Highlights from the 2019 Academy meeting

Message from Martin Roche, MD      

Holy Cross Hospital, Ft. Lauderdale, FL

Stuart Simpson

I’ve just returned, like many of you, from yet another outstanding Academy meeting with over 12,000 HCPs in attendance. This year, more exhibitors and attendees than ever were discussing “robotic” joint replacement. Having performed the first sensor assisted and robotic assisted knee surgery in the world more than 12 years ago, it is exciting that robotics has evolved from an innovative technology to a solid platform that is being adopted by an increasing number of joint surgeons1.

While at the meeting, I had the pleasure of presenting at Stryker’s lunch symposium, “The potential clinical and economic benefits of Mako Robotic-Arm Assisted Surgery”. The event was chaired by Dr. Wael Barsoum from West Palm Beach, FL, and my co-presenters were Dr. Benjamin Domb, Hinsdale, IL, and Dr. Ormonde Mahoney, Athens, GA, and the meeting, of course, featured lots of compelling content. 

Dr. Domb discussed how outpatient THA has the potential to be cost-effective2, and, based on his experience, robotics may improve patient outcomes at two and five years following surgery. Dr. Mahoney’s talk focused on his use of the Mako System, which he’s found to demonstrate enhanced planning3, dynamic joint balancing and kinematic assessment4, accurate bone preparation to plan5, and better prediction of implant sizes than 2D templating6. Dr. Mahoney also touched upon Professor Fares Haddad’s work across two distinct, prospective, consecutive series, single-surgeon studies comparing patients undergoing conventional jig-based total knee replacement versus Mako Total Knee surgery (40 patients7 and 30 patients8 in each cohort). The studies concluded that Mako Total Knee with Triathlon was associated with: less bone and soft tissue damage8 (p<0.05), less need for opiate analgesics6 (p<0.001), less time to hospital discharge7 (26% reduction in LOS), less need for in-patient physical therapy sessions6 (p<0.001), and less post-operative pain7 (p<0.001).

Finally, I spoke about why I expanded my Mako Partial Knee practice and why I consider unicompartmental knee arthroplasty a longer-term procedure vs. an interim one. In the appropriately indicated patients, Mako Partial Knee has been shown to have a higher forgotten joint score vs. TKA (2.5-year follow-up)9, less physical therapy vs. TKA10, reduced post-op pain vs. manual Oxford UKA (day 1 to week 8 post-op)11, decreased analgesia requirements vs. manual Oxford UKA12, shorter time to straight leg raise vs. manual Oxford UKA12, fewer PT sessions (5) vs. manual Oxford UKA (9)12, quicker hospital discharge vs. manual Oxford UKA12, and high patient satisfaction (5.7-year follow-up)13.

This year’s scientific exhibits, posters and podium presentations were extremely powerful, and included a strong presence of ten Mako robotic-themed acceptances, too. Acceptances featuring Stryker’s implant products alone included six knee and five hip related topics. In case you missed them at the meeting, here’s a summary of my top picks. And, in case you’re not aware, you can find all of the posters that were displayed at the meeting on the Academy’s website.


C. Cool, NA Khlopas, M. Mont. Comparing Revision, Readmission Rates and Costs of Robotic-Arm Assisted and Manual Unicompartmental Knee Arthroplasty. 

The results of this study demonstrated that patients who underwent rUKA had fewer revision procedures, shorter LOS, and incurred lower mean costs at 24-months. These results are likely to become even more important for payers and providers as the prevalence of end-stage knee osteoarthritis increases alongside the demand for cost-efficient options for treatment.

Prof. F. Catani, F. Zambianchi, G. Franceschi, A. Marcovigi, A. Ensini, A. Illuminati. Component Positioning and Soft-Tissue Tensioning Influence Clinical Outcomes of Robotic Assisted Lateral Unicompartmental Knee Arthroplasty: A Short-Term Follow Up Study. 

This two-center study demonstrated that patients who underwent Mako Partial Knee surgery had 100% survivorship at 36.3 months and a 92.5% satisfaction rate with their lateral UKA.

K. Blevins, BA, J. Danoff, MD, R. Kant Goel, MD, C. Foltz, PhD, WJ Hozack, MD, AF Chen, MD. Energy Expenditure During Conventional and Robotic Arm-Assisted Total Knee Arthroplasty.

This study compared total and rate of caloric energy expenditure between conventional TKA and Mako Total Knee between a high-volume veteran surgeon and a lower volume, less experienced surgeon. The study demonstrated that while the rate of energy expenditure did not vary between CTKA and RTKA for the low volume surgeon, it did vary significantly for the high-volume surgeon. Additionally, RTKA took longer and increased total energy expenditure, but one less operating room assistant was needed.


