What's New

Patient Specific Instrumentation

What is Patient Specific Instrumentation?

Patient Specific Instrumentation is one of the new and visionary technologies in total knee replacement surgery.

Combination of long standing X-rays of both lower limbs and MRI is used to create a virtual model of the patient knee, based on which, patient specific bone cutting zigs (custom block) are made. These blocks provide a "hand in glove" fit during surgery as they "exactly matches the patient's unique tibial and femoral anatomy".

During surgery they provide accurate bony cuts thus allowing precision to the final implant position. These "Blocks" are patient specific (even to the individual knee) and disposable.

Virtual model of Femur and Tibia with cutting zigs

What is the need of Patient Specific Instrumentation?

There is a close correlation between poor implant alignment and poor clinical outcome in total knee replacement surgery. Most surgeons strive to ensure that implant alignment is optimal for excellent outcome. CAS (Computer Assisted Surgery) offered this as its advantage but cost of systems, extended surgical time, array fixation methods are some of the disadvantages of the system.

Patient Specific Instrumentation is a good alternative to CAS as a technology to replicate the performance of CAS with minimal disadvantages of CAS.

What are the advantages of Patient Specific Instrumentation?

Patient Specific Instrumentation is advantageous to patients, Surgeons and Hospitals alike.

For patients: improves accuracy of alignment without putting extra pin in the bones thereby giving good results. Reduce incidence of DVT & Fat embolism, as femoral canal is not violated in conventional surgery and also reduces blood loss. Even in High Risk category patients the surgical time and anesthesia time is significantly reduced.

For Surgeons: More efficient surgery. Patient Specific Instrumentations not only reduces the number of instruments on the operation table but also reduces the number of surgical steps required to do knee replacement surgery.

Greater accuracy – Patient Specific Cutting Blocks are made from patient's own x-rays images and MRI and nothing can be more accurate for assessing patient's alignment and size. Greater accuracy is expected to give lasting outcome to patients Knee replacement

What are the disadvantages of Patient Specific Instrumentation?

The main disadvantage of Patient specific instrumentation at the moment is waiting period of approximately 4 weeks (time taken to deliver custom bock after patient X-rays & MRI) and additional cost of approx., Rs 45000/- (or approx. 1000$) each knee.

Minimal Invasive Surgery

Broadly speaking a knee replacement surgery can be carried out either through the traditional approach, or newer minimally invasive approach (MIS), also known as quadriceps-sparing approach.

It allows surgeons to insert the same artificial implant through a shorter incision.

This surgical approach avoids trauma to the quadriceps muscle, which is the most important muscle group around the knee, thereby allowing quicker recovery time including walking and knee bending movements.

The less-traumatic nature of the surgical approach may also reduce post-operative pain and diminish the need for rehab and therapy compared to more traditional approaches.

This technique is appropriate for majority patients, however needs expertise from your surgeon to prevent any wound complications or component Malalignment.

Computer Navigation

Joint replacement surgery is a combination of precision and surgical skills. The most important aspect of knee replacement surgery is to accurately restore the mechanical alignment of the leg. Computer navigation improves component position and alignment after knee replacement; thereby it is expected to further improve the results.

The use of such a technology has certain additional benefits. Not only does the computer guide the accurate bony cuts, but they can also be carried out with a small incision, which is called 'minimally invasive surgery' (MIS). Computer navigation also reduces the risk of complications by providing constant guidance and monitoring during the surgery.

However, there are few disadvantages of Computer Navigation. Technology is expensive and has long learning curve. If the bone mapping is not done accurately then there is high chances of error in the component final position.

Fast Track Knee Replacement

Total Knee Replacement is a very successful operation. It has come a long way in improving life of people crippled with knee arthritis. As the numbers of total knee replacement surgeries are increasing, so are the expectations of patients from the procedure.

With improvement in surgical techniques, effective post operative pain control, good physiotherapy protocol and majority patients participation has led to significant reduction in complications besides early post operative recovery.

Patient in Fast track knee replacement program are able to walk few hours after the total knee replacement surgery.

Fast-Track total knee replacement aims for quicker functional recovery i.e., earlier achievement of functional mile- stones and high patient satisfaction. Fast track joint replacement surgery also aims at reducing morbidity & mortality and reduced length of stay in the hospital.