Cubital tunnel: ulnar nerve compression at the elbow

At the elbow the ulnar nerve passes behind the medial epicondyle and enters between the heads of flexor carpi ulnaris. It is the second most common entrapment neuropathy of the upper limb. Its relations are shown here in 3D, together with the ULNT3 test that loads it.

Anatomy of the passage

Retroepicondylar groove and cubital tunnel — Plate derived from Z-Anatomy / BodyParts3D · CC BY-SA 4.0

The ulnar nerve passes behind the medial epicondyle and enters between the heads of flexor carpi ulnaris. The fibrous roof of the tunnel, local bands and changes of space during elbow flexion may contribute to entrapment.

Nerve: Ulnar nerve: cubital tunnel and Guyon's canal
Frequency: Common, well-established site for this nerve.
Type of evidence: Anatomical and clinical review

References

Choi SJ, Ahn JH, Ryu DS, Kang CH, Jung SM, Park MS, Shin DR. Ultrasonography for nerve compression syndromes of the upper extremity. Ultrasonography 2015. PubMed 25682987 · DOI

Ultrasound landmarks

In the retroepicondylar groove the nerve lies between the medial epicondyle and the olecranon; distally it enters between the heads of flexor carpi ulnaris. The roof of the tunnel (Osborne's ligament) is not segmented in this package.