document_title: Hip replacement

question_text: when was the first hip replacement surgery performed

question_tokens: when was the first hip replacement surgery performed

text: Hip replacement

text: Medical uses[edit]

text: Total hip replacement is most commonly used to treat joint failure caused by osteoarthritis. Other indications include rheumatoid arthritis, avascular necrosis, traumatic arthritis, protrusio acetabuli, certain hip fractures, benign and malignant bone tumors, arthritis associated with Paget's disease, ankylosing spondylitis and juvenile rheumatoid arthritis. The aims of the procedure are pain relief and improvement in hip function. Hip replacement is usually considered only after other therapies, such as physical therapy and pain medications, have failed.

text: Modern process[edit]

text: The modern artificial joint owes much to the 1962 work of Sir John Charnley at Wrightington Hospital.  His work in the field of tribology resulted in a design that almost completely replaced the other designs by the 1970s.  Charnley's design consisted of three parts:

text:
stainless steel one-piece femoral stem and head
polyethylene (originally Teflon), acetabular component, both of which were fixed to the bone using
PMMA (acrylic) bone cement

text: The replacement joint, which was known as the Low Friction Arthroplasty, was lubricated with synovial fluid. The small femoral head (7⁄8 in (22.2 mm)) was chosen for Charnley's belief that it would have lower friction against the acetabular component and thus wear out the acetabulum more slowly. Unfortunately, the smaller head dislocated more easily. Alternative designs with larger heads such as the Mueller prosthesis were proposed. Stability was improved, but acetabular wear and subsequent failure rates were increased with these designs. The Teflon acetabular components of Charnley's early designs failed within a year or two of implantation. This prompted a search for a more suitable material. A German salesman showed a polyethylene gear sample to Charnley's machinist, sparking the idea to use this material for the acetabular component. The ultra high molecular weight polyethylene or UHMWPE acetabular component was introduced in 1962. Charnley's other major contribution was to use polymethylmethacrylate (PMMA) bone cement to attach the two components to the bone. For over two decades, the Charnley Low Friction Arthroplasty, and derivative designs were the most used systems in the world. It formed the basis for all modern hip implants.

text: The Exeter hip stem was developed in the United Kingdom during the same time as the Charnley device. Its development occurred following a collaboration between Orthopaedic Surgeon Robin Ling and University of Exeter engineer Clive Lee and it was first implanted at the Princess Elizabeth Orthopaedic Hospital in Exeter in 1970.[3] The Exeter Hip is a cemented device, but with a slightly different stem geometry. Both designs have shown excellent long-term durability when properly placed and are still widely used in slightly modified versions.

text: Early implant designs had the potential to loosen from their attachment to the bones, typically becoming painful ten to twelve years after placement. In addition, erosion of the bone around the implant was seen on x-rays. Initially, surgeons believed this was caused by an abnormal reaction to the cement holding the implant in place. That belief prompted a search for an alternative method to attach the implants. The Austin Moore device had a small hole in the stem into which bone graft was placed before implanting the stem. It was hoped bone would then grow through the window over time and hold the stem in position. Success was unpredictable and the fixation not very robust. In the early 1980s, surgeons in the United States applied a coating of small beads to the Austin Moore device and implanted it without cement. The beads were constructed so that gaps between beads matched the size of the pores in native bone. Over time, bone cells from the patient would grow into these spaces and fix the stem in position. The stem was modified slightly to fit more tightly into the femoral canal, resulting in the Anatomic Medullary Locking (AML) stem design. With time, other forms of stem surface treatment and stem geometry have been developed and improved.

text: Initial hip designs were made of a one-piece femoral component and a one-piece acetabular component. Current designs have a femoral stem and separate head piece. Using an independent head allows the surgeon to adjust leg length (some heads seat more or less onto the stem) and to select from various materials from which the head is formed. A modern acetabulum component is also made up of two parts: a metal shell with a coating for bone attachment and a separate liner. First the shell is placed. Its position can be adjusted, unlike the original cemented cup design which are fixed in place once the cement sets. When proper positioning of the metal shell is obtained, the surgeon may select a liner made from various materials.

text: To combat loosening caused by polyethylene wear debris, hip manufacturers developed improved and novel materials for the acetabular liners. Ceramic heads mated with regular polyethylene liners or a ceramic liner were the first significant alternative. Metal liners to mate with a metal head were also developed. At the same time these designs were being developed, the problems that caused polyethylene wear were determined and manufacturing of this material improved. Highly crosslinked UHMWPE was introduced in the late 1990s. The most recent data comparing the various bearing surfaces has shown no clinically significant differences in their performance. Potential early problems with each material are discussed below. Performance data after 20 or 30 years may be needed to demonstrate significant differences in the devices. All newer materials allow use of larger diameter femoral heads. Use of larger heads significantly decreases the chance of the hip dislocating, which remains the greatest complication of the surgery.

text: When currently available implants are used, cemented stems tend to have a better longevity than uncemented stems. No significant difference is observed in the clinical performance of the various methods of surface treatment of uncemented devices. Uncemented stems are selected for patients with good quality bone that can resist the forces needed to drive the stem in tightly. Cemented devices are typically selected for patients with poor quality bone who are at risk of fracture during stem insertion. Cemented stems are less expensive due to lower manufacturing cost, but require good surgical technique to place them correctly. Uncemented stems can cause pain with activity in up to 20% of patients during the first year after placement as the bone adapts to the device. This is rarely seen with cemented stems.

text: Once an uncommon operation reserved for frail patients with a limited life expectancy, hip replacement is now common, even among active athletes including race car drivers Bobby Labonte and Dale Jarrett, and the 8-time Major-winning American golfer Tom Watson, who shot a 67 in the opening round of the Masters Tournament in the year following his operation.

text: Techniques[edit]

text: There are several incisions, defined by their relation to the gluteus medius. The approaches are posterior (Moore), lateral (Hardinge or Liverpool),[4] antero-lateral (Watson-Jones),[5] anterior (Smith-Petersen)[6] and greater trochanter osteotomy. There is no compelling evidence in the literature for any particular approach, but consensus of professional opinion favours either modified anterolateral (Watson-Jones) or posterior approach.[citation needed]

text: Posterior approach[edit]

text: The posterior (Moore or Southern) approach accesses the joint and capsule through the back, taking piriformis muscle and the short external rotators of the femur. This approach gives excellent access to the acetabulum and femur and preserves the hip abductors and thus minimizes the risk of abductor dysfunction post operatively. It has the advantage of becoming a more extensile approach if needed. Critics cite a higher dislocation rate, although repair of the capsule, piriformis and the short external rotators along with use of modern large diameter head balls reduces this risk.

