Computational approach to correcting joint instability in patients with recurrent patellar dislocation

Area of Science:

• Orthopaedic biomechanics
• Computational modeling
• Sports medicine

Background:

• Recurrent patellar dislocation is common in young, active individuals.
• Conservative treatment often fails, leading to persistent instability.
• Understanding surgical outcomes for patellar stability is crucial.

Purpose of the Study:

• To compare patellofemoral joint stability across different simulated surgical interventions.
• To evaluate the effectiveness of patient-specific surgery versus generic procedures.
• To identify the optimal surgical strategy for restoring knee stability.

Main Methods:

• Developed 3D, subject-specific finite element models for 28 patients with recurrent patellar dislocation.
• Simulated various procedures: restorative MPFL reconstruction, tibial tubercle osteotomy, patient-specific reconstruction, and less invasive patient-specific surgery.
• Applied a 50 N lateral load to assess patellar stability (rotation, translation) from 0° to 40° flexion.

Main Results:

• Healthy controls exhibited the least instability (rotation, translation, MPFL load).
• Isolated medial patellofemoral ligament (MPFL) reconstruction resulted in the most instability.
• Patient-specific reconstruction addressing anatomical abnormalities yielded results comparable to healthy controls.

Conclusions:

• Patient-specific reconstructive surgery correcting anatomical abnormalities is superior for restoring patellofemoral joint stability.
• This approach more effectively replicates healthy knee biomechanics than generic or less invasive methods.
• Tailored surgical interventions offer the best outcomes for recurrent patellar instability.