Seudoartrosis en la deformidad espinal adulta siguiente a la instrumentación…

Yongjung J. Kim, MD1, Keith H. Bridwell, MD1, Lawrence G. Lenke, MD1, Kyu-Jung Cho, MD2, Charles C. Edwards, II, MD3 and Anthony S. Rinella, MD4

1 Washington University in St. Louis, One Barnes-Jewish Hospital Plaza, Suite 11300 West Pavilion, Campus Box 8233, St. Louis, MO 63110. E-mail address for K.H. Bridwell: bridwellk@msnotes.wustl.edu 2 Inha University, College of Medicine, 7-206, 3rd Street, Sinheung-Dong, Jung-Gu, Incheon 400-711, South Korea 3 The Maryland Spine Center, 301 St. Paul Place, Baltimore, MD 21202 4 Loyola University Medical Center, Orthopaedic Surgery and Rehabilitation, Macguire Center, Suite 1700, 2160 South First Avenue, Maywood, IL 60153

Investigation performed at Washington University Medical Center, St. Louis, Missouri

Background: There have been few detailed reports concerning pseudarthrosis following spinal instrumentation and arthrodesis in adults with spinal deformity since the introduction of modern segmental fixation techniques. The purposes of this study were to analyze the prevalence, risk factors, and outcome scores on the Scoliosis Research Society Instrument-24 associated with pseudarthrosis following instrumentation and arthrodesis for the treatment of spinal deformity in adults.

Methods: A clinical and radiographic assessment of 232 adults with spinal deformity who were treated surgically at a single institution was conducted. The average age of the patients was 40.8 years, and the operation was a primary procedure in 150 patients and a revision procedure in eighty-two patients. All patients who underwent a long (four vertebrae or more) spinal instrumentation and arthrodesis with a minimum follow-up of two years were included in the analysis. Clinical outcomes were assessed with the Scoliosis Research Society questionnaire.

Results: Forty patients had a pseudarthrosis. Factors that were found to be significantly associated with pseudarthrosis were preoperative thoracolumbar kyphosis of >20° (p < 0.0001), an age of more than fifty-five years (p = 0.001), arthrodesis to S1 compared with arthrodesis to L5 or a cephalad level (p = 0.002), and arthrodesis of more than twelve vertebrae (p = 0.037). Patients with a pseudarthrosis had lower total outcome scores on the Scoliosis Research Society questionnaire, on the average, than those without a pseudarthrosis (p = 0.001).

Conclusions: The prevalence of pseudarthrosis following long arthrodesis with use of modern segmental spinal instrumentation for the treatment of spinal deformity in adults was 17%, and the clinical outcome in these patients can be negatively affected by the pseudarthrosis.