Rob Hartzler: Welcome to the Arthroscopy Association's Arthroscopy Journal Podcast. The views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association or the Arthroscopy Journal.
Greetings. This is Rob Hartzler from TSAOG Orthopedics in San Antonio. Today, we welcome back to the podcast a surgeon who needs no introduction, Dr. Peter Millett, shoulder and sports medicine specialist at the Steadman Clinic in Vail, Colorado. Dr. Millett, welcome back to the podcast.
Dr. Peter Millett: Thanks. It's great to be here.
Rob Hartzler: Today, we are going to be discussing your editorial commentary published July 2020, entitled Arthroscopic Treatment of Glenohumeral Arthritis - Avoiding Heavy Metal, which accompanies a systematic review on this topic out of Rush.
Dr. Millett, you have tremendous experience in treating these patients arthroscopically with glenohumeral arthritis, and your operation is called the CAM procedure. Could you just describe that for us and tell us a little bit about how you developed that?
Dr. Peter Millett: Sure, thanks Rob. Thanks a lot for inviting me and thanks to Arthroscopy for putting together this podcast. The CAM procedure is a procedure I've developed over the last really 15 or 20 years. I had been a fellow with dr. Richard Steadman and he was doing a procedure for patients with osteoarthritis of the knee. And as I started practice, I started seeing young patients with osteoarthritis and started to think about ways that we could address their functional deficits and their pain. I noticed that many of them had pain in the lateral and posterior aspect of the shoulder, that they were complaining of restricted motion, and that simple debridements were not really restoring function to them and alleviating their pain.
When I came to Vail, Colorado, I started working with my partner, Marc Philippon, who is a well-known hip surgeon, and he started doing CAM procedures in the hip for reshaping the femoral head to improve motion. And I thought maybe that the same type of procedure could be applied to the shoulder, so I started doing some humeral osteoplasty to try and reshape the humerus in an effort to restore motion, but also in an effort to potentially decrease compression on the axillary nerve and therefore alleviate their pain. And that was kind of the Genesis of it. And over time, we've kind of refined it and improved our patient selection criteria. But now we have quite an extensive experience treating patients with glenohumeral osteoarthritis who desire a joint-preserving approach, and want to try and avoid total shoulder replacement, which we jokingly refer to as heavy metal .
Rob Hartzler: In the first paragraph of the commentary, you say, "All procedures are not created equal," and there's a lot to CAM and specifically, I think the difference between that operation and what's been done before is the focus on removal of the humeral head osteophytes, and potentially, the axillary nerve neurolysis. Could you talk a little bit about... Is that true? Are those the main differences between what's been previously described, and why do you think those two facets of the operation are important?
Dr. Peter Millett: Well, I think that some patients have very large humeral head osteophytes and on their x-ray, they may have joint preservation. And I think that that is a space occupying lesion that restricts abduction and can restrict external and internal rotation as well. And moreover, it also displaces the axillary nerve. We did a study looking back at MRIs of patients with large inferior goat's beard osteophytes, and showed that the axillary nerve actually gets displaced inferiorly. And we think that that may be a potential cause of pain in these patients, so the osteophytes are invariably interarticular, and they are something that we can address with arthroscopic surgery, similar to a CAM resection in the hip.
We called it a CAM procedure as an acronym for comprehensive arthroscopic management because, as you know, there's a lot of different factors which play a role in the pain and the functional limitations of patients with glenohumeral arthritis, so we addressed the joint surface, we addressed the capsular restrictions with a capsule release, we reshaped the humeral head with a humeral osteoplasty and directly or indirectly decompressed the axillary nerve. And then in many patients, we're also addressing the long head biceps tendon which is diseased, and we address any subacromial issues as well.
Rob Hartzler: These patients can be a challenge to take care of because they're often young and they're often very high demand, they're often weightlifters or laborers. And so, patient selection is a big issue. I want to come back to that and first just sort of get your thoughts on an issue that might be a little bit more uncomfortable for us to talk about, which is actually surgeon selection.
And I wanted to just get your thoughts on, you know, who do you think should be doing this operation? Is it technically complex enough that you need special training or a specialized practice? And do you think that the surgeons who are doing this kind of complex arthroscopy should also have a shoulder arthroplasty practice so that they don't get, you know, maybe so that they're not biased towards offering arthroscopy when it may not be indicated?
