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If Sharat Kusuma, M.D., needed a hip replacement tomorrow, he would choose hip resurfacing over a conventional total hip.
The joint replacement surgeon traveled to Birmingham, UK, early in his career to learn hip resurfacing techniques from the masters and inventors. He performed nearly 500 of the procedures during his clinical career, including bilateral resurfacings on the father of the best man at his wedding and numerous physician colleagues. And he has closely reviewed the positive outcomes of the procedure published in journals and registries.
Dr. Kusuma believes that a combination of orthopedic surgeons’ resistance to change, the DePuy ASR metal-on-metal total hip catastrophe and improper surgical techniques have led to mass disinformation and the near-demise of hip resurfacing. But now, as a full-time medtech industry executive, he is focused on bringing clinically meaningful technologies like the next generation of hip resurfacing to the orthopedic market.
“The future looks very bright for modern hip resurfacing,” Dr. Kusuma said.
Dr. Kusuma serves as Chief Strategy Officer and Chief Medical Officer at Exactech, where he leads the company’s partnership with JointMedica to commercialize the Polymotion Hip Resurfacing implant. Exactech previously acquired a minority interest in JointMedica and announced that Polymotion received FDA Breakthrough Device Designation. Over the next five years, the companies plan to bring the device to the global orthopedic market.
The Polymotion hip was developed by giants in the field of hip resurfacing, Professors Derek J.W. McMinn, M.D., and Ronan Treacy, M.D., both of whom invented the well-established BIRMINGHAM HIP Resurfacing (BHR) System and mentored Dr. Kusuma during his surgical training.
Restoring Anatomy and Function
Hip resurfacing is a fundamentally different procedure than a conventional total hip replacement.
In a regular total hip, the entire femoral head and undiseased femoral neck are amputated, and a large stem is placed into the femoral canal. A prosthetic ball head, normally much smaller than the patient’s original femoral head, is placed on the femoral stem. In a resurfacing, only a few millimeters of diseased bone and cartilage are shaved from the top of the patient’s femoral head, after which a cap (usually made of metal or ceramic) is placed onto the top of the femur — similar to the way a tooth is capped with a crown instead of entirely replaced.
A board-certified and fellowship-trained orthopedic surgeon, Dr. Kusuma has performed more than 2,000 total hip replacements during his career, and he possesses an objective view of the merits of conventional total hip replacements versus hip resurfacing.
He believes that hip resurfacing offers patients four primary benefits over total hip replacement: It better reproduces the patient’s natural anatomy; it enables a significantly higher level of function; it reduces the risk of dislocation, and studies over the past decade have demonstrated that it’s a physiologically safer procedure versus total hip replacement.
Bone conservation of the femoral neck is essential for maintaining high level function and minimizing the risk of dislocation and deterioration of bone density, and Dr. Kusuma said these goals can be achieved by preserving anatomy with hip resurfacing. He pointed out that osteoarthritis primarily occurs in the femoral head, yet the entire head and the femoral neck are removed in total hip replacement.
“The femoral neck is perfectly normal in most people,” he said. “Why would you take it out? It makes zero sense not to preserve that anatomy.”
Dr. Kusuma said that preserving the femoral neck also leads to better patient function than total joint replacement. While there are decades of literature that back his statement, he said, real-life stories make for fitting examples. Tennis player Andy Murray, WWE star The Undertaker, military members, farmers and firefighters have all returned to their grueling professions without activity restrictions after undergoing hip resurfacing. Total hip replacements would have likely ended their careers.
Total hip replacement leads to an altered gait, the inability to participate in high-impact sports and, in general, cannot match the patient activity and satisfaction rates observed with hip resurfacing, according to Dr. Kusuma.
“In my practice, satisfaction with the post-op joint function was the highest among patients who had a resurfacing,” he said. “It has been published repeatedly that patients with resurfaced hips walk normally, can run, can participate in high-impact sports and have greater stability. That’s not the case with a total hip.”
A lesser-known benefit of hip resurfacing is a lower mortality rate, Dr. Kusuma said. At 10 years, the mortality rate for patients with a hip resurfacing is five to six times lower than those with a total hip. The causes of this lower mortality rate are not fully understood but continue to be studied.