text: Lateral approach[edit]

text: The lateral approach is also commonly used for hip replacement. The approach requires elevation of the hip abductors (gluteus medius and gluteus minimus) to access the joint. The abductors may be lifted up by osteotomy of the greater trochanter and reapplying it afterwards using wires (as per Charnley),[citation needed] or may be divided at their tendinous portion, or through the functional tendon (as per Hardinge) and repaired using sutures. Although this approach has a lower dislocation risk than the posterior approach, critics note that occasionally the abductor muscles do not heal back on, leading to pain and weakness which is often very difficult to treat.

text: Antero-lateral approach[edit]

text: The anterolateral approach develops the interval between the tensor fasciae latae and the gluteus medius. The Gluteus medius, gluteus minimus and hip capsule are detached from the anterior (front) for the greater trochanter and femoral neck and then repaired with heavy suture after the replacement of the joint.

text: Anterior approach[edit]

text: The anterior approach uses an interval between the sartorius muscle and tensor fasciae latae. Dr. Joel Matta and Dr. Bert Thomas have adapted this approach, which was commonly used for pelvic fracture repair surgery, for use when performing hip replacement. When used with older hip implant systems that had a small diameter head, dislocation rates were reduced compared to surgery performed through a posterior approach. With modern implant designs, dislocation rates are similar between the anterior and posterior approaches.[7] The anterior approach has been shown in studies to variably improve early functional recovery, with possible complications of femoral component loosening and early revision compared to other approaches[8][9][10][11][12][13]

text: Minimally invasive approaches[edit]

text: The dual incision approach and other minimally invasive surgery seeks to reduce soft tissue damage through reducing the size of the incision. However, component positioning accuracy and visualization of the bone structures can be significantly impaired as the approaches get smaller. This can result in unintended fractures and soft tissue injury. The majority of current orthopedic surgeons use a "minimally invasive" approach compared to traditional approaches which were quite large comparatively.

text: Computer-assisted surgery and robotic surgery techniques are also available to guide the surgeon to provide enhanced accuracy. Several commercial CAS and robotic systems are available for use worldwide. Improved patient outcomes and reduced complications have not been demonstrated when these systems are used when compared to standard techniques.[14][15]

text: Implants[edit]

text: The prosthetic implant used in hip replacement consists of three parts: the acetabular cup, the femoral component, and the articular interface. Options exist for different people and indications. The evidence for a number of newer devices is not very good, including: ceramic-on-ceramic bearings, modular femoral necks, and uncemented monoblock cups.[16] Correct selection of the prosthesis is important.

text: Acetabular cup[edit]

text: The acetabular cup is the component which is placed into the acetabulum (hip socket). Cartilage and bone are removed from the acetabulum and the acetabular cup is attached using friction or cement. Some acetabular cups are one piece, while others are modular. One-piece (monobloc) shells are either UHMWPE (ultra-high-molecular-weight polyethylene) or metal, they have their articular surface machined on the inside surface of the cup and do not rely on a locking mechanism to hold a liner in place. A monobloc polyethylene cup is cemented in place while a metal cup is held in place by a metal coating on the outside of the cup. Modular cups consist of two pieces, a shell and liner. The shell is made of metal; the outside has a porous coating while the inside contains a locking mechanism designed to accept a liner. Two types of porous coating used to form a friction fit are sintered beads and a foam metal design to mimic the trabeculae of cancellous bone and initial stability is influenced by under-reaming and insertion force.[17] Permanent fixation is achieved as bone grows onto or into the porous coating. Screws can be used to lag the shell to the bone providing even more fixation. Polyethylene liners are placed into the shell and connected by a rim locking mechanism; ceramic and metal liners are attached with a Morse taper.[citation needed]

text: Femoral component[edit]

text: This section  possibly contains original research. Please improve it by verifying the claims made and adding inline citations. Statements consisting only of original research should be removed. (April 2016) (Learn how and when to remove this template message)

text: The femoral component is the component that fits in the femur (thigh bone). Bone is removed and the femur is shaped to accept the femoral stem with attached prosthetic femoral head (ball). There are two types of fixation: cemented and uncemented. Cemented stems use acrylic bone cement to form a mantle between the stem and to the bone. Uncemented stems use friction, shape and surface coatings to stimulate bone to remodel and bond to the implant. Stems are made of multiple materials (titanium, cobalt chromium, stainless steel, and polymer composites) and they can be monolithic or modular. Modular components consist of different head dimensions and/or modular neck orientations; these attach via a taper similar to a Morse taper. These options allow for variability in leg length, offset and version. Femoral heads are made of metal or ceramic material. Metal heads, made of cobalt chromium for hardness, are machined to size and then polished to reduce wear of the socket liner. Ceramic heads are more smooth than polished metal heads, have a lower coefficient of friction than a cobalt chrome head, and in theory will wear down the socket liner more slowly. As of early 2011, follow-up studies in patients have not demonstrated significant reductions in wear rates between the various types of femoral heads on the market. Ceramic implants are more brittle and may break after being implanted.

text: Articular interface[edit]

text: The articular interface is not part of either implant, rather it is the area between the acetabular cup and femoral component. The articular interface of the hip is a simple ball and socket joint. Size, material properties and machining tolerances at the articular interface can be selected based on patient demand to optimise implant function and longevity whilst mitigating associated risks. The interface size is measured by the outside diameter of the head or the inside diameter of the socket. Common sizes of femoral heads are 28 mm (1.1 in), 32 mm (1.3 in) and 36 mm (1.4 in). While 22.25 mm (7⁄8 in) was common in the first modern prostheses, now even larger sizes are available from 38 to over 54 mm. Larger-diameter heads lead to increased stability and range of motion whilst lowering the risk of dislocation. At the same time they are also subject to higher stresses such as friction and inertia. Different combinations of materials have different physical properties which can be coupled to reduce the amount of wear debris generated by friction. Typical pairings of materials include metal on polyethylene (MOP), metal on crosslinked polyethylene (MOXP), ceramic on ceramic (COC), ceramic on crosslinked polyethylene (COXP) and metal on metal (MOM). Each combination has different advantages and disadvantages.

