Soft tissue injury of the knee after tibial plateau fractures.

The purpose of this study was to document the pattern of ligament and meniscal injuries that occur during high-energy tibial plateau fractures. One hundred three patients with fractures due to high-energy mechanisms were evaluated with knee magnetic resonance imaging (MRI). All studies were read by a single musculoskeletal radiologist who was blinded to surgical and physical exam findings. Pertinent demographic information was obtained. There were 66 patients with AO/OTA type 41C fractures and 37 patients with AO/OTA type 41B fractures. Seventy-three (71%) patients tore at least one major ligament group, and 55 (53%) patients tore multiple ligaments. There were 53 torn ligaments in AO/OTA type 41C fractures (80%) compared with 20 torn ligaments in AO/OTA type 41B fractures (54%) (p < 0.001, Fisher's exact test). Using Schatzker's classification, we found the following correlation: type I, 13 fractures with 6 ligaments (46%); type II, 11 fractures with 5 ligaments (45%); type IV, 13 fractures with 9 ligaments (69%); type V, 13 fractures with 11 ligaments (85%); and type VI, 53 fractures with 42 ligaments (79%). A significant difference exists between the groups regarding the incidence of ligament injuries (p < 0.05) and also regarding high-energy (type IV, V, VI) versus low-energy (type I, II, III) fracture patterns. The incidence of knee dislocation was 32% for AO/OTA type 41B fractures and 23% for AO/OTA type 41C fractures. Knee dislocations (dislocated on presentation, bicruciate injury, or at least three ligament groups torn with a dislocatable knee) were most common in Schatzker type IV fractures (46%). Fifty patients sustained meniscus tears (49%), with 25 medial menisci and 35 lateral menisci injuries. Tibial plateau fractures frequently have important soft tissue injuries that are difficult to diagnose on physical examination. High-energy fracture patterns (AO/OTA type 41C or Schatzker type IV, V, VI) clearly have a significantly higher incidence of ligament injury, and these patients should be carefully evaluated to rule out a spontaneously reduced knee dislocation. We believe MRI scanning should be considered for tibial plateau fractures due to high-energy mechanism, allowing identification and treatment of associated soft tissue injuries.