Orthopedic oncologist at Presbyterian/St. Luke’s Medical Center, Dr. Daniel Lerman talks about healing weak bones with new techniques.
Interview conducted by Ivanhoe Broadcast News in 2023.
What is minimally invasive pelvic stabilization?
LERMAN: Minimally invasive pelvic stabilization is a procedure we’ve been pioneering here for a few years. It’s an opportunity to provide palliative care and pain control to patients who suffer from pathologic fractures of their pelvis or have bony erosion of their pelvis from either cancer or from prior to radiation therapy for cancer they may have had. There’s many patients who have cancer in certain organs, say, their breast or their prostate or their colon, that ultimately spreads to the bones and can cause bones to weaken and break. Many of those bones, orthopedic surgery has a long track record in stabilizing and protecting, such as the hips or the femurs. The pelvic ring, the pelvis and the sacrum, however, has been a black box for orthopedics for years. And unfortunately, patients have suffered from fractures that we have been unable to treat effectively with surgical interventions. They’ve been treated with medication and radiation, which is good at killing the tumors, but does not provide stability to the bone. With this minimally invasive procedure, we’re finally able to provide stability to fractures of the pelvic ring, allowing patients who were either bed-bound or wheelchair-bound to be up and walking. The dramatic advancement over prior treatments is really dependent upon new technology in imaging. We’re able to image the pelvis with much greater detail and use that highly detailed imaging in the procedure intraoperatively to have three-dimensional reconstructions of the pelvis and augmented reality guidance system to allow us to be in safe and non-conventional bony corridors nor to stabilize fractures of the pelvis. This is the procedure I performed in combination with an interventional radiology colleague whose name is Anthony Brown. And together, we have been advancing the indications for this procedure over the past four years or so. We are one of a handful of centers across the United States who’s offering this type of intervention and we’re the only center within the region. This is a technology, this is an intervention that continues to evolve. The tools which we use to allow that evolution is really the advancements in the imaging technology and the patients themselves. This procedure is really designed for patients who have metastatic bone disease, meaning cancer that started elsewhere that’s spread to their bone, who then have a fracture or pain in their pelvis from there metastatic bone disease. Metastatic bone disease is a disease that’s increasingly prevalent amongst our society as patients with cancer are living longer and longer. So as patients are living with cancer, and cancer has become essentially a chronic medical problem for these people, it is our role as orthopedic oncologists to help them, to keep them mobile and enjoying their life.
Who would need this procedure?
LERMAN: This procedure is best for patients who have sustained a pathologic fracture or insufficiency fracture of their pelvic ring or their sacrum. The sacrum is really the keystone of the pelvis. So if there’s a sacral fracture, anytime somebody moves, they have significant pain. Pelvic fractures, the pelvis anchors your lower extremities or your legs to your spine. So when that’s broken, any movement, even in being in bed rolling over is exquisitely painful. Patients who have cancer that’s spread to the bones, we call that metastatic bone disease, are often first treated with radiation therapy to kill the tumor in the bone. And radiation is very effective at killing the tumor in the bone. But it does not provide stability to the pelvic ring if there was a fracture through that lesion. Also, with time, some patients who had radiation to their pelvis can also fracture secondarily from some of the long-term effects of radiation. As radiation is very good at killing cancer cells, it also can kill some of the bone cells and cause the bone to weaken and erode with time. As more patients are living with metastatic cancer, as more patients are surviving longer with cancer that’s spread throughout their body. We have a population of people who are wanting to maintain function and quality of life with disease in their pelvis and if they sustain fractures- if they sustain fractures in their pelvis, then we have an option now, where we didn’t before, to provide stability and help them.
What is a pelvic fracture and what symptoms do these people live with?
