Abstract
Some muscular and osteoarticular diseases pose serious diagnostic problems, e.g. subsequent recurrent or persistent conditions of isolated pain in the extremities, most frequently - in the lower extremities, especially knee joints, and isolated pain in the back, usually in the lumbosacral spine. They are often accompanied by gait abnormalities. The paper herein presents a complex differential diagnosis of these conditions, the presented diseases that can cause them, and the role of the family doctor, paediatrician, orthopaedist, and rheumatologist in the diagnosis. A detailed history of the presented complaints, accurate physical examination, plus extensive biochemical and immunological diagnostics, and microbiological and imaging techniques usually allow a diagnosis to be made. Attention was paid to the sequence of imaging procedures conducted in the differential diagnosis of pains of the extremities and the spine and not to overuse procedures that involve exposure to ionising radiation.