Diagnostic Validity Ofclinical Tests for Infrapatellar Fat Pad Impingement Syndrome

The ETICHOFFA study is a clinical research project aiming to improve the diagnosis of Infrapatellar fat pad impingement syndrome, a common source of anterior knee pain. Although MRI remains the gold standard for diagnosis, clinical testing strategies lack validation. This observational study has two main objectives: to assess the diagnostic accuracy of a cluster of standardized clinical provocation tests for IFP impingement compared to MRI findings, and to identify clinical and subjective characteristics associated with IFP involvement confirmed by imaging.

This observational study will recruit 50 patients aged 18 to 70 years with anterior knee pain rated at least 3 out of 10 in intensity. Participants will complete a secure online questionnaire documenting symptoms, pain distribution, aggravating and relieving factors, and pain intensity at rest, during activity, and daily life. They will also complete three validated scales: the Anterior Knee Pain Scale (AKPS), the Knee injury and Osteoarthritis Outcome Score (KOOS), and the Tampa Scale for Kinesiophobia (TSK).

A standardized clinical examination will be performed, including subpatellar skin temperature measurement, knee swelling assessment, passive range of motion testing, and a series of provocation tests targeting Hoffa's fat pad. Tests will be randomized to reduce bias and considered positive if they reproduce the patient's typical pain with an intensity of at least 2/10. Each participant must also undergo a standardized MRI of the knee within two weeks of the clinical assessment, interpreted blindly by an independent musculoskeletal radiologist.

All data will be anonymized, stored securely, and analyzed using SPSS software. Diagnostic accuracy of clinical tests will be evaluated through sensitivity, specificity, predictive values, and likelihood ratios. Functional outcomes related to taping will also be analyzed.

The study has received ethical approval and adheres to GDPR standards for data protection. Participation is voluntary, with the right to withdraw at any time. The ETICHOFFA study is expected to enhance clinical diagnostic pathways for anterior knee pain associated with Infrapatellar fat pad involvement.