Best Practice & Research Clinical Rheumatology 28 (2014) 1–3
Contents lists available at ScienceDirect
Best Practice & Research Clinical Rheumatology journal homepage: www.elsevierhealth.com/berh
Preface Osteoarthritis (OA) is the leading cause of disability among older adults. It is an incredibly prevalent condition affecting upwards of one in eight adults. This highly prevalent disease and attendant disability leads to a formidable individual and societal impact. Increasing the need for urgent attention to this burden, societal trends in aging, obesity and increasing joint injury indicate that there will be an increase, in the number of persons affected, of about 50% over the next 20 years [1–3]. In this context, this issue of Best Practice Clinical Rheumatology is timely, as we envision this increasingly prevalent disabling condition in an era where health-care expenditure is increasingly scrutinized. With these societal trends, new insights are developing into the pervasive disease we know as OA. Consideration of the impact of this condition in our society requires an understanding of the incidence and prevalence of this disease. It is critical that we exploit what we know about epidemiology to develop robust plans to prevent this disease. The first chapter provides a thoughtful appraisal of the epidemiology of OA informing us on how we define OA, the prevalence and incidence of OA and the risk factors for OA. Further, it enumerates opportunities for disease prevention that will become even more critical to deploy with the further strain this disease will place on limited health resources. The risk of knee OA in our society attributed to obesity and injury accounts for approximately 80% of the reason for OA development. Both are eminently preventable, yet little is being done to reduce these risk factors [1]. One area that is ripe for intervention and a research field that is very active is that of post-traumatic OA. Joint injuries such as a tear of the anterior cruciate ligament (ACL) or meniscus increase the risk of knee OA by altering the contact mechanics of the joint environment, that is, the way weight-bearing load is distributed in the joint. ACL ruptures have been found to be linked to OA changes in 50–70% of the patients, 10–15 years following the injury [4]. Estimates suggest that injury accounts for up to 15% of all incident knee OA cases and that this is also eminently preventable. Numerous trials of neuromuscular conditioning programmes have demonstrated efficacy in reducing the risk of ACL injury by as much as 60% [5,6]; yet at this point, little has been done to disseminate them widely. Similarly, much of what we have learned from preclinical research, especially in animal models, has not been immediately translated into improved understanding of the human disease. There are not only fundamental differences between the OA animal models and the human disease but also many similarities that provide a rich opportunity for intervention. Chapter 2 reviews this field but more specifically highlights opportunities for intervention. Many define OA as a condition that primarily affects the hyaline articular cartilage, including William Hunter who in 1743 stated soberly ‘From Hippocrates to the present age it is universally allowed that ulcerated cartilage is a troublesome thing and that once destroyed, is not repaired.’ [7] We now conceptualize OA as a disease of the whole joint organ. Conventional radiography has played an important role in confirming the diagnosis of OA demonstrating late bony changes and joint space narrowing and has been applied as an end point for disease progression in clinical trials. However, OA is a disease of the whole joint including cartilage, bone and intra- and periarticular soft tissues. Thus, the importance to image and assess all joint structures has been recognized in recent years largely using http://dx.doi.org/10.1016/j.berh.2014.02.004 1521-6942/Ó 2014 Elsevier Ltd. All rights reserved.
