A number of demographics are driving the rapid pace of orthopaedic technology innovation: the ageing of the population and the increasing prevalence of osteoporosis; more active lifestyles in older age groups; better education among patients demanding cutting-edge procedures; and the proliferation of obesity, an often ignored risk factor for osteoarthritis and the degeneration of cartilage and bone joints.
Bone and joint diseases affect hundreds of millions of patients throughout the world, and are the leading cause of pain and disability, with a huge impact on individuals, families, societies and economies. According to the WHO, bone and joint diseases account for half of all chronic conditions in people over 50 years of age in developed countries. This is set to sharply increase due to a predicted doubling in the number of people in the world over 50 by 2020. Osteoarthritis affects 9.6 % of men and 18% of women aged over 60 and is predicted to become the fourth leading cause of disability by 2020.
Weight-bearing joints like hips and knees become worn-out over time due to simple ageing, accelerated by over-use or under-use leading to under-nurturing of cartilage. Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to an increased susceptibility to fracture. Bone is composed of a collagen-rich matrix, abundant in mineral salts. Bone undergoes continuous regeneration throughout life; old bone tissue is replaced by new bone tissue at a turnover rate of approximately 20% per year. As we age, this process becomes unbalanced, with more bone being lost than can be replaced. By the age of 20, 97% of bone strength (or density) is formed. Peak bone mass is reached between the ages of 25 and 30.
Risk factors increasing the likelihood of developing osteoporosis are low bone mass, advanced age, family history of osteoporosis, oestrogen deficiency as a result of menopause, low testosterone levels, low lifetime calcium intake, vitamin D deficiency, the use of certain medications, inactive lifestyle, smoking and excessive alcohol intake.
Apart from the usual suspects - diabetes, heart disease, stroke and gallbladder disease - being overweight or obese are also known risk factors for osteoarthritis, the degeneration of cartilage and bone joints. The prevalence of overweight and obese people1 has increased by 10-40% in the majority of European countries in the past 10 years. The most dramatic increase has been in the UK where it has more than doubled since 1980.
Source: European Action Towards Better Musculoskeletal Health, A Guide to the Prevention and Treatment of Musculoskeletal Conditions for the Healthcare Practitioner and Policy Maker (2005)
Bone and joint diseases result in severe financial pressures for health services around the world. 20% of all visits to outpatient facilities are for musculo-skeletal conditions. The incidence of fractures increases exponentially with age. The highest rates are seen in North America and in Europe, particularly Scandinavia. Worldwide, the number of hip fractures is expected to rise from about 1.7 million in 1990 to 6.3 million by 2050. In the United States, musculo-skeletal complaints are the number one category of reported chronic impairment and also rank number one in terms of visits to physicians - more than 130 million visits per year, at a cost of US$215 billion - were recorded in 1995 alone.
Bone and joint disorders cause more functional limitations in the adult population in most welfare states than any other group of disorders. They are the major cause of years lived with disability in all continents and economies. They are also a major cause of absence because of sickness in developed countries; they are second only to respiratory disorders as a cause of short-term sickness absence (less than two weeks), and the most common medical causes of long-term absence. Musculoskeletal complaints are also common reasons for claiming disability pensions, along with mental and cardiovascular disorders. In Sweden, for example, up to 60% of people on early retirement or long-term sick leave claimed musculoskeletal problems as the reason; and musculoskeletal problems constitute the most expensive disease category (22,6% of the total cost of illness), the highest costs being indirect costs related to morbidity and disability.
More information on the Bone & Joint Decade
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Next to the constant improvement of the durability and comfort of orthopaedic devices, implant procedures are becoming increasingly less invasive. The advantages of minimally invasive operating techniques ("keyhole surgery") include less trauma to muscles and tissues, faster recovery (shorter hospital stay), less pain, smaller skin incision and less scarring, less blood loss (50% less on average), shorter hospitalization and in general, lower treatment costs. Moreover, the patient can go back to an active and productive lifestyle much faster.
