In vivo measurements of blood flow and bone metabolism in osteoarthritis

With increasing age, there may be a decrease in femoral blood flow. In some patients, this may result in local ischaemia, which subsequently may lead to local degenerative changes. Consequently, bone blood flow may play an important role in the aetiology of osteoarthritis of the hip. Little is known about bone blood flow in the femoral head of patients with advanced hip osteoarthritis. The purpose of this study was to evaluate bone blood flow and metabolism in vivo in patients with osteoarthritis of the hip. Ten patients with symptomatic osteoarthritis of the hip were enrolled prospectively. Femoral bone blood flow and metabolism were measured using positron emission tomography together with H ₂ ¹⁵ O and [¹⁸F]fluoride, respectively. Blood flow was 0.054 ± 0.032 mL cm⁻³ min⁻¹ and 0.041 ± 0.012 mL cm⁻³ min⁻¹ in symptomatic and contralateral femoral heads, respectively (p = 0.435). The net flux of fluoride from plasma to bone mineral (K _i ) was significantly (p = 0.027) higher in the femoral head of the osteoarthritic hip (0.022 ± 0.012 mL cm⁻³ min⁻¹) than in that of the contralateral hip (0.007 ± 0.005 mL cm⁻³ min⁻¹). This study showed significant increase in bone metabolism in the proximal femur of patients with symptomatic osteoarthritis of the hip joint. There was no evidence of decreased blood flow.