SI-BONE, Inc.

Good afternoon, and welcome to SI Bones' four-quarters earnings conference call. At this time, all participants are in a listen-only mode. We'll be facilitating a question-and-answer session towards the end of today's call. As a reminder, this call is being recorded for replay purposes. I would now like to turn the call over to Matt Vaxell from the Kilmartin Group for a few introductory comments.

Thank you for participating in today's call. Joining me are Laura Francis, Chief Executive Officer, and Anshul Maheshwari, Chief Financial Officer. Earlier today, SI Bone released financial results for the quarter ended December 31st, 2021. A copy of the press release is available on the company's website. Before we begin, I'd like to remind you that management will make statements during this call that include forward-looking statements within the meaning of federal securities laws, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Any statements contained in this call that relate to expectations or predictions of future events, results, or performance are forward-looking statements. These forward-looking statements are based on the company's current expectations and inherently involve risks and uncertainties. These risks include the impact the COVID-19 pandemic will have on the ability and desire of patients and physicians to undergo procedures using the company's products, the duration of the COVID-19 pandemic, and whether the COVID-19 pandemic will recur in the future. Other forward-looking statements include our expectations examination of operating trends and our future financial expectations, such as expectations for hiring, surgeon training and adoption, active surgeons, new products, clinical trial enrollment and reimbursement decisions, and are based upon our current estimates and various assumptions. These statements involve material risks and uncertainties that could cause actual results or events to materially differ from those anticipated or implied by these forward-looking statements. Accordingly, you should not place undue reliance on these statements. For a list and description of the risks and uncertainties associated with our business, please refer to the risk factors section of our most recent Form 10-K and Form 10-Q filed with the Securities and Exchange Commission. SI Bone disclaims any intention or obligation, except as required by law, to update or revise any financial projections or forward-looking statements, whether because of new information, future events, or otherwise. This conference call contains time-sensitive information and is accurate only as of the live broadcast today, February 28, 2022 – And with that, I'll turn the call over to Laura.

