Skip to main content

Impact of Osteoarthritis in Military Personnel and Veterans – October 20, 2021

October 20, 2021

Webinar Information:

Dr. Kenneth L. Cameron will discuss the impact of osteoarthritis in military personnel and veterans. This webinar is being presented in partnership with the Alliance for Balanced Pain Management and the Arthritis Foundation.

Speaker:

Kenneth L. Cameron
PhD, MPH, ATC, FNATA
Director, Orthopaedic and Sports Medicine Research at Keller Army Hospital
John A. Feagin Jr. Sports Medicine Fellowship

Kenneth L. Cameron currently serves as the Director of Orthopaedic and Sports Medicine Research at Keller Army Hospital, West Point, New York, where he holds faculty appointments with the John A. Feagin Jr. Orthopaedic Sports Medicine Fellowship, the US Army-Baylor University Sports Physical Therapy Doctoral Program, and the Uniformed Services University of the Health Sciences. Dr. Cameron earned the Commander’s Award for Civilian Service in recognition of exemplary service to the United States Military Academy in 2004, the Department of the Army Superior Civilian Service Award in 2014 and the Department of the Army Civilian Award for Humanitarian Service in 2021. Dr. Cameron’s primary research interests are in the areas of injury prevention, musculoskeletal injury and disease epidemiology, and outcomes associated with the treatment of these injuries, specifically in physically active and military populations. He also has specific research interests in knee and ankle injuries, shoulder instability, and biomarkers associated with post-traumatic osteoarthritis.

 

Lunch & Learn Recording & Transcript

Disclaimer:

The content displayed in this transcript is the intellectual property of Kenneth Cameron. You may not reuse, republish, or reprint such content without written consent. The contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement, by OA Action Alliance, CDC/HHS, or the U.S. Government. This transcript was automatically generated in Zoom, and edited for clarity, however, the OAAA cannot guarantee there are no mistakes or errors.

October 20, 2021

Title: Impact of Osteoarthritis in Military Personnel and Veterans

Presenter: Dr. Kenneth Cameron, PhD, MPH, ATC, FNATA

Director, Orthopedic and Sports Medicine Research at Keller Army Hospital

John A. Feagin Jr. Sports Medicine Fellowship

INTRODUCTION

(Kirsten Ambrose) Hello, and welcome to the osteoarthritis action alliance lunch and learn webinar for October 20th, 2021. Thank you for joining us this month. Before we get started with the webinar, we want to share that today’s presentation marks the launch of our month-long campaign on osteoarthritis in the military to bring awareness to the impact of osteoarthritis on active-duty service Members who are often considered tactical athletes for the physical demands that training and combat operations require and the subsequent release risk for development due to joint overloading, joint injury, or related causes.

We also want to emphasize the prevalence of osteoarthritis among veterans in particular and empower them to take charge of their own health and manage joint pain through physical activity weight management, disease management, education, and those kinds of strategies that they can do on their own. The campaign kicks off with our presentation today and continues to Veteran’s Day, and we will be sharing educational tools and resources for veterans all month. We will also be sharing links to our Remain in the Game Toolkit, which is for youth athletes, in particular, tactical athletes, and includes training exercises that are proven to be protective, encouraging folks to take advantage of those and incorporate them into their lives. Finally, we will include video testimonials from vets and other resources so check back to our website listed there and be on the lookout in social media. We’re pleased to host this campaign in partnership with the Arthritis Foundation and the Alliance for Balanced Pain Management. And we are grateful for Flexion Therapeutics for their support of the campaign as well, so with that we will move on to today’s presentation.

We are pleased to have Ken Cameron as our lunch and learn presenter today, Dr. Cameron currently serves as the director of orthopedic and sports medicine research at Keller Army Hospital at West Point in New York, where he holds faculty of moments with the junior orthopedic sports medicine fellowship. At the US Army Baylor university sports physical therapy doctoral program and the uniformed services university valid sciences, Dr Cameron earned the commanders Award for civilian service and recognition of exemplary service to the United States military Academy in the Department of the army superior civilian service award in 2014 and the Department of the army civilian Award for humanitarian service in. Dr Cameron’s primary research interests are in the areas of injury prevention, musculoskeletal, injury and disease epidemiology, and outcomes associated with the treatment of these entries specifically in physically active and military populations. He also has specific research interests in knee and ankle injuries, shoulder instability, and biomarkers associated with post traumatic osteoarthritis. We are extremely pleased to invite him to speak today to give a talk entitled Impact of Osteoarthritis in Military Personnel and Veterans. Welcome Dr Cameron.

