Comparison between reliability of Schatzker's classification and CT based four quadrant classification for tibial...

Conventionally used Schatzker and AO/OTA classification, do not identify posterior column injuries in tibial plateau fractures. CT based Four quadrant classification, has been proposed to identify fractures of tibial plateau and help in surgical planning of treatment. However, to assess its validity, there is scanty literature about its reliability (inter and intra-observer variation) and comparison of its reliability with that of the more popular Schatzker classification in classifying tibial plateau fracture.

X-rays and CT scans of 35 patients (18-65 years) of closed tibial plateau fractures were assessed by 5 Orthopaedic surgeons and classified by both Schatzker's and Four Quadrant Classification. A similar observation was recorded after 2 months. All observers were blinded for the demographic and clinical details of the patients. Their responses were noted and interobserver and Intraobserver variation was calculated. Kappa Test of Cohen was used to determine the level of agreement, as per Landis and Koch's criteria. The reliability of four quadrant classification was also compared with that of Schatzker's classification.

There was a moderate agreement in interobserver variation in observations for Schatzker's classification (on X-rays) which improved to substantial agreement when the observations were recorded after showing both CT and X-rays. The intraobserver variation had substantial agreement. On the other hand, there was a perfect agreement in both intra- and interobserver variation for Four Quadrant Classification. This difference between the reliability of both classifications was statistically significant (p < 0.001).

Four Quadrant classification is a more reliable classification having a better agreement on interobserver and intraobserver variation.