An additional radial wrist extensor and its clinical significance

Area of Science:

• Anatomy
• Orthopedics
• Surgical Anatomy

Background:

• Anatomical variations of forearm muscles are crucial for effective hand surgery.
• Known variants of radial wrist extensors include the extensor carpi radialis intermedius and accessorius.
• Understanding these variations aids in preventing surgical complications and interpreting imaging.

Purpose of the Study:

• To describe a newly identified anatomical variation of a radial wrist extensor muscle.
• To propose a name and discuss the clinical significance of this variant.
• To contribute to the detailed anatomical knowledge of the antebrachial region.

Main Methods:

• Anatomical dissection of the antebrachial region.
• Identification and description of an accessory extensor muscle.
• Documentation of its origin, course, and insertion.

Main Results:

• A distinct extensor carpi radialis muscle, termed extensor carpi radialis tertius, was observed.
• This variant originated independently from the common extensor origin, between the extensor carpi radialis longus and extensor digitorum communis.
• Its tendon bifurcated, inserting onto the bases of the second and third metacarpal bones.

Conclusions:

• The extensor carpi radialis tertius represents a significant anatomical variation with potential clinical relevance in hand surgery.
• This finding expands the known spectrum of radial wrist extensor anomalies.
• Awareness of this variant is important for surgeons and clinicians dealing with wrist pathologies.