Background In tibial plateau fracture surgery, radiographic measurements are used to assess preoperative fracture displacement and postoperative results. However, the association between these values and patients’ clinical outcomes remains unclear. Questions/purposes (1) What is the association between preoperative fracture displacement (gap and stepoff), as assessed on CT scans, and full recovery in terms of patient-reported outcome (Knee injury and Osteoarthritis Outcome Score KOOS scores within the minimum clinically important difference MCID range of population-based normative values)? (2) What is the association between postoperative fracture reduction and knee alignment, as assessed on radiographs, and full recovery in terms of patient-reported outcome? Methods A multicenter cross-sectional study was performed including all patients with tibial plateau fractures who were treated surgically between 2003 and 2019 in five trauma centers. During that time, 1121 patients had surgery for these injuries; all were asked to complete the KOOS questionnaire, measured on a scale of 0 to 100 points (100 indicating no problems and 0 indicating severe problems). The general indications for surgery during this time were an initial gap and/or stepoff greater than 2 mm and inadequate coronal and sagittal tibial alignment. In all, 58% (645 of 1121) of patients responded after a mean ± SD follow-up of 7 ± 4 years, the mean age was 52 ± 14 years, and 68% (436 of 645) were women. Nonresponse analysis showed no substantial differences in patient characteristics and fracture classification between those who did and who did not respond. Independent observers reassessed and classified all pre- and postoperative CT images and radiographs according to the Schatzker classification. Initial fracture displacement (gap and stepoff) was measured on preoperative CT scans. The gap was defined as a separation between fracture fragments along the articular surface, and the stepoff was defined as a separation of fracture fragments perpendicular to the articular surface. Residual incongruence (maximum gap and/or stepoff), condylar widening, and tibial alignment (medial proximal tibial angle MPTA), as well as posterior proximal tibial angle PPTA), were measured on postoperative radiographs. Patients were classified as having achieved full recovery when KOOS scores were within the MCID range of KOOS scores from normative data from the general population (data from age-related peers). Binary logistic regression analyses were performed to assess the association between preoperative fracture displacement or postoperative fracture reduction and full recovery (KOOS scores within the MCID range of population-based normative values). The models were adjusted for gender, Schatzker classification, BMI, complications, postoperative fracture reduction, and follow-up time. Results Preoperative radiographic assessment demonstrated that substantial initial fracture displacement (> 10 mm gap or > 8 mm stepoff) was independently associated with increased odds of not reaching full recovery, again defined as achieving KOOS scores within the MCID range of population-based normative values (initial gap: OR 2.5 95% CI 1.3 to 4.7; p = 0.006 and initial stepoff: OR 4.3 95% CI 1.8 to 10.2; p = 0.001). Postoperative radiographic assessment demonstrated that substantial residual fracture displacement (4 to 6 mm incongruence: OR 3.3 95% CI 1.7 to 6.5; p = 6 mm: OR 5.2 95% CI 1.7 to 15.8; p = 0.004) and inadequate tibial alignment (MPTA 92°: OR 1.5 95% CI 1.0 to 2.3; p = 0.04 and PPTA 14°: OR 1.9 95% CI 1.3 to 3.0; p = 0.003) were associated with increased odds of not reaching full recovery. Conclusion In tibial plateau fracture surgery, having a substantial preoperative initial gap > 10 mm or stepoff > 8 mm is associated with an increased odds of not reaching full recovery. In clinical practice, these findings support more informed patient counseling about prognosis. Postoperatively, both residual incongruence > 4 mm (gap and/or stepoff) and inadequate tibial malalignment (MPTA or PPTA) increased these odds, emphasizing the need for meticulous reduction and alignment as well as thoughtful decision-making regarding revision surgery. Level of Evidence Level III, therapeutic study.
Vaartjes et al. (Thu,) studied this question.