My four year old eats like a sparrow. He seems healthy enough, but I am concerned about his diet. Should I give him vitamins?

Children of all ages need a variety of foods to supply all the dietary essentials for their growth and energy needs. They rarely require any vitamin supplement if their diet is adequate.

Eating patterns will change between infant and teenage years. Pre-schoolers often demonstrate a decreased appetite corresponding to the slowing of their growth rate after three or four years of age. Parents are often bewildered and anxious about the finicky and capricious attitudes children of this age have towards food.

Provided foods poor in nutrition are not introduced as eating inducements, eating habits will gradually return to more normal levels in the next few years.

How good are artificial hips?

Very good. It would be quite easy to leave my answer as just those two words, because the modern artificial hip really is very good.

If one goes back in history, hip replacement is not a new operation. Ivory hip replacements, carved from elephant tusks, were first used one hundred years ago. Today, the head of the femur (the ball part at the top of the thigh bone) is made of stainless steel, titanium or other rare metals. The cup part in the pelvis is made of a Teflon type plastic that is smooth, but extremely hard.

The operation is performed on those people who have arthritis (or other disease) in their hip, that is bad enough to significantly affect their lifestyle. The operation itself takes about 60 minutes, and the patient is often up and walking a few days later with the aid of a physiotherapist.

The majority of patients find a new lease of life after the procedure, but there are always a very small number in whom the operation is not a success. It is extremely rare for anyone to be worse off after the operation than before.