Fibula protrusion may be caused by the following reasons: First, it may be due to the patient is too thin. This situation is often seen in some women dieting to lose weight, or severe malnutrition patients, such patients due to the above reasons led to the body of the subcutaneous fat is very thin, and in the fibula this part of the muscle is also undeveloped, at this time will be manifested in the fibula is more prominent; Second, may be due to the fibula around the atrophy of the muscles caused by. This kind of situation is often seen in patients need to lower limbs for a long time of braking, or paralysis of the lower limbs, at this time will produce the muscles around the fibula has a waste of muscle atrophy, at this time the fibula will become relatively more prominent; Third, may be due to the fibula some of the old fracture caused by. If the fibula has been damaged in the past, and has not been treated well, resulting in some deformities such as angulation, it will be more prominent after its recovery. Finally, this condition can also be caused by associated space-occupying diseases of the fibula, such as when there is a bone tumor in the fibula.