Posterolateral tibial plateau fractures, how to buttress? Reversed L posteromedial or the posterolateral approach: a comparative cadaveric study

The selection of a surgical approach for buttressing posterolateral tibial plateau fractures is controversial. This study compared the surgical exposure area between the reversed L posteromedial approach (R-PM) and the posterolateral (PL) approach using the lateral plateau width as a metric. Twenty lower extremities from fresh frozen cadavers were included. The R-PM approach was used first and the boundary of the posterior tibial cortex exposure was marked with metal pins. With the same specimens, the PL approach was then performed and the exposure area was marked. After removing all soft tissue, an imaginary line was drawn from the lateral plateau rim anterior to the fibular head (L) to the posteromedial ridge of the tibia (M). Additional metal pins were used to indicate bony reference landmarks at the joint line on the posterior tibial plateau, including the lateral tibial spine (S), the lateral boundary with the PM approach (LPM) and the lateral boundary with the PL approach (LPL). All distances were measured using S as the reference point. The average distance from S to L, referred to as the lateral plateau width (A), was 32.62 mm. The average distances from S to LPM (B) and from S to LPL measured as a percentage of A were 43.72 and 81.41%, respectively. The average R-PM approach blind distance from LPM to LPL (C) as a percentage of the lateral plateau width was 58.45%, while the distance LPL to L (D), which represents the invisible blind distance with both approaches, was 15.37% of that width. The PL approach provides better access for buttressing the posterolateral tibial plateau fracture than the R-PM approach. With the R-PM approach, the blind area on the lateral plateau which can be accessed only by the PL approach starts approximately at 43.72% and ends at 81.41% of the lateral tibial plateau width. When a fracture is located in this zone, the posterolateral approach is recommended.