 

PRESENTATION

(Dr. Kenneth Cameron) Thank you, I would like to thank the Action Alliance and Partners for the opportunity to speak today. Just standard disclosure that anything I say during the presentation is my own personal opinion and does not reflect official government policy. So, to get started, I would like to provide just an overview of what we’ll talk about. I would first of all like to talk a little bit about the impact of the disease, in general, and particularly how it relates to military service members. I will talk about some of the risk factors for acute traumatic brain injury or the risk of acute traumatic brain injury military populations and the association between these injuries and the onset of osteoarthritis will also discuss the incident and burden of osteoarthritis and military populations, based on the evidence that’s available. And we’ll discuss potential contributing factors and the ways that we may be able to prevent and manage this condition. Finally, we’ll discuss strategies for the primary prevention of joint injury, because if we can prevent joint injuries, we can probably go a long way in preventing post-traumatic osteoarthritis. We’ll also talk about initiatives for secondary and tertiary prevention of post-traumatic osteoarthritis falling joint injury.

So, what is post-traumatic osteoarthritis? It’s important to think about at the outset here at posttraumatic osteoarthritis is really unique phenotype or subset of osteoarthritis. Which is typically associated with a huge dramatic joint injury, the disease typically follows a much shorter time course. Because of the more rapid onset and progression of the disease, following injury and post-traumatic osteoarthritis for PTO typically affects people at a much younger age. Because those are the people you know military service members athletes, these are the people who are engaged in physical activity and who are at risk for these types of joint injuries by and large.

So, what is the impact of posttraumatic osteoarthritis and the general population it’s been estimated that the prevalent is around 12%. Of all arthritis, about 12% is post traumatic osteoarthritis it’s also been estimated that the cost the direct cost for care for post traumatic osteoarthritis is around $3 billion a year, obviously there are additional costs are not accounted in that estimate. And those are particularly related to disability and disability adjusted life years which are probably substantially higher. And there’s also an increased risk for early primary and revision joint total joint replacement surgery, and in this population. Because again the disease is onset is at such a young age that it’s not uncommon to see people having a primary joint replacement under the age of 50 or even in their 40s and that may need to be replaced. So, there is clear and compelling evidence that joint injury leads to osteoarthritis, typically what we call post-traumatic osteoarthritis. And that’s true in the shoulder, it’s true in the needs true and most joints. And again, the evidence suggests that the incidence of poster amount of osteoarthritis again post-traumatic osteoarthritis is seven times higher. And people have had a joint injury compared to those who have not based on well design perspective studies. And, and again, some of the low manners classic work suggests that this really happens in people at a much younger age falling joint injury in the knee, particularly when you looked at female soccer players.

So, we did we put a substantial amount of time into looking at the incident and the burden of joint injuries and military service members and much of that work was summarized in a recent review that we did to look at these types of injuries in the military. And some of the key findings are that you know we see a large proportion of joint injuries that happen in military service members during their time in service, a lot of these injuries are not related to combat that are not related to battle there what we consider what we call non battle injuries and these injuries again place people at increased risk for post traumatic osteoarthritis down the road. So, to track joint injury is common amongst military service Members, we have clear evidence of that. And this joint injury is also associated with subsequent entry these individuals are much more likely to reenter themselves into the same joint as well as injure another joint and the lower extremity or upper extremity and they’re also much more likely to have decreased function after injury, regardless of treatment and they’re also more likely to have higher rates of disability.

