Orthopedic surgery or orthopedics spelled orthopaedics, is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections and congenital disorders. Nicholas Andry coined the word in French as orthopédie, derived from the Ancient Greek words ὀρθός orthos and παιδίον paidion, published Orthopedie in 1741; the word was assimilated into English as orthopædics. Though, as the name implies, the discipline was developed with attention to children, the correction of spinal and bone deformities in all stages of life became the cornerstone of orthopedic practice; as with many words derived with the "æ" ligature, simplification to either "ae" or just "e" is common in North America. In the US, the majority of college and residency programs, the American Academy of Orthopaedic Surgeons, still use the spelling with the digraph ae, though hospitals use the shortened form.
Elsewhere, usage is not uniform: in Canada, both spellings are acceptable. Many developments in orthopedic surgery have resulted from experiences during wartime. On the battlefields of the Middle Ages the injured were treated with bandages soaked in horses' blood which dried to form a stiff, but unsanitary, splint; the term orthopedics meant the correcting of musculoskeletal deformities in children. Nicolas Andry, a professor of medicine at the University of Paris coined the term in the first textbook written on the subject in 1741, he advocated the use of exercise and splinting to treat deformities in children. His book was directed towards parents, while some topics would be familiar to orthopedists today, it included'excessive sweating of the palms' and freckles. Jean-André Venel established the first orthopedic institute in 1780, the first hospital dedicated to the treatment of children's skeletal deformities, he developed the club-foot shoe for children born with foot deformities and various methods to treat curvature of the spine.
Advances made in surgical technique during the 18th century, such as John Hunter's research on tendon healing and Percival Pott's work on spinal deformity increased the range of new methods available for effective treatment. Antonius Mathijsen, a Dutch military surgeon, invented the plaster of Paris cast in 1851. However, up until the 1890s, orthopedics was still a study limited to the correction of deformity in children. One of the first surgical procedures developed was percutaneous tenotomy; this involved cutting a tendon the Achilles tendon, to help treat deformities alongside bracing and exercises. In the late 1800s and first decades of the 1900s, there was significant controversy about whether orthopedics should include surgical procedures at all. Examples of people who aided the development of modern orthopedic surgery were Hugh Owen Thomas, a surgeon from Wales, his nephew, Robert Jones. Thomas became interested in orthopedics and bone-setting at a young age and, after establishing his own practice, went on to expand the field into general treatment of fracture and other musculoskeletal problems.
He advocated enforced rest as the best remedy for fractures and tuberculosis and created the so-called'Thomas Splint', to stabilize a fractured femur and prevent infection. He is responsible for numerous other medical innovations that all carry his name:'Thomas's collar' to treat tuberculosis of the cervical spine,'Thomas's manoeuvre', an orthopedic investigation for fracture of the hip joint, Thomas test, a method of detecting hip deformity by having the patient lying flat in bed,'Thomas's wrench' for reducing fractures, as well as an osteoclast to break and reset bones. Thomas's work was not appreciated in his own lifetime, it was only during the First World War that his techniques came to be used for injured soldiers on the battlefield. His nephew, Sir Robert Jones, had made great advances in orthopedics in his position as Surgeon-Superintendent for the construction of the Manchester Ship Canal in 1888, he was responsible for the injured among the 20,000 workers, he organized the first comprehensive accident service in the world, dividing the 36 mile site into 3 sections, establishing a hospital and a string of first aid posts in each section.
He had the medical personnel trained in fracture management. He managed 3,000 cases and performed 300 operations in his own hospital; this position enabled him to improve the standard of fracture management. Physicians from around the world came to Jones’ clinic to learn his techniques. Along with Alfred Tubby, Jones founded the British Orthopaedic Society in 1894. During the First World War, Jones served as a Territorial Army surgeon, he observed that treatment of fractures both at the front and in hospitals at home was inadequate, his efforts led to the introduction of military orthopedic hospitals. He was appointed Inspector of Military Orthopaedics, with responsibility over 30,000 beds; the hospital in Ducane Road, Hammersmith became the model for both British and American military orthopedic hospitals. His advocacy of the use of Thomas splint for the initial treatment of femoral fractures reduced mortality of compound fractures of the femur from 87% to less than 8% in the period from 1916 to 1918.
