Jess Lonner, MD, an orthopedic surgeon at Rothman Institute in Philadelphia, discusses seven points on why partial knee replacements will continue to be relevant in the future.
1. Why partial knee replacements can be a good option. Traditionally, when someone developed advanced arthritis in the knee and surgery was indicated, the surgeon would perform a total knee replacement, replacing all three compartments of the knee, regardless of how many were actually affected, and removing some of the key ligaments within the joint. Partial knee replacements allow surgeons to treat only the affected compartment(s) of the knee, leaving the healthy anatomy intact and preserving normal joint kinematics.
"Patients are coming in with an earlier stage of arthritis and at a younger age than they were before," says Dr. Lonner. "Total knee replacements aren't going to last forever, and younger patients don't want to miss work for a long period of time. Partial knee replacement gives us a vehicle for returning our patients back to action sooner and with less pain and limitations than we can with total knee replacement."
2. How partial knee replacement can be advantageous. The partial knee replacement is performed through a smaller incision and is a less extensive procedure than total knees because it only resurfaces one or two compartments. "The minimally invasive nature of the procedure means there will be less postoperative pain, less surgical risk of complications, more rapid discharge from the hospital and ultimately a far quicker recovery after surgery," says Dr. Lonner. "Patients often only stay for one day after their procedure. The patients are on pain medications for two or three weeks and can often return to work quicker than if they had undergone total knee replacement."
Recent studies have shown that partial knee replacements, especially those using modern precision technology, can have good and durable outcomes. "For some patients, partial knee replacement is a temporary fix, but for others, it is the last procedure they will need," says Dr. Lonner. "These days, when the procedure is done well, the durability of partial knee replacements often replicates that of total knee replacements. There are numerous studies proving that in most cases, partial knee replacements never need to be converted into total knee replacements."
3. What keeps the procedure relevant. Surgeons can look back at total knee replacement cases over the past several years and may find that as many as 50-70 percent of patients had arthritis that was limited to one or two compartments of the knee. This means they may have been good candidates for partial knee replacement, if it had been available to them. In the past, patients waited until they were profoundly debilitated, in some cases even unable to walk, until they saw a specialist and agreed to surgery. Now, patients are coming in with less advanced arthritis and want to return to normal function. These very patients have different expectations than those from years ago — they are looking for improved functionability that has been lacking with conventional total knee replacements, despite the procedure's overwhelming success. Partial knee replacement can be a good option for these patients, but not all surgeons are picking up on the procedure.
4. Where the problem with partial knee replacements lies. Not every orthopedic surgeon is on board with performing partial knee replacements, in part because the procedure is very unforgiving, says Dr. Lonner. "If we don't put the implants in well, there is a higher risk of failure…Total knees are more accommodating to modest variation of positioning without compromising the results. In partial knee replacements, we have to be more careful to select patients well and to optimize the accuracy of component alignment to enhance outcomes. This is where robotic technology comes into play."
Robotic technology can help make the implant positioning more precise for partial knee replacements. "When we compare X-rays of partial knee replacements performed with the robotic technology versus those performed with conventional technology, we can see that we are more accurate if we use the robot," says Dr. Lonner. Other technologies, such as custom instrumentation, have been made available for partial knee replacements, but there isn't solid evidence showing they improve precision or performance of the partial knee replacements, he says.
5. How physicians can convince hospitals to incorporate robotic technology. For many, robotic technology is seemingly too expensive, but in their analyses hospitals may find it worthwhile to appropriate the funds to build a program around it. Hospitals can either purchase or lease the equipment, and many are choosing to acquire the technology with the hopes of attracting more patients to their system. "The hospitals where I work have found the robotic technology to be profitable because of the large amount of surgical cases we are able to bring to them," says Dr. Lonner. "Compared to total knee replacements, partial knee replacements provide cost savings that appeal to hospitals, such as reduced hospital stay, lower transfusion rates and more limited consumption of hospital resources."
