Complex Patellofemoral Reconstruction for Recurrent Instability.

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomechanical Engineering

Background:

• Patellofemoral instability results from combined bony and soft tissue factors, including patellar height, tibial tubercle (TT) lateralization, and trochlear dysplasia.
• Assessing factors like TT-TG distance, Caton-Deschamps Index, and patellar trochlear index (PTI) is crucial for evaluating patellar alignment and stability.
• Soft tissue restraints, such as the medial quadriceps tendon femoral ligament (MQFL), play a significant role in preventing lateral patellar subluxation.

Purpose of the Study:

• To describe a surgical technique for managing recurrent patellar instability in patients with moderate-to-severe trochlear dysplasia.
• To evaluate the efficacy of combining medial patellofemoral ligament (MPFL) reconstruction with tibial tubercle osteotomy (TTO) and sulcus-deepening trochleoplasty.
• To restore normal patellar tracking and eliminate recurrent subluxation.

Main Methods:

• The surgical technique involves MPFL reconstruction using a quadriceps tendon graft, followed by TTO to correct TT position.
• A V-shaped flap of trochlear cartilage is created and secured to deepen the trochlear groove (sulcus-deepening trochleoplasty).
• The procedure includes fluoroscopic verification of screw depth and location for TT fixation and assessment of patellar tracking before closure.

Main Results:

• Sulcus-deepening trochleoplasty, with or without MPFL reconstruction, has shown satisfactory outcomes, with up to 85% return to sport and 100% return to work.
• MPFL reconstruction combined with TTO has reported a 94.5% patient satisfaction rate in existing literature.
• The combined technique aims to eliminate recurrent patellar subluxation and improve patellar tracking.

Conclusions:

• MPFL reconstruction with TTO and sulcus-deepening trochleoplasty offers excellent subjective outcomes for patients with recurrent patellar instability and Dejour types B-D trochlear dysplasia.
• This surgical approach effectively restores patellar tracking and eliminates recurrent subluxation.
• The procedure leads to significant improvements in functional scores, such as the International Knee Documentation Committee (IKDC) scores.