A study on the association between tibial plateau fractures and intra-articular soft-tissue injuries under valgus injury mechanisms.

backgroundWhile recent investigations have focused on injury mechanism classifications of tibial plateau fractures (TPFs), the association between valgus TPFs and concomitant soft-tissue damage involving menisci and ligaments remains insufficiently elucidated. This study aimed to characterize intra-articular soft-tissue injuries associated with various valgus TPFs and assess the predictive value of lateral plateau depression (LPD) and widening (LPW). Additionally, the analysis extended to other injury mechanisms. MATERIALS AND

methodsThis study included adult patients with acute tibial plateau fractures who had complete imaging data, excluding patients with open fractures and multiple fractures throughout the body. Imaging examinations were used to assess the fracture mechanism and intra-articular soft-tissue damage.

resultsThe study retrospectively analyzed the clinical data of 138 patients with valgus injury TPFs in our hospital. The study compared the incidence of TPFs with intra-articular soft-tissue damage under different injury mechanisms. The result demonstrated that the incidence of valgus hyperextension TPFs combined with medial collateral ligament injuries was relatively high (61.5%) compared with TPFs with other injury mechanism. Multivariable logistic regression and smooth curve fitting revealed significant dose-response relationships of LPD (odds ratio [OR] = 1.408; 95% confidence interval [CI] 1.217, 1.627) and LPW (OR = 1.782; 95% CI 1.387, 2.290) with the risk of lateral meniscus (LM) tears in valgus TPFs. Receiver operating characteristic curves showed the area under the curve (AUC) values and the optimal thresholds of LPD and LPW. For all valgus TPFs, the AUCs of LPD and LPW associated with LM tear were 0.804 (95% CI 0.728, 0.880) and 0.741 (95% CI 0.657, 0.825), respectively. And the optimal threshold for LPD to predict LM tears was 7.11 mm (sensitivity 0.80, specificity 0.74). Subgroup analysis by injury mechanism further demonstrated that, under the valgus extension injury mechanism, the optimal threshold was 8.45 mm (sensitivity 0.68, specificity 0.91). Under the valgus flexion injury mechanism, the optimal threshold was 7.18 mm (sensitivity 0.69, specificity 0.87). Further analyses revealed that varus flexion TPFs demonstrated elevated risks of anterior cruciate ligament injuries (82.5%), lateral collateral ligament injuries (65.0%), and meniscal tears (70.0%), whereas varus hyperextension TPFs showed higher posterior cruciate ligament injury prevalence (56.3%).

conclusionsLPD serves as a reliable predictor of fractures combined with LM tears. Specifically, under the overall valgus injury mechanism, the possibility of LM tears (particularly the posterior horn tears) should be guarded against when LPD exceeds 7.11 mm. For the valgus extension subtype, the possibility of LM tears (especially the anterior horn tears) should be highly suspected when LPD exceeds 8.45 mm. And for the valgus flexion subtype, an LPD exceeding 7.18 mm should prompt evaluation for LM tears, particularly those affecting the posterior horn. LEVEL OF EVIDENCE: Level 3.