Split depression tibial plateau fractures: a biomechanical study.

Area of Science:

• Orthopedic surgery
• Biomechanics
• Trauma research

Background:

• Tibial plateau fractures, particularly split depression types (OTA 41B3.1), present complex fixation challenges.
• Evaluating biomechanical stability of different fixation methods is crucial for optimal patient outcomes.

Purpose of the Study:

• To compare the biomechanical characteristics of four distinct fixation constructs for lateral tibial plateau split depression fractures.
• To assess construct stiffness and resistance to subsidence and tilt under simulated physiological loading.

Main Methods:

• A cadaveric model of simulated split depression tibial plateau fractures was utilized.
• Four fixation constructs were tested: L-buttress plate, raft screws with antiglide plate, L-buttress plate with allograft, and raft screws with periarticular plate.
• Stiffness, vertical subsidence, and condylar tilt were measured using a materials testing machine.

Main Results:

• No significant difference in overall longitudinal stiffness was found among the four constructs.
• Raft screw constructs demonstrated significantly greater local depression stiffness compared to buttress plate constructs.
• Condylar tilt analysis revealed persistent lateral plateau instability post-fixation across all constructs.

Conclusions:

• While overall construct stiffness is comparable, raft screw fixation offers better resistance to local depression in tibial plateau fractures.
• The persistent instability observed supports current clinical guidelines for delayed weight-bearing (10-12 weeks) after these injuries.