The image below shows the European orthopaedic market segmentation in 2002. Click to enlarge the image and see all data.
A recent study2 shows that in knee replacement, minimally invasive surgery (MIS) patients had a significantly shorter length of stay, lower blood transfusion requirements and walked three times farther at the third postoperative day. Their range of motion was significantly better. In addition to the direct patient benefits, the study shows that the potential cost reduction to the healthcare system as a whole is staggering. It compares 34 traditional procedures to 34 MIS procedures. These were early learning curve patients, with somewhat prolonged operation times. The MIS technique demanded a more expensive implant. Even with this equipment and time expense difference, the MIS procedure charges were 26% lower on average, according to the study. The economic benefit of the techniques accrues primarily to the healthcare system and hospitals. The authors conclude, "It is hoped that further studies that support the data presented here will lead to modified reimbursement schedules that reward surgeons, rather than penalize them for their enterprise in adopting MIS procedures that improve the efficiency of their operative performance and result in financial savings for the healthcare system".
Source: Healthcare Technologies Roadmapping: The Effective Delivery of Healthcare in the Context of an Ageing Society, JRC/IPTS-ESTO Study, August 2003
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Today the trend in the treatment of bone and joint disorders is increasingly towards convergence of technologies such as advanced materials science, cell and tissue biology and nanotechnology.
Several orthopaedic medical devices that have already benefited from the application of nanotechnology are in use or are currently being commercialised. Examples include bone replacement materials incorporating nanostructured materials allowing better integration in the body and orthopaedic implants with nanocontoured surfaces to improve fixation in bone.
Click here to read more about the medical applications of nanotechnology
(Picture: collection of nanotubes)
Tissue engineered cartilage and bone products are set to progressively replace traditional medical devices in the treatment of many bone and joint disorders. The most important clinical application of cartilage tissue-engineered products is autologous chondrocyte implantation for traumatic knee joint injuries. A biopsy is performed to obtain healthy chondrocytes from the patient's knee. The cells are expanded and cultivated for three weeks and transferred to the knee in an open surgical procedure. After surgery, two to six months are needed for full regeneration of the cartilage lesion. Another technique is to culture the cells on a three-dimensional biodegradable scaffold. Cut to the required size, the scaffold is then inserted and fixed. This method opens up the possibility of arthroscopic surgery (minimally invasive). Research is being carried out also to extend the application of tissue-engineered cartilage to other joints and to treat arthritis and intervertebral disc damage.
Tissue engineered bone products are under development for treating bone fractures, jawbone surgery, as well as osteoporosis and bone tumours. For small bone fractures, standard therapies are available. But for larger defects autologous bone grafts provide better results. If these are not available, allogeneic (donor) or xenogeneic (animal) grafts or synthetic bone grafts can be used too (most bone defects result from trauma and accident and need acute treatment, which does not leave the time to produce an autologous tissue-engineered bone product). Only a few companies are active in this field today and applications tend to focus on specific areas such as dental or maxillofacial surgery3.
All these new and emerging technologies will bring considerable benefits to the patient, and ultimately, to the European economy also. However a number of challenges remain. Obtaining national reimbursement for innovative therapies is one. Making the right regulatory choices for new and emerging technologies at the European level is another.
[1] Being overweight is defined as having a Body Mass Index (BMI: weight in kg divided by the square of one's height in metres) of 25 to 29,9 kg/m2, and obesity as having a BMI of 30 kg/m2 or greater.
[2] Source: "The Economics of Minimally Invasive Total Knee Surgery" Thomas M. Coon, MD,* Alfred J. Tria, Jr, MD,† Carlos Lavernia, MD,‡ and Leon Randall (2005)
[3] Source: EU Commission Joint Research Centre "Human tissue-engineered products - Today's markets and future prospects" (2003)
