Patella morphological alteration after patella instability in growing rabbits

Area of Science:

• Orthopedics
• Biomechanical engineering
• Developmental biology

Background:

• Patellar instability is linked to patellar shape, but developmental effects are unclear.
• This study investigates patellar morphological changes following instability and its influence on patellar shape.

Purpose of the Study:

• To evaluate patellar morphological changes after inducing patellar instability in a rabbit model.
• To assess the influence of patellar instability on the development of patellar shape.

Main Methods:

• Twenty 2-month-old rabbits underwent medial soft tissue restraint release in the left knee (experimental group).
• The right knee served as the control group without surgical intervention.
• CT scans measured transverse diameter, thickness, Wiberg index, and Wiberg angle pre- and post-surgery (6 months).

Main Results:

• Post-surgery, experimental patellae showed significantly increased transverse diameter and Wiberg angle compared to controls.
• Patellar thickness did not significantly differ, leading to a flattened patellar shape.
• The articular surface of the patella became flattened in the experimental group.

Conclusions:

• Patellar instability can induce flattening of the patella's sectional shape and articular surface.
• This suggests patellar instability may cause patellar dysplasia.
• Early clinical intervention for adolescent patellar instability is recommended.