Torsion of the Tibial Tuberosity, a New Factor of Patellar Instability?

Patellar instability (recurrent patellar dislocation) can occur at any age. It is most often seen in young subjects, especially among adolescents. It is commonly accompanied by anatomical factors known to be driving: Dysplasia of the trochlea, patella alta, lateralisation of the tibial tuberosity, patellar torsion and misalignment, tearing of the Medial Patello Femoral Ligament... The assessment of these factors is essential to evaluate the instability and guide the procedures of the surgical treatment. MRIs have become an important test for the analysis and measurement of these factors. A new factor not described in bibliographic sources and characterized by an external torsion of the tibial tuberosity is frequently found in patients with patellar instability thanks to MRIs. This does not seem to be the case when there is no patellar pathology. A statistical study is needed to assess this rotary anomaly. It will be necessary to take it into account in the future regarding indications and techniques for tibial tuberosity osteotomies, often used to correct patellar instability.

Inclusion criteria

• Men or women
• Subjects who have not expressed opposition to the use of the data for research purposes

Clinical criteria:

• Unstable group:

• Medical history with 2 patellar dislocations or more,
• with or without requiring surgical treatment after an MRI Control group: Men or women over 18 years old
• Subjects who have not expressed opposition to the use of the data for research purposes
• Control group:

• Patients showing meniscal injury on MRI who may or may not have been treated (meniscectomy or stitches)

Exclusion criteria

• Unstable group:

• MRI performed on one knee operated for patellar instability
• Associated tearing of the ligament (ACL, PCL)
• Control group:

• Patients with a medical history of patellar pathology
• Patients with associated ligament injury (ACL, PCL)