BOOK REVIEW / Children at the cutting edge of medicine: 'Children's Consent to Surgery' - Priscilla Alderson: OUP, pounds 37.50 / pounds 12.99

AMY, now aged 10, is very short. Although her head and body are about right for her age, her legs and arms have not grown properly; and they won't. There are no drugs that will make Amy taller, but surgery might, by leg-lengthening: breaking the bone, driving nails into the two halves, and slowly ratcheting them apart in hope that over the months new bone will form in the gap. If, and it is a biggish if, good new bone does develop, and if muscles, nerves and skin stretch to accommodate the enlargement, Amy can then have the other leg done. She decided at the age of eight to go for surgery. 'Only the person who is going to have it can decide,' she said two years later.

Tony has had a badly twisted backbone since he was six. It is forcing his head into his lap, which squeezes his heart, lungs and abdominal parts. For him too, surgery holds out some hope, this time by reassembling his spine and clamping him in a frame while it fuses into a better shape. Such spinal fusions usually involve two or three operations. Now 15, he says he 'wanted to put it off to give me more time (but) I'm so bent over and squashed up.'

Priscilla Alderson's book is not about easy cases. It's not about children who don't want their tonsils out, or even about those whose only hope for life is heroic surgery. The 120 young patients she interviewed for this book suffered from long-term, deteriorating conditions for which treatment is prolonged, often uncertain, always risky and usually painful. Her question is whether children can meaningfully consent to this kind of surgery and, if so, how we judge when they are able to decide, and if not who ought to decide for them?

As Alderson's review reveals, in law those under 18 have few if any rights to control what is done to them medically. However, the legal position notwithstanding, doctors usually prefer patients to be willing. The surgeon who told Alderson that even 'adults don't have the knowledge to make decisions. I make it clear to them. 'This is my opinion. If you don't like it then go elsewhere' ', went on to tell her 'Kids really have to want (leg lengthening). It's important to find out whether the child wants it and not just the parents.' When asked at what age might they decide, he replied: 'Eight. Nine.'

Eight or nine? As any adult knows, meaningful consent requires competence to decide and the freedom to make decisions, and it requires that we understand the necessary information. Are children competent? Can they comprehend sufficiently if given information? Will they make 'good decisions' or decide on impulse? Alderson allows us to hear the voices of these children and their parents as they go about deciding.

Alderson's is a comprehensive text with much information on childhood, but at the heart of her remarkably readable book are the children themselves: brave, fearful, generous, hopeful; usually inquisitive, often articulate, sometimes humorous. What her study shows beyond any doubt is that many children, even very young ones, can digest information and make decisions as well as most adults; or at least as well as their parents. Unsurprisingly, it turns out that children undertaking long treatments and multiple operations often understand better than anyone what is involved.

If children can understand serious illness and what the professions can do for them, why do we not authorise them to give - and, more important, to withhold - consent for medical treatment? The answer seems to show our deep ambivalence about the status of children in society. Despite the Children Act, we cannot decide if they are properly to be treated as people, pets or property. Are they, even at an early age, as capable of making decisions as the rest of us, or are they creatures who need to be protected from the responsibility that comes with making choices - whether those choices concern activities we judge to be criminal, or illness and its treatment? Perhaps one day we will empower children to say, 'I'd rather be short.'