text: Configuration[edit]

text: Post-operative projectional radiography is routinely performed to ensure proper configuration of hip prostheses.

text: The direction of the acetabular cup influences the range of motion of the leg, and also affects the risk of dislocation.[18] For this purpose, the acetabular inclination and the acetabular anteversion are measurements of cup angulation in the coronal plane and the sagittal plane, respectively.

text:
Acetabular inclination.[19] This parameter is calculated on an anteroposterior radiograph as the angle between a line through the lateral and medial margins of the acetabular cup and the transischial line which is tangential to the inferior margins of the ischium bones.[19]

Acetabular inclination is normally between 30 and 50°.[19] A larger angle increases the risk of dislocation.[18]

text:
Acetabular anteversion.[20] This parameter is calculated on a lateral radiograph as the angle between the transverse plane and a line going through the (anterior and posterior) margins of the acetabular cup.[20]

Acetabular anteversion is normally between 5 and 25°.[18] An anteversion below or above this range increases the risk of dislocation.[18] There is an intra-individual variability in this method because the pelvis may be tilted in various degrees in relation to the transverse plane.[18]

text:
Leg length discrepancy after hip replacement is calculated as the vertical distance between the middle of the minor trochanters, using the acetabular tear drops[19] or the transischial line[18] as references for the horizontal plane. A discrepancy of up to 1 cm is generally tolerated.[19][18]

Center of rotation: The horizontal center of rotation is calculated as the distance between the acetabular teardrop and the center of the head (or caput) of the prosthesis and/or the native femoral head on the contralateral side.[19] The vertical center of rotation instead uses the transischial line for reference.[19] The parameter should be equal on both sides.[19]

text: Risks[edit]

text: Risks and complications in hip replacement are similar to those associated with all joint replacements. They can include infection, dislocation, limb length inequality, loosening, impingement, osteolysis, metal sensitivity, nerve palsy, chronic pain and death. Weight loss surgery before a hip replacement does not appear to change outcomes.[21]

text: Infection[edit]

text: Infection is one of the most common causes for revision of a total hip replacement, along with loosening and dislocation. The incidence of infection in primary hip replacement is around 1% or less in the United States.[22] Risk factors for infection include obesity, diabetes, smoking, immunosuppressive medications or diseases, and history of infection.

text: Modern diagnosis of infection around a total knee replacement is based on the Musculoskeletal Infection Society (MSIS) criteria.[23] They are:

text:
1.There is a sinus tract communicating with the prosthesis; or
2. A pathogen is isolated by culture from at least two separate tissue or fluid samples obtained from the affected prosthetic joint;
or

text: Four of the following six criteria exist:

text: 1.Elevated serum erythrocyte sedimentation rate (ESR>30mm/hr) and serum C-reactive protein (CRP>10 mg/L) concentration,

text: 2.Elevated synovial leukocyte count,

text: 3.Elevated synovial neutrophil percentage (PMN%),

text: 4.Presence of purulence in the affected joint,

text: 5.Isolation of a microorganism in one culture of periprosthetic tissue or fluid, or

text: 6.Greater than five neutrophils per high-power field in five high-power fields observed from histologic analysis of periprosthetic tissue at ×400 magnification.

text: None of the above laboratory tests has 100% sensitivity or specificity for diagnosing infection. Specificity improves when the tests are performed in patients in whom clinical suspicion exists. ESR and CRP remain good 1st line tests for screening (high sensitivity, low specificity).  Aspiration of the joint remains the test with the highest specificity for confirming infection.

text: Dislocation[edit]

text: Dislocation is the most common complication of hip replacement surgery. The most common causes vary by the duration since the surgery.

text: Hip prosthesis dislocation mostly occurs in the first 3 months after insertion, mainly because of incomplete scar formation and relaxed soft tissues.[24] It takes eight to twelve weeks for the soft tissues injured or cut during surgery to heal. During this period, the hip ball can come out of the socket. The chance of this is diminished if less tissue is cut, if the tissue cut is repaired and if large diameter head balls are used.

text: Dislocations occurring between 3 months and 5 years after insertion usually occur due to malposition of the components, or dysfunction of nearby muscles.[24]

text: Risk factors of late dislocation (after 5 years) mainly include:[24]

text:
Female gender
Younger age at primary hip arthroplasty
Previous subluxation without complete dislocation
Previous trauma
Substantial weight loss
Recent onset or progression of dementia or a neurological disorder
Malposition of the cup
Wear of the liner, particularly when it causes movement of the head of more than 2 mm within the cup compared to its original position
Prosthesis loosening with migration

text: Surgeons who perform more of the operations each year tend to have fewer patients dislocate. Doing the surgery from an anterior approach seems to lower dislocation rates when small diameter heads are used, but the benefit has not been shown when compared to modern posterior incisions with the use of larger diameter heads. The use of larger diameter head size does in it self decrease the risk of dislocation, even though this correlation is only found in head sizes up to 28 mm, thereafter no additional decrease in dislocation rate is found.[25] Patients can decrease the risk further by keeping the leg out of certain positions during the first few months after surgery.

text: Limb Length Inequality[edit]

text: Most adults prior to a hip replacement have a limb length inequality of 0–2 cm which they were born with and which causes no clinical deficits.[26] It is common for patients to feel a limb length inequality after total hip replacement.[27] Sometimes the leg seems long immediately after surgery when in fact both are equal length. An arthritic hip can develop contractures that make the leg behave as if it is short. When these are relieved with replacement surgery and normal motion and function are restored, the body feels that the limb is now longer than it was. This feeling usually subsides by 6 months after surgery as the body adjusts to the new hip joint. The cause of this feeling is variable, and usually related to abductor muscle weakness, pelvic obliquity, and minor lengthening of the hip during surgery (<1 cm) to achieve stability and restore the joint to pre-arthritic mechanics. If the limb length difference remains bothersome to the patient more than 6 months after surgery, a shoe lift can be used. Only in extreme cases is surgery required for correction.

text: Fracture[edit]

text: Bones with internal fixation devices in situ are at risk of periprosthetic fractures at the end of the implant, an area of relative mechanical stress.  Post-operative femoral fractures are graded by the Vancouver classification.

