The LUCL is the critical lateral elbow stabiliser, running from the lateral epicondyle to the supinator crest of the ulna. Its disruption produces posterolateral rotatory instability (PLRI) — the elbow supinates and the radial head subluxes posterolaterally under varus-supination stress. LUCL reconstruction using a palmaris or gracilis graft through bone tunnels restores PLRI. The lateral pivot shift test demonstrates PLRI under anaesthesia.
| Origin | Lateral epicondyle (isometric point) |
|---|---|
| Insertion | Supinator crest of the ulna |
| Actions | Primary restraint against posterolateral rotatory instability of the elbow; maintains the ulnohumeral articulation during varus and rotational loads |
|---|
LUCL insufficiency produces the snapping, locking elbow that goes out with the arm extended and loaded in the supinated position. Arthroscopic lateral pivot shift test, the chair-rising test, and the floor push-up test all provoke PLRI. LUCL reconstruction is performed for recurrent symptomatic PLRI unresponsive to conservative management.
LUCL disruption from elbow dislocation producing snapping elbow with varus-supination loading managed with LUCL reconstruction.