So, you know, given the types of activities that we asked our military service members to engage in as part of their training and as part of their occupational duties. It shouldn’t be surprising that we see a lot of acute dramatic joint injuries and you know those injuries really lead to posttraumatic osteoarthritis, which is a common outcome of these injuries in this population. We just think about the evidence on away in the military we’ve recently looked at this and we’ll discuss it in detail a little bit further in but the incidence rate among active-duty US military service members is significantly higher when compared to comparable age groups in the general population. And similar results have been observed and veterans’ population so again higher rates of away and veterans’ populations, compared to people who did not serve in the military, at the same age groups, and again, we believe that this is in large part due to the high rate of joint injuries that we’ve documented in this population. Also, nearly 70% 75% of active-duty military personnel that have undergone total knee replacement under the age of 50 had a history of joint injury, and those joint injuries again we’re the most common injuries to the new ligaments and the articular cartilage and cartilage in the knee. And when we look at these types of knee injuries, we find that again that they are endemic and they’re very common in military populations. There are leading causes of medical evacuation from the theater when we looked at Operation Enduring Freedom and Operation Iraqi freedom these battle injuries were a leading cause of why people were being evacuated from those deployments.

We also did a systematic review to look at not just military service members, but other tactical athletes. We looked at firefighters, there’s some evidence in that population. But In other tackle athlete populations, not a lot of evidence, but in those that were there are data it does look like there’s an increased incidence rate of away in these types of professions. Specifically, we wanted to again, based on the burden of joint injury and military service Members, we wanted to specifically look at the incidence of away, and this is not specific to post traumatic away, but just in general in the military population. And these are really the results again at the lowest age groups 20 to 24 we saw about a 30% higher incidence rate of away, which was statistically significant in military service members. And that difference real wider between the general population and our military service Members as age, increase which again would not and should not be surprising.

Some colleagues also looked at the incidence of hip osteoarthritis in military service members, and in our systematic review we pulled some of their data, together, we found that for males in the 20- to 50-year-old age group that military service Members were nearly four times they had a four times higher incidence rate of osteoarthritis of the hip and for females that was nearly 40 times higher, the incidence rate of boy in the hip for females and military service. So again, those were kind of general away incidence rates, we wanted to drill down and really get in the knee particularly to look at post traumatic away so away that that followed a joint injury that was documented in the medical record the previously presented prevalence rate was around 9.8% and the general population, again we speculated that this was probably substantially higher and in the military population. So, we use data from the database, which is the total army injury and health outcomes database that database polls data elements from several VOD and DHS level databases, to allow us to do that. And what we found was that again those who had a joint injury during their time and service were nearly six times more likely to be diagnosed with post traumatic osteoarthritis during their military career.

We also found that the average time from joint injury to diagnosis of neat posttraumatic osteoarthritis was 31 months so less than three years. And that’s in comparison to individuals with primary osteoarthritis and the knee without a joint injury, which was about 118 months so obviously much longer.

We also looked at the period prevalence like we talked about that in military service members 35.8% of all cases were posttraumatic osteoarthritis so nearly five times higher than in the general population and soldiers with incident and post traumatic arthritis individuals were 31% more likely to receive a disability discharge, which was significant, and they also received a disability discharge at a much younger age again some just confirm some of what we had talked about previously. When we look specifically at battlefield injuries, some of our colleagues looked at this to see you know what is the major cause of disability from battlefield injuries. And when they look at this they looked at a couple different ways, so, if you look at the first table. They looked at in terms of frequency, so what was the most frequent reason people were deemed to have disability, following a combat injury. And arthritis was at the top of the list, and primarily that is osteoarthritis from talking to the authors, they also looked at this in terms of the present disability rating, that would be awarded for that condition and, as you can see that you know arthritis is a little bit further down on the list. And then the third way is they multiplied the frequency by the percent disability to get what they call an impact score and arthritis was near the top of the list and again primarily osteoarthritis was driving this. They subsequently took a look at posttraumatic osteoarthritis specifically as a result of battlefield injuries. And they reported that 94.4% of cases were attributed to combat injury, so all of the arthritis that was documented as a disabling condition.

Most of those were due to combat injury so post traumatic osteoarthritis and again, even in the in the even more rapidly onset a more rapid onset in this population of less than two years or 19 months on average from the disabling injury until the diagnosis of post traumatic osteoarthritis. So, our colleagues also want to look at you know how did this change after a decade of combat operations in Iraq and Afghanistan, so they looked at disability from a number of conditions and what they found that was it this really didn’t change over a decade of combat operations in Iraq and Afghanistan. Osteoarthritis in terms of frequency and back pain still remains the two leading causes of disability in military populations. Again, a somewhat good news story is that you know the percent disability awarded for osteoarthritis nearly doubled, but the bad news is that that was still only 12% disability rating that that these individuals were receiving for their osteoarthritis diagnosis. And again, when we look at the impact school impact score which takes into account frequency, as well as percent disability. After a decade of combat operations you’ll see that back pain and osteoarthritis were still among the top conditions for disability discharged in military service members. And one of the key findings from the authors was that you know, despite their expectations, these conditions back pain and osteoarthritis remained the most impactful among the most impactful disabling conditions which significantly impact military readiness and also substantially account for a large proportion of medical costs in this population.