Thanks, Matt. Good afternoon, and thank you for joining us. For today's call, I'll provide opening comments and a business update. Followed by Anshul, who will provide additional detail regarding our financial results and initial 2022 guidance. Let me start with our performance in the fourth quarter and full year 2021. I'm pleased with the team's execution in 2021 as we extended our market leadership position, grew our commercial infrastructure to 150 U.S. sales representatives, expanded exclusive payer coverage to over 160 million U.S. cover lives, and ended the year with a record 690-plus U.S. active surgeons. Our revenue, consistent with our pre-announcement on January 10th for the fourth quarter of 2021, was $25.2 million, representing growth of 14% compared to the fourth quarter of 2020. Despite various COVID surges throughout the year, we were able to generate sequential revenue growth for the third straight quarter. For the full year 2021, we generated revenue of $90.2 million, representing growth of 23% compared to full year 2020. We navigated through the pandemic very well due to consistent and focused commercial execution. Now, let me provide some insight into the impact of COVID-19 on our U.S. operations in the fourth quarter and early 2022. Despite the impact of Delta and Omicron, growing demand for our solutions allowed us to deliver sequential monthly revenue growth in the fourth quarter. Based on our booking records in the fourth quarter, approximately 100 cases which had been scheduled were deferred due to COVID in the U.S. This impacted revenue in the fourth quarter by over $800,000. These are the cases that were booked and then postponed, but of course, there are many more cases that were affected by COVID. We estimate that Omicron resulted in approximately 40 U.S. cases being deferred in the back half of December, representing approximately $350,000 in revenue. We believe that the execution by our dedicated field organization has been a key differentiator as we managed through the pandemic better than many of our peers. We're also well positioned because approximately 80% of our procedures are performed in an outpatient setting or at surgery centers. Thus far, in the first quarter of 2022, we've experienced an increase in the deferral of procedures due to Omicron. Based on our booking records, over 100 cases were deferred in January. These deferred cases represented approximately $900,000 in revenue. Case deferrals in February declined to approximately 40 cases, which gives us optimism that the operating environment is improving. We remain confident based on our prior recovery experience and our ability to recapture the deferred cases over the next few months as the pandemic recedes. Additionally, while anecdotal, based on our conversations with surgeons, We're aware of some surgeons who have built backlogs of three to four months due to the pandemic surges and hospital infrastructure limitations. The resiliency of our performance throughout the pandemic and the record operating milestones we achieved reaffirmed that our investments in growth initiatives over the last 18 months are delivering, and they positioned us to be a much stronger company in 2022. Now let me provide you an update on our growth initiatives as we look to extend our leadership position and drive durable long-term growth. Starting with sales infrastructure expansion, our sales team remains an important driver of growth as we penetrate our core market and expand our presence in trauma and adult deformity. I'm really proud of our commercial leadership team's effort under the leadership of Tony Recupero to attract high-caliber talent and end the year with a 150-person sales force consisting of 85 territory managers and 65 clinical support specialists. These numbers translate to a 30% increase in territories in 2021. The dedicated sales team has been a clear differentiator, especially in this unique co-operating environment, as it allows us to remain focused on surgeons and deliver 25% growth in procedure volume in 2021. In 2022, we'll continue to strategically add headcount by investing in high-quality sales reps to set up the platform to deliver strong and sustainable long-term growth. Additionally, we remain focused on driving Salesforce productivity by adding to our bench of clinical support specialists. We're targeting ending 2022 with an approximately 170-person Salesforce, of which 55% are anticipated to be sales territory managers. Moving on to surgeon engagement, we ended the year with over 690 US active surgeons who performed at least one case in the fourth quarter of 2021, representing a year-over-year increase of approximately 18% and a sequential increase of 10% from the third quarter of 2021. In 2021, we had over 1,000 surgeons perform at least one procedure in the year. To put that in context, Since our inception, around 1,800 surgeons have been trained and treated at least one patient. The growth in active surgeon base in the quarter, driven by both new and re-engaged surgeons, reaffirms that our multi-pronged approach to drive surgeon engagement is delivering. Our investments in building a dedicated sales organization, combined with the introduction of TORC, exclusive coverage with Anthem and UnitedHealthcare, and the expansion of our proprietary simulator to train surgeons have provided the ideal foundation for us to engage new surgeons and reactivate previously trained surgeons. Our goal is to grow our active surgeon base by approximately 15% by the end of 2022. Our simulator technology remains a cornerstone of our surgeon training program. Specifically, over half of our surgeons trained in the fourth quarter were trained using the simulator. we've continued to experience a steady increase in adoption rate among surgeons who have been trained on the simulator. With 24 simulators in use worldwide and approximately 6,000 surgeons to be trained and retrained, we believe we have the infrastructure to drive surgeon engagement and further expand the active surgeon base. As part of our long-term strategy to grow our active surgeon base, we continue to expand our academic programs to educate residents and fellows on primary SI joint diagnosis and the degenerative and deformity surgical applications of our solutions. Since inception of the program, we've held approximately 170 academic programs in the U.S., resulting in the training of over 850 surgical residents and fellows. Turning to products and solutions, the strong performance of IP's TORQ in 2021 reaffirmed that our broadening product strategy is resonating with our customers. In 2021, our initial focus was on targeted competitive conversion to drive adoption and extend our market leadership as a sacral public solutions company. In 2022, we expect iFuse Torque to continue to be a tailwind as we accelerate our penetration into trauma, which we estimate to be a $350 million market opportunity. In adult deformity, we're excited about the opportunity to build on the excess of bedrocks with our second-generation product. We remain on track to launch this differentiated product in the first half of 2022. On the clinical research front, while the pandemic has impacted the pace of enrollment in CILDIA, a two-year prospective international multi-center randomized controlled trial of two different methods for pelvic fixation in adult patients, we've made significant progress on enrollment in the fourth quarter, nearing approximately 80% of target enrollments. We expect enrollment to continue through the first half of 2022 and anticipate the primary endpoint results in 2024. Talking about our patient awareness initiative, we focused our investment in targeted digital marketing programs in our fourth quarter to educate and empower patients in their SI journey. To provide some preliminary insights, we have more than doubled the number of potential patients we are engaging through marketing. while significantly increasing the referral of patients to surgeons at the end of 2021 compared to the prior year, showing the effectiveness and efficiency of the targeted digital marketing spend. While the preliminary insights are encouraging, we continue to take a disciplined approach to continuously optimizing and focusing our investments across various digital platforms. With that, I'll now turn the call over to Anshul to provide more detail on our financial results.