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Preface / Best Practice & Research Clinical Rheumatology 28 (2014) 1–3
magnetic resonance imaging (MRI). Written by leaders in this field, Chapter 3 not only reviews radiography and MRI in OA but also gives insights into other modalities and their role in the diagnosis, follow-up and research of OA. There are numerous limitations to the way we measure and stage OA. Biomarker (both biochemical marker and imaging) research is an extraordinarily active field in OA, with the promise that it will facilitate the development of disease-modifying OA drugs. Before any new biomarker supplants the current regulatory standard of the plain radiograph, it will require both validation and qualification. Chapter 4 illustrates the case for this and elaborates how biomarker research will address the dual steps of biomarker validation and qualification. OA is no longer viewed as a passive, degenerative (yes, that’s right – the use of this term is archaic) disorder but rather an active disease process with an imbalance between the repair and the destruction of joint tissues driven primarily by mechanical factors. Current treatment approaches frequently take a shotgun approach to OA and often ignore the potential for modulation of local mechanical factors. Chapter 5 details the local mechanical factors that play a role in patellofemoral (PF) OA and illustrates a rational approach to the management of this often-challenging OA phenotype. Whilst PF OA is illustrated, the same principles of a pathomechanical approach can also be applied to individualize therapeutic decisions for other types of OA. No one denies that the management of OA is a challenge; however, modern clinicians are armed with a plethora of effective treatment options. Like other chronic diseases, there is no sole treatment or cure, instead there are several strategies to use that can help manage the condition. Clinicians who manage patients with OA recognize that to maximize treatments, it is best to use them as part of a package and incorporate many of the strategies together. For instance, not only just prescribing analgesics to manage symptoms but also considering weight, fitness levels and muscle strength, and evaluating daily patterns of activity. For the practicing clinician, arming themselves with knowledge of mechanisms and evidence for disease management is critical. It is important that symptomatic improvement serves the purpose of increasing tolerance for functional activity. Ultimately, an efficacious treatment for any progressive disorder should also control the factors and forces that drive disease progression. Chapter 6 provides a thorough review of the influence of muscle activity on knee joint loading, describes the deficits in muscle function observed in people with knee OA and summarizes available evidence pertaining to the role of muscle in the development and progression of knee OA. They focus on whether muscle deficits can be modified in knee OA and whether improvements in muscle function lead to improved symptoms and then focus on practical recommendations for exercise prescription for muscle rehabilitation in OA. Despite OA being a typical chronic disease characterized by long disease duration, substantial impact on quality of life and multiple co-morbidities, our current management practices are best described as reactive and palliative. [1] The vast majority of health-care costs are expended on a small minority of individuals, and despite a strong rationale for implementing new service models that will reduce both disability and cost, there has been little shift in policy or practice [8]. The challenge facing clinicians is dwarfed by the experience that persons with OA have to face. Any person with a chronic illness faces a personal daily battle with the condition itself, which in the case of OA is further compounded by a nihilistic ‘broken’ health-care system. Chapter 7 provides an insightful systematic review of the effectiveness, cost-effectiveness and barriers for the use of OA chronic disease management service models. It thoroughly reviews chronic disease management considering the many barriers to effective delivery and the wide array of stakeholders with vested interest in OA health-care delivery. Given that the health systems and resources are not unlimited, both the current economic climate and the rapidly increasing burden from OA calls for urgent attention to this pressing matter. On the failure of prior interventions, OA surgery may become necessary. Current evidence suggests that the most common orthopedic procedure, that is, knee arthroscopy, has little, if any, role in the management of persons with OA. Despite the evidence, this surgical procedure is still in widespread use. Chapter 8 reviews the evidence and the limited indications for knee arthroscopy while illustrating some of the challenges in translating research into changes in clinical practice. While the indications for arthroscopy have narrowed, joint replacement continues to play a pivotal role in disease management. Oftentimes patients ask and clinicians are faced with the decision as to
Preface / Best Practice & Research Clinical Rheumatology 28 (2014) 1–3
3
