Tibial plateau fractures are common injuries. Displaced fractures are treated with open reduction and internal fixation (ORIF). Goals of treatment include restoration of extremity axial alignment, joint stability and congruity, allowing for early motion and prevention of osteoarthritis. Short term results of surgical fixation of tibial plateau fractures are good, however, longer term outcomes have demonstrated a higher risk of end-stage arthritis and total knee arthroplasty. Despite the vast literature around tibial plateau fractures, to our knowledge there are no series examining post-operative reductions using axial imaging. It is our goal to define the incidence of articular malreductions following surgical fixation of tibial plateau fractures, to identify patient or surgeon factors associated with malreductions, and to define any regional patterns of malreduction location.

De-identified post operative computed tomography (CT) scans were reviewed to identify tibial plateau malreductions with a step or gap greater than 2 mm, or condylar width greater than 5 mm. Three independent assessors reviewed the scans meeting criteria using Osirix DICOM software. Steps and gaps were mapped onto the axial sequence at the level of the joint line. Images were then matched to side and overlaid as best fit in Photoshop software to create a map of malreductions. A grid was created to divide the medial and lateral plateaus into quadrants to identify the density of malreductions by location. A multi-variate regression model was used to assess risk factors for malreduction.

Sixty five post-operative CT scans were reviewed. Twenty one reductions had a step or gap more than 2 mm for a malreduction incidence of 32.3%. The incidence in patients undergoing submeniscal arthrotomy or fluoroscopic assisted reduction was 16.6% and 41.4%, respectively (p <0.001). Side of injury, age, BMI, AO fracture type, and use of locking plates were not predictive of malreduction. Malreductions were heavily weighted to the posterior lateral tibial plateau.

The incidence of articular malreductions was high at 32.3%. Fluoroscopic reduction alone was a predictor for articular malreduction with most malreductions located in the posterior lateral quadrants of the plateau.