Thanks, Laura. Good afternoon, everyone. Our fourth quarter total revenue was $25.2 million, representing growth of 14% compared to the prior year period. U.S. revenue was $23.3 million, increasing 13% compared to the prior year period. International revenue was $1.9 million, increasing 28% compared to the prior year period. Even with the multiple surges in the quarter resulting in approximately 100 case deferrals in the U.S. and pressure on Europe case volumes in December, we delivered steady sequential monthly growth in worldwide procedure volumes, with December being the highest case volume month in company history, reaffirming the underlying momentum in the business. Gross margin for the fourth quarter of 2021 was 87% compared to 90% in the corresponding period in 2020. Gross margin in the fourth quarter was impacted by an increase in cost of operations to support the growth of the business. Operating expenses increased 29% to $35.8 million in the fourth quarter 2021 as compared to $27.7 million in the prior year period. The increase was driven by higher sales and marketing costs related to increased sales hiring, higher travel costs, research and development expenses, and increased stock-based compensation. Our net loss was $14.5 million, or 43 cents per diluted share, for the fourth quarter of 2021, as compared to a net loss of $9 million, or 28 cents per diluted share, in the prior year period. As of the end of the quarter, our cash and marketable securities were approximately $147 million, and long-term borrowings were approximately $35 million. We believe we are well positioned from a liquidity standpoint to support our strategic priorities that will allow us to create long-term growth and shareholder value. Moving to guidance. We are entering 2022 with several structural tailwinds, including increasing underlying demand, a productive sales force, growing surgeon engagement near universal coverage in the U.S., and a growing portfolio of highly differentiated products. However, we remain cognizant of the unique external operating environment due to COVID-19 and its impact on elective procedures as well as healthcare infrastructure and staffing levels. Our 2022 outlook is highly sensitive to assumptions on a steady global recovery, which anticipates case scheduling and elective procedure levels normalizing throughout the year. For 2022, we expect annual revenue to range between $106 million to $108 million, representing year-over-year annual growth between 18% and 20%. The guidance reflects the assumed impact from Omicron variant in the first quarter of 2022, which we expect will result in mid to high single-digit revenue growth in the first quarter of 2022 when compared to the first quarter of 2021. We expect the annual gross margin for 2022 to be in the mid to high 80% range. The annual gross margin range assumes a normal low single digit ASP decline based on site of service mix and procedure mix and a higher depreciation of instrument trees based on our investments in 2021. With that, I will turn the call over for questions. Operator?

Thank you. And to ask a question, simply press star 1 on your telephone. To withdraw the question, press the pound or hash key. Please stand by while we compile the Q&A roster. The first question is from Craig Bourdieu with Bank of America. Your line is open.

Good afternoon. Thanks for taking the questions and congrats on a pretty strong quarter. Thanks, Craig. Laura, maybe just talking about the sales reps and productivity with the reps and kind of the thought process for I believe you're not adding too many reps if I have the numbers correct or you're not expecting to add too many reps in 2022. So, maybe just a little bit more understanding of, you know, your thought process there, the philosophy, and, you know, how you see rep productivity, you know, improving in 22.

