Spine: diffuse syndesmophytic ankylosis can give a "bamboo spine" appearance, interspinous ligament ossification can give a "dagger spine" appearance
Sacroiliac joint: no narrowing of the synovial portion.
Hips: bilateral and symmetric uniform joint space narrowing with axial migration of the femoral head causing protrusio acetabuli, with a collar of osteophytes at the femoral head-neck junction more evident on the left side.