6. How to train on the technology. If the hospital is on board with bringing the robotic program into the department, they need one or more committed surgeons who will champion its growth, and not abandon it as many have done with traditional computer navigation systems for total joint replacement. To some extent, Dr. Lonner says, the conventional techniques for partial knee replacement are more difficult than the robotic techniques, so surgeons who perform the procedure in the conventional way should be able to pick up the robotic procedure without too much trouble.
"The key is gaining experience with partial knee replacement, in general, and understanding the nuance of patient selection and critical parameters in implant alignment and soft tissue balance," he says. "The robotic technology surprisingly simplifies the performance of bone preparation in partial knee replacements. Irrespective of the method used — conventional or robotic — there is a tremendous value for our patients in adopting the concept of partial knee replacement for localized arthritis of the knee. Once surgeons embrace the concept of selective knee resurfacing, there are plenty of courses available for training in surgical techniques with or without the robot."
For surgeons who have been in practice for several years and have developed a strong comfort level with the total or partial knee procedures they perform, adding new technology may not be the most desirable option. "These surgeons feel they can provide their patients with a quality product," says Dr. Lonner. "Some surgeons may feel that learning a new technique or training with a contemporary technology might not be necessary because they already have a strong skill set and provide a service that they've used for a number of years."
7. Where partial knee replacement is headed. Dr. Lonner predicts an explosion in the volume of partial knee replacements performed across the country due to the increased number of surgeons training on the procedure, advanced technologies available, changing patient demographics and patient demand. "Younger surgeons are training in partial knee replacements now and are more exposed to emerging advanced technologies and procedures than we were in the past," he says. "Additionally, because patients are coming in at an earlier age, partial knee replacement is becoming far more relevant for the patients we are treating now than 10-15 years ago."
The growth in demand and performance of partial knee replacements will most likely spark a trend of technological development for devices that enhance prosthesis placement and better-performing implants.
Learn more about Dr. Jess Lonner.
Related Articles on Knee Replacement Surgery:
Dr. Boyd Haynes: Q&A About Virginia's First Outpatient Total Knee Replacement
The Physician's Role During MAKOplasty: Q&A With Dr. Frank Noyes of Cincinnati SportsMedicine & Orthopaedic Center
10 Points on Personalized Knee Replacements
"Patients are coming in with an earlier stage of arthritis and at a younger age than they were before," says Dr. Lonner. "Total knee replacements aren't going to last forever, and younger patients don't want to miss work for a long period of time. Partial knee replacement gives us a vehicle for returning our patients back to action sooner and with less pain and limitations than we can with total knee replacement."
2. How partial knee replacement can be advantageous. The partial knee replacement is performed through a smaller incision and is a less extensive procedure than total knees because it only resurfaces one or two compartments. "The minimally invasive nature of the procedure means there will be less postoperative pain, less surgical risk of complications, more rapid discharge from the hospital and ultimately a far quicker recovery after surgery," says Dr. Lonner. "Patients often only stay for one day after their procedure. The patients are on pain medications for two or three weeks and can often return to work quicker than if they had undergone total knee replacement."
Recent studies have shown that partial knee replacements, especially those using modern precision technology, can have good and durable outcomes. "For some patients, partial knee replacement is a temporary fix, but for others, it is the last procedure they will need," says Dr. Lonner. "These days, when the procedure is done well, the durability of partial knee replacements often replicates that of total knee replacements. There are numerous studies proving that in most cases, partial knee replacements never need to be converted into total knee replacements."
3. What keeps the procedure relevant. Surgeons can look back at total knee replacement cases over the past several years and may find that as many as 50-70 percent of patients had arthritis that was limited to one or two compartments of the knee. This means they may have been good candidates for partial knee replacement, if it had been available to them. In the past, patients waited until they were profoundly debilitated, in some cases even unable to walk, until they saw a specialist and agreed to surgery. Now, patients are coming in with less advanced arthritis and want to return to normal function. These very patients have different expectations than those from years ago — they are looking for improved functionability that has been lacking with conventional total knee replacements, despite the procedure's overwhelming success. Partial knee replacement can be a good option for these patients, but not all surgeons are picking up on the procedure.
