Musculoskeletal Disorders or MSDs are injuries and disorders that affect the musculoskeletal system. They are a diverse group with regard to pathophysiology but are linked anatomically as well as by their association with pain and impaired physical function. Globally, it is estimated that there are over 1 billion people with disabilities, 35% have difficulties with mobility and 55% reported pain of which musculoskeletal conditions are the major cause. In addition, they significantly impact the psychosocial status of affected people as well as their families and careers. The prevalence of many of these conditions increases markedly with age, and many are affected by lifestyle factors, such as obesity, lack of physical activity, and occupation. The 2010 World Health Organization Global Burden of Disease (WHO-GBD) study showed that low back pain (LBP) was the leading cause of years lived with disability in the world.
Arab surgeons were pioneers in performing amputations and cauterizations and in using alcohol as an antiseptic. One of the famous figures was Avicenna (980- 1037 AD) who devoted several chapters of his book “Al Qanoon" to human anatomy, including musculoskeletal anatomy. He differentiated between cancellous and cortical bones and described cartilage and muscles of limbs. He divided the spine into cervical, thoracic, lumber, and sacral segments and described each segment separately. In his anatomical descriptions he added biomechanical, functional, and applied clinical descriptions for each relevant section which was novel in the 11thcentury.He was able to differentiate between nerves and tendon and was credited as a pioneer of repairing tendons and nerves, separately.
Human stem cells derived from bone marrow are currently used in clinical medicine for bone and cartilage repair for injuries such as meniscal tears. New clinical stem cell studies underway include the treatment of patients with spinal cord injuries. Rapid advances in stem cell science are opening new avenues for drug discovery and may lead to new uses of stem cells for other musculoskeletal disorders. Stem cells offer a glimpse into a future that might unravel the promising ability of wide-ranging biological reconstructions.
Between 1075 and 2000 due to the advances in molecular and cell biology and in design of newer materials revolutionized the science of musculoskeletal disorders. A good example is joint arthroplasty. Replacements were produced for hips, knees shoulders and other joints and which began in the 1960s, but because of the occurrence of infection, device breakage, loosening, wear and wear-debris-induced bone resorption (osteolysis), improvements had to be found. Improved surgical and aseptic techniques, and prophylactic antibiotics decreased infections drastically although they still remain a serious problem. New implant designs have almost eliminated breakages. Loosening has been reduced due to improved surgical techniques. Wear and tear is still a problem but improved materials like titanium and titanium alloys reduce artifacts associated with other materials used for MRI imaging. Current therapy used reduce bone resorption and the risk of implant failure.
Other advances are in the production of mouse models that facilitates the identification of genes that cause musculoskeletal deformities and disease. Not only does this advance help in identifying genes but also for evaluating therapeutics and new clues to the origin of developmental abnormalities. The major advances will come in functional genomics. In the last few years, genes controlling the development of bone and cartilage have been identified. New drug discoveries together with better understanding of molecular genetics are revolutionizing orthopedic practice.
Rheumatologic diseases encompass a spectrum of musculoskeletal, arthritic and connective tissue disorders. They are characterized by pain, swelling, stiffness and a consequent reduction in the range of motion and function in one or more areas of the musculoskeletal system and often occur in people who are in the prime of their lives and often abruptly interrupt education, careers and other essential daily activities. The scope of diseases incorporate over hundred disorders affecting joints, bones, muscles, soft tissues and other internal organ systems. They include degenerative, inflammatory and autoimmune arthropathies such as Osteoarthritis, Rheumatoid arthritis, Spondyloarthropathies, Juvenile Idiopathic Arthritis (JIA), and gout; beside connective tissue diseases such as Systemic Lupus Erythematosus, Scleroderma (systemic sclerosis) and other systemic conditions as Polychondritis, Polymyalgia rheumatica, Sjögren’s syndrome and systemic vasculitis (including giant cell arteritis).
The prevalence of osteoporosis in Kuwait is estimated to be 18% among women. In Jordan 13% of females above 40 years of age were osteoporotic while in Saudi-Arabia in females over 31 years of age, the rate was 0%–7%, whereas it was about 28% among women over 50 years.
