what does mad stand for in the cold war

Mutual assured destruction or mutually assured destruction (MAD) is a doctrine of military strategy and national security policy in which a full-scale use of nuclear weapons by two or more opposing sides would cause the complete annihilation of both the attacker and the defender (see pre-emptive nuclear strike and second strike).[1] It is based on the theory of deterrence, which holds that the threat of using strong weapons against the enemy prevents the enemy's use of those same weapons. The strategy is a form of Nash equilibrium in which, once armed, neither side has any incentive to initiate a conflict or to disarm.

Mutual assured destruction

Under MAD, each side has enough nuclear weaponry to destroy the other side and that either side, if attacked for any reason by the other, would retaliate without fail with equal or greater force. The expected result is an immediate, irreversible escalation of hostilities resulting in both combatants' mutual, total, and assured destruction. The doctrine requires that neither side construct shelters on a massive scale.[2] If one side constructed a similar system of shelters, it would violate the MAD doctrine and destabilize the situation, because it would not have to fear the consequences of a second strike.[3][4] The same principle is invoked against missile defense.

The doctrine further assumes that neither side will dare to launch a first strike because the other side would launch on warning (also called fail-deadly) or with surviving forces (a second strike), resulting in unacceptable losses for both parties. The payoff of the MAD doctrine was and still is expected to be a tense but stable global peace.

The primary application of this doctrine started during the Cold War (1940s to 1991), in which MAD was seen as helping to prevent any direct full-scale conflicts between the United States and the Soviet Union while they engaged in smaller proxy wars around the world. It was also responsible for the arms race, as both nations struggled to keep nuclear parity, or at least retain second-strike capability. Although the Cold War ended in the early 1990s, the MAD doctrine continues to be applied.

Proponents of MAD as part of U.S. and USSR strategic doctrine believed that nuclear war could best be prevented if neither side could expect to survive a full-scale nuclear exchange as a functioning state. Since the credibility of the threat is critical to such assurance, each side had to invest substantial capital in their nuclear arsenals even if they were not intended for use. In addition, neither side could be expected or allowed to adequately defend itself against the other's nuclear missiles.[citation needed] This led both to the hardening and diversification of nuclear delivery systems (such as nuclear missile silos, ballistic missile submarines, and nuclear bombers kept at fail-safe points) and to the Anti-Ballistic Missile Treaty.

This MAD scenario is often referred to as nuclear deterrence. The term "deterrence" is now used in this context[5]; originally, its use was limited to legal terminology[6].[citation needed]

One of the earliest references to the concept comes from the English author Wilkie Collins, writing at the time of the Franco-Prussian War in 1870: "I begin to believe in only one civilizing influenceâ€”the discovery one of these days of a destructive agent so terrible that War shall mean annihilation and men's fears will force them to keep the peace."[7]

Richard Jordan Gatling patented his namesake rotary gun in 1862 with the partial intention of illustrating the futility of war.[8]

After his 1867 invention of dynamite, Alfred Nobel stated that "The day when two army corps can annihilate each other in one second, all civilized nations, it is to be hoped, will recoil from war and discharge their troops."[9]

Jan Gotlib Bloch in The Future of War, published in 1898, argued that the state could not fight a war "under modern conditions with any prospect of being able to carry that war to a conclusion by defeating its adversary by force of arms on the battlefield. No decisive war is possible that will not entail even upon the victorious Power, the destruction of its resources and the breakup of society. War has therefore become impossible, except at the price of suicide."[10]

In 1937, Nikola Tesla published The Art of Projecting Concentrated Non-dispersive Energy through the Natural Media,[11] a treatise concerning charged particle beam weapons.[12] Tesla described his device as a "superweapon that would put an end to all war."

In March 1940, the Frisch–Peierls memorandum anticipated deterrence as the principal means of combating an enemy with nuclear weapons.[13]

In August 1945, the United States accepted the surrender of Japan after the nuclear attacks on Hiroshima and Nagasaki. Four years later, on August 29, 1949, the Soviet Union detonated its own nuclear device. At the time, both sides lacked the means to effectively use nuclear devices against each other. However, with the development of aircraft like the American Convair B-36 and the Soviet Tupolev Tu-95, both sides were gaining a greater ability to deliver nuclear weapons into the interior of the opposing country. The official nuclear policy of the United States became one of "massive retaliation", as coined by President Dwight D. Eisenhower's Secretary of State John Foster Dulles, which called for massive attack against the Soviet Union if they were to invade Europe, regardless of whether it was a conventional or a nuclear attack.[citation needed]

By the time of the 1962 Cuban Missile Crisis, both the United States and the Soviet Union had developed the capability of launching a nuclear-tipped missile from a submerged submarine, which completed the third leg of the nuclear triad weapons strategy necessary to fully implement the MAD doctrine. Having a three-branched nuclear capability eliminated the possibility that an enemy could destroy all of a nation's nuclear forces in a first-strike attack; this, in turn, ensured the credible threat of a devastating retaliatory strike against the aggressor, increasing a nation's nuclear deterrence.[14][15][16]

The RAND corporation futurist and cold war strategist Herman Kahn (1922â€“1982) believed that although MAD was useful as a metaphor, when pushed to its logical conclusion it became absurd. In his 1960 book On Thermonuclear War he advocated a more reasoned approach to nuclear warfare and was understood by some of his critics to be a nuclear war hawk in his writings. (He did however hold a profound belief in the possibility of success in the event of a nuclear war.) He used the concept of the Doomsday Machine as an "idealized (almost caricaturized) device"[17] to illustrate the danger of taking MAD to its extreme. He writes, "I used to be wary of discussing the concept for fear that some colonel would get out a General Operating Requirement or Development Planning Objective for the device".[18] The term, "mutual assured destruction", was coined by Donald Brennan, a strategist working in Kahn's Hudson Institute, in 1962.[19]

The 1964 film Dr. Strangelove parodies some of Kahn's work, and the titular character makes parodic references to Kahn's research, as in this quote from the film (after the United States mistakenly launched a nuclear attack on the USSR): "Under the authority granted me as director of weapons research and development, I commissioned last year a study of this project [of a doomsday machine] by the Bland Corporation. Based on the findings of the report, my conclusion was that this idea was not a practical deterrent, for reasons which, at this moment, must be all too obvious."

