You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is The most common cause of limp in a child of seven years old is ? and explain in detail?
PEHES DISEASE : Its a disease charecterised by avascular necrosis of head of femur of a child The avascular epiphysis is almost always completely revascularised and replaced but resulting in variable degree of deformity of the femoral head and growth disturbance. pathogenesis : 4 stage on the basis of evolution of disease # Stage of Avascular Necrosis # Stage of Revascularization / Fragmentation # Stage of Ossification / Healing # Remodeling / Residual stage symptoms : 5-10yr old child # Characteristic presentation is a painless limp. # May present with limp alone with pain. # The child appears to be well & not sick . # The hip looks to be deceptively normal -- there may be little wasting. # Abduction & Internal rotation are nearly always limited. # Antalgic gait in the irritable phase or Trendelenburg gait. ref : maheswari 9th ed