LERMAN: So the pelvis essentially is a complex ring that contains your hip sockets and anchors your hips or your lower extremities to your spine, to your skeleton. So the pelvis really connects your legs to the rest of your body. If you have a fracture in your pelvis, people have significant pain essentially with any activity. Most patients with a significant pelvic fracture are wheelchair-bound or bed-bound and they’re not able to walk. There are some patients because- there are some patients with large erosions to their pelvis from the tumor, meaning the tumor ate away at the pelvis and eroded the bone, much like termites can do to wood. And those areas of erosion can be unstable. That’s what we can provide stability to in a minimally invasive manner. When I say minimally invasive, this is a procedure that we’re able to stabilize somebody’s pelvic ring and their sacrum through probably two or three one-centimeter incisions. The benefit of that is much shorter recovery compared to open a more complex surgeries, a lower side-effect profile, meaning less risk for infection and other medical problems to happen around the time of surgery, and the procedure itself has become rather efficient. So we can take patients who have an unstable pelvic ring, who are essentially bed-bound, and after a two-hour procedure, they can be up walking later that day or the next day. Anecdotally, I saw a woman today who we first treated two years ago. We had met her two years ago because she had come into the emergency department with a pelvic fracture from her myeloma. When patients have a pelvic fracture or sacral fracture, it is not subtle. Their symptoms are usually severe and limiting pain. For example, I had a patient who we first met two years ago and she was taken into the operating room because she sneezed and experienced severe pain in her pelvis. A sneeze allowed her to have a pelvic fracture because it has been so weakened and eroded by her bone cancer. She has a cancer called myeloma, which is another type of cancer that can erode the bones. So this woman was at home, sneezed, sustained a pelvic fracture, and after that, she was wheelchair- she was wheelchair-bound and bed-bound. When I met her in the hospital after she got admitted from the emergency department, she said she wished she could die because the pain was so bad. I offered her instead of that option, let’s try this minimally invasive procedure and see how you feel. And literally the next day she left the hospital and was feeling great. I seen her just in the office today after two years and she was relaying a story of how she was standing her deck and physical activity she’s been involved in recently. She just came back from steamboat, went to a ski trip there. So it’s those stories, and it’s patients who are living with their cancer, living with their disease, but sustained a fracture or debilitated from their fracture who were now able to get back moving and get engaged in their life and enjoying their life again.
What help or treatment was available for these patients before the pelvic stabilization?
LERMAN: Prior to this minimally invasive procedure, there really was not a good option for stabilizing fractures in the pelvic ring and the sacrum for patients with metastatic bone disease. Classically patients with disease or cancer that spread to their bones and their pelvis gets treated with radiation therapy. And radiation is very good at killing the cancer. But it doesn’t do anything to reinforce the strength of the bones. Open surgical interventions for pelvic fractures are done routinely for patients with traumatic high-energy pelvic fractures, but they were not performed for patients with fractures from cancer in their pelvis. Because of the weakness of the bone, it would not hold conventional orthopedic hardware. So really, up until two or three years ago, there was no good option for patients with a fracture of the pelvic ring. And those patients suffered and we’re merely treated with pain medication and other palliative modalities to try to minimize their activity. It’s that population for whom this is a tremendous quality of life improvement. It’s patients who would otherwise be stuck at home, bed-bound or wheelchair-bound, who are now up, walking around. And so much so that they say their friends don’t even know they have cancer.
How does your procedure help them? Can you describe how it works?
LERMAN: We’re able to perform this procedure because of advancements in imaging technology and that’s really what we’re reliant on during the operation. So a patient comes into the operating room and they’re put to sleep by the anesthesiologists like they’re having any procedure and then we do an interoperative CT scan. So the patient gets a CT scan, a CAT scan real-time of their pelvis so we know exactly where the bony erosion is and exactly where they’re fractures are. On that CT scan, we then can plan custom screw trajectories. We use two different types of implants. Sometimes we use screws and bone cement to act like cement and rebar to reinforce the eroded bony pelvis. And there’s another implant that we use that is a balloon device that goes in deflated and we inject a liquid monomer into the balloon so that it expands and areas with bonus missing and then that monomer can be hardened by a light source. People equate it to acrylic nails, which I’ve never had so I just take their word for that analogy. But the concept is similar to acrylic nails or dental implants, dental fillings, they can use the same light to cure a liquid solution. So depending upon the patient’s disease or where their fractures may be, we either choose a bone screw and bone cement construct or this balloon construct to reinforce and stabilize the pelvic ring. With patients who have metastatic bone disease, there are typically some portions of their pelvis where their bone strength is relatively normal. And we want to use those normal sites of bony integrity to anchor into, to span the areas of defect, to span the fractures to reinforce again, the entirety of the ring. Its unbelievable.
How big are the screws?