So why do we see such a significantly higher incidence rate in military personnel in terms of away when compared to the general population? So, there’s probably a couple reasons and we’ve already talked about some of it. Obviously, the high rate of acute chromatic joint injuries, I think, is a driving force here but, but we need more information to really tease that out. The physical training and occupational demands that are placed upon this population require a significant amount of repetitive bending and squatting and kneeling and previous research from the Framingham study really suggests that these types of activities place individuals at increased risk for osteoarthritis. So that’s consistent with that work and then, finally, we know that obesity is a leading risk factor for osteoarthritis while our military service members are young and healthy and for the most part, very physically fit. But we take these healthy individuals and we put very large loads on them, which can range from 52 pounds to over 100 pounds when they do their job, particularly during deployments and during some training exercises. And just to give you an idea of what this looks like you know these are some standard combat loads that you may see. And you know, obviously this alters the mechanics of this individual and while there’s been some research to really look at you know what’s the physiologic impact of carrying these types of loads. We really have done less work in terms of determining what this may mean for short and long term joint health so that needs to be looked at a little bit more closely.

So, how can we mitigate this substantial burden of posttraumatic osteoarthritis? You know, the first thing we can really do is focus on primary prevention, so if we can prevent joint injuries from occurring in this population, we can probably eliminate a lot of this post traumatic osteoarthritis that we’re seeing. But we also need to evaluate the effectiveness and implement and develop secondary and tertiary prevention efforts which may alter the course of the disease may slow it down may alter that trajectory so that people can remain in their in their occupational positions. And then, finally, we want to probably spend some time evaluating the impact of these loads and how we how these really affect joint health that that could go a long way for us.

And I know we talked a little bit at the beginning about, you know, some of the kits and some of the tools that the action alliance has developed, you know that can really help in terms of primary prevention. As you see, on the left here kind of breaks our prevention into different levels so primary is really preventing the injury from happening in the first place. And then, secondary and tertiary prevention or kind of those things we can do after injury has occurred to hopefully alter the course of disease or onset or progression of post traumatic osteoarthritis. So, you know we may be able to screen individuals for movement quality we may be able to do interventions to improve their movement quality which can reduce their risk of joint injury and there’s some substantial evidence to support this, but as one of my colleagues likes to say you know once somebody has entered their joints substantially you know the horses already out of the barn at that point. And at that point, we really need to shift our focus in terms of secondary and tertiary prevention to what are the things that we can do downstream to delay initiation on site and progression of osteoarthritis after that joint injury has occurred. And there are definitely some recommendations are out there, the CDC again has put some forward some of these include weight management which we talked about at the beginning.

Self-management education or how can these individuals manage their condition and also, you know, physical activity…low impact/moderate physical activity, making good physical activity choices. These are all principles that can potentially be applied to our military service members in specific settings to help them deal with this and that’s something that we’re looking at right now with some of our ongoing research. There’s also been a call for us to kind of shift our focus and how we deal with these joint injuries to not wait until we have an osteoarthritis diagnosis, but to maybe intervene sooner, we know that these people again are much higher risk. There are things we can do earlier in the time course after a joint injury that will hopefully preserve joint health and there’s some research going on in that area right now. And really you know starting to think of managing the joint injuries is not a one-time thing, you know someone injures their knee joint we replace her ACL we do some rehabilitation and we turn them loose but really trying to monitor their joint health because we know, these people are at risk for substantial complications, including post traumatic osteoarthritis later on down the road. And one of the one of the ways that we’re going to be able to do this is by really better understanding the interplay between the biology, you know that’s going on in the system and the joint mechanics and also the structure and function that’s affected by injury so, so we are really trying to address these critical gaps in our knowledge, so that we can do a better job in terms of our secondary and tertiary prevention efforts, but we are not there yet, unfortunately.