Sometime in the 1980s, a second, but real, doomsday device, called The Dead Hand, entered the picture in the Soviet Union. Unlike Kahn's device, it was not based on radioactive cobalt, but it was self-activated and could not be stopped.[20]

Beginning in 1955, the United States Strategic Air Command (SAC) kept one-third of its bombers on alert, with crews ready to take off within fifteen minutes and fly to designated targets inside the Soviet Union and destroy them with nuclear bombs in the event of a Soviet first-strike attack on the United States. In 1961, President John F. Kennedy increased funding for this program and raised the commitment to 50 percent of SAC aircraft.[citation needed]

During periods of increased tension in the early 1960s, SAC kept part of its B-52 fleet airborne at all times, to allow an extremely fast retaliatory strike against the Soviet Union in the event of a surprise attack on the United States. This program continued until 1969. Between 1954 and 1992, bomber wings had approximately one-third of their assigned aircraft on quick reaction ground alert and were able to take off within a few minutes.[citation needed] SAC also maintained the National Emergency Airborne Command Post (NEACP, pronounced "kneecap"), also known as "Looking Glass," which consisted of several EC-135s, one of which was airborne at all times from 1961 through 1990.[citation needed] During the Cuban missile crisis the bombers were dispersed to several different airfields, and also were sometimes airborne. For example, some were sent to Wright Patterson, which normally didn't have B-52s.[citation needed]

During the height of the tensions between the US and the USSR in the 1960s, two popular films were made dealing with what could go terribly wrong with the policy of keeping nuclear-bomb carrying airplanes at the ready: Dr. Strangelove (1964) and Fail Safe (1964).[citation needed]

The strategy of MAD was fully declared in the early 1960s, primarily by United States Secretary of Defense Robert McNamara. In McNamara's formulation there was the very real danger that a nation with nuclear weapons could attempt to eliminate another nation's retaliatory forces with a surprise, devastating first strike and theoretically "win" a nuclear war relatively unharmed. True second-strike capability could be achieved only when a nation had a guaranteed ability to fully retaliate after a first-strike attack.[2]

The United States had achieved an early form of second-strike capability by fielding continual patrols of strategic nuclear bombers, with a large number of planes always in the air, on their way to or from fail-safe points close to the borders of the Soviet Union. This meant the United States could still retaliate, even after a devastating first-strike attack. The tactic was expensive and problematic because of the high cost of keeping enough planes in the air at all times and the possibility they would be shot down by Soviet anti-aircraft missiles before reaching their targets. In addition, as the idea of a missile gap existing between the US and the Soviet Union developed, there was increasing priority being given to ICBMs over bombers.

It was only with the advent of ballistic missile submarines, starting with the George Washington class in 1959, that a genuine survivable nuclear force became possible and a retaliatory second strike capability guaranteed.

The deployment of fleets of ballistic missile submarines established a guaranteed second-strike capability because of their stealth and by the number fielded by each Cold War adversaryâ€”it was highly unlikely that all of them could be targeted and preemptively destroyed (in contrast to, for example, a missile silo with a fixed location that could be targeted during a first strike). Given their long range, high survivability and ability to carry many medium- and long-range nuclear missiles, submarines were credible and effective means for full-scale retaliation even after a massive first strike.[citation needed]

This deterrence strategy and program has continued into the 21st century, with nuclear submarines carrying Trident II ballistic missiles as one leg of the U.S. strategic nuclear deterrent and as the sole deterrent of the United Kingdom. The USA's other such deterrent comprises the intercontinental ballistic missiles (ICBM)s on alert in the continental United States. Ballistic missile submarines are also operated by the navies of China, France, India and Russia.

The U.S. Department of Defense anticipates a continued need for a sea-based strategic nuclear force.[21] The first of the current Ohio-class SSBNs are expected to be retired by 2029,[21] meaning that a replacement platform must already be seaworthy by that time. A replacement may cost over $4 billion per unit compared to the USS Ohio's $2 billion.[22] The U.S. Navy is exploring two options. The first is a variant of the Virginia-class nuclear attack submarines. The second is a dedicated SSBN, either with a new hull or based on an overhaul of the current Ohio-class.[citation needed]

In the 1960s both the Soviet Union (A-35 anti-ballistic missile system) and the United States (LIM-49 Nike Zeus) developed anti-ballistic missile systems. Had such systems been able to effectively defend against a retaliatory second strike, MAD would have been undermined, because a superpower could launch a first strike without fearing the consequences of a retaliatory second strike. See also Strategic Defense Initiative.[citation needed]

The multiple independently targetable re-entry vehicle (MIRV) was another weapons system designed specifically to aid with the MAD nuclear deterrence doctrine. With a MIRV payload, one ICBM could hold many separate warheads. MIRVs were first created by the United States in order to counterbalance the Soviet A-35 anti-ballistic missile systems around Moscow. Since each defensive missile could be counted on to destroy only one offensive missile, making each offensive missile have, for example, three warheads (as with early MIRV systems) meant that three times as many defensive missiles were needed for each offensive missile. This made defending against missile attacks more costly and difficult. One of the largest U.S. MIRVed missiles, the LGM-118A Peacekeeper, could hold up to 10 warheads, each with a yield of around 300 kilotons of TNT (1.3 PJ)—all together, an explosive payload equivalent to 230 Hiroshima-type bombs. The multiple warheads made defense untenable with the available technology, leaving the threat of retaliatory attack as the only viable defensive option. MIRVed land-based ICBMs tend to put a premium on striking first. The START II agreement was proposed to ban this type of weapon, but never entered into force.

In the event of a Soviet conventional attack on Western Europe, NATO planned to use tactical nuclear weapons. The Soviet Union countered this threat by issuing a statement that any use of nuclear weapons (tactical or otherwise) against Soviet forces would be grounds for a full-scale Soviet retaliatory strike (massive retaliation). Thus it was generally assumed that any combat in Europe would end with apocalyptic conclusions.

MIRVed land-based ICBMs are generally considered suitable for a first strike (inherently counterforce) or a counterforce second strike, due to:

Unlike a decapitation strike or a countervalue strike, a counterforce strike might result in a potentially more constrained retaliation. Though the Minuteman III of the mid-1960s was MIRVed with three warheads, heavily MIRVed vehicles threatened to upset the balance; these included the SS-18 Satan which was deployed in 1976, and was considered to threaten Minuteman III silos, which led some neoconservatives to conclude a Soviet first strike was being prepared for. This led to the development of the aforementioned Pershing II, the Trident I and Trident II, as well as the MX missile, and the B-1 Lancer.

MIRVed land-based ICBMs are considered destabilizing because they tend to put a premium on striking first. When a missile is MIRVed, it is able to carry many warheads (up to eight in existing U.S. missiles, limited by New START, though Trident II is capable of carrying up to 12[23]) and deliver them to separate targets. If it is assumed that each side has 100 missiles, with five warheads each, and further that each side has a 95 percent chance of neutralizing the opponent's missiles in their silos by firing two warheads at each silo, then the attacking side can reduce the enemy ICBM force from 100 missiles to about five by firing 40 missiles with 200 warheads, and keeping the rest of 60 missiles in reserve. As such, this type of weapon was intended to be banned under the START II agreement; however, the START II agreement was never brought into force, and neither Russia nor the United States ratified the agreement.

