Joint preservation forges ahead amid uncertainty
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The CDC has estimated that 58.5 million U.S. adults have arthritis, with the number projected to increase to 78 million by 2040.
Although end-stage arthritis of the hip and knee is generally treated with total joint replacement, sources who spoke with Healio | Orthopedics Today said, if caught early enough, joint preservation may be an alternative treatment.
Source: Haley Ricciardi
“Joint replacements have been an incredible leap forward for the field of medicine — and certainly the field of orthopedics — over the last half a century and provide a great answer for end-stage arthritis,” Benjamin G. Domb, MD, medical director at the American Hip Institute, told Healio | Orthopedics Today. “However, they do not always work.”
Not only can joint replacement be invasive and lead to significant complications, but Domb said joint replacements do not last forever.
“People are living longer than ever, so if we have an opportunity to prevent or even delay the need for joint replacements, that is advantageous for those people’s lives,” he said. “Joint preservation is that opportunity. It is an opportunity for us to take advantage of early diagnosis, to intervene in the process of degeneration of a joint at an early time point when it can be altered and change the natural history of the disease, so that we prevent or delay the onset of arthritis.”
Evolution
Thanks in large part to technological advancements, innovative surgical techniques and improved diagnoses and education, sources said joint preservation has evolved into a potentially game-changing treatment for pre-arthritic joints.
“We can use CT scans and MRIs to look at precise areas that need to be offloaded or treated,” Rafael J. Sierra, MD, orthopedic surgeon at the Mayo Clinic, told Healio | Orthopedics Today. “CT scans get 3D models where you can plan the surgery ahead of time, and there is computerized software that can be done for upper tibial osteotomy corrections so that you know exactly where the load is going to go through the knee joint.”
According to Sierra, robotics could also be used for joint preservation procedures.
“I do not use robotics to do any type of knee or hip preservation procedures, but you can envision a time where you would be able to not only plan the surgery with the CT scan, but then also have a robot or some type of technology helping you with the cuts that you need to do so that they are done precisely, exactly where you want it and how deep you want them,” he said.
Cartilage
One of the most integral parts of joint preservation is the preservation and restoration of cartilage, according to Ernest L. Sink, MD, chief of the Hip Preservation Service at Hospital for Special Surgery.
“Maintaining cartilage is a main reason we are doing these procedures,” Sink told Healio | Orthopedics Today. “We are trying to conservatively prevent cartilage-advanced degeneration by diagnosing these deformities when they lead to hip pain, hopefully before you get to the cartilage changes. Because once you get cartilage changes and more advanced degeneration, you cannot preserve the cartilage with surgery.”
According to Michael J. Alaia, MD, there are several techniques for cartilage restoration. A more traditional technique, which he said is losing steam in the academic community, is microfracture.
“The general philosophy of [microfracture] was that progenitor cells would migrate out of the bone, stick to the lesion and become cartilage,” Alaia, professor in the department of orthopedic surgery at NYU Grossman School of Medicine and associate director of the Sports Medicine Fellowship Program at NYU Langone Orthopedics, told Healio | Orthopedics Today. “Now, this does not become traditional articular cartilage. It becomes fibrocartilage, which does not have the same mechanical properties as articular cartilage, with much less durability. After 2 to 5 years, that tissue starts to break down, but the technique remains in our armamentarium.”
Instead, he said surgeons have turned to replacing the tissue with osteochondral grafts or cell-based restorative procedures, like autologous chondrocyte implantation, which provide better and more reproducible long-term outcomes. In addition, Alaia said there are more developments on the horizon.
“There are coral-based treatment options that have recently been developed and the techniques transposed to the United States,” Alaia said. “In patients with big cartilage defects, we can take one or a few of these coral-based implants, embed that into large defect sites and new cartilage can develop.”
But restoring cartilage can often be one of the most difficult aspects of joint preservation procedures, according to Sierra.
“Restoration of cartilage is not easy because cartilage is avascular, so you cannot get the blood supply to it,” Sierra said. “Once the cartilage is denuded or degenerated off the bone, there is no way to get new hyaline cartilage to grow there.”
Labral repair
Before the cartilage deteriorates, Domb said additional protective structures have often already been lost. In the hip, that includes the labrum, the capsule and the ligamentum teres. By repairing or reconstructing the labrum, surgeons may prevent or delay cartilage damage, according to Domb.
“When a labrum is not functioning, we lose the lubrication and hydrostatic force distribution,” Domb said. “By restoring a labrum, either with an anatomic labral repair or with a labral reconstruction in cases of irreparable labra, we can restore that function in the hip and, in many cases, alter the natural history of the disease.”
However, Sink said the necessity and frequency with which a surgeon should perform labral repair remains the subject of debate.
“It is still unclear what the role of labral reattachment or repair is and if it is always needed,” Sink said. “When we look at periacetabular osteotomies, we also can repair the labrum arthroscopically at the time of the surgery. There are now a couple published studies showing, whether you repair the labrum or not, the outcome is the same. There is a group of patients where repairing the labrum is worth it. We just have to figure out who those patients are.”
Minimally invasive surgery
According to Sierra, one of the most important advances made in joint preservation was making periacetabular osteotomies less invasive.
“When it was initially done in the ’80s and ’90s, the muscles would be completely taken off and skeletonized off the pelvis,” Sierra said. “Through less invasive procedures such as abductor-sparing procedures, then leaving the rectus tendon in the front of the hip and doing hip arthroscopy instead of opening the joint up, those important advancements have made the procedure less invasive.”
