Congenital hypoplasia of the lumbar pedicle with spondylolisthesis: report of 2 cases

Abstract

<jats:p>Congenital hypoplasia of the spinal pedicle is a rare condition. Previously reported cases were treated conservatively or with posterior instrumented fusion. However, the absence or hypoplasia of the lumbar pedicle may increase the difficulty of pedicle screw fixation and fusion. Herein, the authors describe 2 cases of rare adult congenital hypoplasia of the right lumbar pedicles associated with spondylolisthesis. The patients underwent anterior lumbar interbody fusion with a stand-alone cage as well as percutaneous pedicle screw fixation. This method was used to avoid the difficulties associated with pedicle screw fixation and to attain solid fusion. Both patients achieved satisfactory outcomes after a minimum of 2 years of follow-up. This method may be an alternative for patients with congenital hypoplasia of the lumbar spinal pedicle.</jats:p>

Surgical management of congenital thoracic kyphosis and multilevel bilateral thoracic pedicle aplasia: case report

“…4,13 Pedicle aplasia most frequently occurs in the cervical or lumbar spine, although thoracic pedicle aplasia has also been described. [2][3][4][5]8,13,15,17,18,20 Most commonly, only one pedicle and one vertebral level are involved. 13,20 Bilateral pedicle aplasia of multiple vertebrae appears to be exceedingly rare, with one prior case report in the literature.…”

“…8,[10][11][12]21 The absent pedicle is typically evident on plain radiographs, although additional imaging with CT, myelography, or MR may be necessary, particularly in the case of a single missing pedicle, in order to rule out malignancy, vascular anomaly, or inflammatory disease. 4,5,20 Images of pedicle aplasia typically demonstrate an abnormally enlarged neural foramen filled with fat and fibrous tissue. 19,20 When a single pedicle is involved, the contralateral pedicle is often hypertrophied.…”

“…20 Pedicle aplasia is often associated with dysplasia or absence of other ipsilateral pillar or neural arch elements, including the lamina, spinous process, and transverse process. 4,8,19 Pedicle aplasia is also frequently accompanied by hypoplasia of the articular facet and other facet joint abnormalities, which may result in biomechanical abnormalities due to compromised rotational and extensional stability. 5,8,13,20 The most common symptom reported by patients with single-level pedicle aplasia is back pain responsive to conservative management, although patients may develop neurological deficits due to spondylolisthesis or degenerative changes.…”

“…Patients with intractable back pain or neurological deficits require surgical intervention. 4 One prior case report exists in which pedicle aplasia of multiple thoracic vertebrae resulting in severe flexible thoracic kyphosis is described. 15 Rauzzino et al described a patient with bilateral aplasia of the T4-8 pedicles, resulting in 64° of kyphosis.…”

“…Symptomatic patients with pedicle aplasia may undergo either anterior or posterior instrumentation and fusion. 4,14 Hsieh et al noted that pedicle aplasia increases the difficulties associated with pedicle screw placement and solely placed percutaneous pedicle screws in normal pedicles; 4 similarly, in the patient described by Rauzzino et al, hook claw instrumentation was placed. 15 However, Kaito et al noted that pedicle screws may be placed at the site of pedicle aplasia directly into the vertebral body where the pedicle would otherwise be located.…”