The use of intramedullary rods to treat fractures of the femur and tibi
The Suzuki frame is a medical device, used for helping heal broken fingers those with deep, complex intra-articular fractures. Rubber bands are used to generate traction between two metal Kirschner wires that are inserted into the bone on either side of a fracture; the device was named after its inventor, Yasushi Suzuki, who first described it in 1994
In metallurgy, stainless steel known as inox steel or inox from French inoxydable, is a steel alloy, with highest percentage contents of iron and nickel, with a minimum of 10.5% chromium content by mass and a maximum of 1.2% carbon by mass. Stainless steels are most notable for their corrosion resistance, which increases with increasing chromium content. Additions of molybdenum increase corrosion resistance in reducing acids and against pitting attack in chloride solutions. Thus, there are numerous grades of stainless steel with varying chromium and molybdenum contents to suit the environment the alloy must endure. Stainless steel's resistance to corrosion and staining, low maintenance, familiar luster make it an ideal material for many applications where both the strength of steel and corrosion resistance are required. Stainless steels are rolled into sheets, bars and tubing to be used in: cookware, surgical instruments, major appliances. Stainless steel's corrosion resistance, the ease with which it can be steam cleaned and sterilized, no need for surface coatings has influenced its use in commercial kitchens and food processing plants.
Stainless steels do not suffer uniform corrosion, like carbon steel, when exposed to wet environments. Unprotected carbon steel rusts when exposed to the combination of air and moisture; the resulting iron oxide surface layer is fragile. Since iron oxide occupies a larger volume than the original steel this layer expands and tends to flake and fall away exposing the underlying steel to further attack. In comparison, stainless steels contain sufficient chromium to undergo passivation, spontaneously forming a microscopically thin inert surface film of chromium oxide by reaction with the oxygen in air and the small amount of dissolved oxygen in water; this passive film prevents further corrosion by blocking oxygen diffusion to the steel surface and thus prevents corrosion from spreading into the bulk of the metal. This film is self-repairing if it is scratched or temporarily disturbed by an upset condition in the environment that exceeds the inherent corrosion resistance of that grade; the resistance of this film to corrosion depends upon the chemical composition of the stainless steel, chiefly the chromium content.
Corrosion of stainless steels can occur. It is customary to distinguish between 4 forms of corrosion: uniform, galvanic and SCC. Uniform corrosion takes place in aggressive environments chemical production or use and paper industries, etc; the whole surface of the steel is attacked and the corrosion is expressed as corrosion rate in mm/year Corrosion tables provide guidelines This is the case when stainless steels are exposed to acidic or basic solutions. Whether a stainless steel corrodes depends on the kind and concentration of acid or base, the solution temperature. Uniform corrosion is easy to avoid because of extensive published corrosion data or easy to perform laboratory corrosion testing. However, stainless steels are susceptible to localized corrosion under certain conditions, which need to be recognized and avoided; such localized corrosion is problematic for stainless steels because it is unexpected and difficult to predict. Acidic solutions can be categorized into two general categories, reducing acids such as hydrochloric acid and dilute sulfuric acid, oxidizing acids such as nitric acid and concentrated sulfuric acid.
Increasing chromium and molybdenum contents provide increasing resistance to reducing acids, while increasing chromium and silicon contents provide increasing resistance to oxidizing acids. Sulfuric acid is one of the largest tonnage industrial chemical manufactured. At room temperature Type 304 is only resistant to 3% acid while Type 316 is resistant to 3% acid up to 50 °C and 20% acid at room temperature, thus Type 304 is used in contact with sulfuric acid. Type 904L and Alloy 20 are resistant to sulfuric acid at higher concentrations above room temperature. Concentrated sulfuric acid possesses oxidizing characteristics like nitric acid and thus silicon bearing stainless steels find application. Hydrochloric acid will damage any kind of stainless steel, should be avoided. All types of stainless steel resist attack from phosphoric acid and nitric acid at room temperature. At high concentration and elevated temperature attack will occur and higher alloy stainless steels are required. In general, organic acids are less corrosive than mineral acids such as hydrochloric and sulfuric acid.
As the molecular weight of organic acids increase their corrosivity decreases. Formic acid is a strong acid. Type 304 can be used with formic acid. Acetic acid is the most commercially important of the organic acids and Type 316 is used for storing and handling acetic acid. Stainless steels Type 304 and 316 are unaffected by any of the weak bases such as ammonium hydroxide in high concentrations and at high temperatures; the same grades of stainless exposed to stronger bases such as sodium hydroxide at high concentrations and high temperatures will experience some etching and cracking. Increasing chromium and nickel contents provide increasing resistance. All grades resist damage from aldehydes and amines, though in the latter
A veterinary physician called a vet, shortened from veterinarian or veterinary surgeon, is a professional who practices veterinary medicine by treating diseases and injuries in animals. In many countries, the local nomenclature for a veterinarian is a regulated and protected term, meaning that members of the public without the prerequisite qualifications and/or licensure are not able to use the title. In many cases, the activities that may be undertaken by a veterinarian are restricted only to those professionals who are registered as a veterinarian. For instance, in the United Kingdom, as in other jurisdictions, animal treatment may only be performed by registered veterinary physicians, it is illegal for any person, not registered to call themselves a veterinarian or prescribe any treatment. Most veterinary physicians work in clinical settings; these veterinarians may be involved in a general practice. As with other healthcare professionals, veterinarians face ethical decisions about the care of their patients.
