The role of haptics in robotic-arm assisted TKA
Message from Geoffrey H. Westrich, MD
Hospital for Special Surgery in New York City, NY
What is "haptics" and why does it matter with Mako?
My name is Geoffrey H. Westrich and I am the Director of Research for the Adult Reconstruction and Joint Replacement Service at the Hospital for Special Surgery in New York City.
I started using Mako in 2014 and since then I have performed hundreds of procedures using the Mako system. Interestingly, prior to pursuing a career as a physician, I studied engineering at Tufts University. I believe this engineering background gives me a unique perspective on orthopaedic implants and surgical technologies. Two key features of Mako that I'm passionate about, and that differentiate this platform from competitive systems, are the ability to do personalized 3D CT-based operative planning and haptic-guided bone preparation. Why am I so excited about haptics?
In robotic-arm assisted joint replacements, haptics takes the form of virtual boundaries for stereotactic guidance. These boundaries provide tactile, visual and auditive feedback and can be volumetric, planar, or point-to-point object. See Figure 1.
Haptic boundaries can also be designed to encapsulate and maintain the position of the cutting tool in the prescribed location or to prevent the cutting tool from entering a prescribed location. The former is the method currently used for cutting by the Mako system. See Figures 2 and 3.
Examples of where the Mako system uses the various types of haptics include the following: volumetric haptics in its PKA application, planar haptics in TKA and point-to-point haptics in THA. The planar haptics of the TKA application are very thin and flat volumes which interact with the virtual and physical cutting tool. They are designed to help provide containment of the cutting tool and keep it parallel within the allowable bone resection zone. The user is free to move the cutting tool within the allowable zone in all three dimensions. In the Mako TKA application, bone preparation haptics are based on the specifications of the Triathlon femoral cutting block. See figure 4. Haptic boundaries can also be designed to encapsulate and maintain the position of the cutting tool in the prescribed location or to prevent the cutting tool from entering a prescribed location. The former is the method currently used for cutting by the Mako system. See Figures 2 and 3.
Bone preparation haptics are tied to the virtual implants. Therefore, the virtual location of these haptics in space is defined by where the virtual implants are planned relative to the patient’s anatomy. Their location is a function of the patient specific pre-op 3D CT-based plan and intra-op balancing.
As a result, when I perform a Mako Total Knee I am confident that the components will be properly sized1 and well positioned to plan2. Moreover, studies have demonstrated that the patient’s soft tissues are better protected than in conventional procedure3,4.
The potential benefits for my patients include improved early function, lower pain, good outcomes and higher patient satisfaction5,6,7.
In addition, working at a renowned teaching institution, I also see great value in Mako as a teaching tool when training residents and fellows.
Please join us for a live broadcast, featuring Mako Total Hip DA and Cementless Mako Total Knee cadaveric demonstrations as well as Q&A with our surgeon faculty.
References:
- Bhimani S, Bhimani R, Feher A, Malkani A. Accuracy of pre-operative implant sizing using 3D preplanning software for robotic-assisted total knee arthroplasty. Presented at AAHKS 2017.
- Hampp, EL., Chughtai, M., Scholl, L.Y., Sodhi ,N., Bhowmik-Stoker, M., Jacofsky, D.J., Mont, M.A. Robotic-arm assisted total knee arthroplasty demonstrated greater accuracy and precision to plan compared to manual technique. J KneeSurg. 2018.
- Kayani, B., Konan, S., Pietrziek, J., Haddad, F. S. Iatrogenic Bone and Soft Tissue Trauma in Robotic-Arm Assisted Total Knee Arthroplasty Compared with Conventional Jig-Based Total Knee Arthroplasty: A Prospective Cohort Study and Validation of a New Classification System. The Journal of Arthroplasty 2018.
- Eccles C, Smith AF, Denehy K, Bhimani S, Bhimani R, Malkani A. Patient satisfaction following total knee arthroplasty using technologic innovation to achieve balanced gaps: a prospective cohort study. Presented at ORS 2019, Austin, TX.
- B. Kayani, S. Konan, J. Tahmassebi, J.R.T. Pietrzak, F.S. Haddad; Robotic-arm assisted total knee arthroplasty is associated with improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based total knee arthroplasty A PROSPECTIVE COHORT STUDY; The Bone and Joint Journal. 2018;100-B:930–7
- Carroll, K., Nickel, B., Pearle, A., Kleeblad, L.J., Mayman, D.J., Jerabek, S.A., Radiographic and Functional Outcomes of Robotic-Assisted Total Knee Arthroplasty at One. Year ISTA 31st Annual Congress held on October 10-13, 2018.
- Marchand, R.C., Sodhi, N., Khlopas, A., Sultan, A.A., Harwin, S.F., Malkani, A.L., Mont, M.M. Patient satisfaction outcomes after robotic-arm assisted total knee arthroplasty: a short-term evaluation. J Knee Surg. 2017;30(9): 849-853.
Geoffrey H. Westrich, MD is a paid-consultant of Stryker.
The opinions expressed by Geoffrey H. Westrich, MD are those of Geoffrey H. Westrich, MD and not necessarily those of Stryker. Individual experiences may vary.
A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery.
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