OBJECTIVETo study the characteristic, treatment and prognosis of tibial plateau fracture Schatzker type IV.

METHODSAccording to the roentgenogram and CT scan in 51 patients, Schatzker type IV injury is divided into 3 types: split, total condylar, depression. In the treatment of split and total condylar injury, if there was no articular depression on CT scan, reduction is done through medial approach; if CT scan demonstrated articular depression, middle approach was used to reduce the depression and bone graft. In split injury, buttress plate was fix on posterior-medial side. In total condylar injury, buttress plate is fix on medial side. In depression injury, fracture was reduced through medial approach, bone graft and buttress plate was fix on medial side. Thirty-three patients were followed up in 41 months averagely. And the statistical analysis was done.

RESULTSThe average Lysholm score of 33 patients was 83.2. Eight patients were excellent, 9 were good, 14 were fair, 2 were poor. The range of motion from 30 degrees to 147 degrees (average 110 degrees ). The factors that caused bad results were: the fracture was not anatomical reduced; tibial plateau is more than 4 mm wider than femoral condylar or lateral subluxation exceed 8 mm; varus deformity of knee. They also caused the increase of osteoarthritis.

CONCLUSIONSIn order to get anatomical reduction and stable fixation, the approach and fix pattern should be chosen on the bases of classification and CT scan of Schatzker IV injury. The factors which influence the prognosis are: (1) tibial plateau is more than 4mm wider than femur condylar, or lateral subluxation more than 8 mm; (2) Varus deformity. Attention should be paid to avoid these during operation.