi:10.5603/FM.a2017.0047.

12. Yang K, Choi IJ, Lee JH. Accessory head of the extensor carpi radialis longus muscle merging with extensor carpi radialis brevis muscle. Surg Radiol Anat. 2018;40(9):1001-1003. doi:10.1007/s00276-018-2035-z.

13. Coello MA, Coomar LA, Campbell M. A unique bilateral variation of the extensor carpi radialis longus: a case report. J Funct Morphol Kinesiol. 2024;9(3):109. doi:10.3390/jfmk9030109.

14. Smith J, Pourcho AM, Kakar S. Sonographic appearance of the extensor carpi radialis intermedius tendon. PM R. 2015;7(7):789-791. doi:10.1016/j.pmrj.2015.04.005.

15. Olchowy C, Lasecki M, Zaleska-Dorobisz U. Wrist ultrasound examination-scanning technique and ultrasound anatomy. Part 1: dorsal wrist. J Ultrason. 2015;15(61):172-188. doi:10.15557/JoU.2015.0015.