Crepitus is a first indication of patellofemoral osteoarthritis (and not of tibiofemoral osteoarthritis)

Crepitus and history of patellar pain are clinical findings that indicate PFJ lesions seen on MRI. These tests could help to indicate signs of PFJOA. Follow-up data needs to confirm whether these tests have an additional diagnostic value for early knee OA in PFJ or TFJ.