The original U.S. MAD doctrine was modified on July 25, 1980, with U.S. President Jimmy Carter's adoption of countervailing strategy with Presidential DirectiveÂ 59. According to its architect, Secretary of Defense Harold Brown, "countervailing strategy" stressed that the planned response to a Soviet attack was no longer to bomb Soviet population centers and cities primarily, but first to kill the Soviet leadership, then attack military targets, in the hope of a Soviet surrender before total destruction of the Soviet Union (and the United States). This modified version of MAD was seen as a winnable nuclear war, while still maintaining the possibility of assured destruction for at least one party. This policy was further developed by the Reagan administration with the announcement of the Strategic Defense Initiative (SDI, nicknamed "Star Wars"), the goal of which was to develop space-based technology to destroy Soviet missiles before they reached the United States.

SDI was criticized by both the Soviets and many of America's allies (including Prime Minister of the United Kingdom Margaret Thatcher) because, were it ever operational and effective, it would have undermined the "assured destruction" required for MAD. If the United States had a guarantee against Soviet nuclear attacks, its critics argued, it would have first-strike capability, which would have been a politically and militarily destabilizing position. Critics further argued that it could trigger a new arms race, this time to develop countermeasures for SDI. Despite its promise of nuclear safety, SDI was described by many of its critics (including Soviet nuclear physicist and later peace activist Andrei Sakharov) as being even more dangerous than MAD because of these political implications. Supporters also argued that SDI could trigger a new arms race, forcing the USSR to spend an increasing proportion of GDP on defenseâ€”something which has been claimed to have been an indirect cause of the eventual collapse of the Soviet Union.

Proponents of ballistic missile defense (BMD) argue that MAD is exceptionally dangerous in that it essentially offers a single course of action in the event of nuclear attack: full retaliatory response. The fact that nuclear proliferation has led to an increase in the number of nations in the "nuclear club", including nations of questionable stability (e.g. North Korea), and that a nuclear nation might be hijacked by a despot or other person or persons who might use nuclear weapons without a sane regard for the consequences, presents a strong case for proponents of BMD who seek a policy which both protects against attack, but also does not require an escalation into what might become global nuclear war. Russia continues to have a strong public distaste for Western BMD initiatives, presumably because proprietary operative BMD systems could exceed their technical and financial resources and therefore degrade their larger military standing and sense of security in a post-MAD environment. Russian refusal to accept invitations to participate in NATO BMD may be indicative of the lack of an alternative to MAD in current Russian war fighting strategy due to dilapidation of conventional forces after the breakup of the Soviet Union.

After the fall of the Soviet Union, the Russian Federation emerged as a sovereign entity encompassing most of the territory of the former USSR. Relations between the United States and this new power have been less tense than they had been with its predecessor. Tensions also decreased between the United States and China.

The administration of U.S. President George W. Bush withdrew from the Anti-Ballistic Missile Treaty in June 2002, claiming that the limited national missile defense system which they proposed to build was designed only to prevent nuclear blackmail by a state with limited nuclear capability and was not planned to alter the nuclear posture between Russia and the United States.

While relations have improved and an intentional nuclear exchange is more unlikely, the decay in Russian nuclear capability in the post-Cold War era may have had an effect on the continued viability of the MAD doctrine. A 2006 article by Keir Lieber and Daryl Press stated that the United States could carry out a nuclear first strike on Russia and would "have a good chance of destroying every Russian bomber base, submarine, and ICBM." This was attributed to reductions in Russian nuclear stockpiles and the increasing inefficiency and age of that which remains. Lieber and Press argued that the MAD era is coming to an end and that the United States is on the cusp of global nuclear primacy.[24]

However, in a follow-up article in the same publication, others criticized the analysis, including Peter Flory, the U.S. Assistant Secretary of Defense for International Security Policy, who began by writing "The essay by Keir Lieber and Daryl Press contains so many errors, on a topic of such gravity, that a Department of Defense response is required to correct the record."[25] Regarding reductions in Russian stockpiles, another response stated that "a similarly one-sided examination of [reductions in] U.S. forces would have painted a similarly dire portrait".

A situation in which the United States might actually be expected to carry out a "successful" attack is perceived as a disadvantage for both countries. The strategic balance between the United States and Russia is becoming less stable, and the objective, technical possibility of a first strike by the United States is increasing. At a time of crisis, this instability could lead to an accidental nuclear war. For example, if Russia feared a U.S. nuclear attack, Moscow might make rash moves (such as putting its forces on alert) that would provoke a U.S. preemptive strike.[25]

An outline of current U.S. nuclear strategy toward both Russia and other nations was published as the document "Essentials of Post–Cold War Deterrence" in 1995.

Whether MAD was the officially accepted doctrine of the United States military during the Cold War is largely a matter of interpretation. The United States Air Force, for example, has retrospectively contended that it never advocated MAD as a sole strategy, and that this form of deterrence was seen as one of numerous options in U.S. nuclear policy.[26] Former officers have emphasized that they never felt as limited by the logic of MAD (and were prepared to use nuclear weapons in smaller-scale situations than "assured destruction" allowed), and did not deliberately target civilian cities (though they acknowledge that the result of a "purely military" attack would certainly devastate the cities as well). However, according to a declassified 1959 Strategic Air Command study, U.S. nuclear weapons plans specifically targeted the populations of Beijing, Moscow, Leningrad, East Berlin, and Warsaw for systematic destruction.[27] MAD was implied in several U.S. policies and used in the political rhetoric of leaders in both the United States and the USSR during many periods of the Cold War.

To continue to deter in an era of strategic nuclear equivalence, it is necessary to have nuclear (as well as conventional) forces such that in considering aggression against our interests any adversary would recognize that no plausible outcome would represent a victory or any plausible definition of victory. To this end and so as to preserve the possibility of bargaining effectively to terminate the war on acceptable terms that are as favorable as practical, if deterrence fails initially, we must be capable of fighting successfully so that the adversary would not achieve his war aims and would suffer costs that are unacceptable, or in any event greater than his gains, from having initiated an attack.

The doctrine of MAD was officially at odds with that of the USSR, which had, contrary to MAD, insisted survival was possible.[28][29][30] The Soviets believed they could win not only a strategic nuclear war, which they planned to absorb with their extensive civil defense planning,[28][31][32] but also the conventional war that they predicted would follow after their strategic nuclear arsenal had been depleted.[33] Official Soviet policy, though, may have had internal critics towards the end of the Cold War, including some in the USSR's own leadership.[30]

"Nuclear use would be catastrophic."

Second-strike capability

Inability to defend

At an Oxford Union debate in 1985, debating the proposition that Nuclear Weapons are Morally Indefensible, former New Zealand Prime Minister David Lange argued "that the fear [nuclear weapons] inspire is not a justification for their existence," arguing instead that nuclear armament is irrational, morally indefensible and makes us insecure.[36][37]

There is, Mr President, a quality of irrationality about nuclear weapons which does not sit well with good intentions. A system of defence serves its purpose if it guarantees the security of those it protects. A system of nuclear defence guarantees only insecurity. The means of defence terrorise as much as the threat of attack.


what is an ocd lesion of the knee

Osteochondritis dissecans (OCD or OD) is a joint disorder in which cracks form in the articular cartilage and the underlying subchondral bone.[1] OCD usually causes pain and swelling of the affected joint which catches and locks during movement. Physical examination typically reveals an effusion, tenderness, and a crackling sound with joint movement.