4. Where the problem with partial knee replacements lies. Not every orthopedic surgeon is on board with performing partial knee replacements, in part because the procedure is very unforgiving, says Dr. Lonner. "If we don't put the implants in well, there is a higher risk of failure…Total knees are more accommodating to modest variation of positioning without compromising the results. In partial knee replacements, we have to be more careful to select patients well and to optimize the accuracy of component alignment to enhance outcomes. This is where robotic technology comes into play."
Robotic technology can help make the implant positioning more precise for partial knee replacements. "When we compare X-rays of partial knee replacements performed with the robotic technology versus those performed with conventional technology, we can see that we are more accurate if we use the robot," says Dr. Lonner. Other technologies, such as custom instrumentation, have been made available for partial knee replacements, but there isn't solid evidence showing they improve precision or performance of the partial knee replacements, he says.
5. How physicians can convince hospitals to incorporate robotic technology. For many, robotic technology is seemingly too expensive, but in their analyses hospitals may find it worthwhile to appropriate the funds to build a program around it. Hospitals can either purchase or lease the equipment, and many are choosing to acquire the technology with the hopes of attracting more patients to their system. "The hospitals where I work have found the robotic technology to be profitable because of the large amount of surgical cases we are able to bring to them," says Dr. Lonner. "Compared to total knee replacements, partial knee replacements provide cost savings that appeal to hospitals, such as reduced hospital stay, lower transfusion rates and more limited consumption of hospital resources."
6. How to train on the technology. If the hospital is on board with bringing the robotic program into the department, they need one or more committed surgeons who will champion its growth, and not abandon it as many have done with traditional computer navigation systems for total joint replacement. To some extent, Dr. Lonner says, the conventional techniques for partial knee replacement are more difficult than the robotic techniques, so surgeons who perform the procedure in the conventional way should be able to pick up the robotic procedure without too much trouble.
"The key is gaining experience with partial knee replacement, in general, and understanding the nuance of patient selection and critical parameters in implant alignment and soft tissue balance," he says. "The robotic technology surprisingly simplifies the performance of bone preparation in partial knee replacements. Irrespective of the method used — conventional or robotic — there is a tremendous value for our patients in adopting the concept of partial knee replacement for localized arthritis of the knee. Once surgeons embrace the concept of selective knee resurfacing, there are plenty of courses available for training in surgical techniques with or without the robot."
For surgeons who have been in practice for several years and have developed a strong comfort level with the total or partial knee procedures they perform, adding new technology may not be the most desirable option. "These surgeons feel they can provide their patients with a quality product," says Dr. Lonner. "Some surgeons may feel that learning a new technique or training with a contemporary technology might not be necessary because they already have a strong skill set and provide a service that they've used for a number of years."
7. Where partial knee replacement is headed. Dr. Lonner predicts an explosion in the volume of partial knee replacements performed across the country due to the increased number of surgeons training on the procedure, advanced technologies available, changing patient demographics and patient demand. "Younger surgeons are training in partial knee replacements now and are more exposed to emerging advanced technologies and procedures than we were in the past," he says. "Additionally, because patients are coming in at an earlier age, partial knee replacement is becoming far more relevant for the patients we are treating now than 10-15 years ago."
The growth in demand and performance of partial knee replacements will most likely spark a trend of technological development for devices that enhance prosthesis placement and better-performing implants.
Learn more about Dr. Jess Lonner.
Related Articles on Knee Replacement Surgery:
Dr. Boyd Haynes: Q&A About Virginia's First Outpatient Total Knee Replacement
The Physician's Role During MAKOplasty: Q&A With Dr. Frank Noyes of Cincinnati SportsMedicine & Orthopaedic Center
10 Points on Personalized Knee Replacements