Current debates within the profession include the ethics of certain procedures believed to be purely cosmetic or unnecessary for behavioral issues, such as declawing of cats, docking of tails, cropping of ears and debarking on dogs. The word "veterinary" comes from the Latin veterinae meaning "working animals". "Veterinarian" was first used in print by Thomas Browne in 1646. Ancient Indian sage and veterinary physician Shalihotra, the son of a Brahmin sage, Hayagosha, is considered the founder of veterinary sciences; the first veterinary college was founded in France in 1762 by Claude Bourgelat. According to Lupton, after observing the devastation being caused by cattle plague to the French herds, Bourgelat devoted his time to seeking out a remedy; this resulted in his founding a veterinary college in Lyon in 1761, from which establishment he dispatched students to combat the disease. The Odiham Agricultural Society was founded in 1783 in England to promote agriculture and industry, played an important role in the foundation of the veterinary profession in Britain.
A 1785 Society meeting resolved to "promote the study of Farriery upon rational scientific principles." The professionalization of the veterinary trade was achieved in 1790, through the campaigning of Granville Penn, who persuaded the Frenchman Benoit Vial de St. Bel to accept the professorship of the newly established Veterinary College in London; the Royal College of Veterinary Surgeons was established by royal charter in 1844. Veterinary science came of age in the late 19th century, with notable contributions from Sir John McFadyean, credited by many as having been the founder of modern Veterinary research. Veterinarians treat disease, disorder or injury in animals, which includes diagnosis and aftercare; the scope of practice and experience of the individual veterinarian will dictate what interventions they perform, but most will perform surgery. Unlike in human medicine, veterinarians must rely on clinical signs, as animals are unable to vocalize symptoms as a human would. In some cases, owners may be able to provide a medical history and the veterinarian can combine this information along with observations, the results of pertinent diagnostic tests such as radiography, CT scans, MRI, blood tests and others.
Veterinarians must consider the appropriateness of euthanasia if a condition is to leave the animal in pain or with a poor quality of life, or if treatment of a condition is to cause more harm to the patient than good, or if the patient is unlikely to survive any treatment regimen. Additionally, there are scenarios where euthanasia is considered due to the constrains of the client's finances; as with human medicine, much veterinary work is concerned with prophylactic treatment, in order to prevent problems occurring in the future. Common interventions include vaccination against common animal illnesses, such as distemper or rabies, dental prophylaxis to prevent or inhibit dental disease; this may involve owner education so as to avoid future medical or behavioral issues. Additionally veterinarians have the prevention of zoonoses; the majority of veterinarians are employed in private practice treating animals. Small animal veterinarians work in veterinary clinics, veterinary hospitals, or both.
Large animal veterinarians spend more time travelling to see their patients at the primary facilities which house them, such as zoos or farms. Other employers include charities treating animals, colleges of veterinary medicine, research laboratories, animal food companies, pharmaceutical companies. In many countries, the government may be a major employer of veterinarians, such as the United States Department of Agriculture or the Animal and Plant Health Agency in the United Kingdom. State and local governments employ veterinarians. Veterinarians and their practices may be specialized in certain areas of veterinary medicine. Areas of focus include: Exotic animal veterinaria
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. A few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, are present in most of its habitats. Bacteria inhabit soil, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Bacteria live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, only about half of the bacterial phyla have species that can be grown in the laboratory; the study of bacteria is known as a branch of microbiology. There are 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere.
The nutrient cycle includes the decomposition of dead bodies. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Data reported by researchers in October 2012 and published in March 2013 suggested that bacteria thrive in the Mariana Trench, with a depth of up to 11 kilometres, is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are."The famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. There are 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body.
This means that although they do have the upper hand in actual numbers, it is only by 30%, not 900%. The largest number exist in the gut flora, a large number on the skin; the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial in the gut flora. However several species of bacteria are pathogenic and cause infectious diseases, including cholera, anthrax and bubonic plague; the most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium and other metals in the mining sector, as well as in biotechnology, the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two different groups of organisms that evolved from an ancient common ancestor; these evolutionary domains are called Archaea. The word bacteria is the plural of the New Latin bacterium, the latinisation of the Greek βακτήριον, the diminutive of βακτηρία, meaning "staff, cane", because the first ones to be discovered were rod-shaped; the ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, bacteria and archaea were the dominant forms of life. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species.