Osteochondritis dissecans

OCD is caused by blood deprivation in the subchondral bone. This loss of blood flow causes the subchondral bone to die in a process called avascular necrosis. The bone is then reabsorbed by the body, leaving the articular cartilage it supported prone to damage. The result is fragmentation (dissection) of both cartilage and bone, and the free movement of these bone and cartilage fragments within the joint space, causing pain and further damage.[2][3][4] OCD can be difficult to diagnose because these symptoms are found with other diseases. However, the disease can be confirmed by X-rays, computed tomography (CT) or magnetic resonance imaging (MRI) scans.

Non-surgical treatment is rarely an option as the ability for articular cartilage to heal is limited. As a result, even moderate cases require some form of surgery. When possible, non-operative forms of management such as protected reduced or non-weight bearing and immobilization are used. Surgical treatment includes arthroscopic drilling of intact lesions, securing of cartilage flap lesions with pins or screws, drilling and replacement of cartilage plugs, stem cell transplantation, and joint replacement. After surgery rehabilitation is usually a two-stage process of immobilization and physical therapy. Most rehabilitation programs combine efforts to protect the joint with muscle strengthening and range of motion. During the immobilization period, isometric exercises, such as straight leg raises, are commonly used to restore muscle loss without disturbing the cartilage of the affected joint. Once the immobilization period has ended, physical therapy involves continuous passive motion (CPM) and/or low impact activities, such as walking or swimming.

OCD occurs in 15 to 30 people per 100,000 in the general population each year.[5] Although rare, it is an important cause of joint pain in physically active adolescents.[6] Because their bones are still growing, adolescents are more likely than adults to recover from OCD; recovery in adolescents can be attributed to the bone's ability to repair damaged or dead bone tissue and cartilage in a process called bone remodeling. While OCD may affect any joint, the knee tends to be the most commonly affected, and constitutes 75% of all cases. Franz König coined the term osteochondritis dissecans in 1887, describing it as an inflammation of the bone–cartilage interface. Many other conditions were once confused with OCD when attempting to describe how the disease affected the joint, including osteochondral fracture, osteonecrosis, accessory ossification center, osteochondrosis, and hereditary epiphyseal dysplasia. Some authors have used the terms osteochondrosis dissecans and osteochondral fragments as synonyms for OCD.

In osteochondritis dissecans, fragments of cartilage or bone become loose within a joint, leading to pain and inflammation. These fragments are sometimes referred to as joint mice.[7] OCD is a type of osteochondrosis in which a lesion has formed within the cartilage layer itself, giving rise to secondary inflammation. OCD most commonly affects the knee, although it can affect other joints such as the ankle or the elbow.[8]

People with OCD report activity-related pain that develops gradually. Individual complaints usually consist of mechanical symptoms including pain, swelling, catching, locking, popping noises, and buckling / giving way; the primary presenting symptom may be a restriction in the range of movement.[9] Symptoms typically present within the initial weeks of stage I; however, the onset of stage II occurs within months and offers little time for diagnosis. The disease progresses rapidly beyond stage II, as OCD lesions quickly move from stable cysts or fissures to unstable fragments. Non-specific symptoms, caused by similar injuries such as sprains and strains, can delay a definitive diagnosis.[10]

Physical examination typically reveals fluid in the joint, tenderness, and crepitus. The tenderness may initially spread, but often reverts to a well-defined focal point as the lesion progresses. Just as OCD shares symptoms with common maladies, acute osteochondral fracture has a similar presentation with tenderness in the affected joint, but is usually associated with a fatty hemarthrosis. Although there is no significant pathologic gait or characteristic alignment abnormality associated with OCD, the patient may walk with the involved leg externally rotated in an attempt to avoid tibial spine impingement on the lateral aspect of the medial condyle of the femur.[11]

Despite much research, the causes remain unclear but include repetitive physical trauma, ischemia (restriction of blood flow), hereditary and endocrine factors, avascular necrosis (loss of blood flow), rapid growth, deficiencies and imbalances in the ratio of calcium to phosphorus, and problems of bone formation.[12][13][14][15] Although the name "osteochondritis" implies inflammation, the lack of inflammatory cells in histological examination suggests a non-inflammatory cause. It is thought that repetitive microtrauma, which leads to microfractures and sometimes an interruption of blood supply to the subchondral bone, may cause subsequent localized loss of blood supply or alteration of growth.[16]

Trauma, rather than avascular necrosis, is thought to cause osteochondritis dissecans in juveniles.[17] In adults, trauma is thought to be the main or perhaps the sole cause, and may be endogenous, exogenous or both.[18] The incidence of repetitive strain injury in young athletes is on the rise and accounts for a significant number of visits to primary care;[19] this reinforces the theory that OCD may be associated with increased participation in sports and subsequent trauma.[19][20] High-impact sports such as gymnastics, soccer, basketball, lacrosse, football, tennis, squash, baseball and weight lifting may put participants at a higher risk of OCD in stressed joints (knees, ankles and elbows).[9][21]

Recent case reports suggest that some people may be genetically predisposed to OCD.[22][23][24] Families with OCD may have mutations in the aggrecan gene.[25] Studies in horses have implicated specific genetic defects.[26]

Osteochondritis dissecans differs from "wear and tear" degenerative arthritis, which is primarily an articular surface problem. Instead, OCD is a problem of the bone underlying the cartilage, which may secondarily affect the articular cartilage. Left untreated, OCD can lead to the development of degenerative arthritis secondary to joint incongruity and abnormal wear patterns.[27]

OCD occurs when a loose piece of bone or cartilage partially (or fully) separates from the end of the bone, often because of a loss of blood supply (osteonecrosis) and decalcification of the trabecular bone matrix. The loose piece may stay in place or slide around, making the joint stiff and unstable. OCD in humans most commonly affects the knees,[8] ankles, and elbow but can affect any joint.[28]

In skeletally immature individuals, the blood supply to the epiphyseal bone is good, supporting both osteogenesis and chondrogenesis. With disruption of the epiphyseal plate vessels, varying degrees and depth of necrosis occur, resulting in a cessation of growth to both osteocytes and chondrocytes. In turn, this pattern leads to disordered ossification of cartilage, resulting in subchondral avascular necrosis and consequently OCD.[29]

Four minor stages of OCD have been identified after trauma. These include revascularization and formation of granulation (scar) tissue, absorption of necrotic fragments, intertrabecular osteoid deposition, and remodeling of new bone. With delay in the revascularization stage, an OCD lesion develops. A lesion can lead to articular-surface irregularities, which in turn may cause progressive arthritic deterioration.[29]