Dr. Peter Millett: Yeah, I think those are great questions. In general, I think you have to know your limits. I want to try and advance the field and offer something to these patients that is an advantage for them, which is to preserve their joint when they're in their 30s or 40s or early 50s. If we can buy them five to 10 years, or even 15 years of time, I think it offers an advantage. But like you said, you have to know your limits.
I personally do perform shoulder arthroplasty. There are many patients that come to me asking about joint-preserving approaches like the CAM procedure, that I just tell them their arthritis is too far advanced. They have too much flattening of the humeral head or too much deformity, or there's just no joint space left. And I tell them that I think that they'd be better served with a total shoulder. So I try not to be... I mean, I'm somewhat biased because I have had good success treating these patients with arthroscopic surgery, and we're trying to push the envelope, but I've learned over the years that there are certain patients that are better off having a well done arthroplasty, as opposed to trying to salvage something which is unsalvageable.
Getting back to the technical aspects, it is technically challenging, there are some risks to it. The axillary nerve obviously is displaced by these large goat's beard bone spurs, and I think that it should be done by people who are expert arthroscopists, who are very comfortable with the anatomy, and who have experience with this. I do use fluoroscopy so I can ensure an adequate resection, and also to assist with just the visualization of the spur, because it's not just a two-dimensional structure, it's a complex three-dimensional structure, and as you rotate the arm, you might think that you've gotten all the spur, but you'll see that there's some that still remains. And there are some that are just... It's rare, but there are some that are just so large or in such a location that it becomes unsafe to completely resect them. So there's some patients where an incomplete resection, or a partial resection, may be necessary.
Rob Hartzler: The humeral osteophyte removal, probably, it's the most technically demanding part. Would you say that's true?
Dr. Peter Millett: Yes. I think that establishing the posterior inferior portal to access the axillary pouch is probably the most technically challenging. And then, removing the spur is probably the second most challenging.
Rob Hartzler: So what I've found, let me hit you up with just a couple of technical questions about that part of the operation. So what I've found to be the hardest parts are once I've got my two posterior portals going, then getting started, which I think fluoroscopy can sort of help with, because you're just looking at this big white sclerotic kind of surface, and I think that it can be a little bit hard to know kind of where to go. But once you get going, it seems to be okay, but then, once you start to get really far anterior, I think that it can also be difficult to get all of that bone out. Thoughts on those parts of the operation?
Dr. Peter Millett: Yeah, Rob, those are great points. For me, what I usually will do is I'll usually put the scope in the anterior superior portal before I get started and remove any synovitis in that posterior inferior aspect of the shoulder. Then I'll go back and put my scope posteriorly, and then I'll establish my posterior inferior portal. If you try and establish it right away, and there's a lot of synovitis, sometimes it can be very difficult to see, initially.
Another thing that I do is I preserve the whole joint capsule before I establish that portal so that I don't get extravasation of fluid. And I try and do that first, really. I do a limited debridement in the joint and then go ahead and establish that posterior inferior portal. Once that's established, I'll frequently go in just with a small five-millimeter cannula so I can clean up the space and then I can see, and then I'll frequently put in an 8.25-millimeter cannula which has some wings on it that keeps it in place so that I'm not going in and out by the nerve. And when I make that portal, I use a spinal needle to localize it, then I'll go in with a... I'll cut the skin, just the skin, and then I'll go in with a blunt switching stick and place cannula dilators just to guide the soft tissues as I put the cannulas in so that if the axillary nerve is close, it will be pushed out of the way and wouldn't be injured.
And then, once I have that 8.25-millimeter cannula in there that's really secure with the wings, then I can really start taking off bone and I'll usually use a 5.5 [mm] shaver in the back. And as I go to the front, I'll typically internally rotate the arm. And the anterior inferior quadrant is probably the most difficult to access, but that's where a lot of the spurs, the mass of bone, is. So I have some long curved curettes that I'll use to scrape the bone off anterior inferiorally and then I'll take it out with a pituitary rongeur or a piecemeal with the shaver.
I'll also typically preserve the inferior capsule throughout this point of the procedure, because if you cut the capsule to try and improve your visualization or to try and see better, what happens is the fluid starts extravasating and then the nerve actually gets closer. So I keep that capsule intact until I have all the bone resected. And then, that's when I'll do the inferior capsule release.
Rob Hartzler: Do you ever use curved osteotomes to try to get those far anterior inferior osteophytes?
