Computer Navigated Knee/Hip Replacement Surgery

Computer navigated replacement: A fusion of technology with human skill-Uncompromised Accuracy

When the world is driven by technology, does we as surgeons can be far behind? What does technology has to offer a replacement surgeon?

Precise alignment and balancing of the new knee implants is imperative for its long time survival – that’s where technology kicks in .

The computer helps us to accurately define the axis and the angles so that your new knee fits well and is placed within millimeters of defined scientific parameters.

It reduces the chances of human error in placement of the new knee implants.

If the implants are not aligned well it leads to pain, poor function and early loosening and failure of the surgery.

This technology has lead to an improvement in the precision factor of the surgery and made the results more predictable and reproducible.

How’s computer navigation different from conventional/Manual Technique of Knee Replacement?

For years, the conventional way of doing replacement surgery has produced time and again good long term results. Conventionally, while doing a knee replacement, surgeon uses manual examination which is aided by the use of jigs and alignment guides which use bony landmarks to align the components correctly with respect to bone.

It has been found that despite the available instrumentation system, at times, human errors and minor toggle in the jigs up to few degrees are unavoidable. There are other valid limitations like obesity, post-fracture deformity, narrow bone, previous operation around the joint which tend to reduce the surgical accuracy with conventional technique even in the hands of very experienced surgeons.

An error of more than 3-5 degrees can result in poor recovery and reduce the longevity of the artificial implant.

What Is Computer Navigation?

Computer Navigation is an Infra-red based real time tool for performing total knee replacement.

Navigation helps to reduce errors during surgery by providing real time visual information about the accuracy of the bone cuts, implant positioning, ligament balancing, and final alignment of the limb.

How Does Computer Navigation Work?

During knee replacement surgery, the surgeon uses infrared markers and trackers to mark the patient’s own bony landmarks.

The data is captured by the Infrared cameras in the navigation system which generates a real time 3D model of the patient’s knee joint.

Also, the landmarks which are vital for implant positioning but cannot be seen by human eye or approximated with conventional instruments (hip centre and ankle centre) are accurately located with the help of software algorithms.

Finally each step of the surgery is monitored real time and errors can be precisely fine-tuned.

What advantages can you derive from the procedure?

A number of benefits can be derived from computer navigated knee replacement surgery such as:

• It enables us to make smaller incisions with minimal soft tissue dissection occurring as well. As a consequence, there’s greater protection of your quadriceps tendon and muscle during the procedure which helps in early rehabilitation.
• Bone cuts are more precise in nature as well as are reproduced in a highly clear manner imparting greater accuracy and fit of the implant.
• In a computer navigated knee replacement the ligament balancing is done in a highly precise manner which ensures longetivity of the new knee.
• It eliminates the need to place a rod inside the intramedullary bone canal of the thigh bone, thereby, decreasing chances of post operative bleeding and embolism.
• In complex cases involving deformity of the thigh or leg bones due to previous fracture, excessive bowing, previous osteotomy and trauma implants such as plate and screws in situ, traditional alignments systems are difficult to use. In these cases, computer navigated knee surgery is the most preferred method as all these doesn’t pose any challenge.

The outcome is a better performance of the replaced knee, both short and long-term in nature.

The results though are not well reproducible in a Hip replacement as compared to knee replacement, in which it offers distinctive advantages over a conventional jig based surgery.