text: Vein thrombosis[edit]

text: Venous thrombosis such as deep vein thrombosis and pulmonary embolism are relatively common following hip replacement surgery. Standard treatment with anticoagulants is for 7–10 days; however treatment for more than 21 days may be superior.[28] Research from 2013 has on the other hand suggested that anticoagulants in otherwise healthy patients undergoing a so-called fast track protocol with hospital stays under five days, might only be necessary while in the hospital.[29]

text: Some physicians and patients may consider having an ultrasonography for deep vein thrombosis after hip replacement.[30] However, this kind of screening should only be done when indicated because to perform it routinely would be unnecessary health care.[30]

text: Osteolysis[edit]

text: Many long-term problems with hip replacements are the result of osteolysis. This is the loss of bone caused by the body's reaction to polyethylene wear debris, fine bits of plastic that come off the cup liner over time. An inflammatory process causes bone resorption that may lead to subsequent loosening of the hip implants and even fractures in the bone around the implants. In an attempt to eliminate the generation of wear particles, ceramic bearing surfaces are being used in the hope that they will have less wear and less osteolysis with better long-term results. Metal cup liners joined with metal heads (metal-on-metal hip arthroplasty) were also developed for similar reasons. In the lab these show excellent wear characteristics and benefit from a different mode of lubrication. At the same time that these two bearing surfaces were being developed, highly cross linked polyethylene plastic liners were also developed. The greater cross linking significantly reduces the amount of plastic wear debris given off over time. The newer ceramic and metal prostheses do not always have the long-term track record of established metal on poly bearings. Ceramic pieces can break leading to catastrophic failure. This occurs in about 2% of the implants placed. They may also cause an audible, high pitched squeaking noise with activity. Metal-on-metal arthroplasty releases metal debris into the body raising concerns about the potential dangers of these accumulating over time. Highly cross linked polyethylene is not as strong as regular polyethylene. These plastic liners can crack or break free of the metal shell that holds them.

text: Loosening[edit]

text: On radiography, it is normal to see thin radiolucent areas of less than 2 mm around hip prosthesis components, or between a cement mantle and bone. However, these may still indicate loosening of the prosthesis if they are new or changing, and areas greater than 2 mm may be harmless if they are stable.[33] The most important prognostic factors of cemented cups are absence of radiolucent lines in DeLee and Charnley zone I, as well as adequate cement mantle thickness.[34] In the first year after insertion of uncemented femoral stems, it is normal to have mild subsidence (less than 10 mm).[33] The direct anterior approach has been shown to itself be a risk factor for early femoral component loosening.[9][35][8]

text: Metal sensitivity[edit]

text: Concerns are being raised about the metal sensitivity and potential dangers of metal particulate debris. New publications[36][37] have demonstrated development of pseudotumors, soft tissue masses containing necrotic tissue, around the hip joint. It appears these masses are more common in women and these patients show a higher level of iron in the blood. The cause is unknown and is probably multifactorial. There may be a toxic reaction to an excess of particulate metal wear debris or a hypersensitivity reaction to a normal amount of metal debris.

text: Metal hypersensitivity is a well-established phenomenon and is common, affecting about 10–15% of the population.[38] Contact with metals can cause immune reactions such as skin hives, eczema, redness and itching. Although little is known about the short- and long-term pharmacodynamics and bioavailability of circulating metal degradation products in vivo, there have been many reports of immunologic type responses temporally associated with implantation of metal components.  Individual case reports link hypersensitivity immune reactions with adverse performance of metallic clinical cardiovascular, orthopedic and plastic surgical and dental implants.[38]

text: Metal toxicity[edit]

text: Most hip replacements consist of cobalt and chromium alloys, or titanium. Stainless steel is no longer used. All implants release their constituent ions into the blood. Typically these are excreted in the urine, but in certain individuals the ions can accumulate in the body. In implants which involve metal-on-metal contact, microscopic fragments of cobalt and chromium can be absorbed into the patient's bloodstream. There are reports of cobalt toxicity with hip replacement patients.[39][40]

text: Nerve palsy[edit]

text: Post operative sciatic nerve palsy is another possible complication. The incidence of this complication is low. Femoral nerve palsy is another but much more rare complication. Both of these will typically resolve over time, but the healing process is slow. Patients with pre-existing nerve injury are at greater risk of experiencing this complication and are also slower to recover.

text: Chronic pain[edit]

text: A few patients who have had a hip replacement suffer chronic pain after the surgery. Groin pain can develop if the muscle that raises the hip (iliopsoas) rubs against the edge of the acetabular cup. Bursitis can develop at the trochanter where a surgical scar crosses the bone, or if the femoral component used pushes the leg out to the side too far. Also some patients can experience pain in cold or damp weather.[citation needed] Incision made in the front of the hip (anterior approach) can cut a nerve running down the thigh leading to numbness in the thigh and occasionally chronic pain at the point where the nerve was cut (a neuroma).

text: Death[edit]

text: The rate of death for elective hip replacements is significantly less than 1%.[41][42]

text: Metal-on-metal hip implant failure[edit]

text: By 2010, reports in the orthopaedic literature increasingly cited the problem of early failure of metal on metal prostheses in a small percentage of patients.[43] Failures may relate to release of minute metallic particles or metal ions from wear of the implants, causing pain and disability severe enough to require revision surgery in 1–3% of patients.[44] Design deficits of some prothesis models, especially with heat-treated alloys and a lack of special surgical experience accounting for most of the failures. Surgeons at leading medical centers such as the Mayo Clinic have reported reducing their use of metal-on-metal implants by 80 percent over the last year in favor of those made from other materials, like combinations of metal and plastic.[45] The cause of these failures remain controversial, and may include both design factors, technique factors, and factors related to patient immune responses (allergy type reactions). In the United Kingdom the Medicines and Healthcare Products Regulatory Agency commenced an annual monitoring regime for metal-on-metal hip replacement patients from May 2010.[46]  Data which are shown in The Australian Orthopaedic Association's 2008 National Joint replacement registry, a record of nearly every hip implanted in that country over the previous 10 years, tracked 6,773 BHR (Birmingham Hip Resurfacing) Hips and found that less than one-third of one percent may have been revised due to the patient's reaction to the metal component.[47]  Other similar metal-on-metal designs have not fared as well, where some reports show 76% to 100% of the people with these metal-on-metal implants and have aseptic implant failures requiring revision also have evidence of histological inflammation accompanied by extensive lymphocyte infiltrates, characteristic of delayed type hypersensitivity responses.[48] It is not clear to what extent this phenomenon negatively affects orthopedic patients. However, for patients presenting with signs of an allergic reactions, evaluation for sensitivity should be conducted. Removal of the device that is not needed should be considered, since removal may alleviate the symptoms.  Patients who have allergic reactions to cheap jewelry are more likely to have reactions to orthopedic implants.  There is increasing awareness of the phenomenon of metal sensitivity and many surgeons now take this into account when planning which implant is optimal for each patient.