J. Nevelos, L. Maclean, SM Sporer, SF Harwin, D. Nam, RM Nunley, R. Barrack, AL Malkani. Design, Migration and Early Clinical Results of the First Mass Produced 3D Printed Cementless Total Knee Implants.

The studies summarized in this scientific exhibit demonstrated that at a minimum 2-year follow-up, the novel, additively manufactured cementless titanium baseplates have demonstrated low migration, equivalent pain and blood loss to cemented, excellent survivorship and post-operative functional outcomes.


R. Huang, MD, A. Malkani, MD, M. Mont, MD, W. Hozack, MD, S. Harwin, MD, G. Westrich, MD. Multicenter Evaluation of a Modular Dual Mobility Construct for Revision Total Hip Arthroplasty.

The study discussed in this podium presentation demonstrated that, at latest follow-up, revision THA with the MDM construct provided a low rate of revision in a cohort with instability, namely 2.9%, with good functional improvement. Recurrent instability following use of MDM in revision THA was associated with retention of the acetabular component, likely due to cup malposition.


  1. Stryker’s sales and medical education data.
  2. Richard M, Alyousif H, Kim JK, Poitras S, Penning J, Beaule PE. An evaluation of the safety and effectiveness of total hip arthroplasty as an outpatient procedure: a matched-cohort analysis. J Arthroplasty. 2018 Oct;33(10):3206-3210.
  3. Pietrzak, JRT, Rowan, FE, Kayani, B., Donaldson MJ, Huq SS, Haddad FS. Preoperative CT-Based Three-Dimensional Templating in Robot-Assisted Total Knee Arthroplasty More Accurately Predicts Implant Sizes than Two-Dimensional Templating. J Knee Surgery. 2018 Aug 1. doi: 10.1055/s-0038-1666829.
  4. Marchand RC, Sodhi N, Bhowmik-Stoker M, Scholl L, Condrey C, Khlopas A, Sultan AA, Newman JM, Mont MA. Does the robotic arm and preoperative CT planning help with 3D intraoperative total knee arthroplasty planning? J Knee Surg. 2018 Aug 15.
  5. Hampp EL, Chughtai M, Scholl LY, Sodhi N, Bhowmik-Stoker M, Jacofsky DJ, Mont MA. Robotic-arm assisted total knee arthroplasty demonstrated greater accuracy and precision to plan compared to manual technique. J Knee Surg. Feb 2018.
  6. Bhimani, S., Bhimani, R., Feher, A., Malkani, A. Accuracy of Preoperative Implant Sizing Using 3D Preplanning Software for Robotic-Assisted Total Knee Arthroplasty. Presented at AAHKS Annual Meeting 2017.
  7. Kayani B, Konan S, Tahmassebi J, Pietrzak JRT, Haddad FS. 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. Bone and Joint Journal: 2018; 100-B:930–7.
  8. 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. J Arthroplasty. 2018 Aug;33(8):2496-2501.
  9. Zuiderbaan, HA, Van der list, JP, Khamaisy, S., Nawabi, DH, Thein R., Ishmael C., Paul S., Pearle AD. Unicompartmental knee arthroplasty versus total knee arthroplasty: Which type of artificial joint do patients forget? Knee Surg Sports Traumutol Arthrosc. 2015;25(3):681-686.
  10. Borus, T., Roberts, D., Fairchild, P., Pirtle, K., Baer, M. Early Functional Performance of Unicompartmental Knee Arthroplasty Compared to Total Knee Arthroplasty. 2nd World Arthroplasty Congress (WAC) 2018. Rome, Italy. ePosterP4. April 19-21, 2018.
  11. Blyth, MJ, Anthony, I., Rowe, P., Banger, MS, MacLean A., Jones B. Robotic-arm assisted versus conventional unicompartmental knee arthroplasty: exploratory secondary analysis of a randomized controlled trial. Bone and Joint Research. 2017;16(11):631-9.
  12. Kayani, B., Konan, S., Tahmassebi, J., Rowan FE, Haddad, FS. An assessment of early functional rehabilitation and hospital discharge in conventional versus robotic-arm assisted unicompartmental knee arthroplasty: a prospective cohort study. Bone Joint J. 2019 Jan;101-B(1):24-33.
  13. Kleeblad, LJ, Borus, T., Coon, T., Dounchis, J., Nguyen, J., Pearle, A. Midterm Survivorship and Patient Satisfaction of Robotic-Arm Assisted Medial Unicompartmental Knee Arthroplasty: A Multicenter Study. The Journal of Arthroplasty. 2018: 1-8.