Yeah, thanks for the question, and you're right. We are pretty pleased with our performance in the quarter and for the fiscal year, and We like the sequential revenue growth that we saw in the quarter. We like the fact that Q4 was a record quarter with sequential monthly growth on top of it. And we think that we really did navigate quite well through a very difficult environment. I'm also really pleased that the team was able to hit their targets for the year in terms of number of sales reps getting to that 150 people dedicated sales force or 30% growth in territories. So going forward for 2022, we certainly have the opportunity to grow our productivity in terms of our sales team. So They're an important driver of our growth as we're penetrating our core market and expanding our presence in trauma and adult deformity, especially with our second-generation product coming online during the first half of this year. We think that having a dedicated sales team has been a clear differentiator, especially in this unique COVID operating environment and did contribute to 25% procedure growth during the year. But it does help us to enter 2022 with a strong bench that we should be able to leverage over time. And so we're currently targeting to end 2022 with 170 individuals in the sales force, and then more than half of them are going to be quota-bearing territory managers. So a mid-teens increase from that particular perspective. But it really all comes to gaining that leverage on the existing sales force. We know that a rep in a territory by himself or herself can do around a million and a half of business. And then in a territory with a rep plus a clinical support specialist, they can do on average approximately $2 million of business. So the goal is to continue to add reps, but then start to see that leverage on our sales force as well in 2022.

Great. That's helpful, Laura. Thank you. And I do want to ask about expenses and kind of how to think about expenses going forward. Obviously, there was a bit of an uptick this year, but I know in the past you've made comments about getting back to normal spending levels. And it sounds like you might be able to get some leverage as you're not bringing on as many salespeople next year. And maybe some of the R&D spending that you've done over the last couple of years, you'll get some leverage out of that also.

That's exactly – I would love to – Yeah, no, I was saying that's exactly right, Craig. And – The investments that we've made from a sales perspective and an R&D perspective, we believe that 2022 is a year where we can start to gain leverage on those particular investments. So our primary focus has been on revenue growth and capturing the opportunity that we have in the sacropelvic space. But we do also see 2022 as a year where we can gain leverage on that sales force and those R&D investments. And maybe Anshul can add a little bit more in terms of our thoughts there. Yeah, thanks, Laura.

Hey, Craig, good to talk to you. So when you think about OPEX growth rate, Craig, you know, from the way we've modeled it, the OPEX growth rate is going to be a bit lower than the revenue growth rate. And like Laura said, it's going to be balancing between continued reinvestment in the business and the productivity gains. So that's what we're targeting. And when you think about this spend from a dollar perspective, it'll increase for a few reasons. One is, you know, you just annualize the new hires that we did last year. Laura said, you know, we grew our sales force by 30% last year. Our PMs by 30% last year. You start annualizing some of the costs there. You know, we will continue to invest in R&D, even though we'll get leverage out of our existing portfolio. But Torque's a great example of when we've come up with a differentiated product, we've actually had a big impact on the market. So we feel good about that. And then we're also making some investments to scale our operating infrastructure, Craig, to be able to support the top-line growth that we're looking at over the next few years.

Great. Thanks for taking the questions. I'll hop back in the queue.

Thanks, Craig. Thank you. Your next question comes from Kyle Rose with Canaccord. Your line is open.

Hi, everyone, and congrats on the quarter. I wanted to see if we could just dig a little bit more into Craig's previous question just around productivity. I think you've provided that 1.5 and that 2 million number for a few years now. When I just look at the backdrop, I mean, you've got much better reimbursement. You now have a product portfolio that's arguably three products when you include trauma, deformity versus just primary. So I'm just trying to understand how we should really think about, you know, where those productivity gains from, you know, a one million territory to a two million territory, you know, really comes from. And then if you could just help us quantify the impact of TORC in 2021 and we think about the competitive gains versus, you know, moving into trauma, more of a trauma focus in 22 would be helpful.

