Pediatric Spine Foundation

Title: A New Classification System to Report Complications in Growing Spine Surgery: A Multicenter Consensus Study.

Authors: Smith JT, Johnston C, Skaggs D, Flynn J, Vitale M.

Journal: J Pediatr Orthop

Date: December 01, 2015

Excerpt: Classification, Complications, Surgery

Keywords: Classification, Complications, Surgery


What is the purpose of this study?

In the last decade, the use of growth-friendly spine surgery devices have increased significantly over early fusion for the treatment of early onset scoliosis. These devices have a known high complication rate however, there is no structured or classifed system in place to report complications, compare them in terms of severity and assess the impact of the complications in terms of developing a treatment plan. The goal of this study was two- fold, one to develop a new classification system and two to test the system and evaluate it for ease of use.

Lead surgeons from five major pediatric spine centers collaborated to develop a new classification system to report complications. The new system was then tested on a minimum of 10 patients from each center who had at least two year follow up after initial implant.

  • Complications were defined as an unexpected medical event in the course of treatment that may or may not impact the final treatment outcome.
  • Severity of the complication was defined as the level of urgency required to treat the complication.
  • Complications were then grouped as either device related or disease related. Device related refers to the device itself, anchor points for the device, or surgical incisions related to the procedure. Disease related refers to repetitive surgeries for things like pneumonia or pain.

Complications Classification System

Severity Grades for Complications
Device Related
Disease Related
Complication that does not require an unplanned surgery or hospitalization and can be corrected at the next planned surgery
Complication that does not require hospitalization (i.e. minor infection)
Complication that requires hospitalization (i.e. pneumonia)
Complication that requires a single surgery (i.e. replacing a broken rod)
Complication that requires multiple surgeries to fix the problem (i.e. device infections)
Complication that requires permanently abandoning the use of growth-friendly technique and removing the device
Complication that requires permanently abandoning the use of growth-friendly technique and removing the device



64 patients were enrolled in the study, all had a minimum of three expansion surgeries and two years follow up.

  • 352 total lengthenings; average of 5.4 lengthenings per patient; average of 1.6 revision surgeries
  • There were 173 complications in 56 patients for an average of 2.66 complications per patient.
  • 9 patients had no complications.
Device Related Complications
Disease Related Complications
31% were Grade I
(could be managed at next scheduled surgery)
2% were Grade I
(did not require hospitalization)
46% were Grade IIA
(required a single unplanned surgery)
11% were Grade II
(hospitalization was required)
6% were Grade IIB
(required multiple unplanned surgeries)
Less than ½% were Grade III
(required growth friendly strategy be abandoned)
3% were Grade III
(required growth friendly strategy be abandoned)

Discussion Points

  • While complications are common in the use of growth-sparing instruments, there has not been a clear way to distinguish minor complications from major complications to allow for constructive comparison that can help impact the overall plan of care for children with early onset scoliosis. For example, a complication such as 'device migration' is considered an 'expected' complication during the course of treatment, with minimal impact on the overall treatment plan. It's also something that can usually be corrected without an unplanned surgery. This should not be compared to a deep infection for example that may require multiple unplanned surgical procedures for resolution. Examples like these are what prompted the development of a classification system
  • The new classification system developed here was found to be easy to use and provided meaningful information allowing surgeons the ability to access the impact of complications on the overall course of care.
  • While complications regardless of instrument type were still common, only 3% were Grade III and required the treatment strategy be abandoned.