text: On March 12, 2012, The Lancet published a study, based on data from the National Joint Registry of England and Wales, finding that metal-on-metal hip implants failed at much greater rates than other types of hip implants and calling for a ban on all metal-on-metal hips.[49] The analysis of 402,051 hip replacements showed that 6.2% of metal-on-metal hip implants had failed within five years, compared to 1.7% of metal-on-plastic and 2.3% of ceramic-on-ceramic hip implants. Each 1 mm (0.039 in) increase in head size of metal-on-metal hip implants was associated with a 2% increase of failure.[50] Surgeons of the British Hip Society are recommending that large head metal-on-metal implants should no longer be performed.[51][52]

text: On February 10, 2011, the U.S. FDA issued an advisory on metal-metal hip implants, stating it was continuing to gather and review all available information about metal-on-metal hip systems.[53] On June 27–28, 2012, an advisory panel met to decide whether to impose new standards, taking into account findings of the study in The Lancet.[40][54][55] No new standards, such as routine checking of blood metal ion levels, were set, but guidance was updated.[56] Currently, FDA has not required hip implants to be tested in clinical trials before they can be sold in the U.S.[57]  Instead, companies making new hip implants only need to prove that they are "substantially equivalent" to other hip implants already on the market.  The exception is metal-on-metal implants, which were not tested in clinical trials but because of the high revision rate of metal-on-metal hips, in the future the FDA has stated that clinical trials will be required for approval and that post-market studies will be required to keep metal on metal hip implants on the market.[58]

text: Alternatives and variations[edit]

text: Conservative management[edit]

text: The first line approach as an alternative to hip replacement is conservative management which involves a multimodal approach of oral medication, injections, activity modification and physical therapy.[59] Conservative management can prevent or delay the need for hip replacement.

text: Preoperative care[edit]

text: Preoperative education is currently an important part of patient care. There is some evidence that it may slightly reduce anxiety before hip or knee replacement, with low risk of negative effects.[60]

text: Hemiarthroplasty[edit]

text: Hemiarthroplasty is a surgical procedure which replaces one half of the joint with an artificial surface and leaves the other part in its natural (pre-operative) state. This class of procedure is most commonly performed on the hip after a subcapital (just below the head) fracture of the neck of the femur (a hip fracture). The procedure is performed by removing the head of the femur and replacing it with a metal or composite prosthesis. The most commonly used prosthesis designs are the Austin Moore prosthesis and the Thompson Prosthesis. More recently a composite of metal and HDPE which forms two interphases (bipolar prosthesis) has also been used. The monopolar prosthesis has not been shown to have any advantage over bipolar designs. The procedure is recommended only for elderly and frail patients, due to their lower life expectancy and activity level. This is because with the passage of time the prosthesis tends to loosen or to erode the acetabulum.[61]

text: Hip resurfacing[edit]

text: Hip resurfacing is an alternative to hip replacement surgery. It has been used in Europe for over seventeen years and become a common procedure. Health-related quality of life measures are markedly improved and patient satisfaction is favorable after hip resurfacing arthroplasty.[62]

text: The minimally invasive hip resurfacing procedure is a further refinement to hip resurfacing.

text: Viscosupplementation[edit]

text: Current alternatives also include viscosupplementation, or the injection of artificial lubricants into the joint.[63] Use of these medications in the hip is off label. The cost of treatment is typically not covered by health insurance organizations.

text: Some believe that the future of osteoarthritis treatment is bioengineering, targeting the growth and/or repair of the damaged, arthritic joint. Centeno et al. have reported on the partial regeneration of an arthritic human hip joint using mesenchymal stem cells in one patient.[64] It is yet to be shown that this result will apply to a larger group of patients and result in significant benefits. The FDA has stated that this procedure is being practiced without conforming to regulations, but Centeno claims that it is exempt from FDA regulation. It has not been shown in controlled clinical trials to be effective[citation needed], and costs over $7,000.

text: Prevalence and cost[edit]

text: Total hip replacement incidence varies in developed countries between 30 (Romania) and 290 (Germany) procedures per 100,000 population per year.[65] Approximately 0.8% of Americans have undergone the procedure.[66]

text: According to the International Federation of Healthcare Plans, the average cost of a total hip replacement in 2012 was $40,364 in the United States, $11,889 in the United Kingdom, $10,987 in France, $9,574 in Switzerland, and $7,731 in Spain.[1] In the United States, the average cost of a total hip replacement varies widely by geographic region, ranging from $11,327 (Birmingham, Alabama) to $73,927 (Boston, Massachusetts).[67]

text: History[edit]

text: The earliest recorded attempts at hip replacement were carried out in Germany in 1891 by Themistocles Gluck (1853–1942),[68][69] who used ivory to replace the femoral head (the ball on the femur), attaching it with nickel-plated screws, Plaster of Paris, and glue.[70]

text: On September 28, 1940 at Columbia Hospital in Columbia, South Carolina, American surgeon Dr. Austin T. Moore (1899–1963)[71] performed the first metallic hip replacement surgery.  The original prosthesis he designed was a proximal femoral replacement, with a large fixed head made of the cobalt-chrome alloy Vitallium.  It was about a foot in length and bolted to the resected end of the femoral shaft (hemiarthroplasty).  A later version, the so-called Austin Moore Prosthesis which was introduced in 1952, is still in use today, although rarely.  Like modern hip implants, it is inserted into the medullary canal of the femur, and depends on bone growth through a hole in the stem for long-term attachment.


document_title: Cynthia Lamontagne

question_text: who plays fat rhonda on that 70s show

question_tokens: who plays fat rhonda on that 70s show

root

text: Cynthia Lamontagne

text:
Cynthia Lamontagne

Born
(1966-02-15) February 15, 1966 (age 52)
California, U.S.