So just to summarize briefly, posttraumatic osteoarthritis is a unique form of osteoarthritis it’s typically associated with joint injury. Acute traumatic joint injuries are common in military service members and veterans and they really substantially contribute to the increased risk of a way that we see in this population. These musculoskeletal injuries that we see in this population significantly impact force readiness, there are substantial health care costs associated with these injuries, as well as the long-term outcomes and disability discharge ratings that go along with this in this population. As we talked about there really is critical need to try and prevent as many joint injuries as we can in this population and where those injuries can be prevented, we need effective secondary and tertiary prevention strategies following injury that can really help manage the risk of away delay the onset and long-term consequences that may be associated with post traumatic osteoarthritis in these individuals. And chronic management models may really have promise in doing that, we just, we need to further refine and expand those and you know, develop these interventions that can be used along that time course.

And then, finally, we really need to improve our ability to understand how biology mechanics and structure really contribute to the initiation and progression of post traumatic osteoarthritis which really remains a barrier in terms of our ability to prevent injury, in the first place, and then to alter the course of disease once someone has sustained an injury. And I would just like to thank again the only action alliance and partners for the opportunity to present today on this important topic and I will turn it back over to the moderators to facilitate any questions that we may have.

Question and Answers

(Kirsten Ambrose) Thank you, Dr Cameron, this is really fascinating and I think for those who are not as familiar with the military population, just really kind of astonishing to see the impact. So I will open up the chat now for a couple of we have time for questions so if you have a question, please go ahead and type it into the chat box. Also, a couple of things in a few minutes…you will see a pop up on your screen, with some survey questions as well, we always like to be sure we’re doing well by our viewers, so please answer those before you leave the webinar and at this point I don’t see anything in the chat just yet, while people are thinking, let me go ahead and ask you a question.

QUESTION: What research gaps currently limit our ability to mitigate the impact of joint injury and post traumatic away in military populations?

ANSWER: Kenneth Cameron: Yeah so that’s a great question, I think you know, one of the primary gaps is our ability to really detect early disease, I know a lot of investigators, are working on that. Like I said, we know people once they sustain a joint injury there is a much higher risk for the onset and progression of osteoarthritis but we really don’t have good tools to detect or monitor that so you know that that really is a critical gap that hopefully we can address. We also because of that, because we can’t really monitor those early changes, we really are lagging behind and developing those secondary and tertiary intervention, so you know I think those are really critical research areas that we need to focus on, you know if we can answer those questions, we can really move in a direction that that hopefully can mitigate this problem.

(Kirsten Ambrose) I think you’re right about that and, as you know, we have, excuse me, we have a particular interest in not just prevention, but also in that space of secondary prevention efforts and have been doing a little bit of work in that area.

QUESTION: Can you tell me what secondary and tertiary prevention efforts may be useful in addressing posttraumatic away and an active military population.

ANSWER: Kenneth Cameron: Sure, so um again the evidence is still emerging, but you know that there is some evidence that that you know early biological interventions may be able to impact or alter you know the inflammatory response which, which you know may or may not contribute to pto I, we believe that it may. But we’re still not certain on that, but there may be, you know things that can be done very short term after injury has uttered which could preserve joint health, and you know we’re still looking into those things that research is ongoing. And then longer term, you know, like we talked about there may be some of the work that we’re currently doing is through the mirror project, which is the musculoskeletal injury and rehabilitation research for operational readiness program out of the uniformed services university, one of the projects were working at is it’s a mobile APP. Which you know, is for individuals who had a joint injury to really kind of implement or to make them aware of some of these self-management techniques or weight management techniques, you know, in terms of activity, you know if they have some choice in the activities they do in their free time. Maybe running five days a week is not the best choice if you’ve had an acl injury or a meniscus tear in the past, you know, maybe doing some lower impact exercise no avoiding maybe basketball, maybe institute instead choosing swimming. Maybe, something that would be a better choice for you, so you know, helping to provide tools will help individuals make better decisions that will preserve their joint health for a longer time.

(Kirsten Ambrose) I think that is very important and appreciate the work you’re doing in that area. We have had a couple of questions come into the chat box, so I know that we are approaching the end of our 30-minute time slot, but we will get to all of these questions. For those who are willing to stay on an extra minute so with the first question we have:

QUESTION: With body Armor soldiers are carrying more and more weight, in fact, an average marine corps infantry officer should be physically able to carry 152 pounds for nine miles What steps are being done to mitigate this burden.