It is thought, in part, that the difference in mortality rate is attributed to the insertion of a large femoral stem in the femur, according to Dr. Kusuma. When a stem is placed into the femur, it pushes the bone’s fat and marrow contents into the body, and debris ultimately lands in the heart and lungs. The use of intraoperative transesophageal echocardiograms during hip resurfacing and total hip replacement shows the fat and marrow debris doesn’t appear during resurfacing procedures.
Hip resurfacing is often considered a procedure for younger, more active patients, but Dr. Kusuma said the benefits of the procedure could apply to patients of various ages, as long as they are active and have good bone quality in their femoral head and neck.
“I agree that the procedure benefits young people, because they tend to be more active. But if you believe the mortality data about total hip, why wouldn’t you perform the safer operation on older patients?” he said. “Ten years from now, hip resurfacing could be a safer operation for elderly patients, too, because the physiologic insult to the body is less.”
Reviewing the Rise and Fall of Hip Resurfacing
If hip resurfacing offers clear benefits over hip replacement, why hasn’t the procedure been widely adopted by orthopedic companies and surgeons? History provides some answers.
The first intention of Sir John Charnley, who pioneered hip replacement surgery in the 1960s, was to resurface the joint. Other ground-breaking surgeons designed hip resurfacing systems in the following decades. Dr. Kusuma said they all failed not because of biology but material science. The bearing surface materials that were chosen — polytetrafluoroethylene, polyurethane, polyacetal and nylon — were nascent.
In 1997, the BHR System, a metal-on-metal implant, was introduced and later acquired by Smith+Nephew. BHR has more than 50,000 implantations worldwide and a survival rate above 95% in some patient groups at 15-20 years follow-up. These survival rates are also observed in younger, more active total hip replacement patients, who generally tend to wear out implants much earlier.
More than a dozen hip resurfacing systems were on the market in the mid-2000s. At the time, analysts predicted the procedure could potentially grow to 15% of the hip replacement market. However, the narrative around the implant and the procedure were hijacked by the metal-on-metal hip replacement controversy that rocked the orthopedic industry. Most orthopedic companies pulled their systems from the market, as noted in our Device Company Directory. Long-term data shows that most hip resurfacing implants have not faced the metal ion risk to the extent of metal-on-metal total hip implants, he said.
Another potential disadvantage to hip resurfacing is the potential for femoral neck fracture. A small percentage of patients have experienced this fracture and needed their hip resurfacing revised to a total hip replacement. Better surgeon training on proper resurfacing technique and careful patient selection could virtually eliminate this risk, Dr. Kusuma said.
Properly implanted BHRs have performed “phenomenally well” over the years, Dr. Kusuma said. He believes that better implant materials and surgical techniques will lead to consistent outcomes and easier adoption of hip resurfacing systems in the future.
The Polymotion hip implant is a monoblock, Vitamin E infused, all-polyethylene acetabular component with a highly porous titanium back surface
Bringing the Next-Generation System to Market
The benefits and disadvantages of hip resurfacing are well-established and accounted for in the next generation of implants. At the onset of the metal-on-metal controversy, Drs. McMinn and Treacy restarted their R&D efforts and leaned on proven design principles and materials.
Their Polymotion hip implant is a monoblock, Vitamin E infused, all-polyethylene acetabular component with a highly porous titanium back surface. The design was implanted in 174 patients from 2015 to 2022 and has an over 95% survival rate.
Exactech and JointMedica are using the early clinical data as they seek regulatory approval around the world. In the U.S., the companies are working closely with FDA via the Breakthrough Device Designation program and hope to bring the device to the market in the next 2 to 3 years. They’ve also leveraged Canada’s Special Access Program (SAP) to conduct surgeries there.
“The hip resurfacing procedure has a dialed-in, captive audience in several countries,” Dr. Kusuma said, noting the U.S., Canada, Australia, New Zealand and the UK. “There’s a lot of interest in markets that we already serve, and we’re strategically looking at those markets.”
The UK’s National Joint Registry and the Australian Orthopaedic Association (AOA) National Joint Replacement Registry show about 3% of tracked hip replacements have been resurfacings. According to AOA, the number of hip resurfacing procedures in 2021 was down 70.3% from 2005, when hip resurfacing peaked. The American Joint Replacement Registry (AJRR) noted 0.1% of hip replacement procedures in 2021 were resurfacings, a decrease from 3.1% 10 years earlier.
