Radiolunate

Radiolunate refers to the radiolunate joint, the articulation between the distal radius and the lunate bone at the wrist. It is a key component of the radiocarpal joint, formed by the lunate facet on the distal radius interacting with the lunate.

Anatomy and ligaments: The radiolunate articulation is stabilized by the dorsal radiolunate and palmar radiolunate ligaments, which are part of the larger radiocarpal ligament complex. This joint works with neighboring articulations such as the radioscaphoid and radiotriquetral joints to permit wrist motion and help distribute axial load across the carpus.

Clinical relevance: Radiolunate alignment is routinely evaluated on wrist radiographs when assessing carpal injuries. Disruption of the radiolunate articulation can accompany perilunate dislocations or lunate dislocations. The radiolunate angle, measured on lateral views, is used to assess carpal instability and ligamentous injury; abnormal angles suggest malalignment or instability of the radiocarpal complex.

Imaging and interpretation: On standard X-ray views, the radiolunate joint is seen as the contact between the lunate and the distal radius. Accurate interpretation of the radiolunate space and angle aids in diagnosing acute injuries and guiding treatment decisions.