Thanks, Kyle. So as I said, from a productivity perspective, you know, we definitely have the opportunity to grow the average sales per rep in the United States. And it's, it's, Given how important the sales team is to our revenue growth, it also can be regional in terms of the decisions that we're making. It's how large is a particular territory in terms of the number of surgeons or the size of the particular territory, how much travel is required in a particular territory. But we're getting to that point where we're big enough and we have enough coverage at this point in order to really focus a little bit more on sales productivity. So we increased the number of sales reps this last year, and I'm talking about the senior territory managers by 30% over the last 12 months. And so what we're trying to do now is to get some leverage from those reps that we've added, plus And it takes around 12 to 18 months in order to get those reps productive. So let's be clear on that as well. But the goal in 2022 is to moderate the number of ads that we have and to start really pushing that productivity. And so the productivity comes from the senior sales rep, but it also comes from these junior clinical support specialists that we hire that are less expensive than the the senior reps. So we're already thinking about ways in order to gain leverage on the channel. And so our plan is to start gaining leverage in 2022 and beyond. So that's the answer to your first question. Your second question on TORC, we are not giving, breaking out the specific revenues for TORC, but I will tell you we are very pleased with the strong performance of the product, particularly with competitive conversions, which were our focus in 2021. And the commercial team has really done an exceptional job in targeting competitive surgeons to drive that additional or initial adoption momentum. And we know who these surgeons actually are that are performing these procedures. In many cases, we originally trained those surgeons. And so we've had the ability to go out to those that we think TORC would be of interest, and we've been quite successful in gaining that business. So it really does provide us with the potential to expand the market and extend our market leadership position. But I'll also say that we're just scratching the surface right now on the core market opportunity for TORC, and that's the trauma market. You know, we increased our investment in inventory and instrument trays in the second half of 2021, which you've seen in the Q3 report. You're going to see that in the 10K as well. And a lot of that increase in inventory and instrument trays is actually related to TORC as we methodically accelerated our penetration of the trauma opportunity. And so it provides a really nice tailwind for us into 2022.

Great, thank you. And then just one follow-up on my end is just I think you've made a change or brought on a new marketing leader that's really focusing around some of the direct-to-patient initiatives. I heard some of the commentary in the prepared remarks just about, you know, seeing a doubling of the patients targeted. Can you just talk about, you know, how that translates into, you know, demand and the pull-through you've seen in the field?

Sure. There's a couple of key areas that we invested in in the second half of 2021 as it relates to direct to patient. The first was just an increase in search spend because we had such a tight amount of search spend that the addition of spending actually showed very similar ROI on those additional dollars as the core dollars that we were spending previously. So our new VP of digital marketing really just started with the nuts and bolts of search, driving patients to our website, having them complete the pain quiz, going through our find a doctor function, and then ultimately being referred to surgeons. So And we are able to track all of that information. And some of the metrics that we were mentioning are actually directly tied to those items that I just discussed. In addition, in the fourth quarter, the team engaged in more direct-to-patient marketing, focusing on the lower part of the funnel, using display advertising, using an educational type of campaign. And what I mean by the lower part part of the funnel is those patients who have been in pain management with a chronic SI joint issue for an extended period of time. And so ultimately, these sorts of investments normally take around 12 months for us to actually see the impact from them. But as I said, we've already been making pretty significant investments during the second half of 2021. And so we would expect to see the impact directly turn into case development in the second half of 2022.

Your next question comes from David Rescott with Truist Securities. Your question, please.

Hi, Laura. Thanks for taking the questions. First on the expanded reimbursement that you talked about in the comparative marks, I mean, it's been a couple months so far where that's been in place, and you have a couple months so far this year already. But I guess could you discuss, if at all, whether it's anecdotal or more broadly, just where the impact of these factors have started to come out of the business? I mean, is this opening up the door for new reps to reengage in new accounts? Is it reactivating inactive physicians or just more utilization within the uh, you know, some of the existing accounts and then, you know, how should we think about that impact throughout the year? I mean, is that something that scales and starts to, uh, better impact the business in the second half of the year? Um, any call that would be helpful. Yep.