ANSWER: Kenneth Cameron: I think that’s a great question. I don’t know the answer to that is in terms of what exactly is being done, I know there definitely has been some innovation there’s actually a air force academy cadet who came up with a much lighter version of the of the flak jacket, so you know, there is some research that’s being done to try and lighten the load. You know, just like anywhere, the people typically developing the equipment or not the people carrying the equipment, which is unfortunate. And we knew need to do a much better job of getting that type of feedback and also trying to figure out how we can lighten the load. I think that’s you know that’s a great point and something that we need to do a better job of like I said before, a lot of times the testing that’s done, as you know physiologically can you do this and not necessarily what is the impact or outcome of doing this, so some of that work definitely needs to be done and that’s another critical gap which I tried to highlight during the presentation.

QUESTION: Thank you yeah and a follow-up question to that, can technologies such as exoskeletons and Rovers help carry the weight?

ANSWER: Kenneth Cameron: Yeah, I know that definitely some work bits out of DARPA right now is looking at some of those things developing some exoskeleton some technology some other technologies that may help reduce the load. You know it’s pretty amazing some of the stuff that they’re doing. So yeah Hopefully there is some opportunity to do that, or you know even have you know. There are also some work looking at robotics as well that could potentially help to carry some of this load, so the soldier maybe doesn’t necessarily have to do that. But I think they’re definitely looking at that, but we obviously are not there yet, did you could tell from the pictures that I shared during the presentation.

(Kirsten Ambrose) Great and then we have another question that’s come in-

QUESTION: What are your thoughts on ways to improve management of vets with osteoarthritis within the VA many are triage to stage three and experienced prolonged weight and or need to seek out care in the community.

ANSWER: Kenneth Cameron: yeah I think you know I think our providers in general, you know, in the VA as well as out of the VA, we need to do a better job educating them about away, I think that you know, we still a lot of people still see this as an old and aging disease, something that happens to people as they get older and there’s not much that can be done about it.

There was a paper published not too long ago that had recommendations on management of OA and there were consensus recommendations across several organizations that that made those types of recommendations, there was generally good agreement about management recommendations for away but in terms of clinicians really understanding those and implementing those in any consistent manner, was not happening within the VA or even outside of the VA so I think we really need to do a much better job of getting those recommendations out. And, seeing that they’re you know getting them to clinicians helping clinicians understand that those tools are available to them. You know some of the things like we talked about exercise low impact exercise can go a long way and managing symptoms weight loss. You know, choosing the right types of exercise to be involved with So those are those are well established recommendations that have an impact, but they’re not being consistently implemented in clinical practice, unfortunately.

Kirsten Ambrose: Thank you yeah and that response everything you just said resonates very deeply with the OA action alliance that’s an avenue that we are constantly trying to provide resources and educational materials and stuff in service of changing the viewpoint about arthritis like you said that it’s, not just for older adults are aging adults, that it can impact younger adults and also just making sure that people know where to go to get resources and what can be done to mitigate away I think that’s very important.

Kenneth Cameron: Just from there, I think yeah. I think, also just empowering the patient to give them some choices that you know hey you do some of this is under your control, and these are things that you can do to potentially you know alter the, you know, how your diseases progressing or how your symptoms are being managed.

Kirsten Ambrose: Right well and you’re so familiar with the current guidelines that for arthritis care and management that those types of self-management activities physical activity weight management rank. Basically, as first line strategies for treating OA often above clinical care and drug treatments, given the fact that drug treatments are not disease mitigating at this point so that is vitally important for people to keep in mind.

Closing remarks

(Kirsten Ambrose) Well, I think that’s it for our questions today and I want to thank you again, Dr Cameron for your presentations very enlightening and also for your willingness to stay on and address all of our questions you’ll see that pole just popped up and for everyone. I just wanted to thank you again for joining us today and tune in next month on November 17 for the Lunch and Learns featuring Patricia Lawson who will present Walking through water TAI Chi for arthritis for falls prevention. So, look forward to seeing you then and once again thanks for joining today, thank you, Dr Cameron.

Kenneth Cameron: Thank you for the opportunity to present.

Kirsten Ambrose: Absolutely, bye everyone.


COST

Free  

Register