LERMAN: The screws that we use to stabilize the pelvis are somewhere between 10 and 15 centimeters in length. So they can be up to that long. Because again, the pelvic bone can be quite large in certain trajectories. And they are approximately a centimeter in diameter. So think about the size of a stainless steel ballpoint pen and that’s what we’re using to help interface with the bone against screws alone in this population or sometimes ineffective and can loosen because of the weakness of the bony foundation. So to augment the screw interdigitation with the bone, we oftentimes use bone cement to add a reinforce stability to the screws.
It’s not just the procedure you’ve changed, but the operating room in which you perform the procedure is different, correct?
LERMAN: The procedure is performed in a hybrid operating room. And what that is is a combination between an interventional radiology procedural suite and an operating theater that I’m most accustomed to. The benefits of doing it within a hybrid operating room is the advancements in the imaging modalities that they have so we can perform the interoperative CT scan. We can use augmented reality guidance systems to make sure implants are going in the correct trajectories. In addition to the high level of sterility that we are accustomed to in an operating room, we are implanting metal into patients bodies. It is critical that we have surgical-level sterility in order to minimize any risks and complications.
How long does the surgery take?
LERMAN: The procedure varies in time depending upon the complexity of the pelvic fractures and how much bone is missing. But on average, the procedure is somewhere between one and a half to two hours. Now that’s the surgical time that has improved dramatically over the years as our whole team is become more efficient and familiar with this procedure. It is a time that is on par with a routine hip replacement that will be performed for regular arthritis nowadays. So that is a procedural time that we’re very happy with. Between that and the minimally invasive nature of the procedure, the recovery is quite limited for these patients, and that’s a dramatic benefit for this intervention. If you have somebody who has metastatic bone disease and if they have limited prognosis for longevity, you don’t want them to be recovering from your operation for months and months and months. But when a patient can recover in a day or two days and get home the next day after the procedure, that’s really what we’re shooting for. That’s what we’re able to accomplish with this.
These patients do not have to stop their cancer treatments, correct?
LERMAN: Another benefit of a minimally invasive procedure like this is that patients are able to stay on their chemotherapies or stay in their targeted therapy their immune therapy throughout the procedure, we have not held anybody’s chemo or cancer treatments in order to have this procedure, which is important because of course, we want to keep the cancer being fighted, the cancer at bay and not have a chance to balloon while they’re off for the procedure.
How have you seen it change people’s lives?
LERMAN: For somebody with a pelvic fracture or a sacral fracture, it is significantly debilitating. As I’ve stated, patients can be physically limited, being wheelchair or bed-bound. Even those who were up walking with a walker have significant pain and significant limitations to how far they can walk. And some people with a sacral fracture can even experience urinary incontinence, secondary to pain or irritation of the nerve roots that control the bladder. Patients who’ve undergone this procedure have a dramatic improvement in their quality of life and their mobility secondary to paint improvements. And we’ve had some patients who did have urinary incontinence from their fracture who then were able- that was able to resolve and they were able to be confident again. So those quality of life improvements are dramatic.
Who’s a good candidate for this procedure?
LERMAN: Anybody who is suffering from metastatic bone disease in the pelvis, it is worth thinking about, is it from the tumor or the cancer growing itself, or is it from weakness of the bone? This procedure is designed for patients who have instability of the pelvic ring. They have a mechanical failure of their bone and that’s where we can come in and help stabilize the bone, help stabilize their pelvis and allow them to function better.
It must be rewarding to know you’re helping these cancer patients who are already going through a tough time to have less pain and be more mobile.
LERMAN: I can truly say this is the greatest thrill I get as a doc is taking somebody who is so impaired and really struggling and being able to regain their function, being able to get them out of the hospital and get them home with their family. When I have a patient who says their pain is so bad that they can’t even enjoy being with their family and then after the procedure, they’re home and they’re engaged in their normal activities, as a physician, there’s no greater thrill.
Anything else you think you should add?
LERMAN: So one of the challenges we face and one of the benefits of this interview is really being able to get this information out there. This procedure is being pioneered at our institution and a handful of other institutions across the United States but it is not part of the normal treatment paradigm for any oncologists or radiation oncologists who is out there in the community. Most medical doctors who are faced with this problem are used to orthopedic surgeons shrugging their shoulders and saying there’s nothing we can do. Therefore, medical oncologists and radiation oncologists who treat these patients, have really stopped asking orthopedics, is there a solution for this? I’m here trying to educate the community and whoever would be interested that now there’s an option for these patients, patients who have a pathologic fracture of their pelvis, their sacrum can be treated in a minimally invasive manner that can improve their quality of life.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
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