Over 7 million Americans suffer from inflammatory rheumatic diseases. 1.3 million adults have Rheumatoid arthritis, 161,000-322,000 adults have lupus. Nearly 300,000 American children suffer from rheumatic diseases, the most common of which is juvenile idiopathic arthritis. 8.4 percent of women and five percent of men in the U.S. will develop a rheumatic disease during their lifetime. Osteoporosis is a leading cause for fractures, especially of the hip, spine, and wrist. 1.7 million hip fractures occurred worldwide in 1990. This figure is expected to rise to 6 million by 2050. This latter is the most costly, and is fatal in 20% of cases and permanently disables a further 50%.
In the past decades, our understanding of the various cellular components that function in the immune response has expanded at a rapid pace. The ground breaking work of Henry Claman, who defined separate lineages of cooperating bone marrow and thymic derived immune cells, and studies by Cantor and Boyce, who were the first to use surface markers to define functional T cell subsets set the stage for further study into the immune system. Now, it is recognized that there are multiple lineages of bone marrow derived cells and a vast array of lineage unique subsets that play key roles in the immune process either as direct effector cells or having an immunoregulatory role. Studying twins besides the clustering of different autoimmune diseases in the same families, suggest the genetic and environmental influences that may cause rheumatic diseases. One of the strongest examples of this genetic influence on a rheumatic disease is the connection between ankylosing spondylitis (AS) and a gene called HLA-B27.
In rheumatoid arthritis, juvenile arthritis, and lupus, for example, patients may have a variation in a gene that encodes for an enzyme called protein tyrosine phosphatase non-receptor 22 (PTPN22). Nowadays, scientists know that more than one gene is involved in determining whether a person develops rheumatoid arthritis and how severe the disease will become.
In people who are genetically susceptible, factors in the environment may trigger the disease. For example, scientists have found a connection between Epstein-Barr virus and lupus. Excessive stress on a joint from repeated injury may lead to osteoarthritis. Hormone or other male-female differences may also play a role. For example, lupus, rheumatoid arthritis, scleroderma, and fibromyalgia are more common among women.
Rheumatologists have led the way in discovering that the chronic inflammation associated with many rheumatic diseases can lead to increased risk of other systems disorders. People with RA are twice as likely to develop heart disease as the average person. Nearly 40 percent of people with lupus develop prematurely hardened arteries, compared with 15 percent of their peers who do not have lupus. Giant cell arteritis increases the risk of aneurysms, while scleroderma, RA and lupus can cause Raynaud’s syndrome.
Over the past several years, researchers have made considerable progress in understanding connections between bone physiology and the broader network of biologic processes involving many different organs and tissues. They are working to explain the connection between the skeleton, the nervous system and other tissues such as fat, muscle, cartilage; the immune system; digestion and nutrition (including the role of the microbiome) and energy metabolism.
Translational research is expanding rapidly due to recent discoveries about the genetic factors that influence disease susceptibility and severity. The studies aim at discovering the genes that cause rheumatic diseases, their interactions and, potentially, their targeting for therapeutic and diagnostic purposes. Human translational research projects involving early testing of biomarkers of disease are also included.
The recent advancements such as the biologic treatments for rheumatoid arthritis led to the development of breakthrough biologic medications that inhibit specific pathways. Further development of tailored treatments will rely on knowledge of disease mechanisms, molecular characterization of disease subtypes, individual responses and adverse reactions to drugs. This approach is also appropriate for less common diseases, such as scleroderma, which are currently treated with agents that act upon general systems of inflammation or autoimmunity, rather than on disease-specific pathways.
Scientists are making rapid progress in understanding the complexities of common disorders such as rheumatoid arthritis. They begin to apply novel technologies such as stem cell transplantation and new imaging techniques. These and other innovations will lead to an improved quality of life for people with rheumatoid arthritis, enabling them to stay active in life, family, and work far longer than was possible 20 years ago.
Despite its relatively recent specialization, orthopedic surgery has a rich history rooted in ancient practices dating back to primitive man. Over time, there has been significant development in the field in terms of surgical and nonsurgical treatment and it is remarkable to see that several practices have persisted since the time of these ancient civilizations.
