Hip Osteoarthritis Associated with Prominent Synovitis Revealed by 68Ga-FAPI PET/CT.

A 56-year-old patient was initially diagnosed with aseptic loosening of a left acetabular prosthesis based on 68Ga-FAPI. Half a year after revision, this patient developed right hip pain and a subsequent 68Ga-FAPI was performed revealing increased tracer uptake in the right hip, leading to a diagnosis of synovitis-induced osteoarthritis. This case highlights the utility of 68Ga-FAPI-PET/CT in visualizing synovial activity and underscores the potential role of synovitis in the pathogenesis of osteoarthritis.