Bone Shape Feature Differences in Single and Recurrent Patellar Dislocations via Statistical Shape Modeling

Area of Science:

• Orthopedics
• Radiology
• Biomedical Engineering

Background:

• Patellar dislocation is a common knee injury.
• Distinguishing between single and recurrent dislocations is crucial for treatment.
• Understanding underlying bone morphology can aid in risk assessment.

Purpose of the Study:

• To develop MRI-based 3D statistical shape models of the femur and patella.
• To identify specific bone shape features differentiating control, single, and recurrent patellar dislocation groups.
• To assess the potential of these features in predicting dislocation risk.

Main Methods:

• Utilized MRI data from 16 single dislocation, 17 recurrent dislocation, and 20 control subjects.
• Constructed 3D statistical shape models for femur and patella.
• Performed statistical analysis (p < 0.05) to identify significant shape differences.

Main Results:

• Identified significant bone shape features differentiating the three groups.
• Shallower trochlear groove and smaller patellar ridge distinguished dislocation from control groups.
• Prolonged lateral femoral condyle and altered patellar ridge/facet distinguished recurrent from single dislocations.

Conclusions:

• 3D statistical shape models highlight unique anatomical variations in patellar dislocation.
• Specific femoral and patellar features correlate with dislocation severity and recurrence.
• This knowledge can improve identification of at-risk individuals and inform personalized treatment strategies.