Fossil evidence suggests that the orthopedic pathology of today, such as fractures and traumatic amputations, existed in primitive times. In ancient Egypt, crutches and splints made of bamboo, reeds, wood, or bark, and padded with linen have been found on mummies. A papyrus thought to have been composed by Imhotep, describes the reduction of a dislocated mandible, signs of spinal or vertebral injuries, description of torticollis, and the treatment of fractures such as clavicle fractures and discussed the purulent discharge from osteomyelitis.
In ancient Greece, Hippocrates details the treatment for dislocations of the shoulders, knees, and hips, as well as treatments for infections resulting from compound fractures. Later during the rise of Rome, the learning of Galen, a gladiatorial surgeon, helped provide the best care possible for the Roman army. Many of his techniques and teachings were standard throughout the middle Ages. He studied the skeleton, the muscles and the relationship of the brain's response from the nerves to the muscles.
In the Islamic empire era, Avicenna described osteomyelitis, chronic osteomyelitis, and spinal deformities. He believed that kyphosis and scoliosis involved more than one vertebra and might be caused by internal factors (spinal tuberculosis was the leading culprit) or external factors due to trauma fractures and dislocations. He introduced several techniques to reduce dislocated shoulders and his preferred technique was the Hippocratic technique. Moreover, he discussed the general principles of fracture management like the use of splints to treat femoral fractures, noticing that intra-articular fractures have a poor prognosis and result in loss of joint movement. His careful observation and description brought to light serious problems such as compartment syndrome, open fractures, mal-union, and infections.
In Modern ages, Nicholas Andry coined the word "orthopedics", derived from Greek words for "straight" (orthos) and "child" (paidion). He published Orthopedia: or the Art of Correcting and Preventing Deformities in Children. His book has an engraving of a sapling being splinted with a stake, a symbol now referred to as the "Tree of Andry" and adopted by many orthopedic associations internationally.
The increase patient demand to live not only a longer life but also a more active and productive one, put some challenges for the professionals in the field to solve present device problems and Improve implant materials and introduce knee implants that mimic the body's real motion with less invasive surgeries.
Over the last decades, orthopedic surgery proved that it is a rapidly advancing medical field with several recent advances noted within orthopedic subspecialties, basic science and clinical research. Since WWII, treatments have evolved to include joint replacements, arthroscopy, and a whole host of technologies.
Recent researches focus on the genetic, biological and mechanical factors that shape the development of diseases such as arthritis and investigate their molecular basis, the biological repair processes and bioengineering approaches to tissue regeneration with special emphasis on cartilage repair, taking into consideration the evaluation of new methods including the use of bioactive materials.
Bone grafting is a commonly performed surgical procedure to boost bone regeneration in a variety of orthopedic procedures. Surgeons are using either autologous bone or bone-graft substitutes. Researchers are aiming to produce bone-graft substitutes with biomechanical properties that are matching to normal bone and to accelerate the regeneration process.
Currently, and in an effort to overcome the constraints of the current methods, researchers explore local strategies in terms of tissue engineering and gene therapy, or even systemic enhancement of bone repair to address systemic conditions such as skeletal disorders and osteoporosis.
Tissue-engineering methods are promising strategies added in the field of bone regenerative medicine, which aims to generate new cell-driven functional tissues rather than just to implant non-living scaffolds. This alternative treatment of conditions requiring bone regeneration, could overcome the limitations of current therapies, by combining the principles of orthopaedic surgery with knowledge from biology, physics, materials science and engineering. Moreover its clinical application offers great prospective to provide therapeutic options for those who already have irreparable cartilage and joint damage. One approach being tested is to replace damaged cartilage with stem cells taken from a person's healthy knee cartilage, from bone marrow, and even from fat harvested from liposuction.
Advances made in cellular and molecular biology have allowed detailed histological analyses, in vitro and in vivo characterization of bone-forming cells and identification of transcriptional and translational profiles of the genes and proteins involved in the process of bone regeneration and fracture repair. Researchers are testing a type of gene therapy in which genetically altered cells are injected into the joint to block cartilage breakdown.
The use of 'Orthobiologics' and the concept to stimulate the local 'biology' by applying growth factors could be beneficial for bone regeneration or even for speeding up of normal bone healing to reduce the length of fracture treatment. Their clinical use, either alone or combined with bone grafts, is constantly increasing. However, there are several concerns about their use, including safety because of the high concentrations of growth factors needed to obtain the desired osteoinductive effects, the high cost of treatment, and more significantly, the possibility for ectopic bone formation. Biologic therapies have transformed the approach we take to deal with rheumatoid arthritis, due to their ability to improve outcomes when non-biologic treatments have failed to achieve adequate disease control.
