11.5.18  Postoperative Deformity

11.5.18.1\ Discussion

Postoperative deformity can manifest as kyphosis and flat-back syndrome. Flat-back syndrome is an iatrogenic loss of lumbar lordosis due to the presence of thoracolumbar lordosis. Clinically, this condition consists of forward inclination of the spine, back pain, and inability to stand erect. Imaging plays an important role in the work-up

a

of patients with flat-back syndrome. Sagittal CT or MRI and full-length lateral views of the spine with the knee and hips flexed are particularly useful­ for confirming the diagnosis. In addition, these studies are necessary for planning corrective procedures when conservative therapy fails. Several techniques are available to correct lumbar spine sagittal plane deformities, including pedicle subtraction (Fig. 11.117) and wedge osteotomies (Fig. 11.118).

b

Fig. 11.117  Postoperative deformity treated with pedicle subtraction osteotomy. The patient presented with long-­standing focal kyphosis following fusion from L4 to the sacrum. Lateral radiograph (a) shows straightening of L4 to the sacrum and kyphosis at the level above the sur-

gically fused levels. Lateral radiograph after osteotomy (b) shows resection of a portion of the pedicles and posterior vertebral body with correction of lumbar lordosis (bracket)

Fig. 11.119  Baclofen pump components. The patient has a history of cerebral palsy with a baclofen pump for spastic quadriparesis. Scout image (a) and axial CT image

(b) show the pump mechanism in the subcutaneous tissues and the infusion catheter (arrows) within the spinal canal. Photograph of the pump device (c)

Fig. 11.120  Spinal hypotension syndrome. The patient presented with postural headaches after baclofen pump insertion. Coronal (a) and sagittal (b) post-contrast

T1-weighted MR images show diffuse pachymeningeal thickening and enhancement, as well as prominence of the anterior spinal venous epidural plexus (arrow)