The global total hip replacement market reached $7.9 billion in 2022 and is estimated to surpass $8.8 billion by 2026, according to THE ORTHOPAEDIC INDUSTRY ANNUAL REPORT®. If Exactech is able to change the trajectory of the hip resurfacing market with a new device, the technology could lead to meaningful revenue for the mid-tier joint replacement player.
“In my experience, any time that you show a patient an x-ray or a bone model of a hip resurfacing versus a total hip replacement, the answer is always the same. Nearly intuitively, they look at the resurfacing and prefer to have that procedure, if they are candidates,” Dr. Kusuma said.
Dr. Kusuma predicted that more orthopedic companies could pursue hip replacement systems due to revived surgeon interest and patient demand. Smith+Nephew (BHR) and MatOrtho (ADEPT and ReCerf) have experienced success with their systems. Embody is also in clinical trials for its H1 system.
“We’ve seen a resurgence in hip resurfacing at academic meetings in the last couple of years. Surgeons realize that resurfacing is a good operation and a safe operation for the right patient,” Dr. Kusuma said. “I think more companies will follow in our footsteps. It’s exciting as a small company to lead the effort to develop something that we know can be disruptive and also great for clinical care.
“The patient demand is strong and will drive industry. Even though we don’t have a hip resurfacing product approved yet, patients have called us to ask when they can get one. The story of developing a hip resurfacing that avoids the risk of a metal-on-metal articulating surface resonates with patients and surgeons. As a doctor and industry executive, it’s a dream come true to lead the development and commercialization of a device and procedure I’ve had the good fortune of learning and implanting in my patients previously. I left my orthopedic clinical practice to be able to work on initiatives like this one.”
If Sharat Kusuma, M.D., needed a hip replacement tomorrow, he would choose hip resurfacing over a conventional total hip.
The joint replacement surgeon traveled to Birmingham, UK, early in his career to learn hip resurfacing techniques from the masters and inventors. He performed nearly 500 of the procedures during his clinical career,...
If Sharat Kusuma, M.D., needed a hip replacement tomorrow, he would choose hip resurfacing over a conventional total hip.
The joint replacement surgeon traveled to Birmingham, UK, early in his career to learn hip resurfacing techniques from the masters and inventors. He performed nearly 500 of the procedures during his clinical career, including bilateral resurfacings on the father of the best man at his wedding and numerous physician colleagues. And he has closely reviewed the positive outcomes of the procedure published in journals and registries.
Dr. Kusuma believes that a combination of orthopedic surgeons’ resistance to change, the DePuy ASR metal-on-metal total hip catastrophe and improper surgical techniques have led to mass disinformation and the near-demise of hip resurfacing. But now, as a full-time medtech industry executive, he is focused on bringing clinically meaningful technologies like the next generation of hip resurfacing to the orthopedic market.
“The future looks very bright for modern hip resurfacing,” Dr. Kusuma said.
Dr. Kusuma serves as Chief Strategy Officer and Chief Medical Officer at Exactech, where he leads the company’s partnership with JointMedica to commercialize the Polymotion Hip Resurfacing implant. Exactech previously acquired a minority interest in JointMedica and announced that Polymotion received FDA Breakthrough Device Designation. Over the next five years, the companies plan to bring the device to the global orthopedic market.
The Polymotion hip was developed by giants in the field of hip resurfacing, Professors Derek J.W. McMinn, M.D., and Ronan Treacy, M.D., both of whom invented the well-established BIRMINGHAM HIP Resurfacing (BHR) System and mentored Dr. Kusuma during his surgical training.
Restoring Anatomy and Function
Hip resurfacing is a fundamentally different procedure than a conventional total hip replacement.
In a regular total hip, the entire femoral head and undiseased femoral neck are amputated, and a large stem is placed into the femoral canal. A prosthetic ball head, normally much smaller than the patient’s original femoral head, is placed on the femoral stem. In a resurfacing, only a few millimeters of diseased bone and cartilage are shaved from the top of the patient’s femoral head, after which a cap (usually made of metal or ceramic) is placed onto the top of the femur — similar to the way a tooth is capped with a crown instead of entirely replaced.
