A boy of age of 5 years presents with right lower limb pain and he refuses to walk. He keeps his hip flexed and doesn't allow to move the limb for examination. The child is febrile.
What is the most likely diagnosis?
a. Tenosynovitis of the hip joint
b. Osteomyelitis of the femur
c. septic arthritis of the hip
d. Perthes' disease