To diagnose osteochondritis dissecans, an X-ray, CT scan or MRI scan can be performed to show necrosis of subchondral bone, formation of loose fragments, or both.[30] Occasionally a nuclear medicine bone scan is used to assess the degree of loosening within the joint.[31]

Physical examination often begins with examination of the patient's gait. In OCD of the knee, people may walk with the involved leg externally rotated in an attempt to avoid tibial spine impingement on the lateral aspect of the medial condyle of the femur.[11]

Next, the examining physician may check for weakness of the quadriceps. This examination may reveal fluid in the joint, tenderness, and crepitus. The Wilson test is also useful in locating OCD lesions of the femoral condyle.[32] The test is performed by slowly extending the knee from 90 degrees, maintaining internal rotation. Pain at 30 degrees of flexion and relief with tibial external rotation is indicative of OCD.[33]

Physical examination of a patient with ankle OCD often returns symptoms of joint effusion, crepitus, and diffuse or localized tenderness. Examination often reveals symptoms of generalized joint pain, swelling, and times with limited range of motion. Some with loose body lesions may report catching, locking, or both.[34] The possibility of microtrauma emphasizes a need for evaluation of biomechanical forces at the knee in a physical examination. As a result, the alignment and rotation of all major joints in the affected extremity is common, as are extrinsic and intrinsic abnormalities concerning the affected joint, including laxity.[35]

X-rays show lucency of the ossification front in juveniles. In older people, the lesion typically appears as an area of osteosclerotic bone with a radiolucent line between the osteochondral defect and the epiphysis. The visibility of the lesion depends on its location and on the amount of knee flexion used. Harding described the lateral X-ray as a method to identify the site of an OCD lesion.[36]

Magnetic resonance imaging (MRI) is useful for staging OCD lesions, evaluating the integrity of the joint surface, and distinguishing normal variants of bone formation from OCD by showing bone and cartilage edema in the area of the irregularity. MRI provides information regarding features of the articular cartilage and bone under the cartilage, including edema, fractures, fluid interfaces, articular surface integrity, and fragment displacement.[37][38] A low T1 and high T2 signal at the fragment interface is seen in active lesions. This indicates an unstable lesion or recent microfractures.[30] While MRI and arthroscopy have a close correlation, X-ray films tend to be less inductive of similar MRI results.[38]

Computed tomography (CT) scans and Technetium-99m bone scans are also sometimes used to monitor the progress of treatment. Unlike plain radiographs (X-rays), CT scans and MRI scans can show the exact location and extent of the lesion.[39] Technetium bone scans can detect regional blood flow and the amount of osseous uptake. Both of these seem to be closely correlated to the potential for healing in the fragment.[40][41]

CT scan and projectional radiography of a case of osteochondritis dissecans of parts of the superio-medial talus.

Sagittal MRI: Linear low T1 signal at the articular surfaces of the lateral aspects of the medial condyle of the femur confirms the presence of OCD.

Sagittal MRI: High T2 signal at the articular surfaces of the lateral aspect of the medial femoral condyle confirms the presence of OCD. Diffuse increase in T2 signal at the medial femoral condyle indicates marrow edema.

OCD is classified by the progression of the disease in stages. There are two main staging classifications used; one is determined by MRI diagnostic imaging while the other is determined arthroscopically. However, both stagings represent the pathological conditions associated with OCD's natural progression.[9]

While the arthroscopic classification of bone and cartilage lesions is considered standard, the Anderson MRI staging is the main form of staging used in this article.[42] Stages I and II are stable lesions. Stages III and IV describe unstable lesions in which a lesion of the cartilage has allowed synovial fluid between the fragment and bone.

Treatment options include modified activity with or without weight bearing; immobilization; cryotherapy; anti-inflammatory medication; drilling of subchondral bone; microfracture; removal or reattachment of loose bodies; mosaicplasty and osteoarticular transfer system (OATS) procedures.[20][44] The primary goals of treatment are:[45]

The articular cartilage's capacity for repair is limited:[46] partial-thickness defects in the articular cartilage do not heal spontaneously, and injuries of the articular cartilage which fail to penetrate subchondral bone tend to lead to deterioration of the articular surface.[47] As a result, surgery is often required in even moderate cases where the osteochondral fragment has not detached from the bone (Anderson StageÂ II, III).[48]

Candidates for non-operative treatment are limited to skeletally immature teenagers with a relatively small, intact lesion and the absence of loose bodies. Non-operative management may include activity modification, protected weight bearing (partial or non-weight bearing), and immobilization. The goal of non-operative intervention is to promote healing in the subchondral bone and prevent potential chondral collapse, subsequent fracture, and crater formation.[45]

Once candidates for treatment have been screened, treatment proceeds according to the lesion's location. For example, those with OCD of the knee are immobilized for four to six weeks or even up to six months in extension to remove shear stress from the involved area;[49] however, they are permitted to walk with weight bearing as tolerated. X-rays are usually taken three months after the start of non-operative therapy; if they reveal that the lesion has healed, a gradual return to activities is instituted.[48][50] Those demonstrating healing by increased radiodensity in the subchondral region, or those whose lesions are unchanged, are candidates to repeat the above described three-month protocol until healing is noted.[28]

The choice of surgical versus non-surgical treatments for osteochondritis dissecans is controversial.[51] Consequently, the type and extent of surgery necessary varies based on patient age, severity of the lesion, and personal bias of the treating surgeonâ€”entailing an exhaustive list of suggested treatments. A variety of surgical options exist for the treatment of persistently symptomatic, intact, partially detached, and completely detached OCD lesions. Post-surgery reparative cartilage is inferior to healthy hyaline cartilage in glycosaminoglycan concentration, histological, and immunohistochemical appearance.[52] As a result, surgery is often avoided if non-operative treatment is viable.

If non-surgical measures are unsuccessful, drilling may be considered to stimulate healing of the subchondral bone. Arthroscopic drilling may be performed by using an antegrade (from the front) approach from the joint space through the articular cartilage, or by using a retrograde (from behind) approach through the bone outside of the joint to avoid penetration of the articular cartilage. This has proven successful with positive results at one-year follow-up with antegrade drilling in nine out of eleven teenagers with the juvenile form of OCD,[53] and in 18 of 20 skeletally immature people (follow-up of five years) who had failed prior conservative programs.[54]

Pins and screws can be used to secure flap (sometimes referred to as hinged) lesions.[55] Bone pegs, metallic pins and screws, and other bioresorbable screws may be used to secure these types of lesions.[56]

The three methods most commonly used in treating full thickness lesions are arthroscopic drilling, abrasion, and microfracturing.

