Impact of MRI on treatment plan and fracture classification of tibial plateau fractures.

OBJECTIVE: To evaluate the interobserver agreement for both treatment plan and fracture classification of tibial plateau fractures using plain radiographs, computed tomography (CT) scan, and magnetic resonance imaging (MRI).

DESIGN: Prospective study to assess the impact of an advanced radiographic study on the agreement of treatment plan and fracture classification of tibial plateau fractures among three orthopaedic surgeons.

SETTING/PARTICIPANTS: Patients presenting with tibial plateau fractures to a level I trauma center were evaluated with plain knee radiographs (anteroposterior, lateral, two oblique views), CT scan, and MRI. Three experienced attending orthopaedic trauma surgeons were randomly presented three sets of studies for each injury: radiographs alone, radiographs with CT, and radiographs with MRI (including soft tissue injuries documented by an experienced MRI radiologist). The surgeons were asked to render fracture classification and treatment plan based upon the blind reading of each individual radiographic set.

MAIN OUTCOME MEASURES: Agreement among the three surgeons was measured using kappa coefficients.

RESULTS: For fracture classification, radiographs alone yielded a mean kappa coefficient of 0.68, which increased to 0.73 for radiographs with CT scan and 0.85 for radiographs with MRI. Fracture classification (Schatzker) was changed an average of 6% with the addition of the CT scan and 21% based on radiographs with MRI. For the fracture management plan, the mean interobserver kappa coefficient for radiographs alone was 0.72, which increased to 0.77 for radiographs with CT scan and 0.86 for radiographs with MRI. MRI changed treatment plan in 23% of the cases.

CONCLUSION: Magnetic resonance imaging increases the interobserver agreement on fracture classification and operative management of tibial plateau fractures.