Predisposing Anatomical Patellofemoral Factors for Subsequent Patellar Dislocation

Area of Science:

• Orthopedics
• Radiology
• Sports Medicine

Background:

• Primary patellar dislocation is an uncommon knee injury with a high recurrence rate in young, active adolescents.
• Patellofemoral joint anatomy is a key factor in knee instability.
• Identifying anatomical risk factors is crucial for predicting recurrence after initial patellar dislocation.

Purpose of the Study:

• To evaluate anatomical risk factors for recurrent patellar dislocation using MRI.
• To investigate the association between specific MRI-derived parameters and patellar instability recurrence.

Main Methods:

• MRI analysis of 54 patients with first-time lateral patellar dislocation.
• Measurement of tibial tuberosity-trochlear groove (TT-TG) distance, patellar tendon length, and other parameters.
• Assessment of trochlear dysplasia using the Dejour classification; recurrence defined within three years.

Main Results:

• Patients with recurrent dislocation showed significantly lower TT-TG distance and shorter patellar tendon length (p < 0.05).
• No significant differences were found in patellar tilt angle, Insall-Salvati ratio, or patella height.
• These findings suggest specific anatomical variations predispose to recurrent patellar instability.

Conclusions:

• Anatomical factors identified via MRI can predict the risk of recurrent patellar dislocation.
• Imaging-based identification of these variables aids clinical decision-making.
• Individualized treatment strategies can be developed based on identified anatomical risk factors.