A new classification system of patellar instability and patellar maltracking

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomechanics

Background:

• Patellar dislocations lack a unified classification system, hindering consistent treatment strategies.
• Existing research often conflates underlying pathologies, leading to varied therapeutic recommendations.
• A structured approach is needed to address patellar instability and maltracking effectively.

Purpose of the Study:

• To introduce a novel classification for patellar dislocations based on clinical and radiological findings.
• To establish a diagnostic and treatment algorithm for patellar instability and maltracking.
• To differentiate patellar dislocation types to guide surgical interventions.

Main Methods:

• Literature review to establish classification criteria.
• Categorization based on instability, maltracking, and patellar tracking loss.
• Analysis of five distinct patellar instability and maltracking types.
• Inclusion of case examples and treatment consequences for each type.

Main Results:

• Five types of patellar instability and maltracking are defined.
• Type 1: Simple dislocation, low redislocation risk.
• Type 2: High redislocation risk, requires MPFL reconstruction.
• Type 3: Instability with maltracking, needs osseous corrective surgery.
• Type 4: "Floating patella" due to trochlear dysplasia, requires trochleoplasty.
• Type 5: Maltracking without instability, treated with corrective osteotomy.

Conclusions:

• The proposed classification provides a structured framework for diagnosing and treating patellar dislocations.
• Tailored treatment algorithms based on the classification improve management of patellar instability and maltracking.
• This system aids in selecting appropriate surgical interventions, including MPFL reconstruction, osseous correction, trochleoplasty, and osteotomy.