Adding Tibial Tuberosity Medialization to Medial Patellofemoral Ligament Reconstruction Reduces Lateral Patellar...

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Computational modeling

Background:

• Patellar instability often involves lateral maltracking, necessitating surgical intervention.
• Medial patellofemoral ligament (MPFL) reconstruction is a common treatment for patellar instability.
• The role of tibial tuberosity medialization in conjunction with MPFL reconstruction requires further investigation.

Purpose of the Study:

• To evaluate if adding tibial tuberosity medialization to MPFL reconstruction reduces lateral patellar maltracking during dynamic activity.
• To determine when medial patellofemoral contact pressures are elevated during daily activities like squatting.

Main Methods:

• Seven computational knee models with patellar instability were simulated.
• MPFL reconstruction was performed, followed by the addition of tibial tuberosity medialization in each model.
• Simulations included pivot landing for dynamic motion analysis and knee squatting for pressure analysis.

Main Results:

• Adding tibial tuberosity medialization significantly decreased lateral patellar maltracking (bisect offset index) during pivoting.
• Tibial tuberosity medialization significantly increased medial patellofemoral contact pressure during simulated squatting.
• Patellar dislocation occurred in some models with isolated MPFL reconstruction, but less frequently with added medialization.

Conclusions:

• While tibial tuberosity medialization improved patellar tracking during dynamic motion, it also increased medial cartilage pressure during squatting.
• MPFL reconstruction alone may not sufficiently address patellar maltracking in all cases.
• The findings suggest a trade-off between improved tracking and increased medial pressure with combined surgical techniques.