who is a good candidate and at what stage in the disease course should joint replacement be considered. Chapter 9 expands on this area and illustrates who will likely benefit from surgery and, potentially more importantly, who will not. As a single disease, OA has a major effect on productivity and places an enormous burden on the health-care system, in addition to its individual impacts through pain, disability and reduced quality of life. Sociodemographic changes are driving up the disease prevalence such that the burden of OA is increasing more rapidly than any other health condition. We have been afforded an opportunity to study a much maligned disease that is rapidly evolving. Let us learn from the insights that our research is providing to focus even more on important modifiable risk factors such as mechanics, injury and obesity as we develop the therapeutic armamentarium of the 21st century. Assuming we maintain a meaningful motivation with the patient at the forefront of our mind, we have an opportunity to make a difference in millions of peoples’ lives. I would sincerely like to thank my friends and colleagues for their valuable contributions to this issue. They were a pleasure to work with and I am sure you will see the contents reflect wonderful insight and appraisal of a complex and developing field. References [1] Hunter DJ. Lower extremity osteoarthritis management needs a paradigm shift. Br J Sports Med 2011 Apr;45(4):283–8. [2] Hootman JM, Helmick CG. Projections of US prevalence of arthritis and associated activity limitations. Arthritis Rheum 2006 Jan;54(1):226–9. [3] Perruccio AV, Power JD, Badley EM. Revisiting arthritis prevalence projections–it’s more than just the aging of the population. J Rheumatol 2006 Sep;33(9):1856–62. [4] Lohmander LS, Ostenberg A, Englund M, et al. High prevalence of knee osteoarthritis, pain, and functional limitations in female soccer players twelve years after anterior cruciate ligament injury. Arthritis Rheum 2004 Oct;50(10):3145–52. [5] Hewett TE, Ford KR, Myer GD. Anterior cruciate ligament injuries in female athletes: part 2, a meta-analysis of neuromuscular interventions aimed at injury prevention. Am J Sports Med 2006 Mar;34(3):490–8. [6] Yoo JH, Lim BO, Ha M, et al. A meta-analysis of the effect of neuromuscular training on the prevention of the anterior cruciate ligament injury in female athletes. Knee Surg Sports Traumatol Arthrosc 2010 Jun;18(6):824–30. [7] Buchanan WW. William Hunter (1718–1783). Rheumatology 2003 Oct;42(10):1260–1. [8] Brand C, Hunter D, Hinman R, et al. Improving care for people with osteoarthritis of the hip and knee: how has national policy for osteoarthritis been translated into service models in Australia? Int J Rheum Dis 2011 May;14(2):181–90.
David J. Hunter, MBBS, MSc, PhD, FRACP* Kolling Institute and Institute of Bone and Joint Research, University of Sydney, Sydney, Australia Rheumatology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia. E-mail address: [email protected]
Contents lists available at ScienceDirect
Best Practice & Research Clinical Rheumatology journal homepage: www.elsevierhealth.com/berh
Preface Osteoarthritis (OA) is the leading cause of disability among older adults. It is an incredibly prevalent condition affecting upwards of one in eight adults. This highly prevalent disease and attendant disability leads to a formidable individual and societal impact. Increasing the need for urgent attention to this burden, societal trends in aging, obesity and increasing joint injury indicate that there will be an increase, in the number of persons affected, of about 50% over the next 20 years [1–3]. In this context, this issue of Best Practice Clinical Rheumatology is timely, as we envision this increasingly prevalent disabling condition in an era where health-care expenditure is increasingly scrutinized. With these societal trends, new insights are developing into the pervasive disease we know as OA. Consideration of the impact of this condition in our society requires an understanding of the incidence and prevalence of this disease. It is critical that we exploit what we know about epidemiology to develop robust plans to prevent this disease. The first chapter provides a thoughtful appraisal of the epidemiology of OA informing us on how we define OA, the prevalence and incidence of OA and the risk factors for OA. Further, it enumerates opportunities for disease prevention that will become even more critical to deploy with the further strain this disease will place on limited health resources. The risk of knee OA in our society attributed to obesity and injury accounts for approximately 80% of the reason for OA development. Both are eminently preventable, yet little is being done to reduce these risk factors [1]. One area that is ripe for intervention and a research field that is very active is that of post-traumatic OA. Joint injuries such as a tear of the anterior cruciate ligament (ACL) or meniscus increase the risk of knee OA by altering the contact mechanics of the joint environment, that is, the way weight-bearing load is distributed in the joint. ACL ruptures have been found to be linked to OA changes in 50–70% of the patients, 10–15 years following the injury [4]. Estimates suggest that injury accounts for up to 15% of all incident knee OA cases and that this is also eminently preventable. Numerous trials of neuromuscular conditioning programmes have demonstrated efficacy in reducing the risk of ACL injury by as much as 60% [5,6]; yet at this point, little has been done to disseminate them widely. Similarly, much of what we have learned from preclinical research, especially in animal models, has not been immediately translated into improved understanding of the human disease. There are not only fundamental differences between the OA animal models and the human disease but also many similarities that provide a rich opportunity for intervention. Chapter 2 reviews this field but more specifically highlights opportunities for intervention. Many define OA as a condition that primarily affects the hyaline articular cartilage, including William Hunter who in 1743 stated soberly ‘From Hippocrates to the present age it is universally allowed that ulcerated cartilage is a troublesome thing and that once destroyed, is not repaired.’ [7] We now conceptualize OA as a disease of the whole joint organ. Conventional radiography has played an important role in confirming the diagnosis of OA demonstrating late bony changes and joint space narrowing and has been applied as an end point for disease progression in clinical trials. However, OA is a disease of the whole joint including cartilage, bone and intra- and periarticular soft tissues. Thus, the importance to image and assess all joint structures has been recognized in recent years largely using http://dx.doi.org/10.1016/j.berh.2014.02.004 1521-6942/Ó 2014 Elsevier Ltd. All rights reserved.
