Local | Mind, Body & Spirit

Robotic arm system puts Tucson surgeon on the cutting edge

Russell Cohen, M.D., with Stryker’s Mako robotic-arm assisted surgery system (Courtesy Stryker)

People are living longer than ever before — but living with a painful joint can restrict daily activities and decimate quality of life. In the 1950s, few retirees lived beyond their mid-60s, but today the average length of retirement is 18 years. During that time, joints often degenerate. As a result, the number of knee and hip replacements performed in the United States has soared, exceeding one million per year, accompanied by revolutionary advances in surgical techniques and technology.   

Twice a week, orthopaedic surgeon Russell Cohen, M.D., of Tucson Orthopaedic Institute, performs up to eight partial knee, total knee or total hip replacements in a day. In October 2016, he began using a device called the Mako robotic arm, which he says provides extreme precision in the placement of the new joint. As a consultant for Stryker, the company that owns Mako, Cohen has contributed to developing new technology and surgical techniques since 2008, as well as providing surgeon and sales force teaching.

Hip surgery problems, like slipping out of joint, are often due to implant malpositioning, says Cohen. “The robotic-arm assisted surgery has been a really big improvement in operative precision.” Helping patients recover mobility is tremendously rewarding, he says. “It’s a great feeling to see them come back with minimal pain and being able to restore their lifestyle.”

Born in South Africa, Cohen immigrated with his family to the U.S. at age 13, following his bar mitzvah. They settled in Phoenix in 1979. Cohen moved to Tucson in 1983, and attended Temple Emanu-El, where his three children later celebrated their b’nai mitzvah.

Cohen graduated in 1991 from the University of Arizona College of Medicine, where he also completed his residency in orthopaedic surgery in 1996. Since then, he has focused his career on improving outcomes for joint replacement patients.

In 2013, together with six colleagues nationwide, Cohen developed a new hip replacement procedure, the “Direct Superior Approach,” in which the incision avoids the iliotibial, or IT band, improving outcomes. He’s continued to explore ways to refine joint replacement surgery, and as the capabilities of the Mako system progressed, he began using it in his operating room.

When a patient needs a joint replacement, Cohen first orders a CT scan of the hip or knee. Next, he creates a 3-D model of the joint, to determine the exact size and orientation of the implant. The information is programmed into the Mako System, says Cohen, “Then we use the robotic-arm assisted technology to help guide the cuts, staying within the planned boundaries defined when the personalized pre-operative plan was created.”

Accuracy is within a half-millimeter, he says, whereas former techniques involved making a standardized incision, without the ability to customize the operation for individual patients.

Seeing his patients’ lives transformed by surgery motivated Cohen to volunteer as a disaster-relief physician when an earthquake devastated Haiti in 2010. “When I realized how much need there was out there, I caught the [volunteering] bug,” he says.

He contacted Operation Walk, a not-for-profit volunteer organization that provides free surgical treatment for patients with no access to care for bone and joint conditions. In 2011, he joined a trip to Vietnam to provide free hip and knee replacements for local patients. In 2013, he returned to Vietnam, and made a similar trip to Guatemala in August 2017. Volunteer surgeons pay their own way, he says, sometimes subsidizing other volunteers and contributing additional funding.

In 2014, Cohen participated in an Operation Walk USA initiative at Tucson Medical Center, providing free joint replacements for underserved community members. Additionally, he says, “Tucson Orthopaedic has an annual program where a few of us go down to Ecuador and do knee replacements. I’ve done that a couple of times — I enjoy it … and patients are extremely grateful; they’re just amazing.”

Cohen doesn’t necessarily view his pro bono work in terms of Jewish values. “I think of them more as human values,” he says. “There are a lot of good people in the world, with a lot of needs, so we try and take our values and upbringing and find a way to give back to them a little bit.”

Kaye Patchett is a freelance writer and editor in Tucson.