Yep. David, thanks for the question. And we are really pleased with what we've seen from a reimbursement perspective. You know, we, we finished 2021 with near universal coverage of, um, of minimally invasive SI joint fusion, and even more so with over 160 million patients who are exclusively covered for IFUSE. So we're really pleased with what we've seen there. In terms of the impact of some of those decisions, I think in particular talking about Anthem and United, those exclusives. So Anthem, first of all, was really one of the last payers to cover this procedure. They had a non-coverage procedure prior to August of 2021. And so they finally moved to a positive coverage recommendation, and that recommendation was exclusive to iFEWS. So it was a huge win for us. And then a little bit surprising was the decision by UnitedHealthcare to switch from a positive general coverage decision to an exclusive decision. In terms of what we're seeing right now, we're seeing these payers enforce the exclusive policy. While it's early days, we did see an uptick in Anthem case volumes in the fourth quarter that we do attribute to the Anthem decision. We do think that some of these early increases in Anthem cases are likely due to patients who are already in the system for some period of time. Certainly some patients that had been denied coverage and then that coverage was overturned, it was appealed, and there was a a positive decision that was made. So that's what we believe that we're seeing here in these early days. But I will say we are quite excited about the potential tailwind for 2022 from the coverage decisions and the exclusives, especially in the case of Anthem since they were a non-coverage decision. So in terms of what we would expect, it normally takes anywhere from six to 12 months for a new case to work itself through the system before seeing a meaningful impact on volume. But we have been, you know, really focused on the potential impact of these exclusives in our 2022 guidance. And so, like I said, more of a six to 12 month timeframe in terms of impact.

Okay, that's helpful. I guess just you provided some commenters around the canceled procedures and backlog of cases coming from Q4 and then into January and early February. I guess what does the backlog look like at this point? I know you mentioned there's some physicians that are scheduled out to three months or so. But I guess... What does the current backlog look like? How is the pipeline of patients looking? And then how should we think about these patients, I guess, progressing throughout the year? And how did you kind of contemplate that within your guidance? Thank you.

Yeah, it's been an unusual period of time, obviously. We had Delta in Q3 and then the start of Omicron in Q4. Then we did talk very openly about what we saw in January and February as well. What we've tried to do is to think about this contribution from these procedures over the next few months. We're encouraged by the fact that we're seeing a decline in the deferrals between January and February. We don't know what March will necessarily look like. And in terms of backlog, the way that our system works is we typically will see the scheduling of cases at the point in time where it's put on the books at a surgeon's office. So it's normally only a few weeks. but we do know anecdotally that there are significant backlogs in the three to four month range as I had mentioned in my prepared remarks from talking with some of our surgeons. We also know that historically the way that this has worked, we've gone through so many surges at this point that what typically happens is you'll have a surge, you'll see a lot of deferrals, then you'll see a decline, then a stabilization, and then the rescheduling of cases. And so the way that our guidance is looking at this right now is that January was a tough month, February a decline, a stabilization in March, and then starting to see some of this rescheduling in the second quarter.

Okay, that's helpful. Thanks for taking the questions.

Thanks, David.

Thank you. Our next question is from David Saxon with Needham. Your question, please.

Hi, good afternoon, and thanks so much for taking the questions. I guess just one on 2022, you know, guidance implies 20% at the high end. But, you know, in the past, you've talked about being able to grow well into the 20% range. I think Jeff once said, you know, 30% plus. So, you know, just want to hear your view on whether, you know, the lower implied growth reflects any change in confidence and, you know, the opportunity in front of you. Or if it's really just, you know, a tougher COVID impacted market with perhaps some conservatism baked in.

