A new study, a systematic analysis of the spine literature, published in Journal of Neurosurgery: Spine in August 2010, has concluded that retrospective reviews significantly underestimate the overall incidence of complications in spine surgery.
Investigators, Rani Nasser et al, wrote that their analysis is the first to critically assess differing complication incidences reported in prospective and retrospective cervical and thoracolumbar spine surgery studies.
Authors of the study say that the overall incidence of complications or adverse events in spinal surgery is unknown. “Both prospective and retrospective analyses have been performed, but the results have not been critically assessed. Procedures for different regions of the spine (cervical and thoracolumbar) and the incidence of complications for each have been reported but not compared,” they wrote.
Nasser et al searched the the MEDLINE database using the key words “spine surgery” and “complications.” They found 105 relevant articles detailing 80 thoracolumbar and 25 cervical studies. Among the 105 articles were 84 retrospective studies and 21 prospective studies. The authors evaluated the study designs and compared cervical, thoracolumbar, prospective, and retrospective studies as well as the durations of follow-up for each study.
In the study, 105 articles reviewed, there were 79,471 patients with 13,067 reported complications for an overall complication incidence of 16.4% per patient. Complications were more common in thoracolumbar (17.8%) than cervical procedures (8.9%; p<0.0001, OR 2.23). Prospective studies yielded a higher incidence of complications (19.9%) than retrospective studies (16.1%; p<0.0001, OR 1.3). The complication incidence for prospective thoracolumbar studies (20.4%) was greater than that for retrospective series (17.5%; p<0.0001). This difference between prospective and retrospective reviews was not found in the cervical studies. The year of study publication did not correlate with the complication incidence, although the duration of follow-up did correlate with the complication incidence (p=0.001).
Spine surgery still an “imperfect art”
An accompanying editorial in the same journal by Michael G Fehlings, Division of Neurosurgery, University of Toronto, Ontario, Canada, emphasised that the issue of complications in spinal surgery is exceedingly important, especially in the prevailing climate of healthcare reform. He urged colleagues to recognise that spine surgery is still an imperfect art and that there is a clear need for critical appraisal for continued improvement in the field.
Fehlings drew attention to the fact that spinal surgery is heavily driven by outcomes, and that it is highly examined. He wrote in the editorial: “Intuitively, it is exceedingly difficult to justify invasive procedures in an area—the spine and spinal cord—in which the stakes can be so high if the associated outcomes are not positive.”
Commenting on the results of Nasser’s study, Fehlings said: “It is sobering, although not surprising that retrospective studies significantly underestimate the overall incidence of complications in spine surgery. He also highlighted that Nasser and colleagues’ revelation that there is no uniform standard for reporting complications is alarming. Fehlings stated that his clinical research team has previously drawn attention to this issue and that they have proposed a standardised classification system for intraoperative adverse events. According to Fehlings, there is currently no consensus on what defines a complication in the spine surgery literature. He added that a consensus group of surgeons from AOSpine North America has recently met and published on a series of consensus-based systematic reviews on complications and complications avoidance in spine surgery.