The current approach in Kinetically-Aligned Total Knee Arthroplasty (KA-TKA) involves compensating for bone loss using makeshift washers. These washers, however, pose challenges for surgeons in terms of stability between the jig and bone surfaces. Given their size, they can also be easily misplaced within the patient's knee joint, making them cumbersome and impractical for use.

 

The objective of this project is to standardise the KA-TKA surgical procedure by designing streamlined and specialised jigs that seamlessly integrate with existing commercial jigs. These jigs should offer stability without any loose components or micro-motions.

 

There are 3 main cuts in KA-TKA: the distal femur cut, posterior condyle cut, and proximal tibial cut.

 

For the distal femur cut, our jig was designed with a dial for selective increment, and the counter at the side of each dial informs the surgeon of the amount compensated.

 

In cases of a worn-out posterior condyle, bone loss is often overlooked in the current KA-TKA procedure, potentially leading to undesirable outcomes such as limited extension and flexion. To address this, we've developed a jig that compensates for bone loss, enabling improved rotation for the patient.

 

As tibial bone cut need to be parallel to the distal femur cut, the conventional KA-TKA method of eyeballing can lead to inaccuracies. Our jig features an extension plate that allows for precise alignment of the bone cut in parallel.

 

 

Designed with Jolyn Kang

(Jan - Apr 2017)

 

National University of Singapore

In collaboration with the Department of

Orthopaedic Surgery, National University 

Hospital

Studio leaders: Dr Yen Ching Chiuan

& Ulrich Schraudolph

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Domain: Medical Product Design

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