Which bony landmark acts as a hook for the extensor pollicis longus tendon?

The bony landmark that acts as a hook for the extensor pollicis longus tendon is the dorsal tubercle of the radius, also known as Lister's tubercle. This prominence on the radius serves as a pulley, redirecting the tendon of the extensor pollicis longus as it travels towards the thumb. This anatomical feature aids in the efficient extension of the thumb at the metacarpophalangeal and interphalangeal joints.