Extensor carpi radialis brevis. An anatomical analysis of its origin

Area of Science:

• Anatomy
• Histology
• Orthopedics

Background:

• Lateral epicondylitis, commonly known as tennis elbow, is a frequent cause of elbow pain.
• The extensor carpi radialis brevis (ECRB) tendon is often implicated as the primary source of pain in lateral epicondylitis.
• Understanding the precise anatomical origin and structure of the ECRB tendon is crucial for accurate diagnosis and treatment.

Purpose of the Study:

• To investigate the anatomical origin and histological characteristics of the extensor carpi radialis brevis tendon.
• To determine the degree of separation between the extensor carpi radialis brevis and extensor carpi radialis longus tendons at their origin.
• To evaluate the relationship between the extensor tendons and the joint capsule.

Main Methods:

• Examination of 40 fresh frozen human cadaver specimens.
• Gross anatomical observation of the extensor tendon origins.
• Histological analysis using haematoxylin and eosin and trichrome staining to visualize collagenous structures.

Main Results:

• No definitive anatomical separation was observed between the extensor carpi radialis brevis and extensor carpi radialis longus tendons at the osseotendinous junction.
• Histological findings confirmed the lack of distinct separation between these two tendons.
• The extensor tendons were found to be in close proximity to the joint capsule, but no interdigitation with the capsule was evident.

Conclusions:

• The anatomical and histological findings suggest that the extensor carpi radialis brevis tendon does not have a clearly defined, separate origin.
• The pain associated with lateral epicondylitis may originate from the common extensor tendon origin rather than solely from the extensor carpi radialis brevis.
• These findings necessitate a re-evaluation of the etiological basis of lateral epicondylitis and the role of the ECRB tendon.