Dr. Peter Millett: I have tried just about everything, but what I've found works best is I have some long curettes that are from a total hip set that reach around there. And I have one that's angled about 45 degrees, and I can just put that through my 8.25-millimeter cannula, and I can scrape the osteophyte off on the part that is difficult to reach with the shaver.
Rob Hartzler: So the whole osteophyte removal process is two posterior portals. You don't change to another view to complete the work.
Dr. Peter Millett: I've tried to look from the front down, but I've not had good success. So I typically work with two posterior portals.
Rob Hartzler: Excellent. And then, so then you go ahead with capsular release and then... Is every case an axillary neurolysis?
Dr. Peter Millett: Well, when I'm releasing the capsule, I usually use a combination of a basket forceps and a hook tip radio frequency device to just precisely release the capsule. I like the monopolar device, it seems to have less heat and it causes less stimulation of the nerve. The nerve usually runs obliquely from medial to lateral. And as you release the capsule, the nerve is frequently right there. So I'll take a blunt switching stick or obturator and just kind of dissect and free up the nerve to make sure there's no compression on it. It's mainly an indirect decompression by taking off the spur, but then also, when you release the capsule, frequently, the nerve is right there.
Rob Hartzler: Got it. Question about the biceps. Do you ever have patients who ask you to preserve the biceps for them, and how do you handle that situation? A lot of these are weightlifters, and I've found in my own practice some nervousness about biceps tenodesis and the patients wonder if it's really necessary.
Dr. Peter Millett: That's a great question. I take it as indicated, like for example, I did one yesterday in a 45-year-old gentlemen, and his biceps was not really that painful. When we went in, he had somewhat of a degenerative slap tear that we debrided. The biceps tendon itself didn't have any erythema. It didn't have a pulley lesion. So we left his biceps alone. If the biceps look diseased, there's an hourglass deformity, there's a very degenerative slap tear, there's associate pulley lesion or tearing of the pulley, or there's significant tenosynovitis, then I will do a biceps tenodesis in those patients. And I would say probably about 75 or 80% of the time, we do a biceps tenodesis.
Rob Hartzler: In the editorial commentary, you've snuck in some unpublished data that you've presented now, for sure at ASES Fellows, and I'm sure that's in a forthcoming publication, but I thought it was very interesting that you have minimum 10-year follow-up data now with only a 40% conversion to arthroplasty rate, which I think, that seems very good at 10 years. And this is probably part of your initial experience. Any comments on that?
Dr. Peter Millett: Yeah. I mean, I think that the question is, when we first published our two-year data, was the patient just coping with it because they just had surgery and they didn't want to have a replacement? Then we had a five-year data, which Justin Mitchell looked up, and we had pretty good results, but now we've recently gone and looked at our minimum 10-year follow-up, we have about 63% survivorship. So at 10 years, if somebody still hasn't converted, they're not just coping with it, they're satisfied and they decided that they can live with their underlying glenohumeral osteoarthritis.
I'm hopeful that in the future, with better patient selection, that I will be able to improve that, because some of those were my early series when I probably was operating on some patients that were more advanced than would be ideal, with flattening of the humeral head, with significant glenoid deformity or significant severe joint space narrowing that now I would probably suggest to those patients that they consider an arthroplasty. So I'm hopeful that with better patient selection and that maybe even with biologics, BMAC, PRP, other types of things that we can do to maybe enhance the longevity of this procedure, that we'll have better survivorship in the future.
Rob Hartzler: That was one of my questions for you, is if you were doing anything in terms of biologic adjuvants, so I'm glad you brought that up.
Dr. Peter Millett: Yeah. Now, we usually will do a PRP for the patients at the same time as the CAM procedure. I don't know if that, at this point, we don't have the data compiled to see whether it makes a difference or not. There's some evidence that maybe it has nociceptive effects that they'll have less pain, perhaps it can help them with regenerating of some fibrocartilage, but those are things that we're kind of hopeful in the future that would be sort of adjuvant to the underlying arthroscopic procedure.
Rob Hartzler: I noticed that, well, I've paid very close attention to what you've published in the past for my own practice about risk factors for poor outcomes with CAM, and I noticed that you've started talking about that issue of humeral head congruity as a risk factor, which I think is new with this minimum 10-year follow-up data. And I just was wondering, is it advanced imaging? Is it MRI, CT that you're making that decision about incongruity? Is it plain radiographs? How are you making that decision?