In 1946, Magnusson established the use of stem cells from bone marrow with the first surgical debridement of an OCD lesion. These cells typically differentiate into fibrocartilage and rarely form hyaline cartilage. While small lesions can be resurfaced using this form of surgery, the repair tissue tends to have less strength than normal hyaline cartilage and must be protected for 6 to 12 months. Results for large lesions tend to diminish over time; this can be attributed to the decreased resilience and poor wear characteristics of the fibrocartilage.[57]

In attempts to address the weaker structure of the reparative fibrocartilage, new techniques have been designed to fill the defect with tissue that more closely simulates normal hyaline articular cartilage. One such technique is autologous chondrocyte implantation (ACI), which is useful for large, isolated femoral defects in younger people. In this surgery, chondrocytes are arthroscopically extracted from the intercondylar notch of the articular surface. The chondrocytes are grown and injected into the defect under a periosteal patch. ACI surgery has reported good to excellent results for reduced swelling, pain and locking in clinical follow-up examinations.[58][59] However, some physicians have preferred to use undifferentiated pluripotential cells, such as periosteal cells and bone marrow stem cells, as opposed to chondrocytes. These too have demonstrated the ability to regenerate both the cartilage and the underlying subchondral bone.[60]

Similar to OATS, arthroscopic articular cartilage paste grafting is a surgical procedure offering cost-effective, long-lasting results for stage IV lesions. A bone and cartilage paste derived from crushed plugs of the non-weight-bearing intercondylar notch can achieve pain relief, repair damaged tissue, and restore function.[61]

Some methods of fixation for unstable lesions include countersunk compression screws and Herbert screws or pins made of stainless steel or materials that can be absorbed by the body.[62] If loose bodies are found, they are removed. Although each case is unique and treatment is chosen on an individual basis, ACI is generally performed on large defects in skeletally mature people.

Continuous passive motion (CPM) has been used to improve healing of the articular surface during the postoperative period for people with full-thickness lesions. It has been shown to promote articular cartilage healing for small (< 3Â mm in diameter) lesions in rabbits.[63] Similarly, Rodrigo and Steadman reported that CPM for six hours per day for eight weeks produced an improved clinical outcome in humans.[64]

A rehabilitation program often involves protection of the compromised articular surface and underlying subchondral bone combined with maintenance of strength and range of motion. Post-operative analgesics, namely a mix of opioids and NSAIDs, are usually required to control pain, inflammation and swelling.[65] Straight leg raising and other isometric exercises are encouraged during the post-operative or immobilization period. A six to eight-week home or formal physical therapy program is usually instituted once the immobilization period has ended, incorporating range of motion, stretching, progressive strengthening, and functional or sport-specific training. During this time, patients are advised to avoid running and jumping, but are permitted to perform low impact activities, such as walking or swimming. If patients return to activity before the cartilage has become firm, they will typically complain of pain during maneuvers such as squatting or jumping.[48]

The prognosis after different treatments varies and is based on several factors which include the age of the patient, the affected joint, the stage of the lesion and, most importantly, the state of the growth plate.[34] It follows that the two main forms of osteochondritis dissecans are defined by skeletal maturity. The juvenile form of the disease occurs in open growth plates, usually affecting children between the ages of 5 and 15 years.[66] The adult form commonly occurs between ages 16 to 50, although it is unclear whether these adults developed the disease after skeletal maturity or were undiagnosed as children.[67]

The prognosis is good for stable lesions (stage I and II) in juveniles with open growth plates; treated conservatively—typically without surgery—50% of cases will heal.[68] Recovery in juveniles can be attributed to the bone's ability to repair damaged or dead bone tissue and cartilage in a process called bone remodeling. Open growth plates are characterized by increased numbers of undifferentiated chondrocytes (stem cells) which are precursors to both bone and cartilaginous tissue. As a result, open growth plates allow for more of the stem cells necessary for repair in the affected joint.[69] Unstable, large, full-thickness lesions (stage III and IV) or lesions of any stage found in the skeletally mature are more likely to fail non-operative treatment. These lesions offer a worse prognosis and surgery is required in most cases.[70][71]

OCD is a relatively rare disorder, with an estimated incidence of 15 to 30 cases per 100,000 persons per year.[5] Widuchowski W et al. found OCD to be the cause of articular cartilage defects in 2% of cases in a study of 25,124 knee arthroscopies.[72] Although rare, OCD is noted as an important cause of joint pain in active adolescents. The juvenile form of the disease occurs in children with open growth plates, usually between the ages 5 and 15 years and occurs more commonly in males than females, with a ratio between 2:1 and 3:1.[8][73] However, OCD has become more common among adolescent females as they become more active in sports.[74] The adult form, which occurs in those who have reached skeletal maturity, is most commonly found in people 16 to 50 years old.[70]

While OCD may affect any joint, the knee—specifically the medial femoral condyle in 75–85% of knee cases—tends to be the most commonly affected, and constitutes 75% of all cases.[8][75][76][77] The elbow (specifically the capitulum of the humerus) is the second most affected joint with 6% of cases; the talar dome of the ankle represents 4% of cases.[78] Less frequent locations include the patella, vertebrae, the femoral head, and the glenoid of the scapula.[79]

The condition was initially described by Alexander Monro (primus) in 1738.[80] In 1870, James Paget described the disease process for the first time, but it was not until 1887 that Franz König published a paper on the cause of loose bodies in the joint.[81] In his paper, König concluded that:[82]

KÃ¶nig named the disease "osteochondritis dissecans",[83] describing it as a subchondral inflammatory process of the knee, resulting in a loose fragment of cartilage from the femoral condyle. In 1922, Kappis described this process in the ankle joint.[84] On review of all literature describing transchondral fractures of the talus, Berndt and Harty developed a classification system for staging of osteochondral lesions of the talus (OLTs).[85] The term osteochondritis dissecans has persisted, and has since been broadened to describe a similar process occurring in many other joints, including the knee, hip, elbow, and metatarsophalangeal joints.[86][87]

OCD also is found in animals, and is of particular concern in horses, as there may be a hereditary component in some horse breeds.[94] Feeding for forced growth and selective breeding for increased size are also factors. OCD has also been studied in other animals—mainly dogs, especially the German Shepherd[95]—where it is a common primary cause of elbow dysplasia in medium-large breeds.[96]

In animals, OCD is considered a developmental and metabolic disorder related to cartilage growth and endochondral ossification. Osteochondritis itself signifies the disturbance of the usual growth process of cartilage, and OCD is the term used when this affects joint cartilage causing a fragment to become loose.[97]

According to the Columbia Animal Hospital the frequency of affected animals is dogs, humans, pigs, horses, cattle, chickens, and turkeys, and in dogs the most commonly affected breeds include the German Shepherd, Golden and Labrador Retriever, Rottweiler, Great Dane, Bernese Mountain Dog, and Saint Bernard.[98] Although any joint may be affected, those commonly affected by OCD in the dog are: shoulder (often bilaterally), elbow, knee and tarsus.[98]

