Spinous process

a part of a vertebra that projects backward from the arch, to which some muscles of the back are attached; alternatively, a portion of the scapula. Also, see spinous process.

2. Pathology

The spinous process of the scapula may undergo fracture, usually as a result of direct trauma.

In rheumatoid arthritis, spinous process erosions or destruction may occur at one or more locations in the cervical spine. Tapering of the spinous elements may result from inflammation of the adjacent supraspinous ligaments or neighboring bursae. A similar appearance is seen in some patients with ankylosing spondylitis.

In degenerative disease, the spinous processes may become closely approximated or in direct contact, leading to kissing spines with reactive eburnation (Baastrups disease). The spinous processes may also be enlarged.

Hypertrophy of the tips of the spinous processes may occur in the lumbar region in older persons, especially those with an occupational history of long periods of back flexion.

Fractures of the spinous processes of the cervical vertebrae may occur from direct or indirect trauma or chronic stress. An example is the avulsion injury occurring in persons shovelling heavy soil or clay (clay shovellers fracture), probably related to repeated stress caused by the pull of the trapezius and rhomboid muscles on the spinous processes.

DR