Lateral tibial plateau fractures with posterior comminution. Can a rim plate offer sufficient support?

Tibial plateau fractures with posterior comminution are difficult to reduce and stabilise. Standard lateral approach doesn't offer adequate visualisation. Posterior approach is suitable for isolated posterior fractures. The addition of a specifically contoured rim plate can enable fixation of posterior fragments through a modified lateral approach.The purpose of this study was to evaluate the advantages and limitations of this novel technique. We present a prospective series of 16 tibial plateau fractures with posterolateral depression, operated over a period of 7 years (04.2014-09.2021). The mean age of the patients was 52 years .They were followed for an average period of one year.Clinical and functional assessment was performed according to the criteria of Knee Society Clinical Rating Score. The lateral and posterior component of the fracture was stabilised by a horizontal rim plate, through a posterolateral approach, with or without fibular osteotomy. 9 patients had excellent, 5 had good, 2 had average ratings. The average objective rating was 87,5 (70- 97), and the average functional rating was - 74,4 (40-100). The average ROM was 110° (100°-120°). Two of the fractures healed in 5° varus and 8° valgus respectively. One knee joint ended up with 10° flexion deficit. Three knees had medio- lateral instability, with no functional impairment. In 4 cases the K wires of the weber fibular osteotomy fixation migrated. The absence of late articular collapse of the treated fractures may be attributed to the initial stability of fixation.The addition of a rim plate addresses the posterior comminution and makes early rehabilitation safe.