Interobserver and intraobserver reliability of the Spinal Deformity Study Group classification of lumbosacral spondylolisthesis

English Keywords:Lumbosacral spondylolisthesis  Classification  Spinal Deformity Study Group  Reliability  Interobserver  Intraobserver

English Abstract:

  【Abstract】 Objectives: To evaluate the interobserver and intraobserver reliability of the Spinal Deformity Study Group(SDSG) classification for lumbosacral spondylolisthesis. Methods: All patients with lumbosacral developmental or acquried isthmic spondylolisthesis treated surgically in our clinic from 2001 to 2010 were identified and reviewed. Fifty-three patients met the inclusion criteria, including 12 males and 41 females with a mean age of 28.7 years(range, 10 to 40 years)． Pre-operative standing anteroposterior and lateral radiographs were taken in all patients and none of these radiographs had any premeasurements． The SDSG type for all subjects were determined by four spine surgeons independently． The procedure was repeated two weeks later in a different and randomly assigned order． Percentage of agreement and Kappa coefficients were used to determine the intraobserver and interobserver reliability. Results: Overall intra- and inter-observer agreements were 71.7%-86.8%(Kappa value 0.572-0.794) and 83.0%-92.5%(Kappa value 0.721-0.891), respectively. The intra-and inter-observer agreements and repeatability associated with slip grade were 94.0%(Kappa value 0.777) and 96.7%(Kappa 0.862), respectively. As for the determination of sacro-pelvic and spinal balance, intra- and inter observer agreements and repeatability were 86.1%(Kappa value 0.744) and 86.6%(Kappa value 0.751) for low-grade slips, while which were 83.3%(Kappa value 0.693) and 87.5%(Kappa value 0.788) for high-grade slips. Conclusions: SDSG classification has substantial intra-and inter-observer relia