An imaging study of tibial plateau fractures combined with avulsion fracture of medial femoral condyle

Objective To explore the cross classification of tibial plateau fractures combined with avulsion fracture of medial femoral condyle. Methods The 16 patients were retrospectively analysed as an observation group who had been treated at Department of Lower Limbs, Sichuan Orthopaedic Hospital for tibial plateau fracture and avulsion fracture of the medial condyle of the same femur from January 2015 to December 2018. They were 9 males and 7 females, aged from 27 to 78 years (average, 51.5 years). By the Schatzker classification, there were 2 cases of type Ⅰ, 8 cases of type Ⅱ, 3 cases of type Ⅲ and one case of type Ⅳ; by the cross classification, there were 10 cases of type Ⅰe, one case of type Ⅱe and 2 cases of type Ⅲe and 3 cases of type Ⅰv. The 332 patients were included as a control group who had been treated at the same department for simple tibial plateau fracture from January 2010 to December 2015. The imaging data of the 2 groups were compared to find out the charateristics of cross type distribution; the widened distance of the lateral tibial plateau, collapse depth of the tibial plateau, separation of avulsion fracture of medial femoral condyle, maximum clearance of the medial knee and eversion angle of the tibial plateau were investigated in the patients with cross types e and Ⅰv in the observation group. Results In the observation group, the widened distance of the lateral tibial plateau averaged 7.18 mm, the collapse depth of the tibial plateau 8.74 mm, the separation of avulsion fracture of medial femoral condyle 3.44 mm, the maximum clearance of the medial knee 7.77 mm, and the eversion angle of the tibial plateau 87.03°. There was a significant difference in the cross type distribution of tibial plateau fractures between the 2 groups (P=0.002). In the observation group, the average widened distance of the lateral tibial platea for the 13 type e patients (8.49±4.26 mm)was significantly larger than that for the 3 type Ⅰv patients (1.51±2.11 mm) (t=2.706, P=0.017). Conclusion The cross classification of tibial plateau fractures with avulsion fracture of mediall condyle of the same femur may result mainly in types e and type Ⅰv. The widened distance of lateral tibial plateau helps distinction between types e and type Ⅰv. Key words: Tibial fractures; Femoral fractures; Classification; Radiology