A board-certified and fellowship-trained orthopedic surgeon, Dr. Kusuma has performed more than 2,000 total hip replacements during his career, and he possesses an objective view of the merits of conventional total hip replacements versus hip resurfacing.
He believes that hip resurfacing offers patients four primary benefits over total hip replacement: It better reproduces the patient’s natural anatomy; it enables a significantly higher level of function; it reduces the risk of dislocation, and studies over the past decade have demonstrated that it’s a physiologically safer procedure versus total hip replacement.
Bone conservation of the femoral neck is essential for maintaining high level function and minimizing the risk of dislocation and deterioration of bone density, and Dr. Kusuma said these goals can be achieved by preserving anatomy with hip resurfacing. He pointed out that osteoarthritis primarily occurs in the femoral head, yet the entire head and the femoral neck are removed in total hip replacement.
“The femoral neck is perfectly normal in most people,” he said. “Why would you take it out? It makes zero sense not to preserve that anatomy.”
Dr. Kusuma said that preserving the femoral neck also leads to better patient function than total joint replacement. While there are decades of literature that back his statement, he said, real-life stories make for fitting examples. Tennis player Andy Murray, WWE star The Undertaker, military members, farmers and firefighters have all returned to their grueling professions without activity restrictions after undergoing hip resurfacing. Total hip replacements would have likely ended their careers.
Total hip replacement leads to an altered gait, the inability to participate in high-impact sports and, in general, cannot match the patient activity and satisfaction rates observed with hip resurfacing, according to Dr. Kusuma.
“In my practice, satisfaction with the post-op joint function was the highest among patients who had a resurfacing,” he said. “It has been published repeatedly that patients with resurfaced hips walk normally, can run, can participate in high-impact sports and have greater stability. That’s not the case with a total hip.”
A lesser-known benefit of hip resurfacing is a lower mortality rate, Dr. Kusuma said. At 10 years, the mortality rate for patients with a hip resurfacing is five to six times lower than those with a total hip. The causes of this lower mortality rate are not fully understood but continue to be studied.
It is thought, in part, that the difference in mortality rate is attributed to the insertion of a large femoral stem in the femur, according to Dr. Kusuma. When a stem is placed into the femur, it pushes the bone’s fat and marrow contents into the body, and debris ultimately lands in the heart and lungs. The use of intraoperative transesophageal echocardiograms during hip resurfacing and total hip replacement shows the fat and marrow debris doesn’t appear during resurfacing procedures.
Hip resurfacing is often considered a procedure for younger, more active patients, but Dr. Kusuma said the benefits of the procedure could apply to patients of various ages, as long as they are active and have good bone quality in their femoral head and neck.
“I agree that the procedure benefits young people, because they tend to be more active. But if you believe the mortality data about total hip, why wouldn’t you perform the safer operation on older patients?” he said. “Ten years from now, hip resurfacing could be a safer operation for elderly patients, too, because the physiologic insult to the body is less.”
Reviewing the Rise and Fall of Hip Resurfacing
If hip resurfacing offers clear benefits over hip replacement, why hasn’t the procedure been widely adopted by orthopedic companies and surgeons? History provides some answers.
The first intention of Sir John Charnley, who pioneered hip replacement surgery in the 1960s, was to resurface the joint. Other ground-breaking surgeons designed hip resurfacing systems in the following decades. Dr. Kusuma said they all failed not because of biology but material science. The bearing surface materials that were chosen — polytetrafluoroethylene, polyurethane, polyacetal and nylon — were nascent.
In 1997, the BHR System, a metal-on-metal implant, was introduced and later acquired by Smith+Nephew. BHR has more than 50,000 implantations worldwide and a survival rate above 95% in some patient groups at 15-20 years follow-up. These survival rates are also observed in younger, more active total hip replacement patients, who generally tend to wear out implants much earlier.
More than a dozen hip resurfacing systems were on the market in the mid-2000s. At the time, analysts predicted the procedure could potentially grow to 15% of the hip replacement market. However, the narrative around the implant and the procedure were hijacked by the metal-on-metal hip replacement controversy that rocked the orthopedic industry. Most orthopedic companies pulled their systems from the market, as noted in our Device Company Directory. Long-term data shows that most hip resurfacing implants have not faced the metal ion risk to the extent of metal-on-metal total hip implants, he said.