2
Preface / Best Practice & Research Clinical Rheumatology 28 (2014) 1–3
magnetic resonance imaging (MRI). Written by leaders in this field, Chapter 3 not only reviews radiography and MRI in OA but also gives insights into other modalities and their role in the diagnosis, follow-up and research of OA. There are numerous limitations to the way we measure and stage OA. Biomarker (both biochemical marker and imaging) research is an extraordinarily active field in OA, with the promise that it will facilitate the development of disease-modifying OA drugs. Before any new biomarker supplants the current regulatory standard of the plain radiograph, it will require both validation and qualification. Chapter 4 illustrates the case for this and elaborates how biomarker research will address the dual steps of biomarker validation and qualification. OA is no longer viewed as a passive, degenerative (yes, that’s right – the use of this term is archaic) disorder but rather an active disease process with an imbalance between the repair and the destruction of joint tissues driven primarily by mechanical factors. Current treatment approaches frequently take a shotgun approach to OA and often ignore the potential for modulation of local mechanical factors. Chapter 5 details the local mechanical factors that play a role in patellofemoral (PF) OA and illustrates a rational approach to the management of this often-challenging OA phenotype. Whilst PF OA is illustrated, the same principles of a pathomechanical approach can also be applied to individualize therapeutic decisions for other types of OA. No one denies that the management of OA is a challenge; however, modern clinicians are armed with a plethora of effective treatment options. Like other chronic diseases, there is no sole treatment or cure, instead there are several strategies to use that can help manage the condition. Clinicians who manage patients with OA recognize that to maximize treatments, it is best to use them as part of a package and incorporate many of the strategies together. For instance, not only just prescribing analgesics to manage symptoms but also considering weight, fitness levels and muscle strength, and evaluating daily patterns of activity. For the practicing clinician, arming themselves with knowledge of mechanisms and evidence for disease management is critical. It is important that symptomatic improvement serves the purpose of increasing tolerance for functional activity. Ultimately, an efficacious treatment for any progressive disorder should also control the factors and forces that drive disease progression. Chapter 6 provides a thorough review of the influence of muscle activity on knee joint loading, describes the deficits in muscle function observed in people with knee OA and summarizes available evidence pertaining to the role of muscle in the development and progression of knee OA. They focus on whether muscle deficits can be modified in knee OA and whether improvements in muscle function lead to improved symptoms and then focus on practical recommendations for exercise prescription for muscle rehabilitation in OA. Despite OA being a typical chronic disease characterized by long disease duration, substantial impact on quality of life and multiple co-morbidities, our current management practices are best described as reactive and palliative. [1] The vast majority of health-care costs are expended on a small minority of individuals, and despite a strong rationale for implementing new service models that will reduce both disability and cost, there has been little shift in policy or practice [8]. The challenge facing clinicians is dwarfed by the experience that persons with OA have to face. Any person with a chronic illness faces a personal daily battle with the condition itself, which in the case of OA is further compounded by a nihilistic ‘broken’ health-care system. Chapter 7 provides an insightful systematic review of the effectiveness, cost-effectiveness and barriers for the use of OA chronic disease management service models. It thoroughly reviews chronic disease