Ability of modern proximal tibial lateral plates to capture posterolateral tibial plateau fracture fragments

BACKGROUND: The surgical treatment of posterolateral tibial plateau fractures involves a challenging and diverse set of considerations, one of which is the lack of proper and satisfactory internal fixations to purchase posterolateral fragments. Evaluating the configuration of internal fixations is often overlooked, despite it being important to outcomes of fracture fixation. This study aimed to (I) propose a new digital methodology of internal fixation evaluation that based on actual fracture cases and (II) evaluate the fixation effectiveness of four commercially available proximal tibial lateral plate-screw constructs for posterolateral fragments. METHODS: Tibial plateau fractures involving the posterolateral column were retrospectively reviewed. The reconstructed three-dimensional (3D) fracture models were virtually reduced, and targeted internal fixations were modeled digitally in specialized software. Four implants from three manufacturers (DePuy Synthes, Westchester, NY, USA; Zimmer, Warsaw, IN, USA; and Biomet, Warsaw, IN, USA) were placed on each fracture in an optimal position to simulate surgical fixation and quantitatively evaluate fixation effectiveness. The fragment was considered to be “captured” if it was purchased by at least two screws. The 3D fracture maps and heat maps were created by graphically superimposing all uncaptured fracture fragments onto a tibia template. RESULTS: This study included 144 posterolateral tibial plateau fractures. When not using screws in a variable angle (VA) manner, the fixation effectiveness for posterolateral fragments was 58.3% for the DePuy Synthes locking compression plates (LCP), 47.9% for the DePuy Synthes VA-LCP, 50.7% for the Zimmer plate, and 43.8% for the Biomet plate. In contrast, the capturing rates boosted to 76.4% and 71.5% when utilizing VA screws in the DePuy Synthes VA-LCP and the Biomet plate. The high-frequency uncaptured areas tended to concentrate on the rim of the posterolateral wall and were mainly distributed in the posterior 1/2 to 3/4 of the parallel position of the fibula head. CONCLUSIONS: The proposed new digital methodology was demonstrated feasible and may improve the quantitative evaluation of the implants and optimize the design of implants. The commercially available proximal tibial lateral plate-screw constructs were insufficient in capturing posterolateral fragments, and design-improved or additional implants may be necessitated.