Years active
1993-present

Known for
That '70s Show

Spouse(s)
Aaron Zelman (m. 2006)

Relatives
Daniel Zelman (brother-in-law)

tag: table

text: Cynthia Ann LaMontagne (born February 15, 1966) is an American actress who has appeared in numerous television shows and films. She is best known for her recurring role as "Big Rhonda" in the fourth season of That '70s Show.

tag: p

text: Television[edit]

text:
Eyes .... Nicole Talbert (2007)
Criminal Minds .... Becky the Reporter (uncredited) (2006)
Veronica Mars .... Catherine Lenova/Yelena Sukarenko (2005) (Episode: "Ruskie Business")
Buffy the Vampire Slayer .... Lydia (2001, 2002) (Two episodes)
That '70s Show .... Big Rhonda (2001–2002) (Six episodes)
Frasier ....Episode: 'The Ski Lodge' - played Annie, a 'sex mad' friend of Daphne who fancies Niles Crane, but Frasier thinks she fancies him. All ends in 'Theatre Farce' (1998, 2001)
Maybe This Time .... Bethany (1995)

tag: ul

text: Filmography[edit]

text:
Forgetting Sarah Marshall (2008) .... Female Bartender
Would I Lie to You? (2002) .... Serenity
American Virgin (1999) ... Gloria
Border to Border (1998) .... The Other Woman
My Engagement Party (1998) .... Stacy
Austin Powers: International Man of Mystery (1997) .... Fembot
American Virgin (2000) .... Gloria
The Cable Guy (1996) .... Restaurant Hostess
Flirting with Disaster (1996) .... Sandra
Carlito's Way (1993) .... Woman at Elevator


document_title: International rankings of India

question_text: where does india stand in world richest country

text: International rankings of India

text: Demographics[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Population
2/ 221
CIA World Factbook[1]
Estimated Population(July 2017) 1,281,935,911

Population Density
33 / 246
Economist Intelligence Unit
2017 - 403 people per km2

Fertility rate
103 / 210
Population Reference Bureau
2016 - 2.3

Net migration (rate)
85 / 194
World Bank
2012 - 2.06 per thousand

Net migrants
2 / 194
World Bank
2012 - 2,598,218 emigrated

Health

Life expectancy
125 / 183
World Health Organization
2015 - 68.3 years

Infant Mortality
113 / 223
CIA
2016 est - 40.5 per 1000

Ethnic and cultural diversity
88 / 215
Alesina et al[2]
2003

Epidemiology of diabetes mellitus
2 / 194
World Health Organization
2016 (69.2 of 422 million diagnosed adult diabetics, live in India)

Cigarette consumption
7 / 185
tobaccoatlas.org
2014[3]

Cigarette consumption per capita
159 / 185
tobaccoatlas.org
2014

Alcohol consumption per capita
119 / 191
World Health Organization
2014

Global Hunger Index
97 / 119
International Food Policy Research Institute
2018

Suicide rate
41 / 106
World Health Organization

Health Expenditure per capita (PPP)
140 / 190
World Health Organization
2014 - $267 (inflation-adjusted 2011 dollars)

Height

Average Height - male
90/ 101
averageheight.co
2016 - 1.647m

Average Height - female
45 / 103
averageheight.co
2016 - 1.612m

Education

Literacy rate
168 / 234
UNESCO Institute for Statistics
2015 - 72.1%

Human capital
103 / 130
WEF - The Global Human capital Report
2017[4]

Education Index
145 / 191
United Nations
2013

Programme for International Student Assessment
72 to 74 / 74
OECD
2009

Languages

Linguistic diversity index
14 / 232
SIL International
2017

Official languages
2 / 41

22 Official languages

English-speaking population
2 / 133
Census of India
10.35% (125,226,449) English speakers out of 1,210,000,000 eligible population

text: Society[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Happiness

World Happiness Report
133 / 155
United Nations
2018 report[5]

Happy Planet Index
50 / 140
New Economics Foundation
2016 - Score 29.2[6]

Aggregate metrics

Human Development Index
131 / 188
United Nations
2016 report - score 0.624

Inequality-adjusted HDI
97 / 151
UNDP
2016 report - score 0.454

Social Progress Index
93 / 128
Social Progress Imperative
2017 - score 58.39

Where-to-be-born Index
66 / 80
Economist Intelligence Unit
2013 - score 5.67

Legatum Prosperity Index
104 / 149
Legatum
2016[7]

Global Youth Development Index
134 / 183
Global Youth Development Index
2016

List of countries by homeless population
8 / 52
Business Standard
2011 - 1,770,000 homeless

Urbanization by country
161 / 199
CIA The World Factbook
2015 est

Estimated number of guns per capita by country
107 / 175
Small Arms Survey
2007 - 4.2 guns per 100 residents

Gender

Global Gender Gap Report
87 / 144
World Economic Forum
2018[8]

Gender Inequality Index
125 / 188
UNDP
2015 - value: 0.530 - female Labour force participation rate: 26.8%[9]

State of the World's Mothers report
73 / 77
Save the Children
2010[10][11]

Crime

Intentional homicides
2 / 219
United Nations Office on Drugs and Crime
2015 - 41,623 Intentional homicides

Global Slavery Index
4 / 167
Walk Free Foundation
2016 - 18,354,700 living in modern slavery[12]

text: Economy[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Product

GDP growth rate
15 / 225
CIA The World Factbook[13]
2017-18 - 6.7%

Nominal GDP
6 / 181
International Monetary Fund
2017-18 - 2.611 trillion

GDP (PPP)
3 / 181
International Monetary Fund
2017-18 - 9.459 trillion

Per capita GDP
139 / 187
International Monetary Fund
2017-18 - $1,983

tax revenue to GDP ratio
109 / 180
The Heritage Foundation
2015 - 17.7% of GDP

Trade

Imports
12 / 222
CIA The World Factbook
2017 est - $426,800,000,000

Exports
21 / 222
CIA The World Factbook
2017 est - $299,300,000,000

Received FDI
31 / 115
CIA The World Factbook
2017 est - $156,100,000,000

Wealth

Number of Billionaires
3 / 71
Forbes
2018 - 131

Gold reserve
10 / 18
World Gold Council
2017 June - 557.8 tonnes

Public debt
82 / 189
CIA The World Factbook
2016 est - 52.3% GDP NET / 41.11% GDP Gross

