A 72-year-old woman presents to your primary care office wit…

A 72-yeаr-оld wоmаn presents tо your primаry care office with a 4-week history of progressively worsening bilateral shoulder and hip pain. She reports morning stiffness lasting nearly 90 minutes and says she now requires assistance getting out of bed and lifting her arms to comb her hair. She denies recent trauma, fever, or joint swelling. Physical examination demonstrates limited active range of motion due to pain but no muscle weakness. Laboratory studies reveal an ESR of 88 mm/hr and an elevated CRP.Which diagnosis is most likely?