Entheseal bone remodeling in the anterior patella is associated with worse functional knee outcomes – new insights from [18F]NaF-PET MRI

Motivation: Attachment points of tendons, or entheses, in the anterior patella have been discussed as independent pain generators in osteoarthritis (OA). Pain from the entheses may be related to bone remodeling. Goal(s): To investigate the association of entheseal [18F]-NaF-uptake at the patellar entheses on PET MRI and patient reported knee outcomes. Approach: Patients with early isolated patella-femoral joint (PFJ) OA and healthy controls received both 3D PDFS FSE MRI and [18F]-NaF-PET of both knees. Association of uptake and patient reported outcomes was investigated. Results: [18F]-NaF uptake in the anterior patella is significantly associated with patient reported knee outcomes. Impact: Bone remodeling at the enthesis of the patellar tendon quantified by [18F]-NaF PET-MRI is related to pain and other patient reported outcomes and may offer inroads to understanding the poor correlation between structural lesions and symptoms in OA.