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Published 7/1/2015
Peter Pollack

Learning from a Complications Database

SRS database sees ups and downs, but still provides valuable data

It’s difficult to maintain participation in an organizational database,” explained Howard M. Place, MD, of the Scoliosis Research Society (SRS), speaking during the Federation of Spine Associations 2015 Specialty Day program. “As the detail of the data collection increases, participation tends to decline.”

Dr. Place pointed out that, despite the difficulties in maintaining member involvement, valuable information often can be gleaned from sources such as the SRS Morbidity and Mortality Database. That database was officially proposed in 1968, during the annual meeting of SRS. By the following year, 13 SRS members had submitted data, with participation increasing to 45 members in 1970.

“Originally, data were collected for only 6 months of the year,” said Dr. Place. “Participation was compulsory, but people only had to participate for 6 months. By 1975, 83 percent of SRS members were contributing to the database. Around that same time, the first paper based on database data was published.”

However, enthusiasm for participation in the SRS database did not hold steady. Between 1994 and 2006, participation varied between 17 percent and 70 percent, with member involvement exceeding 50 percent during only 4 years of that 13-year span.

“At that time, participating surgeons had to report data on every case they performed, whether there were complications or not,” said Dr. Place. Participation dropped to the point that the SRS stopped collecting data entirely during 2008.

In 2009, the database was redesigned with a new approach, focusing on three specific diagnoses: scoliosis, kyphosis, and spondylolisthesis. Complications were limited to death, visual acuity, and neurologic deficit. Recently, infection data have been added. “As you might anticipate,” said Dr. Place, “we’ve seen a dramatic increase in participation, with 90 percent of members contributing during the last 2 years.”

Learning from the data
“What medical lessons have we learned from the database?” asked Dr. Place. “From that very first paper published in 1975, we see that scoliosis treatment is actually relatively safe overall, with a less than 1 percent rate of neurologic complications, based on data from 7,800 patients.”

The following conditions are associated with increased risk of complications:

  • kyphosis
  • congenital scoliosis
  • severe scoliosis
  • preexisting neurologic deficits
  • deficits that occur with traction

Additionally, Dr. Place noted that the following procedures may be associated with increased risk:

  • skeletal traction
  • spinal osteotomy
  • instrumentation to gain correction in congenital scoliosis
  • instrumentation to gain additional correction after traction

“We also learned that if a neurologic complication occurs, the prognosis is better for incomplete lesions than for complete lesions. Removing the instrumentation within 3 hours of diagnosis improves results,” he said.

Dr. Place also cited several recent studies drawn from the SRS database, including one that reviewed 683 patients with Scheuermann’s kyphosis. That study found that adults were more likely than children to experience complications and that wound complications were more common than neurologic deficits.

A 2011 study reviewed data on 605 patients with spondylolisthesis and found a 10.4 percent rate of complications, including neurologic deficit (5 percent), dural tear (1.3 percent), and wound infection (2.0 percent). The largest study he cited looked at 108,419 procedures (including diskectomy, anterior cervical decompression and fusion, and lumbar decompression). It found a 1.38 percent rate of pulmonary embolism (PE), a 1.18 percent rate of deep vein thrombosis, and a 0.34 percent rate of death due to PE.

“One important consideration is the accuracy of the data,” Dr. Place admitted. “Detail was high, but compliance and consistency weren’t very good. Many of these studies are looking at data from 2004 through 2007, and during that period, the best member participation was only 43 percent.”

According to Dr. Place, the most recent iteration of the SRS database shows that the likelihood of neurologic deficit has increased, from 0.34 percent in 2009 to 0.79 percent during 2012 and 2013.

“One final consideration, looking at the database now and trying to break down the data through a gap analysis, is to identify which surgeon demographics are most likely to be associated with complications. We looked at complication rates by member status, surgeon age, and surgeon volume. We found no clear differences in complication rates among any group we examined, which is somewhat surprising,” he said.

Dr. Place’s disclosure information, including potential conflicts of interest, can be viewed at www.aaos.org/disclosure

Peter Pollack is electronic content specialist for AAOS Now. He can be reached at ppollack@aaos.org

Bottom Line

  • The SRS Morbidity and Mortality Database was established in 1965, but has had varying rates of participation through the years.
  • Studies based on data from the database have examined Scheuermann’s kyphosis, spondylolisthesis, and the incidence of neurologic deficit.
  • Based on surgeon demographics (member status, surgeon age, and surgeon volume), no clear differences in complication rates were found.