Nuclear medicine

The researches find that the distribution of [18F]‐sodium fluoride (NaF) uptake and blood flow in the femur and acetabulum in hip osteoarthritis (OA) patients to find associations between bone remodeling and cartilage composition in the presence of morphological abnormalities using simultaneous positron emission tomography and magnetic resonance imaging PET/MR, quantitative magnetic resonance imaging (MRI) and femur shape modeling. Ten patients underwent a [18F]‐NaF PET/MR dynamic scan of the hip simultaneously with: (i) fast spin‐echo CUBE for morphology grading and (ii)  T1ρ/T2 magnetization‐prepared angle‐modulated partitioned k‐space spoiled gradient echo snapshots for cartilage, bone segmentation, bone shape modeling; and T1ρ/T2 quantification.

Magnetic resonance imaging PET/MR

The standardized uptake values (SUVs) and Patlak kinetic parameter (Kpat); are calculate for each patient as PET outcomes; using an automate post‐processing pipeline. Shape modeling was performed to extract the variations in bone shapes in the patients. Therefore Pearson’s correlation coefficients are use to study the associations between bone shapes; PET outcomes, and patient reported pain. Because Direct associations between quantitative MR and PET evidence of bone remodeling are establish in the acetabulum and femur. But Associations of shaft thickness with SUV in the femur (p = 0.07) and Kpat in the acetabulum (p = 0.02), cam deformity with acetabular score (p = 0.09), osteophytic growth on the femur head with Kpat (p = 0.01) are observe.

Pain had increased correlations with SUV in the acetabulum (p = 0.14) and femur (p = 0.09); when shaft thickness was accounted for. This study demonstrated the ability of [18F]‐NaF PET‐MRI, 3D shape modeling, and quantitative MRI to investigate cartilage‐bone interactions and bone shape features in hip OA; providing potential investigative tools to diagnose OA. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals; Inc. on behalf of Orthopaedic Research Society. J Orthop Res.

Cartilage‐bone interactions

Osteoarthritis (OA) is the most common debilitating joint disease; affecting more than 25% of the adult population. The etiology of OA is multi‐factorial and includes joint injury, aging, obesity; and hereditary factors. Hip OA is characterized by a number of pathological changes; including progressive proteoglycan loss and collagen disruption in the early stages, destruction of the articular cartilage; thickening of the sub chondral bone, osteophyte formation, and bone deformation in the later stages. As symptoms of OA do not manifest until the later more painful stages, hence, there is a need for establishing biomarkers to detect OA in its early, reversible stages.

Currently, OA progression is evaluate by measuring joint space narrowing by radiograph base Kellgren–Lawrence (KL) scores, Croft scores, and minimal joint space width; however; proteoglycan depletion and water loss occur before joint space narrowing. Similarly, early changes in cross‐talk between early bone remodeling and cartilage changes have been implicate in the development of cartilage lesions, joint degeneration; and the progression of OA.