A new surgical robot is making medical undergraduates three
times more accurate during practice hip operations, according to
pilot study to be discussed at a conference this week (8 February
Delegates at the British Society for
Computer Aided Orthopaedic Surgery
Conference will hear that results from a
pilot study saw graduates 95 per cent more
confident using this robotic technique than
when using conventional surgical methods in
Professor Justin Cobb, Head of the
Biosurgery and Surgical Technology Group at
Imperial College London, conducted the trial
on 32 undergraduate medical students at
Imperial College London from December 2006
to December 2007. The pilot study tested
whether planning before an operation,
combined with the latest robotic navigation
equipment could increase the success rates
of students practising hip resurfacing
arthroplasty procedures – a method for
correcting painful hip bone deformities by
coating the femoral head with a cast of
Up to 5,000 hip resurfacing operations happen each year. These operations are
technically demanding and require precision and accuracy. Surgeons rely on years
of experience and on different cameras, lasers and hand held tools to help them
navigate during an operation.
Inexperienced surgeons often face a steep learning curve to gain the experience
necessary to carry out hip resurfacing operations. Until now, this has only been
gained through repeatedly performing the operations. This can cause problems
because if hip bones are repaired incorrectly wear and tear occurs, requiring
patients to undergo further painful and expensive corrective operations.
Imperial researchers believe their method will address the issue at the
Third year medical undergraduates were asked to trial a state-of-the-art robot
called the Navigation Wayfinder – a new navigation tool never before used in the
The Wayfinder is similar to a GPS tracking system. It helps the user to navigate
during surgery by plotting correct surgical incisions. It also calculates the
correct angles for inserting chrome alloy parts needed to repair hip bones.
It has twin digital arms protruding from a console. One senses the movement of
surgical tools as they slice through a patient’s hip area. The other takes
detailed images of the bones. This information is fed into software which
generates a virtual model of a patient’s hip as it is being operated on. Similar
to a 3D roadmap, it allows the user to plot the progress of an operation as they
are performing it – a vital technique for ensuring that it is being carried out
Professor Cobb saw the benefits of incorporating the Wayfinder into
undergraduate training and developed a three step training programme.
Students used model replicas of deformed hip bones for the trial, scanned by the
Wayfinder’s digital arm. This information was used to create a 3D virtual model
of the bone area.
The Wayfinder’s computer programme developed an operation plan setting out the
actions required for undergraduates to correct the hip deformity.
Students were asked to carry out a virtual operation on the 3D model of the hip.
Using the tool tracking arm, they practised techniques for fastening chrome
alloy on virtual deformed hip bones. This built up their confidence, technique
They were asked to perform surgery on model casts of real hip bones. By using
the Wayfinder to help them navigate, undergraduates were able to attach a post
to the centre of the femoral head and thread it, via a guide wire, to the femur.
Professor Cobb then asked students to perform the same operation using
conventional navigation tools. One method involved the use of jigs and
alignments. Similar to geometry sets, they are metal surgical guides which
helped undergraduates to manually align the femoral head as they attached it to
The second method required students to operate using an optical navigation
device. A camera and pinpoint lights were used to create an image of the hip on
a computer screen. This was used by undergraduates for visual navigation during
Professor Cobb compared how undergraduates performed with each different method.
He found that they were three times more accurate and precise using the
Wayfinder than if they used the two other conventional methods.
Clinical trials using the Wayfinder are currently being carried out at Warwick
Hospital, Bath Hospital, Truro Hospital and the London Clinic. Professor Cobb
believes his training method could be applied throughout the UK to improve
outcomes for patients. He said:
“Our research proves that we can take untrained surgeons and make them an expert
in a new technique rapidly. More importantly, we’ve also demonstrated that no
patient has to be on an inexperienced surgeon’s learning curve. This could
significantly improve a patient’s health and wellbeing and ensure they do not
have to undergo repeat operations.”
The British Society for Computer Aided Orthopaedic Surgery Conference will be
held at the Beardmore Conference Centre, Glasgow, from 7th to 9th February 2008.
For further conference details go to:
Notes to editors:
1. About Imperial College London
Imperial College London – rated the world’s fifth best university in the 2007
Times Higher Education Supplement University Rankings – is a science-based
institution with a reputation for excellence in teaching and research that
attracts 12,000 students and 6,000 staff of the highest international quality.
Innovative research at the College explores the interface between science,
medicine, engineering and business, delivering practical solutions that improve
quality of life and the environment – underpinned by a dynamic enterprise