What is the impact of the fracture location on patient-reported functional outcomes in patients with lateral tibial plateau fractures?

Abstract

Lateral-sided tibial plateau fractures are most common and can range from minor to very extensive injuries of the lateral plateau. The impact of fracture location and extent on functional outcomes remains unclear. This study aimed to investigate this relationship. A retrospective cross-sectional study was performed in 529 patients treated for a lateral tibial plateau fracture within 6 hospitals between 2003-2018. Patients were approached by posted mail and completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire after a median follow-up of six years (IQR: 4-9 years). Fractures were classified according to the Krause 'Ten segment method'. The seven most prevalent fracture patterns were identified and compared using descriptive statistics. Multivariate regression analysis, adjusted for age, sex, Schatzker classification, treatment, and residual incongruity, was performed to assess the association between fracture location, number of affected segments, and patient-reported outcome. The most frequent lateral tibial plateau fracture patterns were: pattern 1 - two posterior segments (KOOS = 82, IQR:66-93); pattern 2 - four lateral segments (KOOS = 74, IQR:53-94); pattern 3 - two anterolateral and one posterior segment (KOOS = 82, IQR:62-93); pattern 4 - anterolateral involvement (KOOS = 87, IQR:59-97); pattern 5 - involvement of the entire lateral plateau (KOOS = 60, IQR:40-71); pattern 6 - two posterior and one anterolateral segment (KOOS = 81, IQR:67-93); and pattern 7 - isolated lateral involvement (KOOS = 60, IQR:46-84). Patterns 5 and 7 showed the lowest KOOS scores (p = 0.008). Overall KOOS declined by 2.59 points per additional segment involved (p = 0.010), with similar trends observed in the ADL, sport, and QoL subscales (p < 0.05). Surgeons should be aware during management of lateral tibial plateau fractures that all regions of the plateau-anterior, medial, lateral, and posterior-are crucial in preserving function. Fractures involving the entire lateral plateau (pattern 5) and isolated lateral segments (pattern 7) result in worse functional outcomes, likely due to the severity of the injury and associated soft tissue involvement, especially in the meniscal area. Greater fracture extent, as indicated by increased segment involvement, correlates with worse patient-reported outcomes.