Sagittal Slope-Reducing High Tibial Osteotomy Decreases Anterior Cruciate Ligament Force and Coupled Internal Tibial...

Area of Science:

• Orthopedic biomechanics
• Knee joint kinematics
• Anterior Cruciate Ligament (ACL) injury prevention

Background:

• High posterior tibial slope increases ACL injury risk.
• The biomechanical impact of slope-reducing high tibial osteotomy (HTO) on knee kinematics and ACL forces is not fully understood.

Purpose of the Study:

• To investigate the biomechanical effects of slope-reducing HTO on ACL force, coupled internal tibial rotation (ITR), and anterior tibial translation (ATT).
• To determine if decreased tibial slope correlates with reduced ACL force and altered tibiofemoral kinematics.

Main Methods:

• Developed computational models of 10 cadaveric knees.
• Simulated virtual slope-reducing HTO across a range of tibial slopes (-5° to 15°).
• Applied axial compression and combined compression/valgus loads to assess ACL force, ITR, and ATT using linear regression analysis.

Main Results:

• A 10° slope-reducing HTO decreased ACL force by 53% (compression) and 47% (compression/valgus).
• This procedure reduced coupled ITR by 64% and ATT by 54% under specific loading conditions.
• Significant linear relationships were found between tibial slope reduction and decreased ACL force, ITR, and ATT (P < .001).

Conclusions:

• Slope-reducing HTO effectively reduces ACL force by decreasing anterior tibial translation (ATT) under compression.
• The procedure also diminishes coupled internal tibial rotation (ITR) under combined compressive and valgus loads.
• These biomechanical changes provide a basis for HTO's efficacy in reducing ACL injury risk.