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By Selina Hurley on


How do you develop a new medical tool? Many of the objects in the Science Museum’s collections are the finished article. You rarely see the hours of perspiration or the moment of inspiration that led to the tool being made in the first place. This is why I really enjoy looking at and researching prototypes.

Prototype version of the Dobbie bone saw for use in hip replacement, 1966-7 (Science Museum, London)

Developed by Kenneth Dobbie in the 1960s, these saws were the first step towards creating a power-operated saw for use during hip replacement surgery.

He was working as an Electrical Safety Engineer at the Royal National Orthopaedic Hospital in Stanmore when he was ‘challenged’ by a sister to produce a power-operated saw to reduce the physical effort involved in cutting through bone and to reduce the time a patient needed to be under anaesthetic.

Dobbie’s second prototype was sent to one of the pioneers of hip replacement surgery, Sir John Charnley (1911-1982). 

He worked closely with Kenneth Dobbie in the development of the saws, suggesting improvements. By working with Charnley, Kenneth Dobbie made a tool that could be used easily by surgeons as it took into account their needs.

Final prorotypes of Dobbie bone saw, 1967 ( Science Museum, London )

Kenneth Dobbie’s invention went onto to become an oscillating bone saw made by Desoutter Brothers Ltd.

John Charnley was also at the forefront for developing hip prostheses.

Charnley type hip prosthesis (© Science Museum / Science & Society )

He found that ones made from acrylic plastic squeaked badly and set about designing replacements. This example is made from a cobalt alloy, durable and light. Many of the designs he produced are still in use today – at least 50,000 hip replacements are carried out in the UK every year.

One comment on “Prototypes

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