REIDER PART 239

Chapter 8_Cervical and Thoracic Spine 299

prominens, and it identifics thc spinous process of C7. Above this, the spinous processes of the cervical vcrtebrae arc bifid and less prominent. Forward flexion of thc neck and back tends to make the C7 and Tl spinous processes morę prominent in a thin individual ( Fig. 8-3). Trapezius. The trapezius is the most superficial and the most easily identifiable of the posterior neck muscles. Fach trapezius is roughly triangular, originating from the occiput and the spinous processes of C7 through Tl2 and inserting laterally on the clavicle, thc acromion, and the scapular spine. The upper border of the trapezius is quite prominent as it blends into the medial shoulder.

Deep to the trapezius lies the transversocostal group of muscles and the even deeper transversospinal group. The transversocostal group includes the splenius capitis, the splenius cervicis, the iliocostalis cervicis, and the longis-simus cervicis and is visible in thc proximal neck lateral to the superior trapezius.

Lateral Structures. Lateral to the spine, the other struc-tures visiblc from the posterior position should also appear symmetric. The shoulders should be level, and the scapulac located eąuidistant from the spine. The rib prominences on either side of the spine should be symmetric. When the patient is instructcd to relax and to allow the upper extremities to hang limply at the sides, the size and the shape of the space between the arms and the sides of the body should be identical. At the base of thc spine, the posterior landmarks of the pclvis should appear symmetric and level. A pclvis that does not appear to be level may be the rcsult of either a leg length discrep-ancy in a patient with an otherwise normal spine or a fixed spinał deformity.

Departure from symmetry in any of these parameters may suggest a localized anomaly or a deformity of the spine in the coronal piane. An example of a localized anomaly is SprengeFs deformity, a congenital condition in which one of the scapulae remains fixed proximally in a

Figurę 8-3. Posterior aspect of the neck in forward flexion.

tightly contracted position (see Fig. 2-21). Coronal defor-mities of the spine include a list and scoliosis.

List. A list is a pure planar shift to one side in the coronal piane (Fig. 8-4). It may be caused by pain, muscle spasm, or certain anomalies. When a list is present, the proximal part of the spine is shifted to one side, so that a plumb linę dropped from the occiput or the yertebra prominens does not hang directly over the natal cleft and the spaces between the upper extremities and the trunk are asym-metric. Lists are morę common in the lumbar spine than in the cervical or thoracic spine.

Scoliosis. Scoliosis is a morę complex, helical deformity in which a curve in the coronal piane is combined with abnormal rotation of the vertebrac in the transversc piane (Fig. 8-5). A well-compcnsated scoliosis, defincd as one in which thoracic and lumbar curves are roughly equal in magnitude but opposite in direction, may be surprisingly difficult to detcct during observation of the spine in the standing patient. In these cases, visually trac-ing the path of the spinous processes may help the exam-iner appreciatc that they follow a subtle S curve, although the yertebra prominens is located directly above the natal cleft.

If a subtle scoliosis is suspected, looking for the rib prominence usually associated with thoracic scoliotic curves makes the deformity easier to dctect. The rib prominence is a reflection of the rotational component of

Figurę 8-4. A list to the left side.