More recently "Chondroprotective" agents are under intense investigation, they protect cartilage from further breakdown and could play an important role in early disease prevention or help in slowing down joint damage and perhaps even reverse the disease by stimulating cartilage growth.
"I visualize biomechanics as a powerful and indispensable ally of the orthopedic clinician."
Arthur Steindler - 1933
The orthopedic mechanics apply principles of engineering and the science of materials with direct relevance to clinical applications in order to solve orthopedic problems.
Orthopedic mechanics required the study of basic anatomy and musculoskeletal tissues. The static analysis of skeletal systems, the muscle mechanics, bone structural analysis, mechanics of aging, drug treatment, and the forces acting on human joints are all the focus of this field. It also studies the composition and mechanical behavior of orthopedic biomaterials, the science of design and analysis of prosthesis and Implants.
Engineers collaborate with biologists to study cellular, and even genetic levels of the body mechanisms trying to solve the tissue engineering issues of joints in an aging, obese population, It also addresses the effects of traumatic injuries and sports activities to determine how well joint replacement and reconstruction techniques as well as the use of experimental prostheses, can restore joint mechanics and range of motion.
Conduction of basic and applied research translates to the development of orthopedic devices that aimed at improved patient care. They concentrate on joint reconstruction and joint restoration, joint mechanics, mechano-biology of bone adaptation and the performance of bone-implant systems. This is accomplished through studying joint injuries, post-traumatic osteoarthritis, limb trauma, articular contact stresses as they relate to joint degeneration, joint arthroplasty, compromised bone mechanics in cancer treatment, and surgical skills training and simulation.
Some laboratories study both mechanical testing and computer simulation which allow researchers to perform stress tests on bones and implants, mimicking real-life situations. Such simulations can also help surgeon test a specific implant's performance under stress by simulating the patient's weight and activity level. This customized approach means even better results for patients and a faster return to normal activities. Also sensors impeded inside the knee implant allow the measurement of load from the patient during regular activities. The electronic or smart knee implant (e-knee) measures forces in the knee experienced by patients during physical rehabilitation. Researchers are using e-knee data to explore new design methods to help make stronger and more wear-resistant knee implants, and to develop rehabilitation regimens with the aim of producing better outcomes for joint replacement patients.
Orthopedic mechanics not only can use virtual surgery technology to help physicians customize the best treatment solutions and to narrow choices, but also simulates how the repaired bone or joint will respond to strain over time given the patient's own profile. The simulations are well suited to many orthopedic conditions, including: joint replacements, traumatic bone injuries, bone cancer, chronic back and joint pain and pediatric orthopedic problems.
In addition, researches focus on the mechanical adaptation of bone with the aim of providing therapies that keep the bone healthy in problems like osteoporosis and fracture healing.
Moreover, researches could revolutionize treatment of some musculoskeletal diseases and disorders, including arthritis and osteoarthritis through experimenting 3D printers that may provide an alternative to joint replacement and offer patients improved quality of life through increased mobility and decreased pain from joint conditions.
Others develop artificial cartilage implant allografts of human cartilage. Cartilage research targets repair using new implant biomaterials, testing joint implant designs that improve surgical techniques & instruments; and even rehabilitation programs. Although cartilage tissue engineering holds promise for the future, current efforts should be devoted to optimizing tribological performance and reducing wear in artificial joints.
Tribology is a branch of mechanical engineering and materials science that studies the interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear. Significant progress has been made in the understanding of the tribological mechanisms of the natural synovial joint and in the application of these engineering principles to improve the function of artificial joints.
Scientists are also exploring possible stem cell use as a therapeutic option to treat osteoarthritis. The new approaches could provide relief to thousands of younger orthopedics patients who don’t need a joint replacement or who have undergone an unsatisfactory joint replacement surgery. In the area of genomics, work to identify the genes linked to osteoarthritis has also started which could lead to earlier diagnoses in patients and fewer surgical interventions.
This is one field of many medical fields where technology has led to significant advances in patients outcomes.
