MAN OF MANY PARTS

THE BROADER PICTURE

In Centuries to come, when archaeologists dig up our skeletons, they will discover that we possessed some very different features from those of our predecessors. Medical technology means that few people alive today in the Western world will die before some inanimate object is added to their body as a permanent, functioning component.

When today's archaeologists study old skeletons, the broken bones, holed skulls and abscessed jaws that they find help them to build up a picture of the deceased's life-history. Scientists of the future are just as likely to find evidence of life's unavoidable traumas - but the bones of late- 20th-century man will be beautifully healed and often enhanced by artificial inserts (I, for example, have two metal rods incorporated into my right-hand index finger, inserted five years ago by surgeons repairing a break).

And it is not just our bones that are becoming replaceable. The last 80 years have seen the opening of the floodgates to the artificial - as our picture of the Science Museum's new exhibit, the two-metre-high "Clear Man" shows, a latter-day Dr Frankenstein could almost begin to make a totally artificial man or woman. Battery-powered pacemakers to control unruly heart muscle, artificial eye lenses, plastic heart valves to replace the faulty or worn originals, middle-ear bones, even rubber-and-metal implants to erect the penis. Hips, knees, fingers, spinal discs, shoulder joints, toes, ankle joints, larynxes, bone pins made of a metal alloy that "remembers" the shape it should set into, plastic blood vessels, even artificial skin - they're all out there. The message from the surgeons is an inspirational one. "We can rebuild you," they say - assuming, that is, you have the time and the money.

The surgical implant is very much a phenomenon of this century. When the Queen Mother was born in 1900, the idea of replacing worn-out or painful joints had only just been mooted; five years later the first artificial hip-joints were developed by John Murphy, an American surgeon then aged 48. But it was not until 1938 that John Wiles, a British surgeon, developed the totally artificial stainless-steel hip replacement.

Since then, thousands have been inserted to replace the ground-down heads of femurs and their accompanying hip sockets, relieving pain and making walking possible again. The Queen Mother is simply one of the more famous recipients.

The only problem is that, though we can mimic nature, we can't truly improve on the real thing. As well as their tendency to generate odd reactions from the immune system, hip replacements are hampered by being made of materials which often degrade more quickly than the original bone did (some people have worn out their first replacement, and gone back for a second). And efforts to produce wholly artificial replacements for entire organs can never match the wonderful efficiency of those created by millions of years of evolution. We have not yet made an artificial heart that can work away from power sources. Artificial kidneys - in the form of dialysis machines - are still far too large to be implanted. The chemistry and functions of the liver are so complex that we may never be able to replicate it.

Inserting an implant is mainly an operation of necessity - though the ever-increasing popularity of silicone breasts, buttocks and other assorted "body enhancers" testifies to the boom in vanity surgery, the darker side of our obsession for artificial self- improvement. But in some cases implants have passed from being items of necessity, through vanity, to legitimate business expenses. In 1994 the "exotic dancer" Cynthia Hess - stage name Chesty Love - won a court battle in the US with the Internal Revenue Services, when a judge ruled that the pounds 1,000 she had spent for surgical breast implants - creating a 56FF chest, in which each breast weighed about 10lbs - was a legitimate business deduction. In his ruling, the judge said the stripper's bust "contorted her body into a grotesque appearance, all for the purpose of making money". As a silicone implant is virtually indestructible, long outlasting the frail flesh that once enclosed it, what, one wonders, would an archaeologist think on digging up her skeleton?

Clear Man, a resin model featuring over 50 different medical devices, is part of "The Challenge of Materials", a new pounds 3m gallery which opens on Tuesday at the Science Museum, SW7 (0171 938 8000).

SILICONE EAR

Mainly used for cosmetic reconstruction

DENTAL IMPLANT

A titanium `root', which can be capped

ELBOW

Similar to artificial toe and finger joints

CARBON-FIBRE BONE PLATE

More flexible than metal, so fractures tend to repair themselves with greater speed

PACEMAKER

Emits a regular electronic pulse, which artificially stimulates heart contractions

INTERBODY FUSION DEVICE

Used to separate and support vertebrae after diseased discs have been removed

KNEE

Another implant commonly found in arthritic ex-dancers and sportspeople

GLASS EYE

Supports the shape of the eyelid when the original eyeball has been damaged

ARTIFICIAL LARYNX

Replaces damaged or diseased vocal cords

VASCULAR GRAFT

Artificial blood vessel; this type (like the cheaper sort of shirt) is made of polyester

UPPER DENTURES

The most common artificial implant? Otherwise known as Gran's false teeth

ANTERIOR CERVICAL PLATE

Fuses head and neck bones; prevents excessive movement in a broken neck

PENILE PROSTHESIS

Bendy, stretchy internal support which helps the recipient maintain an erection

EXTERNAL FIXATION DEVICE

Pins inserted into the bone support an external `cage' which will prevent any movement; used for multiple breaks

TOE AND ANKLE

Vital replacements to maintain mobility

MAXILLOFACIAL PLATE

Tiny titanium insert which holds together fractured facial bones while they mend

SHOULDER

Titanium-coated joint; most often given to young arthritis sufferers, such as ex- dancers and professional sportspeople

SHAPE MEMORY ALLOY BONE STAPLES

Constructed from a special alloy which contracts when exposed to body heat, so pulling broken bone ends together

ARTIFICIAL HEART VALVE

Replaces damaged aortic valve. May be used in conjunction with a pacemaker

SUTURES

Indissoluble `thread' for stitching wounds

HIPS

On both right and left, showing the internal and external parts of the joint. The Queen Mother sports one of these

DISTAL FEMORAL AND TIBIAL NAILS

Quicker to put in than a plate, but not for the squeamish: to insert, simply bang one straight up the centre of the bone