The problem develops in puppyhood although often subclinically, and there may be pain or stiffness, discomfort on extension, or other compensating characteristics. Diagnosis generally depends on X-rays, arthroscopy, or MRI scans. While cases of OCD of the stifle go undetected and heal spontaneously, others are exhibited in acute lameness. Surgery is recommended once the animal has been deemed lame.[95]

Osteochondritis dissecans is difficult to diagnose clinically as the animal may only exhibit an unusual gait. Consequently, OCD may be masked by, or misdiagnosed as, other skeletal and joint conditions such as hip dysplasia.[95]


who discovered treacher collins syndrome and when was it first diagnosed

Treacher Collins syndrome is not curable.[6] Symptoms may be managed with reconstructive surgery, hearing aids, speech therapy, and other assistive devices.[6] Life expectancy is generally normal.[6] TCS occurs in about one in 50,000 people.[5] The syndrome is named after Edward Treacher Collins, an English surgeon and ophthalmologist, who described its essential traits in 1900.[7][8]

Treacher Collins syndrome

Treacher Collins syndrome (TCS) is a genetic disorder characterized by deformities of the ears, eyes, cheekbones, and chin.[5] The degree a person is affected, however, may vary from mild to severe.[5] Complications may include breathing problems, problems seeing, cleft palate, and hearing loss.[5] Those affected generally have a normal intelligence.[5]

TCS is usually autosomal dominant.[5] More than half the time it occurs as a result of a new mutation rather than being inherited from a person's parents.[5] The involved gene may include TCOF1, POLR1C, or POLR1D.[5] Diagnosis is generally suspected based on symptoms and X-rays, and potentially confirmation by genetic testing.[3]

Symptoms in people with Treacher Collins syndrome vary. Some individuals are so mildly affected that they remain undiagnosed, while others have moderate to severe facial involvement and life-threatening airway compromise.[9] Most of the features of TCS are symmetrical and are already recognizable at birth.[citation needed]

The most common symptom of Treacher Collins syndrome is underdevelopment of the lower jaw and underdevelopment of the zygomatic bone. This can be accompanied by the tongue being retracted. The small mandible can result in a poor occlusion of the teeth or in more severe cases, trouble breathing or swallowing. Underdevelopment of the zygomatic bone gives the cheeks a sunken appearance.[10][11]

The external ear is sometimes small, rotated, malformed, or absent entirely in people with TCS. Symmetric, bilateral narrowing or absence of the external ear canals is also described.[11][12] In most cases, the bones of the middle ear and the middle ear cavity are misshapen. Inner ear malformations are rarely described. As a result of these abnormalities, a majority of the individuals with TCS have conductive hearing loss.[11][13]

Most affected people also experience eye problems, including colobomata (notches) in the lower eyelids, partial or complete absence of eyelashes on the lower lid, downward angled eyelids, drooping of upper and lower eyelids, and narrowing of the tear ducts. Vision loss can occur and is associated with strabismus, refractive errors, and anisometropia. It can also be caused by severely dry eyes, a consequence of lower eyelid abnormalities and frequent eye infections.[11][12][14][15]

Although an abnormally shaped skull is not distinctive for Treacher Collins syndrome, brachycephaly with bitemporal narrowing is sometimes observed.[12] Cleft palate is also common.[11]

Dental anomalies are seen in 60% of affected people, including tooth agenesis (33%), discoloration (enamel opacities) (20%), malplacement of the maxillary first molars (13%), and wide spacing of the teeth. In some cases, dental anomalies in combination with mandible hypoplasia result in a malocclusion. This can lead to problems with food intake and the ability to close the mouth.[11]

Less common features of TCS may add to an affected person's breathing problems, including sleep apnea. Choanal atresia or stenosis is a narrowing or absence of the choanae, the internal opening of the nasal passages. Underdevelopment of the pharynx, can also narrow the airway.[11]

Features related to TCS that are seen less frequently include nasal deformities, high-arched palate, macrostomia, preauricular hair displacement, cleft palate, hypertelorism, notched upper eyelid, and congenital heart defects.[10][11][15]

The general public may associate facial deformity with developmental delay and intellectual disability, but more than 95% of people affected with TCS have normal intelligence.[11] The psychological and social problems associated with facial deformity can affect quality of life in people with TCS.

Mutations in TCOF1, POLR1C, or POLR1D genes can cause Treacher Collins syndrome.[16] TCOF1 gene mutations are the most common cause of the disorder, accounting for 81 to 93% of all cases. POLR1C and POLR1D gene mutations cause an additional 2% of cases. In individuals without an identified mutation in one of these genes, the genetic cause of the condition is unknown. The TCOF1, POLR1C, and POLR1D genes code for proteins which play important roles in the early development of bones and other tissues of the face. Mutations in these genes reduce the production of rRNA, which may trigger the self-destruction (apoptosis) of certain cells involved in the development of facial bones and tissues. It is unclear why the effects of a reduction in rRNA are limited to facial development. Mutations in TCOF1 and POLR1D cause the autosomal dominant form of Treacher Collins, and mutations in POLR1C cause the autosomal recessive form.[11]

TCOF1 is the primary gene associated with TCS; a mutation in this gene being found in 90-95% of the individuals with TCS.[10][17] However, in some individuals with typical symptoms of TCS, mutations in TCOF1 have not been found.[18] Investigation of the DNA has resulted in the identification of the kind of mutations found in TCOF1. The majority of mutations are small deletions or insertions, though splice site and missense mutations also have been identified.[10][19][20][21]

Mutation analysis has unveiled more than 100 disease-causing mutations in TCOF1, which are mostly family-specific mutations. The only recurrent mutation accounts for about 17% of the cases.[22]

TCOF1 is found on the 5th chromosome in the 5q32 region. It codes for a relatively simple nucleolar protein called treacle, that is thought to be involved in ribosome assembly.[17] Mutations in TCOF1 lead to haploinsufficiency of the treacle protein.[23] Haploinsufficiency occurs when a diploid organism has only one functional copy of a gene, because the other copy is inactivated by a mutation. The one normal copy of the gene does not produce enough protein, causing disease. Haploinsufficiency of the treacle protein leads to a depletion of the neural crest cell precursor, which leads to a reduced number of crest cells migrating to the first and second pharyngeal arches. These cells play an important role in the development of the craniofacial appearance, and loss of one copy of treacle affects the cells' ability to form the bones and tissues of the face.[11][19][24]

POLR1C and POLR1D mutations are responsible for a minority of cases of Treacher Collins. POLR1C is found on chromosome 6 at position 6q21.2 and codes for a protein subunit of RNA polymerase I. POLR1D is found on chromosome 13 at position 13q12.2 and codes for a protein subunit of RNA polymerase III. Both of these polymerases are important for ribosome biogenesis.[11]