Yeah, thanks for the question, David. And you're hinting in the right direction for us. We're really pleased with the execution in 2021. We actually had 25% growth in case volumes, even with multiple surges. And it does reaffirm the growing demand for our procedure. You know, we're in the strongest position in the history of the company with our universal coverage, 160 million patients covered exclusively, all of the surgeon engagement and the increase in the number of active surgeons, our, you know, 30% increase in the number of territories in the United States with our sales team, and then the growing portfolio of products. So we feel great about that, too. But, you know, the operating environment, was difficult in January, it's definitely improved in February with fewer deferrals. And we believe that the healthcare environment is still progressing toward becoming fully normalized. And so when we think about procedure volumes continuing to grow month over month, we remain bullish on the underlying business momentum. But Given the macro environment, we really think it's prudent to take a more conservative position around the pace of normalization and being deliberate on the impact of the tailwinds, including the exclusives, expansion into trauma, our new product launch, all of those things on 2022 revenue growth. But I will reaffirm, we are extremely excited about the year 2022. We believe the underlying demand for our products remains robust and There is definitely upside assuming a sustained recovery from Omicron and COVID more broadly, and that certainly could further accelerate growth in the second half of 2022 through higher surgeon productivity from a backlog in growth in our trauma and adult deformity businesses.

The only thing I would add there, David, is you were spot on in the low end of our guidance. As Laura said, it assumes a very conservative scenario. with some amount of impact from COVID throughout the year, including continued case deferrals and prolonged backlog recapture rates. So similar to some of the disruptions we've seen over the last two years, which, again, if those are on the sidelines, we do believe there's tremendous upside in the second half of the year.

Got it. That's super helpful. And then just one on COVID. the exclusive policies. I was just wondering if you've seen any benefit with regards to search and training and, you know, how are you messaging the exclusive coverage to docs that, you know, maybe were reluctant to engage in the past? Thanks so much for taking the questions.

Thanks, David. So, as it regards the exclusive policies, at the point in time where the decisions were made, By Anthem and UnitedHealthcare, we had a very major marketing campaign that worked with our field sales team in order to reach out to all of the surgeons who were impacted around the country by those decisions. And so there was a first round of very significant sales and marketing activities around the Anthem decision in the third quarter. And then there were more activities that we engaged in in the fourth quarter with UnitedHealthcare. And you're correct that it did give us the opportunity to re-engage with surgeons that we hadn't engaged with for a while. It allowed us to train some of those surgeons using the simulator. It makes it very easy to reactivate surgeons who may have been trained previously with or those that have expressed interest but never gone through training. And then it also even gave us the opportunity to talk about what's new within the business. So we went in and there were some cases where it was appropriate to talk to the surgeons about our new torque product. There were cases where it made sense to talk about bedrock and adult deformity. And so What our team was able to do was use the opportunity to speak with those surgeons once again, show them all of our clinical data, show them the five-year data that's driving a lot of these exclusive decisions, and then talk to them about ways to engage with us. So it was a major focus point for the sales team along with our field marketing team and gave us a lot of opportunities for engagement in the second half of the year.

Great. Thanks, and congrats on the quarter.

Thanks, David. Your next question comes from Drew Ranieri with Morgan Stanley. Your question, please.

Hi, Laura and Anshul. Thanks for taking the questions. Just as we're thinking about 2022, can you maybe talk about some of the trends that you're seeing in your procedures moving to the ASC setting? I mean, are you seeing more of a, or are you expecting more of a shift in the current operating environment? But I'll stop there, and I have a follow-up.

