K.RASAPPAN1, M.J LIM2, I.T.H. CHUA3, E.B.K. KWEK4
National University Hospital1, MOH Holdings Pte Ltd (MOHH)2, Tan Tock Seng Hospital3, Woodlands Health4
The Schatzker classification for tibial plateau fractures is one of the most commonly used systems. There has been controversy if a Schatzker type III fracture exists as additional fracture lines are revealed on CT imaging compared to X-rays. In this paper, we correlate the X-rays and CTs of type III fractures, and determine if these fractures do exist by their original description.
This was a multicenter retrospective cohort observational study where 740 patients with tibial plateau fractures admitted across 5 trauma centers in Singapore over 9 years were identified. Two independent fellowship trained, Orthopaedic trauma surgeons reviewed knee X-rays of included patients and classified them according to the Schatzker system. The CTs were subsequently reviewed and the fractures were reclassified based on CT findings.
569 Tibial plateau fractures in 566 patients were analyzed. All X-ray classified Schatzker III fractures (66 and 29 cases by the first and second assessor respectively) were reclassified to a Schatzker II type after review of CT scans by both assessors independently as there was always a fracture line propagating from the depressed fragment to the lateral cortex on axial CT cuts. The interobserver variability for X-rays and CT based classifications were k=0.274 and k=0.906 respectively. The majority of these fractures had 2 lateral cortical breaks (83.8%) which were not visible on plain radiographs. In addition, the depression occurred mostly in the anterolateral and posterolateral positions (60.3%) of the lateral tibial plateau.
This study did not support the existence of true Schatzker Type III fractures.