Which cervical orthosis is a four-poster design?

• A. Knight brace
• B. Halo orthosis
• C. Minerva orthosis
• D. Four-poster orthosis

Answer: (D)

In cervical orthoses, the way the device restrains the head to the torso determines how rigid and invasive it is. A four-poster design is defined by four vertical posts that connect a headpiece to a thoracic vest, creating a rigid scaffold that immobilizes the cervical spine across flexion–extension, lateral bending, and rotation. This four-post configuration provides strong stabilization without skull pins, making it a clearly identifiable design among cervical immobilizers.

This is distinct from a halo, which uses pins screwed into the skull to achieve immobilization, and from a cervicothoracic shell like the Minerva, which relies on a solid shell and plates rather than four posts. The Knight brace is another type of cervical orthosis with its own anchorage pattern and does not epitomize the four-post setup.