Foreign-Exchange reserves
8 / 193

2017 Sept

Income

Minimum wages
124 / 156

2017 - $743/yr (Bihar)

GNI nominal
9 / 15
World Bank
2016 - value $2,027,964,000,000

GNI PPP
3 / 15
World Bank
2016 - value $8,594,226,000,000 international dollars

GNI (PPP) per capita
124 / 179
World Bank
2015 - $6,030 international dollars

Employment

Unemployment rate
103 / 217
CIA The World Factbook[14]
2016 - 8% unemployment

Employment rate
42 / 47
OECD
2012 - 53.3% of 15-64 year olds in employment

Business environment

Globalization Index
107 / 184
ETHZ KOF Index of Globalization [1]
2017

World Competitiveness Yearbook scoreboard
45 / 63
IMD International [2]
2017

Global Resilience Index
60 / 130
FM Global
2017[15] [3]

Index of Economic Freedom
123 / 178
The Wall Street Journal [4]
2016

Quality-of-life index
43 / 56
Economist Intelligence Unit [5]
2017

Ease of doing business index
100 / 190
World Bank Group
2017

Global Competitiveness Index
40 / 137
World Economic Forum [6]
2017-2018

Index of Economic Freedom
128 / 178
The Heritage Foundation and The Wall Street Journal
2016

Economic Freedom of the World
95 / 157
Fraser Institute
2015 - score 6.63

Financial Development Index
51 / 183
IMF
2016

Technology

IT industry competitiveness index
18 / 66
BSA Global Index [7]
2016

ICT Development Index
134 / 176
International Telecommunication Union
2017[16]

Global Innovation Index
57 / 130
Global Innovation Index
2018

Space Competitiveness Index
6 / 15
Futron Corporation,
2013

Networked Readiness Index
91 / 139
World Economic Forum
2016 - Score 3.8[17]

Passengers carried in rail transport
2 / 86
International Union of Railways
2016[18][19] - 8.224 billion passengers

Longest Railway platforms
1 / 5
The Times of India

rail transport network size
3 / 149
International Union of Railways
2015 - 68,525 km

Traffic-related deaths
2 / 180
WHO
2013 - 238,562 deaths

Vehicles per capita
84 / 163

2015 - 0.167 per capita, 55,725,543 total

Industry

Electricity production
3 / 209
BP
2016 - 1,400,800

Steel production
3 / 38
World Steel Association
2016 - 95.6 million metric tons

text: Communications[edit]

text: Following rankings involving technological advances in communication are taken from the CIA World Factbook.[20]

text:
List

World rank

Source

Demographics (est.)

Telephone Lines in Use
12 / 218
CIA The World Factbook
2014 - 27 million est. (2017 Aug - 23.77 million[21])

Mobile Phones in Use
1 / 222

908,358,714 million lines (74.71% density) for 1.2 billion population as of August 2012959825*851*8*/4
6546+5+8165466

Internet users (pct of population)
127 / 191
ITU estimate
2015 - 26%

4G LTE penetration
15 / 75
OpenSignal
2017 - 81.56%

Internet connection speeds
89 / 149
Akamai Technologies
2017 Q1 - Average 6.5Mbit/s[22]

Television broadcast stations
4 / 233

2016 - 857 licensed stations

text: Sport[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Cricket - men's
1 / 10
International Cricket Council
2017 Nov

Cricket - women's
3 / 10
International Cricket Council
2017 Oct

Kabaddi - men's
1/12
IKF
2017

Field Hockey - men's
6 / 91
International Hockey Federation
2017

Field Hockey - women's
10 / 74
International Hockey Federation
2017

Football - men's
97 / 206
FIFA
april 2018

Football - women's
56 / 177
FIFA
2017

Rugby Union - men's
77 / 103
World Rugby
2017

Chess - men's
5 / 173
FIDE
2017[23]

Chess - women's
7 / 142
FIDE
2017[23]

Olympic Gold Medals
48= / 151
IOC
2016 - 9 Golds from 33 Games (24 - Summer, 9 - Winter)

Olympic Medals
60= / 151
IOC
2016 - 28 medals from 33 Games (24 - Summer, 9 - Winter)

Paralympic Gold Medals
64= / 122
IOC
2016 - 4 Golds from 11 Games (11 - Summer, 0 - Winter)

Paralympic Medals
71 / 122
IOC
2016 - 12 medals from 11 Games (11 - Summer, 0 - Winter)

text: Entertainment[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Film productions
1 / 15
UNESCO
2015

Cinema box office
4 / 15
MPAA
2016 - $1.9bn

Cinema admissions
1 / 10
European Audiovisual Observatory
2013 - 9,164,000,000

text: Politics[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Corruption Perceptions Index
81 / 180
Transparency International
2016[24]

Press Freedom Index
138 / 180
Reporters Without Borders
2018[25]

Soft power
24 / 25
Monocle
2016-17[26]

Rule of Law Index
66 / 113
World Justice Project
2016

Democracy Index
42 / 167
Economist Intelligence Unit
2017 - score 7.23 - Flawed democracy

Democracy Ranking
65 / 112
democracyranking.org
2014-2015

Corporate Governance
20 / 38
GMI Ratings
2010

E-Government
107 / 192
UN
2016 - score 0.4638[27]

text: Military[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Military expenditure
5 / 186
Stockholm International Peace Research Institute
2016 - $55.9bn or 2.5% of GDP[28]

Military Strength
5 / 20
Credit Suisse
2015

Active troops
2 / 171
International Institute for Strategic Studies
1,395,100 active troops (1.1 active troops per 1000 capita)

Total troops
4 / 171
International Institute for Strategic Studies
4,941,600 total troops (3.9 troops per 1000 capita)

Composite Index of National Capability
3 / 193
National power
2003 - score 0.073444

Overseas Bases
5 / 10

4 overseas bases

text: Awards[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Academy Award nominations - Foreign Language Film
33 / 125
Academy of Motion Picture Arts and Sciences
3 nominations, from 50 submissions

Nobel laureates
24= / 76
Nobel Prize
3 Indian Citizens, at the time they were made a Nobel laureate: Mother Teresa (Peace), Amartya Sen (Economics), Kailash Satyarthi (Peace), two British Indian subjects: Rabindranath Tagore (Literature), and C. V. Raman (Physics), along with two Indian born British subjects: Rudyard Kipling (Literature), Ronald Ross (Medicine), have received the honour.