In addition, Brett D. Crist, MD, orthopedic surgeon at the University of Missouri Health Care and professor of orthopedic surgery at the University of Missouri School of Medicine, said minimally invasive procedures with orthobiologics can help preserve a joint.
“Some people have used minimally invasive techniques to support a bone bruise, particularly in the knee, where you have irritation of the bone from a traumatic episode,” Crist told Healio | Orthopedics Today. “That may be where you are injecting a resorbable type of bone cement product to help support the bone. People would think of that as minimally invasive or biologic like injecting different orthobiologics, whether that is from the patient themselves, like [platelet-rich plasma] PRP or bone marrow aspirate concentrate, or different commercially available products that you would inject in the joint to potentially try to preserve the joint.”
Sink said open surgeries, like periacetabular osteotomies, have significantly benefitted from minimally invasive approaches, among other operative improvements.
“We used to make long incisions that started way up in the pelvis and curved and went over the hip onto the thigh,” Sink said. “Now we do these smaller transverse incisions that are not much different than the anterior hip replacement incisions. We are leaving the rectus muscle intact. We are working through smaller anatomical windows, and now patients are going home at day 1 and 2, where they used to be in the hospital for 5 days. We are also faster in the procedure and have less blood loss. We started using tranexamic acid, which we have shown is important to decrease blood loss and transfusions, so patients recover quicker. We are also more precise and efficient with our osteotomy cuts.”
However, Alaia said minimally invasive approaches may not always be possible in joint preservation.
“Obviously, being minimally invasive is always helpful. [There is] less damage to the muscle, less damage to the tissue, hopefully faster rehab and less pain,” Alaia said. “That is not always an option, unfortunately. We are working on ways for that. But at this point, if it takes an incision to get the surgery right, then it takes an incision to get the surgery right.”
Complications
Joint preservation is not without its complications, such as infection with bone correction surgery, according to Crist.
“For graft procedures, the grafts may not heal in the place that you want them to for a meniscal allograft or labral allograft. They still have to heal down to the areas that you fixed them to,” Crist said. “For cartilage transplants, they still have bone that needs to heal to the native bone and the host bone remodel it or take it over.”
One of the biggest challenges in joint preservation surgery is identifying which joints may — and may not — benefit from intervention, according to Domb.
“If we can identify certain joints and exclude them from joint preservation and, on the other end of the spectrum, if we can diagnose problems early and treat them with preventative surgeries before the hip heads down this irreversible path of deterioration, those refinements in our indications will elevate the success of all the surgeries we do,” he said.
Path forward
However, there are still questions that remain unanswered in the burgeoning field of joint preservation, according to Alaia.
“There are so many biologic, immunologic and histologic issues that we have yet to understand. That is why our success rates are not 100%,” Alaia said. “Obviously, we are aiming for 100%. We are aiming for perfection, and we do not have it. And we are trying to make it better. We are trying to understand why we are not perfect.”
Alaia said understanding a patient’s symptoms and pathologies, as well as their goals and expectations, is paramount to joint preservation.
“With a lot of these surgeries, we are simply trying to get patients to be symptom free. It sometimes is more of a lifestyle operation, as opposed to a return to full sport operation, meaning we want our patients to do things like work out again. We want them to do the things they enjoy doing,” he said.
Although the joint preservation procedures performed at high-volume institutions by well-experienced surgeons can make a difference to patients, Domb said “the technical complexity and the complexity of concepts and diagnostics in making surgical decisions” have limited the accessibility of these procedures for many surgeons.
“One of the unanswered questions is how we can simplify these procedures, make them faster, easier, more reproducible and easier to learn, so that they become more accessible to more surgeons and, therefore, can help more patients,” Domb said.
Overall, Sink said the emergence of joint preservation as its own specialty will be integral to the growth of the field.
“We need to always be honest with our outcomes and know which patients benefit from surgery and who does not. There is a group of patients whose symptoms remain after surgery, and we have to focus on this group,” Sink said. “That is why now there is the International Society of Hip Arthroscopy and Hip Preservation, which is growing. We are all together, both open and arthroscopic surgeons. We meet once a year, and this is a critical society for the advancement of treatment for the pre-arthritic hip. Now, we have a unique specialty that is international and growing where everybody is committed to hip preservation and not just a small part of other specialties.”
- References:
- Arthritis. https://www.cdc.gov/cdi/indicator-definitions/arthritis.html#toc. Published June 3, 2024. Accessed Sept. 13, 2024.
- Kraeutler MJ, et al. J Bone Joint Surg Am. 2023;doi:10.2106/JBJS.23.00212.
- Lott A, et al. Bull Hosp Jt Dis (2013). 2024;PMID:38431980.
- Murray IR, et al. J Cartil Jt Preserv. 2023;doi:10.1016/j.jcjp.2023.100116.
- Saks BR, et al. Am J Sports Med. 2021;doi:10.1177/03635465211046932.
- For more information:
- Michael J. Alaia, MD, of the NYU Grossman School of Medicine, can be reached at marlene.naanes@nyulangone.org.
- Brett D. Crist, MD, of the University of Missouri Health Care, can be reached at mazee@health.missouri.edu.
- Benjamin G. Domb, MD, of the American Hip Institute, can be reached at drdomb@americanhipinstitute.org.
- Rafael J. Sierra, MD, PhD, of the Mayo Clinic, can be reached at bureau.mayo@mayo.edu.
- Ernest L. Sink, MD, of Hospital for Special Surgery, can be reached at rennichr@hss.edu.
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