This is a superb paper on the topic of pseudarthrosis in adult spinal deformity following multisegmental instrumentation and arthrodesis. The senior authors have tremendous experience in this area. The paper reviews 232 adult patients, of whom 150 underwent a primary operation and eighty-two underwent a revision. Forty patients had a pseudarthrosis, a prevalence of 17%. The strengths of this article are the long-term follow-up averaging five years (range, two to 16.8 years) and the outcomes that were based on the internationally used Scoliosis Research Society Instrument-24 patient questionnaire. The indications for surgery were a major deformity (scoliosis of >40°, thoracic kyphosis of >75°, coronal imbalance, documented progression of the deformity with pseudoarthrosis and back pain, and/or symptoms of spinal stenosis). Anterior and posterior combined arthrodesis was used for patients who were determined to be at high risk for pseudoarthrosis and included a long arthrodesis to the sacrum, large and stiff coronal and/or sagittal deformities, and areas of pseudarthrosis from prior surgery with associated kyphosis. The average age of the patients at the time of surgery was 40.8 years, and the preoperative diagnosis was adult scoliosis in 131 patients, sagittal imbalance syndrome in ninety, and Scheuermann kyphosis in eleven.
The importance of this paper, which cannot be overemphasized, is the analysis of risk factors associated with pseudarthrosis: a thoracolumbar kyphosis of >20°, an age of more than fifty-five years, arthrodesis to S1 rather than to L5, and arthrodeses to more than twelve vertebrae. Equally important, the patients with pseudarthroses had lower outcome scores. I believe this is a landmark paper that will guide adult deformity surgeons to the appropriate indications and techniques to perform adult scoliosis surgery. The findings published in this article will benefit patient care for years to come.
*The author did not receive grants or outside funding in support of the research or preparation of this manuscript. He did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author is affiliated or associated.