Another potential disadvantage to hip resurfacing is the potential for femoral neck fracture. A small percentage of patients have experienced this fracture and needed their hip resurfacing revised to a total hip replacement. Better surgeon training on proper resurfacing technique and careful patient selection could virtually eliminate this risk, Dr. Kusuma said.
Properly implanted BHRs have performed “phenomenally well” over the years, Dr. Kusuma said. He believes that better implant materials and surgical techniques will lead to consistent outcomes and easier adoption of hip resurfacing systems in the future.
The Polymotion hip implant is a monoblock, Vitamin E infused, all-polyethylene acetabular component with a highly porous titanium back surface
Bringing the Next-Generation System to Market
The benefits and disadvantages of hip resurfacing are well-established and accounted for in the next generation of implants. At the onset of the metal-on-metal controversy, Drs. McMinn and Treacy restarted their R&D efforts and leaned on proven design principles and materials.
Their Polymotion hip implant is a monoblock, Vitamin E infused, all-polyethylene acetabular component with a highly porous titanium back surface. The design was implanted in 174 patients from 2015 to 2022 and has an over 95% survival rate.
Exactech and JointMedica are using the early clinical data as they seek regulatory approval around the world. In the U.S., the companies are working closely with FDA via the Breakthrough Device Designation program and hope to bring the device to the market in the next 2 to 3 years. They’ve also leveraged Canada’s Special Access Program (SAP) to conduct surgeries there.
“The hip resurfacing procedure has a dialed-in, captive audience in several countries,” Dr. Kusuma said, noting the U.S., Canada, Australia, New Zealand and the UK. “There’s a lot of interest in markets that we already serve, and we’re strategically looking at those markets.”
The UK’s National Joint Registry and the Australian Orthopaedic Association (AOA) National Joint Replacement Registry show about 3% of tracked hip replacements have been resurfacings. According to AOA, the number of hip resurfacing procedures in 2021 was down 70.3% from 2005, when hip resurfacing peaked. The American Joint Replacement Registry (AJRR) noted 0.1% of hip replacement procedures in 2021 were resurfacings, a decrease from 3.1% 10 years earlier.
The global total hip replacement market reached $7.9 billion in 2022 and is estimated to surpass $8.8 billion by 2026, according to THE ORTHOPAEDIC INDUSTRY ANNUAL REPORT®. If Exactech is able to change the trajectory of the hip resurfacing market with a new device, the technology could lead to meaningful revenue for the mid-tier joint replacement player.
“In my experience, any time that you show a patient an x-ray or a bone model of a hip resurfacing versus a total hip replacement, the answer is always the same. Nearly intuitively, they look at the resurfacing and prefer to have that procedure, if they are candidates,” Dr. Kusuma said.
Dr. Kusuma predicted that more orthopedic companies could pursue hip replacement systems due to revived surgeon interest and patient demand. Smith+Nephew (BHR) and MatOrtho (ADEPT and ReCerf) have experienced success with their systems. Embody is also in clinical trials for its H1 system.
“We’ve seen a resurgence in hip resurfacing at academic meetings in the last couple of years. Surgeons realize that resurfacing is a good operation and a safe operation for the right patient,” Dr. Kusuma said. “I think more companies will follow in our footsteps. It’s exciting as a small company to lead the effort to develop something that we know can be disruptive and also great for clinical care.
“The patient demand is strong and will drive industry. Even though we don’t have a hip resurfacing product approved yet, patients have called us to ask when they can get one. The story of developing a hip resurfacing that avoids the risk of a metal-on-metal articulating surface resonates with patients and surgeons. As a doctor and industry executive, it’s a dream come true to lead the development and commercialization of a device and procedure I’ve had the good fortune of learning and implanting in my patients previously. I left my orthopedic clinical practice to be able to work on initiatives like this one.”
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Carolyn LaWell is ORTHOWORLD's Chief Content Officer. She joined ORTHOWORLD in 2012 to oversee its editorial and industry education. She previously served in editor roles at B2B magazines and newspapers.