However, gene sequences can be used to reconstruct the bacterial phylogeny, these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The most recent common ancestor of bacteria and archaea was a hyperthermophile that lived about 2.5 billion–3.2 billion years ago. Bacteria were involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves related to the Archaea; this involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya. Some eukaryotes that contained mitochondria engulfed cyanobacteria-like organisms, leading to the formation of chloroplasts in algae and plants; this is known as primary endosymbiosis. Bacteria display a wide diversity of sizes, called morphologies.
Bacterial cells are about one-tenth the size of eukaryotic cells
Sterilization refers to any process that eliminates, kills, or deactivates all forms of life and other biological agents present in a specified region, such as a surface, a volume of fluid, medication, or in a compound such as biological culture media. Sterilization can be achieved through various means, including: heat, irradiation, high pressure, filtration. Sterilization is distinct from disinfection and pasteurization, in that sterilization kills, deactivates, or eliminates all forms of life and other biological agents which are present. One of the first steps toward sterilization was made by Nicolas Appert who discovered that thorough application of heat over a suitable period slowed the decay of foods and various liquids, preserving them for safe consumption for a longer time than was typical. Canning of foods has helped to reduce food borne illness. Other methods of sterilizing foods include high pressure. In general, surgical instruments and medications that enter an aseptic part of the body must be sterile.
Examples of such instruments include scalpels, hypodermic needles, artificial pacemakers. This is essential in the manufacture of parenteral pharmaceuticals. Preparation of injectable medications and intravenous solutions for fluid replacement therapy requires not only sterility but well-designed containers to prevent entry of adventitious agents after initial product sterilization. Most medical and surgical devices used in healthcare facilities are made of materials that are able to go under steam sterilization. However, since 1950, there has been an increase in medical devices and instruments made of materials that require low-temperature sterilization. Ethylene oxide gas has been used since the 1950s for heat- and moisture-sensitive medical devices. Within the past 15 years, a number of new, low-temperature sterilization systems have been developed and are being used to sterilize medical devices. Steam sterilization is the most used and the most dependable. Steam sterilization is nontoxic, inexpensive microbicidal and heats and penetrates fabrics.
There are strict international rules to protect the contamination of Solar System bodies from biological material from Earth. Standards vary depending on both the type of its destination. Many components of instruments used on spacecraft cannot withstand high temperatures, so techniques not requiring excessive temperatures are used as tolerated, including heating to at least 120 °C, chemical sterilization, oxidization and irradiation; the aim of sterilization is the reduction of present microorganisms or other potential pathogens. The degree of sterilization is expressed by multiples of the decimal reduction time, or D-value, denoting the time needed to reduce the initial number N 0 to one tenth of its original value; the number of microorganisms N after sterilization time t is given by: N N 0 = 10. The D-value is a function of sterilization conditions and varies with the type of microorganism, water activity, pH etc.. For steam sterilization the temperature, in degrees Celsius, is given as an index.
Theoretically, the likelihood of the survival of an individual microorganism is never zero. To compensate for this, the overkill method is used. Using the overkill method, sterilization is performed by sterilizing for longer than is required to kill the bioburden present on or in the item being sterilized; this provides a sterility assurance level equal to the probability of a non-sterile unit. For high-risk applications, such as medical devices and injections, a sterility assurance level of at least 10−6 is required by the United States Food and Drug Administration. A used method for heat sterilization is the autoclave, sometimes called a converter or steam sterilizer. Autoclaves use steam heated to 121–134 °C under pressure. To achieve sterility, the article is placed in a chamber and heated by injected steam until the article reaches a temperature and time setpoint. All the air is removed from the chamber, because air is undesired in the moist heat sterilization process; the article is held at the temperature setpoint for a period of time which varies depending on what bioburden is present on the article being sterilized and its resistance to steam sterilization.
A general cycle would be anywhere between 3 and 15 minutes, at 121 °C at 100 kPa, sufficient to provide a sterility assurance level of 10−4 for a product with a bioburden of 106 and a D-value of 2.0 minutes. Following sterilization, liquids in a pressurized autoclave must be cooled to avoid boiling over when the pressure is released; this may be achieved by depressurizing the sterilization chamber and allowing liqui
The medullary cavity is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow is stored. Located in the main shaft of a long bone, the medullary cavity has walls composed of spongy bone and is lined with a thin, vascular membrane. However, the medullary cavity is the area inside any bone; this area is involved in the formation of red blood cells and white blood cells, the calcium supply for bird eggshells. The area has been detected in fossil bones despite the fossilization process. Intramedullary is a medical term meaning the inside of a bone. Examples include intramedullary rods used to treat bone fractures in orthopedic surgery and intramedullary tumors occurring in some forms of cancer or benign tumors such as an enchondroma. "Medullary cavity" at Dorland's Medical Dictionary