The radiohumeral meniscus is an unusual anatomical variant found within the elbow joint. Presenting as meniscus-like tissue interposed between the radial head and capitellum it is similar to the knee's meniscus 1 and rarely symptomatic 1,2.
On this page:
Anatomy
The radiohumeral meniscus is typically a small, triangular structure located between the capitellum and the radial head, within the radiohumeral joint. It comprises fibrocartilaginous tissue, similar to the menisci in the knee 1, making it distinct from a synovial fold.
Radiographic features
Ultrasound
The radiohumeral meniscus is a small, triangular echogenic structure interposed between the capitellum and the radial head. It is important to compare it with the contralateral joint to confirm its presence as an anatomical variant.
MRI
MRI can provide detailed images of the radiohumeral meniscus, showing its size, shape, and any associated pathology. It is advantageous in differentiating the meniscus from other intra-articular structures or pathologies. However, it is difficult to differentiate it from a synovial fold 1,2.
Development
No evidence of a radiohumeral meniscus has been found during embryological development 1,3. However, it has been described in patients as young as 15 months old 3 and considered a developmental anomaly 1.
Its exact relationship to synovial folds, and loose annular ligaments and whether they are distinct entities or different stages of the same continuum remains unclear 2 although histological studies have confirmed that it is a true meniscus, composed of fibrocartilage without a synovial layer, and associated with small chondrocytes and fibroblasts 1,2,4.
Clinical importance
Patients with a radiohumeral meniscus may present with symptoms like the following:
snapping and/or elbow locking during elbow flexion and extension 1,2,5
lateral elbow pain
restricted range of motion
However, many cases are discovered incidentally during imaging for other conditions, as the meniscus is often asymptomatic.
Unable to process the form. Check for errors and try again.