Mako TKA

Patient Specific Pre-Operative Planning

CT data is segmented to create a 3D model of the patient’s bony anatomy. The total knee application allows a surgeon to manipulate the Triathlon implant on the patient’s virtual 3D anatomy taking into account the 6 degrees of freedom, implant alignment in all three planes, and consider key anatomic landmarks such as the transepicondylar axis, posterior condylar axis and the mechanical axis during planning.

Functional Implant Positioning

After assessing the patient’s ligament tension, gap analysis, and limb alignment, surgeon controlled intra-operative adjustments can be made to the pre-operative plan in both flexion and extension before bone preparation.

Robotic-Arm Assisted Bone Preparation

The Mako Total Knee application does not require cutting blocks, A/P sizing guides, ankle cradles, or intramedullary rods for bone preparation.  Similar to Mako Partial Knee, the total knee application creates a stereotactic boundary which assists the surgeon in executing both the tibial and femoral bone resections to plan. The stereotactic boundary has the potential to protect essential anatomical structures of the knee during bone preparation including the PCL and the popliteal artery.

The Mako Total Knee Arthroplasty application is compatible with Stryker’s Triathlon Total Knee System that has over a decade of proven performance in both Australia and New Zealand, recording one of the highest published survivorship rates of all knee prostheses in the market at 96.6%¹ and 97.4%² respectively after ten years.

Stryker’s knee philosophy is focused around ‘Soft Tissue Guided Motion’ where the implant respects the soft tissue envelope of the patient and works with the body rather than simply within it. This results in patients being able to experience a high flexion and high functioning knee, and quicker post-surgery recovery³.

Mako robotic-arm assisted Total Knee Arthroplasty has the potential to increase the accuracy of TKA bone cuts and component placement to plan, even for an experienced user of manual instrumentation who is new to robotic technology.⁴

Accuracy

• Comparing the means for all six matched pairs (n=6), RATKA final bone cuts and final component positions were as or more accurate to plan than MTKA control, for 11/12 and 5/5 measurements, respectively, and all (17/17) measurements when comparing the last three matched pairs (n=3).
• On average, RATKA (n=6) final bone cuts and final component positions were 4.2 and 3.2 times more accurate to plan than the MTKA control, respectively.

Precision

• Comparing the standard deviations for all six matched pairs (n=6), RATKA final bone resections and final component positons were as or more precise to plan than the MTKA control on all femoral and tibial V/V measurements, and all measurements when comparing the last three matched pairs (n=3).
• On average, RATKA (n=6) final bone cuts and final component positions were 5.0 and 3.1 times more precise to plan than the MTKA control, respectively.

Soft Tissues Protection

Adequate soft tissue protection is achieved using Mako robotic-arm assisted surgery for Total Knee Arthroplasty.  It offers protection of the medial collateral ligament (MCL), lateral collateral ligament (LCL), posterior cruciate ligament (PCL), and patellar ligament with no visible evidence of disruption of any of the ligaments. Tibial subluxation was not required for tibial cutting, which may reduce ligament stretching. All cases were left with a bone island on the tibial plateau, which protected the PCL. In addition, patella eversion was not required for visualization.⁵

Examples of corresponding robotically performed TKA with A) planned tibial resection and B) bone island preparation in front of PCL.