How tibial tubercle torsion impacts patellar stability: A biomechanics study

Area of Science:

• Orthopedics
• Biomechanics
• Surgical Innovation

Background:

• Patellofemoral instability is a common orthopedic condition.
• External tibial tubercle torsion has been identified as a contributing factor.
• The effect of internal tibial tubercle osteotomy (TTO) on patellar stability was previously uncharacterized.

Purpose of the Study:

• To investigate the biomechanical effects of internal torsion tibial tubercle osteotomy (TTO) on experimentally induced patellar instability.
• To test the hypothesis that internal TTO can enhance patellar stability.

Main Methods:

• In vitro biomechanical analysis using six fresh anatomical knee specimens.
• Patellar instability was created by sectioning soft tissues and applying quadriceps traction.
• A 3D stereovision system quantified patellar displacement and tilt before and after a 30° internal torsion TTO.

Main Results:

• Internal torsion TTO significantly reduced patellar displacement and tilt (p<0.05).
• Patellar dislocation, consistently induced before osteotomy, was prevented after the procedure.
• The osteotomy was performed without medialization of the tibial tubercle.

Conclusions:

• Internal torsion of the tibial tubercle effectively improves patellar stability.
• These findings support the hypothesis that internal TTO can stabilize an unstable patella.
• Internal TTO presents a potential surgical option for managing patellofemoral instability.