management considering the many barriers to effective delivery and the wide array of stakeholders with vested interest in OA health-care delivery. Given that the health systems and resources are not unlimited, both the current economic climate and the rapidly increasing burden from OA calls for urgent attention to this pressing matter. On the failure of prior interventions, OA surgery may become necessary. Current evidence suggests that the most common orthopedic procedure, that is, knee arthroscopy, has little, if any, role in the management of persons with OA. Despite the evidence, this surgical procedure is still in widespread use. Chapter 8 reviews the evidence and the limited indications for knee arthroscopy while illustrating some of the challenges in translating research into changes in clinical practice. While the indications for arthroscopy have narrowed, joint replacement continues to play a pivotal role in disease management. Oftentimes patients ask and clinicians are faced with the decision as to
Preface / Best Practice & Research Clinical Rheumatology 28 (2014) 1–3
3
who is a good candidate and at what stage in the disease course should joint replacement be considered. Chapter 9 expands on this area and illustrates who will likely benefit from surgery and, potentially more importantly, who will not. As a single disease, OA has a major effect on productivity and places an enormous burden on the health-care system, in addition to its individual impacts through pain, disability and reduced quality of life. Sociodemographic changes are driving up the disease prevalence such that the burden of OA is increasing more rapidly than any other health condition. We have been afforded an opportunity to study a much maligned disease that is rapidly evolving. Let us learn from the insights that our research is providing to focus even more on important modifiable risk factors such as mechanics, injury and obesity as we develop the therapeutic armamentarium of the 21st century. Assuming we maintain a meaningful motivation with the patient at the forefront of our mind, we have an opportunity to make a difference in millions of peoples’ lives. I would sincerely like to thank my friends and colleagues for their valuable contributions to this issue. They were a pleasure to work with and I am sure you will see the contents reflect wonderful insight and appraisal of a complex and developing field. References [1] Hunter DJ. Lower extremity osteoarthritis management needs a paradigm shift. Br J Sports Med 2011 Apr;45(4):283–8. [2] Hootman JM, Helmick CG. Projections of US prevalence of arthritis and associated activity limitations. Arthritis Rheum 2006 Jan;54(1):226–9. [3] Perruccio AV, Power JD, Badley EM. Revisiting arthritis prevalence projections–it’s more than just the aging of the population. J Rheumatol 2006 Sep;33(9):1856–62. [4] Lohmander LS, Ostenberg A, Englund M, et al. High prevalence of knee osteoarthritis, pain, and functional limitations in female soccer players twelve years after anterior cruciate ligament injury. Arthritis Rheum 2004 Oct;50(10):3145–52. [5] Hewett TE, Ford KR, Myer GD. Anterior cruciate ligament injuries in female athletes: part 2, a meta-analysis of neuromuscular interventions aimed at injury prevention. Am J Sports Med 2006 Mar;34(3):490–8. [6] Yoo JH, Lim BO, Ha M, et al. A meta-analysis of the effect of neuromuscular training on the prevention of the anterior cruciate ligament injury in female athletes. Knee Surg Sports Traumatol Arthrosc 2010 Jun;18(6):824–30. [7] Buchanan WW. William Hunter (1718–1783). Rheumatology 2003 Oct;42(10):1260–1. [8] Brand C, Hunter D, Hinman R, et al. Improving care for people with osteoarthritis of the hip and knee: how has national policy for osteoarthritis been translated into service models in Australia? Int J Rheum Dis 2011 May;14(2):181–90.
David J. Hunter, MBBS, MSc, PhD, FRACP* Kolling Institute and Institute of Bone and Joint Research, University of Sydney, Sydney, Australia Rheumatology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia. E-mail address: [email protected]
