Keynote Speakers
Dr. Stephen M. Howell

Dr. Stephen M. Howell

Professor of Biomedical Engineering, University of California at Davis, USA
Orthopedic Surgeon, Adventist Health/Lodi Memorial Hospital, USA
Speech Title: Calipered Unrestricted Kinematically Aligned TKA: The Target, Verification Checks, Accuracy, Implant Survival, and ‘Athletic’ Implant Design

Abstract: Purpose: Cover the following five talking points in 25 minutes
1. Restoring the pre-arthritic joint lines is the calipered unrestricted kinematic alignment (cuKA) target;
2. Mechanical alignment (MA) to the femoral head and ankle changes the joint lines causing adverse consequences;
3. Calipered unrestricted KA with manual instruments cuts the femur to target more accurately and quickly than robotics, navigation, and PSI;
4. Calipered unrestricted KA restores native tibial compartment forces, which promotes long-term implant survival;
5. The medial ball-in-socket and flat lateral insert (GMK Sphere) restores ‘athletic’ like function!
Methods: Evidence for these talking points is provided 1) by published clinical and biomechanical studies from 2006 to present and 2) by sharing observations based on a 15-year clinical experience of over >6000 consecutive primary TKAs that I performed with unrestricted calipered KA and verification checks.
Results: I will provide references that support each talking point in the presentation.
Discussion: Performing calipered unrestricted KA TKA with verification checks over the last 15-years provided many benefits to my office, hospital practice, and costs when compared to my prior 20-year experience with MA TKA.
1. In terms of the office, patients recover faster, have a higher function, better motion, and are more satisfied at six weeks after calipered unrestricted KA TKA than after MA TKA. These benefits translate into shorter post-operative visits, fewer post-operative visits, with more than half of those patients with bilateral osteoarthritis scheduling their contralateral TKA at the six-week follow-up visit. I perform ~ 500 KA TKA/year. Eliminating a 3-month and 1-year visit in 90% of these patients results in 900 fewer office visits/year. Assuming a post-op visit requires 15 minutes of my time, and I perform 20 hours of office per week, then the use of KA TKA with verification checks frees me from 225 hours and 11 weeks of office hours/year.
2. In terms of the hospital, we now perform calipered unrestricted KA TKA as a same-day discharge, which we initiated as a work around when COVID closed elective admissions to the hospital in July 2020. A 90cc intraoperative periosteal injection that costs $20 (US) provides 30 hours of post-operative pain relief.
3. In terms of costs, our use of a comprehensive pre-operative education program since 2017 eliminated the cost and use of physical therapists and visiting nurses after discharge. Coupled with same-day discharge, the health system saves ~$4000/patient.

Biography: Stephen M Howell, MD is an orthopedic surgeon specializing in treating knee disorders, an Adjunct Professor of Biomedical Engineering at the University of California at Davis, and holds 34 patents as an inventor of orthopedic devices.

He graduated from Northwestern University Medical School in 1981 and an orthopedic surgical residency at the Rothman Institute at Thomas Jefferson University in 1986. He served three years in the United States Air Force as an orthopedic surgeon and an additional 14 years as a reservist. He was recalled to active duty for the first Persian Gulf War and retired as a Lieutenant Colonel.

Dr. Howell’s clinical practice is in Lodi and Sacramento California, where he focuses on treating degenerative and sports-related injuries of the knee. He performs over 500 calipered kinematically aligned total knee arthroplasty (TKA) and 80 ACL reconstructions per year.

Since 1989 he has collaborated with Distinguished Professor Maury Hull. They have collectively educated and graduated 4 Ph.D. students and 33 master students in mechanical or biomedical engineering. Dr. Howell has published over 189 scientific articles in peer-review journals and is the senior editor of the definitive textbook entitled Calipered Kinematically aligned Total Knee Arthroplasty (Elsevier).

His innovations since 2005 include pioneering the concept of calipered unrestricted kinematically aligned TKA. Kinematic alignment has gained worldwide interest as seven of nine randomized or case-controlled trials, and a national multi-center study showed that patients treated with kinematic alignment reported significantly better pain relief, function, flexion, a more normal feeling knee and alignment than mechanically aligned TKA. In 2006, he co-founded the first company to commercialize patient-specific instrumentation for TKA. He also identified and reported the clinical presentations, adverse consequences, and methods for reducing the risks of roof impingement and PCL impingement of the ACL graft in the late 1980s and 1990s, respectively.

He maintains two-industry relationships that enabled him to transform his concepts into products that benefit patients. Since 2016 he has consulted with the engineers at Medacta, Inc ( and assisted them with developing the calipered unrestricted kinematic alignment platform for total knee arthroplasty. Since 1992 he has consulted with Zimmer-Biomet Sports Medicine, contributing to the design of ACL instrumentation for tunnel placement and fixation devices for soft-tissue grafts.

Dr. Howell frequently shares his clinical experiences and research findings as a presenter and invited speaker at national and international meetings and universities worldwide. For his work, he received an honorary membership in the German Arthroplasty Association in 2018. Dr. Howell is a past-president of the International ACL Study Group and a member of the American Association of Hip and Knee Surgeons, the International Society of Arthroscopy, Knee Surgery and Orthopedic Sports Medicine, the American Academy of Orthopedic Surgeons, as well as the Arthroscopy Association of North American.

Dr. Howell is committed to surgeon education. He maintains an educational website for those that wish to learn more about calipered kinematically aligned TKA ( and regularly publishes instructional videos ( Weekly, he hosts experienced orthopedic surgeons worldwide who seek education in his techniques through the observance of patient care in the office, hospital, and operating room.

More details will be updated...