Turing Award
6= / 13
Association for Computing Machinery
Indian-American Raj Reddy, became first person of Asian origin to receive the ACM Turing Award, in 1994, for his work in the field of Artificial Intelligence.

text: Environment[edit]

text:
List

INDIA Ranking/Total Countries

Source

Notes

Carbon dioxide emissions by country
8 / 214
United Nations Statistics Division
2010

Carbon dioxide emissions per capita
145 / 214
United Nations Statistics Division
2009

Climate Change Performance Index
31 / 61

2015

Environmental Performance Index
141 / 180
Yale Center for Environmental Law & Policy
2016

Environment Democracy Index
20 / 70
World Resources Institute
[29]

Air Quality - average PM 2.5 concentration
84 / 92
WHO[30]
2014 - 60.6 µg/m3[31]

Freshwater withdrawal
1 / 170
CIA World Factbook
2008 - 645.84 km³/year

Irrigated land area
2 / 221
CIA World Factbook
2012 - 667,000 km²

text: Geography[edit]

text:
List

INDIA Ranking/Total Countries

Notes

Total Area
7/233
All  Over India 32,87,364 km2
(1,222,559 sq mile) including land and water

Length of coastline
18/196
7,000 km coastline with 2.00 coast/area ratio (m/km sq). According to the Indian naval hydrographic charts, the mainland coastline consists of the following: 43% sandy beaches; 11% rocky shores, including cliffs; and 46% mudflats or marshy shores.

text: Agriculture, Fisheries and Live Stock[edit]

text:
Field
Rank
Date

Apple Production, output of 2,203,000 tons
5
2013

Bananas Production, output of 29,800,000 metric tons
1
2013

Bean Production, output of 4,870,000 tons
1
2010

Buffalo, milk output of 56,960,000 tons
1
2008

Black Pepper, 19% of world output
2
2008

Cauliflowers and Broccoli Production, output of 5,014,500 tons
2
2008

Cardamom Production, output of 15 thousand metric tons
2
2012

Cashew Apple Production, output of 613,000 metric tons
2
2010

Chicken Population, output of 648,830,000
5
2004

Chickpea Production, output of 5,970,000 tons
1
2008

Coconut Production, output of 10,824,100
3
2010

Coffee Production, output of 300,300,000 kg
6
2011

Cotton Production, output of 27.0 million bales
2
2011

Cow Numbers, 281,700,000 cows
1
2009

Fish Production, output of 6,318,887 tons (capture 3,481,136 & aquaculture 2,837,751)
3
2005

Garlic Production, output of 833,970 tons
2
2010

Ginger Production, output of 380,100 tons
1
2008

Goat Numbers, 125,700,000 goats
2
2008

Goat Milk Production, output of 4,000,000 metric tons
1
2008

Goat Meat Production, output of 480,000 metric tons
2
2008

Jute Production, output of 17,43,000 tons
1
2008

Lemon & Lime Production, output of 2,060,000 tons
1
2007

Lentil Production, 950,000 tons
2
2009

Mango Production, output of 16,340,000 tons
1
2011

Millet Production, output of 8,810,000 tons
1
2009

Milk Production, output of 110,040,000 metric tons (cow milk 50.3 million metric tons)
2
2018

Onion Production, output of 13,372,100 metric tons
2
2010

Orange Production, output of 5,000,000 tons
3
2010

Peanut Production, output of 6.25 metric tons
2
2009

Pineapple Production, output of 1,341,000 tons
7
2010

Potato Production, output of 36,600,000 metric tons
2
2010

Rice Production, output of 120,600,000 metric tons
1
2015-16

Saffron Production, output of 2,300 kg
3
2005

Sheep Stock, output of 65,000,000
3
2008

Silk Production, output of 77,000,000 kg
2
2005

Sorghum Production, output of 7,900,000 metric tons
3
2008

Soybean Production, output of 9.8 metric tons
5
2010

Sugarcane Production, output of 285,029,000 tons
2
2009

Sweet Potato Production, output of 1,100,000 tons
7
2009

Tea Production, output of 991,180 metric tons
2
2010

Tomato Production, output of 11,979,700 tons
3
2010

Wheat Production, output of 80.7 million metric tons
2
2010

text: Cities[edit]

text: UN World's Largest Morphological Cities ranking(physically contiguous urban area) ranks

text:
City
Rank

bangalore
1

text: List of cities with the most high-rise buildings above 35 meters has following Indian cities: Mumbai 12th with 2480 buildings, Chennai 35th with 689 buildings, Kolkata 40th with 594 buildings, Pune 47th with 510 buildings, Bangalore 53rd with 460 buildings.

text:
City
Rank
Buildings

Mumbai
4
7053

Chennai
35
689

Kolkata
40
594

Pune
47
510

text: List of cities with most skyscrapers above meters ranks Mumbai behind Dubai.

text:
City
Rank
Buildings

Mumbai
1
2

text:
Globalization and World Cities Study Group and Network (GaWC), Loughborough University listed Mumbai, New Delhi & Bangalore as emerging world city[32]
List of most polluted cities by particulate matter concentration

text: Religion[edit]

text:
List

INDIA Ranking

Source

Notes

Hindu
1st
2011 Census of India[33]
2011 - 966,257,353 (India: 79.80%, World: )

Muslim
3rd
2011 Census of India
2011 - 172,245,158 (India: 14.23%, World: 9.57%) [34]

Christian
22nd
2011 Census of India
2011 - 27,819,588 (India: 2.30%, World: 1.16%)

Sikh
1st
2011 Census of India
2011 - 20,833,116 (India: 1.72%, World: 90.02%)

Buddhist
9th
2011 Census of India
2011 - 8,442,972 (India: 0.70%, World: 63%)

Jain
1st
2011 Census of India
2011 - 4,451,753 (India: 0.37%, World: 64%)[35]

Zoroastrian
1st
2011 Census of India
2001 - 69,000 (India: 0.006%, World: 50%)

Bahá'í Faith
-
2011 Census of India
2011 - 4,572 (India: 0.0%, World: 0.0%)