Robotic Hip Replacement Surgery

A Hip replacement is made up of 4 components:

• The Cup (Acetabular shell)
• The Head (ceramic, metal or oxinium)
• The liner (Poly-ethelene or ceramic)
• Stem (uncemented or cemented)

Xrays and sometimes CT scans are used to determine the position of components of a hip replacement – mainly the cup and majority of the times the stem.

The ultimate aim is :

• To restore a patients Hip centre of rotation
• Offset (restore optimal hip bio mechanics and muscle function)
• Leg lengths  - To make the legs even
• Maintaining stability (Reducing Dislocation Risk)

Accuracy of placement of the cup – the depth and orientation (inclination and ante-version) comes with experience – which is directly related to the number of those operations a surgeon has done.

What does a Robot do in a Hip Replacement?

It tells the surgeon "where to put the cup". This will in turn depend on how the surgeon puts in data into the robotic computer.

The Robot can only identify bone and not soft tissue (Muslces, ligaments, tendons, blood vessels and Nerves)

In all cases patients need prior imaging (CT scanning or MRI) done, which is then fed into the robotic computer. This can be analyzed before surgery to determine where the cup will sit.

During surgery the surgeon uses identifiable bony landmarks with a probe during the operation to correspond to the computer images.

The robotic arm is then used to prepare the acetabulum (socket) to the appropriate depth and the robotic arm can be used to put the cup in the desired position.
An experienced surgeon can achieve this well with minimally invasive techniques. After all, the surgeon still has to operate the robot. The Robot can play a big part in less experienced hands.

There are No convincing studies done yet to prove that robots are superior to standard techniques of an experienced surgeon.

Advantages:

• CT scans enable to determine the pelvic architecture / Acetabulum
• Surgeon can plan surgery with the aid of the computer to determine cup position

Disadvantages:

• Preparation time
• Learning curve
• Robot does not identify soft tissues
• Surgeon will have to abandon operation if there are is any failure and move to conventional replacement

Ultimately no machine can take over the mind and technical skills of a well trained, experienced orthopaedic surgeon.