Yeah, the ASC environment has been a really important site of service for us over the last couple of years. So, As I stated in my prepared remarks, approximately 80% of our procedures are either hospital outpatient procedures or ASC procedures. Before the pandemic, that number was in the single-digit range. We now have gotten in certain months and quarters into the 20% to 25% range for ASC sales. We do see the ASC as... a long-term growth opportunity for us just because a lot of procedures are shifting to that site of service. It is a cost-effective location for service, and it's appealing for quite a few different reasons. It also has been absolutely critical to our business over the last two years with the pandemic during surges if hospitals were not able to perform procedures. So I'm not sure how much business we're going to see in the ASC setting. That has yet to be stated. I originally thought that around 25% was going to be getting toward a maximum for us, and I simplistically did that by thinking 50% of our surgeons are... Employed by hospitals, the other 50% are private practice. And simplistically said, those in private practice, half of them may do procedures in ASCs. But that's changed. There are more of the private practice surgeons that want to do business in ASCs. And in fact, a lot of the hospitals are actually... developing relationships with ASCs and are shifting business there as well. So I think it's a long-term growth opportunity for the business.

Got it. Understood. And then just to shift gears to gross margins, but you made some comments about the quarter, but I'd like to better understand kind of your guidance for 2022 and some of the pieces there and whether or not kind of the inflationary cost environment is really being a factor in the gross margin guidance. And is 85% is this kind of range kind of the right go forward SI bone gross margin rate? Thank you.

Hey, Drew. Thanks a lot for that question. You know, we obviously are really proud of our industry leading gross margins. And, you know, we came in or 2021 at about 88%. So when you think about our guidance, both in 2022 and as we think longer term, the way we model it here is we've got a few levers that we look at. One is, you know, the ASP decline that we tend to price in on a per procedure basis, not a per implant basis. And a lot of that is driven by site of service, like Laura said, you know, more procedures in ASC. They tend to be a little bit more price sensitive, especially if you see contribution from torque and adult deformity, which tend to use fewer implants than the primary SI joint fusion. So you've got some of that ASP pressure that we tend to model in. And then we look into two other aspects, the second one being the depreciation expense, especially as we expand our product portfolio, we're expanding the amount of instrument trades that are in the field, that depreciation flows through a gross margin, so that will put some pressure on it. And then when you think about inflation as well, we do model in some amount of inflation, especially this year, given everything that's going on. Even though our supply chain team has done a phenomenal job in managing through the cost element and actually being very forward-looking in terms of the demand trends and what we need, we do model that in. Now, where do you see long-term gross margins? Sort of that mid to potentially high 80s is where we look at. We're not going to be able to say, is it 85? But our aim is to keep it above that 85 number.

Our next question comes from Dave Torkaly with JMP Securities. Your line is open.

Great, thanks. Laura, I think I heard you say that the re-engaged surgeons and maybe some of the new products were helping with that, but of the 690 active, do you comment at all at sort of how many of them were re-engaged guys versus, let's say, brand-new customers?

We don't comment on it, but it definitely has been a focal area for us to re-engage surgeons. There was a pretty major push in the second half of 2022 to speak with surgeons who had previously been trained. Second half of 2021. In the second half of 2021, yes. Right. And we'll continue to do that going forward as well. As we said, there were 1,800 surgeons who have trained and treated at least one patient, and 1,000 of them approximately did at least one procedure in all of 2021. So what that means is there are approximately 800 surgeons who did not engage with us in that 12-month period. And so those continue to be targets for us.

Got it. Thanks a lot.

Thanks, Dave. Thank you. And this ends our Q&A session. I will pass it back to Laura Francis for her final remarks.

Thanks so much, Carmen. I'm pleased with the team's execution in 2021. We hit several record milestones and As we look beyond the near-term impact from the recent resurgence of COVID-19, including the pressure on hospital infrastructure, we see strong underlying momentum in our business. In 2022, we'll continue to leverage our investments to expand the market for sacropelvic surgical solutions and drive strong top-line growth. I want to thank you for joining us today, and I look forward to meeting you at upcoming investor conferences and events. Goodbye.

And with that, ladies and gentlemen, we thank you for participating in today's program. You may now disconnect. Have a wonderful day.