Robotics

As a consultant for Smith & Nephew, (The company that makes the implants I use for hip and knee replacement because they have the best UK Joint Registry results), I form part of an international group of surgeons that are early adopters of their Robotic / computer enhanced hip and knee replacement systems.

I am part of a group who regularly lecture on the subject and run training courses. Outside of the USA we have been part the systems evaluation in Europe, Asia and Africa. The System provided by Smith and Nephew has two components that are unique.

The first is to do with the planning.

 Everyone has a difference in how their pelvis moves with the spine. Some are stiff and others hypermobile. When we sit and stand the pelvis normally move to accommodate the ball in the socket. This is import wrt hip replacements because it may be a reason for dislocations. Added to this the tortional angle of the femoral neck will also influence where the ball sits in the socket. The aim is to keep the ball as centred as possible and to limit any impingement of the neck on the rim of the socket. Impingement can result in the ball hinging out the socket.

Planning has always been two dimensional on the xrays and most surgeons still do this, if they template at all. This Smith and Nephew system is called “Modeller”, and for the 1^st time allows me to template in 3D taking into consideration spinopelvic movement, the implant configuration and the anatomy on both sides of the hip. In addition, we use AI driven movement models for everyday hip movement to confirm that the hip does not impinge in the position we plan for.

Now we have a first-rate template and plan preoperatively.

The second part is converting the plan accurately into reality during surgery.

 This is where the computer / robotic component of the process comes into play. By placing temporary pins in your pelvic rim and connecting them to reflectors that an Infrared Camera can see, the computer knows your position and shape. I have the same reflectors on my instruments and the computer can now guide me wrt accurately placing the components as per the plan.

The result is a hip replacement in as stable a position, for you, as can be made and an accurate correction or replication of you centre of rotation and leg length.

Future plans are to apply these concepts to abnormal anatomy and revision surgery with CT scans and Guided reamers and broaches to minimise bone loss and optimise implant positioning in these difficult cases.