Dr. Peter Millett: Well, most of these patients get x-rays and then they also get an MRI in most cases, sometimes a CT. You can see it on plain films. You can also see it on the MRI. It's just an observation that I made over the years that some of these patients had had, and you've probably seen it, where they have more central flattening of the humeral head, they might still have joint space. They might still have a good joint space, but I started looking at those and thinking maybe those patients weren't doing as well. And when we went back with our 10-year data, indeed, that was shown to be one of the predictors of a negative outcome.
Rob Hartzler: Nothing to measure, really. It's just sort of if you see significant flattening of the humeral head, then that's a...
Dr. Peter Millett: We've come out with a classification scheme, which will be in our new paper for the humeral head flattening, to try and grade it. And more severe degrees of flattening, I would say, are probably not as good candidates for a CAM procedure.
Rob Hartzler: So let's say that you're a 45-year-old weightlifter with significant risk factors for doing poorly, you've got bone on bone, no glenohumeral joint space, you've got significant flattening, you've got a B2 glenoid, what's your current go-to for an arthroplasty procedure for that type of patient? Is it hemi, is it ream and run, is it an anatomic total shoulder?
Dr. Peter Millett: I've been sort of an anatomic total shoulder person for my whole career. I've been in practice 20 years now and I have not seen high degrees of glenoid loosening. Of course, I've seen some, but I've not seen high degrees. We have an extremely active patient population here. I put in a cemented pegged hybrid peg and keeled glenoid. And I'm careful to try and meticulously ream it with minimal reaming, but enough to get congruity and then pressurize the cement well, and then let the patients, once they're ready, get back to full activities. I don't put any specific restrictions on my patients, but I've not seen high amounts of failure of the glenoid. So, for me, I've been a total shoulder advocate. I think that the first chance at arthroplasty is probably your best chance.
Another point that I'd like to bring up is we've done a comparison group which is not out yet, but we've looked at patients who've had a CAM procedure and then failed and underwent a total shoulder replacement, and compared those with an age-matched cohort that underwent a primary total shoulder arthroplasty, and we have not seen a difference in their outcomes. So it doesn't seem like you're burning any bridges by doing an arthroscopic joint preserving CAM procedure before... If that fails, you're not burning any bridges for a subsequent arthroplasty.
Rob Hartzler: Yes. I've thought about that a lot, and I've wondered if it may be that we don't have enough power to really pick that up. It seems that in the knee that it's been demonstrated, I'm sure you're a little bit more familiar with that literature, but in the knee, it seems like having prior arthroscopy is a risk factor for complications after total knee. Is that your understanding?
Dr. Peter Millett: Yeah, so I wanted to look at that and make sure that we weren't adversely compromising people for future arthroplasty. And at least, with the data we have, we can't demonstrate that now. With more patients and more power, there might be. But so far, we haven't shown that.
Rob Hartzler: So what do you think the future of arthroscopic joint preservation is for these patients? Is it that we get better technically at removing the osteophytes, maybe computer-guided osteophyte resection, something biologic? How can we improve this operation besides patient selection that you brought up before?
Dr. Peter Millett: That's a great question. I mean, I try and think about it, whether it's some type of osteoarticular allograft, is it arthroscopic total shoulder replacement? Is it some type of biologic arthroplasty with resurfacing? Is it stem cells? I don't really know. I think there's a lot of potential options out there. What I do know is that we are seeing a lot of patients. Well, I'm seeing, at least, a lot of patients who are young, who have glenohumeral osteoarthritis, it's advanced, and we need some type of a solution for them. So there's definitely a big need for this, and I think that with continued research and continued innovation that we're going to improve the options for our patients.
Rob Hartzler: Excellent. Well, from my practice to you, we greatly appreciate your work on this topic, and I've learned a tremendous amount of information from you and your experience. And so, thank you for documenting this carefully and for pushing the envelope and moving the ball down the field. Any closing thoughts?
Dr. Peter Millett: No, thanks for inviting me. It's always great to be invited to share my thoughts on this topic. I just share my experience and we carefully track our patients. There may be other options which are better in the future. So I think I would encourage all your listeners to just try and study your patients carefully and report your outcomes so we can all learn from each other and get better options and better treatments for our patients for the future.
Rob Hartzler: Excellent. Well, this editorial from the July 2020 issue of the journal entitled Arthroscopic Treatment of Glenohumeral Arthritis - Avoiding Heavy Metal can be found on the Arthroscopy Journal's website at arthroscopyjournal.org.