Degree of articular injury as measured by CT cross sectional area is associated with physical function following the treatment of bicondylar tibial plateau fractures.

Background: Bicondylar tibial plateau fractures are complex injuries that commonly require surgical repair. Long-term clinical outcome has been associated with discrepancies in leg alignment, instability and condylar width abnormalities. While intuitive, the degree of articular damage at time of injury has not been linked to outcomes in patients with bicondylar tibial plateau fractures. The aim of this study was to quantify percentage of articular surface cross sectional area disruption and assess for correlation between the degree of articular injury and patient reported physical function.

Methods: Retrospective cohort study at two level 1 trauma centers. 57 consecutive patients undergoing surgical repair for bicondylar tibial plateau fractures between 2013 and 2016.

Main outcome measure: Preoperative CT scans were reviewed, and the percentage of articular surface disruption cross sectional area was calculated. PROMIS^® scores were collected from patients at a minimum of 2 years.

Results: 57 patients with an average age of 58 ± 14.3 years were included. The average PROMIS^® score was 45.5. There was a correlation between percentage of articular surface disruption and total PROMIS^® scores (0.4, CI: 0.2-0.5, p = .007) and the physical function of the PROMIS^® score (0.4, CI: 0.2-0.6, p < .001).

Conclusion: Our method for calculating articular surface disruption on CT is a simple, reproducible and accurate method for assessing the degree of articular damage in patients with bicondylar tibial plateau fractures. We found that the percentage of cross-sectional articular surface disruption correlates with patient reported outcomes and physical function.