Data from the US National Inpatient Sample (NIS) indicate that of 51,911 patients undergoing spinal fusion for idiopathic scoliosis between 1993 and 2002, the in-hospital complication rate was 14.9% for paediatric patients and 25.1% for adult patients, with an in-hospital mortality rate was 0.2% and 0.4% for paediatric and adult patients, respectively.

Age, male gender, comorbidities, high ASA score, extent of fusion, performing a vertebral osteotomy, fusion down to the sacrum, and high preoperative curve magnitude can contribute to the increased risk of complications.1,2 Interestingly, one study showed that perioperative outcomes and complications in scoliosis surgery were not influenced by the experience level of the surgical assistants, supporting the benefits of teaching scoliosis surgery to residents and fellows in academic centres.

For adolescent idiopathic scoliosis (AIS), a retrospective study from the Scoliosis Research Society (SRS) reported an overall complication rate of 5.7% in 6,334 patients, including two deaths (0.03%). The authors also observed a significant increase in the overall and neurologic complication rates when combined anterior-posterior procedures were performed.

Recently, a first prospective study from the Spinal Deformity Study Group (SDSG) on 702 patients undergoing surgical correction of AIS showed a non-neurologic complication rate of 15.4%, with respiratory complications, excessive bleeding, infections, and other wound-related problems being the most common. Age, body mass index, presence of cardiac or respiratory disease, previous surgery, pulmonary function, surgical approach, number of levels fused, graft material, use of diaphragmatic incision, curve type, and region of the major curve did not correlate with the increased prevalence of non-neurologic complications. However, increased blood loss as well as prolonged operative and anaesthesia times were associated with a higher prevalence of non-neurologic complications.

The complication mostly feared by patients and surgeons remains neurologic injury. There are many potential causes of neurologic deficits during or following scoliosis surgery:

  • Mechanical – from extrinsic compression of the spinal cord by implants (hooks, wires, screws), an epidural hematoma or abscess, or intraoperatively – by direct iatrogenic injury to neural elements from an instrument
  • Infolding of ligamentum flavum, posterior longitudinal ligament, or disc material due to correction manoeuvres
  • Distraction of the spinal cord during correction, especially in the presence of increased thoracic kyphosis
  • Ischemic injury resulting in reduction of the blood supply to the spinal cord

In the SRS report on AIS surgery, neurologic complication rates were higher for combined procedures (1.75%) when compared to anterior-only (0.26%) or posterior-only procedures (0.32%). Of the 18 (0.3%) patients with a spinal cord injury, complete recovery was noted in 11, incomplete recovery in six, and no recovery in one.

More recently, the SDSG reviewed 1,301 cases of surgical treatment of AIS from their prospective database and reported nine (0.7%) neurologic complications, of which four were spinal cord injuries that resolved spontaneously within 3 months postop. It should be underlined, however, that in this study, all surgeons were experienced spine surgeons performing at least 10 cases per annum of AIS surgery.

To reduce the risk and severity of neurologic complications, neuromonitoring using either somatosensory-evoked potentials (SSEP) or motor-evoked potentials (MEP) has become a standard of care in scoliosis surgery, replacing the Stagnara wake-up test. When a neurologic injury is recognized intraoperatively, optimizing blood pressure, hematocrit and oxygenation remain the first steps in order to minimize the risk of vascular ischemia. Then, based on a wake-up test, the decision to release or remove the instrumentation is made.

In summary, surgical treatment of idiopathic scoliosis is a safe procedure, but a thorough knowledge of potential complications – especially neurologic – and associated risk factors is essential for patient selection and counseling.


  1. Patil C.G., Santaralli J, Lad S.P., et al. Inpatient complications, mortality, and discharge disposition after surgical correction of idiopathic scoliosis: a national perspective. Spine J 2008;8:904-910

  2. Guigui P., Blamoutier A., Groupe d’Étude de la Scoliose. Complications of surgical treatment of spinal deformities: a prospectve multicentric study of 3311 patients [Article in French]. Rev Chir Orthop Reparatrice Appar Mot 2005;91:314-327

  3. Auerbach J.D., Lonner B.S., Antoniacci M.D., et al. Perioperative outcomes and complications related to teaching residents and fellows in scoliosis surgery. Spine 2008;33:1113-1118

  4. Coe J.D., Arlet V., Donaldson W., et al. Complications in spinal fusion for adolescent idiopathic scoliosis in the New Millenium. A report of the Scoliosis Research Society Morbidity and Mortality Committee. Spine 2006;31:345-349

  5. Carreon L.Y., Puno R.M., Lenke L.G., et al. Non-neurologic complications following surgery for adolescent idiopathic scoliosis. J Bone Joint Surg Am 2007;89:2427-2432

  6. Bridwell K., Lenke L.G., Baldus C., et al. Major intraoperative neurologic deficits in pediatric and adult spinal deformity patients: incidence and etiology at one institution. Spine 1998;23:324-331

  7. Diab M., Smith A.R., Kuklo T.R., et al. Neural complications in the surgical treatment of adolescent idiopathic scoliosis. Spine 2007;32:2759-2763

Reprinted with permission from Summer 2009 issue of the COA Bulletin