Radiographic Predictors of Conversion to Total Knee Arthroplasty After Tibial Plateau Fracture Surgery

Abstract

Background: Radiographic measurements of initial displacement of tibial plateau fractures and of postoperative reduction are used to determine treatment strategy and prognosis. We assessed the association between radiographic measurements and the risk of conversion to total knee arthroplasty (TKA) at the time of follow-up. Methods: A total of 862 patients surgically treated for tibial plateau fractures between 2003 and 2018 were eligible for this multicenter cross-sectional study. Patients were approached for follow-up, and 477 (55%) responded. The initial gap and step-off were measured on the preoperative computed tomography (CT) scans of the responders. Condylar widening, residual incongruity, and coronal and sagittal alignment were measured on postoperative radiographs. Critical cutoff values for gap and step-off were determined using receiver operating characteristic curves. Postoperative reduction measurements were categorized as adequate or inadequate on the basis of cutoff values in international guidelines. Multivariable analysis was performed to assess the association between each radiographic measurement and conversion to TKA. Results: Sixty-seven (14%) of the patients had conversion to TKA after a mean follow-up of 6.5 ± 4.1 years. Assessment of the preoperative CT scans revealed that a gap of >8.5 mm (hazard ratio [HR] = 2.6, p < 0.001) and step-off of >6.0 mm (HR = 3.0, p < 0.001) were independently associated with conversion to TKA. Assessment of the postoperative radiographs demonstrated that residual incongruity of 2 to 4 mm was not associated with increased risk of TKA compared with adequate fracture reduction of <2 mm (HR = 0.6, p = 0.176). Articular incongruity of >4 mm resulted in increased risk of TKA. Coronal (HR = 1.6, p = 0.05) and sagittal malalignment (HR = 3.7 p < 0.001) of the tibia were strongly associated with conversion to TKA. Conclusions: Substantial preoperative fracture displacement was a strong predictor of conversion to TKA. Postoperative gaps or step-offs of >4 mm as well as inadequate alignment of the tibia were strongly associated with an increased risk of TKA. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Schatzker IV tibial plateau fractures: are they always unicondylar?

“…Our study revealed that a lateral articular surface depression depth ≥10.6 mm was associated with the use of dual incisions to obtain reduction. The importance of achieving adequate articular reduction is supported by a recent multicenter study by Assink et al 30 evaluating 477 tibial plateau fractures at 6.5-year average follow-up, showed that patients with residual articular incongruency 4.0–6.0 mm and ≥6.0 mm were 2.7x and 5.0x more likely, respectively, to undergo conversion to total knee arthroplasty. In planning articular reduction, surgeons may choose to use dual incisions in cases of increased depth of lateral articular surface depression.…”

3D surgical planning including patient-specific drilling guides for tibial plateau fractures

“…The observers consisted of an attending orthopaedic trauma surgeon (> ten years of experience) and technical physician (> five years of experience). CT scans were assessed in the axial, sagittal, and coronal planes to measure the initial displacement in terms of gap and step-off according to previously described methods, 11,12 and to determine the fracture classification according to the AO/OTA classification system. 13 Patient characteristics were retrieved from the electronical patient file.…”

Initial and Residual 3D Fracture Displacement Is Predictive for Patient-Reported Functional Outcome at Mid-Term Follow-Up in Surgically Treated Tibial Plateau Fractures

“…Poor articular reduction and tibial alignment are associated with worse functional outcome [ 15 , 16 , 17 ]. In order to correct for the quality of the reduction in patients without a postoperative CT scan, the quality of the fracture reduction and the tibial alignment were evaluated on the postoperative radiographs using three radiographic parameters: articular fracture reduction, coronal alignment, and sagittal alignment.…”