TCS is inherited in an autosomal dominant manner and the penetrance of the affected gene is almost complete.[25] Some recent investigations, though, described some rare cases in which the penetrance in TCS was not complete. Causes may be a variable expressivity, an incomplete penetrance [26] or germline mosaicism.[27] Only 40% of the mutations are inherited. The remaining 60% are a result of a de novo mutation, where a child has a new mutation in the responsible gene and did not inherit it from either parent.[11][28] In the outcome of the disease, inter- and intrafamilial variability occurs. This suggests, when an affected child is born, it is important to investigate the parents to determine whether the affected gene is present, because the parent could have a mild form of the disease that has not been diagnosed. In this case, the risk of having another affected child is 50%. If the parents do not have the affected gene, the recurrence risk appears to be low.[25] In following generations, the severity of the clinical symptoms increases.[20]

Mutations in the main genes responsible for TCS can be detected with chorionic villus sampling or amniocentesis. Rare mutations may not be detected by these methods. Ultrasonography can be used to detect craniofacial abnormalities later in pregnancy, but may not detect milder cases.[11]

TCS is often first suspected with characteristic symptoms observed during a physical exam. However, the clinical presentation of TCS can resemble other diseases, making diagnosis difficult.[29] The OMENS classification was developed as a comprehensive and stage-based approach to differentiate the diseases. This acronym describes five distinct dysmorphic manifestations, namely orbital asymmetry, mandibular hypoplasia, auricular deformity, nerve development, and soft-tissue disease.[30]

A few techniques are used to confirm the diagnosis in TCS.[29][31]

An orthopantomogram (OPG) is a panoramic dental X-ray of the upper and lower jaw. It shows a two-dimensional image from ear to ear. Particularly, OPG facilitates an accurate postoperative follow-up and monitoring of bone growth under a mono- or double-distractor treatment. Thereby, some TCS features could be seen on OPG, but better techniques are used to include the whole spectrum of TCS abnormalities instead of showing only the jaw abnormalities.[29]

Another method of radiographic evaluation is taking an X-ray image of the whole head. The lateral cephalometric radiograph in TCS shows hypoplasia of the facial bones, like the malar bone, mandible, and the mastoid.[29]

Finally, occipitomental radiographs are used to detect hypoplasia or discontinuity of the zygomatic arch.[31]

A temporal-bone CT using thin slices makes it possible to diagnose the degree of stenosis and atresia of the external auditory canal, the status of the middle ear cavity, the absent or dysplastic and rudimentary ossicles, or inner ear abnormalities such as a deficient cochlea. Two- and three-dimensional CT reconstructions with VRT and bone and skin-surfacing are helpful for more accurate staging and the three-dimensional planning of mandibular and external ear reconstructive surgery.[citation needed]

Other diseases have similar characteristics to Treacher Collins syndrome. In the differential diagnosis, one should consider the acrofacial dysostoses. The facial appearance resembles that of Treacher Collins syndrome, but additional limb abnormalities occur in those persons. Examples of these diseases are Nager syndrome and Miller syndrome. The oculoauriculovertebral spectrum should also be considered in the differential diagnosis. An example is hemifacial microsomia, which primarily affects development of the ear, mouth, and mandible. This anomaly may occur bilaterally. Another disease which belongs to this spectrum is Goldenhar syndrome, which includes vertebral abnormalities, epibulbar dermoids and facial deformities.[32]

The treatment of individuals with TCS may involve the intervention of professionals from multiple disciplines. The primary concerns are breathing and feeding, as a consequence of the hypoplasia of the mandibula and the obstruction of the hypopharynx by the tongue. Sometimes, they may require a tracheostomy to maintain an adequate airway,[33] and a gastrostomy to assure an adequate caloric intake while protecting the airway. Corrective surgery of the face is performed at defined ages, depending on the developmental state.[34]

An overview of the present guidelines:

Hearing loss in Treacher Collins syndrome is caused by deformed structures in the outer and middle ear. The hearing loss is generally bilateral with a conductive loss of about 50-70Â dB. Even in cases with normal auricles and open external auditory canals, the ossicular chain is often malformed.[40]

Attempts to surgically reconstruct the external auditory canal and improve hearing in children with TCS have not yielded positive results.[41]

Auditory rehabilitation with bone-anchored hearing aids (BAHAs) or a conventional bone conduction aid has proven preferable to surgical reconstruction.[37]

The disorder can be associated with a number of psychological symptoms, anxiety, depression, social phobia, body image disorders, and patients may be subjected to discrimination, bullying and name calling especially when young. A multi-disciplinary team and parental support should include these issues.

TCS occurs in about one in 50,000 births in Europe.[42] Worldwide, it is estimated to occur in one in 10,000 to one in 50,000 births.[11]

The syndrome is named after Edward Treacher Collins (1862â€“1932), the English surgeon and ophthalmologist who described its essential traits in 1900.[7][8][43] In 1949, Adolphe Franceschetti and David Klein described the same condition on their own observations as mandibulofacial dysostosis. The term mandibulofacial dysostosis is used to describe the clinical features.[44]

A July 1977 New York Times article[45] that was reprinted in numerous newspapers nationwide over the ensuing weeks brought this malady to many people's attention for the first time.

The disorder was featured on the show Nip/Tuck, in the episode "Blu Mondae".[46]

TLC's Born Without a Face[47] features Juliana Wetmore, who was born with the most severe case in medical history of this syndrome and is missing 30%â€“40% of the bones in her face.[47]

In 2010, BBC Three documentary Love Me, Love My Face[48] covered the case of a man, Jono Lancaster, with the condition. In 2011, BBC Three returned to Jono to cover his and his partner Laura's quest to start a family,[2] in So What If My Baby Is Born Like Me?,[49] which first aired as part of a BBC Three season of programmes on parenting.[50] The first film was replayed on BBC One shortly ahead of the second film's initial BBC Three broadcast. Lancaster's third BBC Three film, Finding My Family on Facebook, which looked at adoption, aired in 2011.[51]

In Wonder, the children's novel, the main character is a child who has Treacher Collins syndrome.[52] A 2017 film adaptation, starring Julia Roberts, Owen Wilson and Jacob Tremblay, was released in November 2017.[53]


when did the word lunch start being used

The abbreviation lunch is taken from the more formal Northern English word luncheon, which is derived from the Anglo-Saxon word nuncheon or nunchin meaning 'noon drink'.[2]  The term has been in common use since 1823.[3][a] The Oxford English Dictionary (OED) reports usage of the words beginning in 1580 to describe a meal that was eaten between more substantial meals. It may also mean a piece of cheese or bread.[3]

Lunch

Lunch, the abbreviation for luncheon, is a meal typically eaten at midday.[1] During the 20th century, the meaning gradually narrowed to a small or mid-sized meal eaten midday. Lunch is commonly the second meal of the day, after breakfast. The meal varies in size depending on the culture, and significant variations exist in different areas of the world.

In medieval Germany, there are references to similariar, a sir lunchentach according to the OED, a noon draught – of ale, with bread – an extra meal between midday dinner and supper, especially during the long hours of hard labour during haying or early harvesting.

Meals have become ingrained in each society as being natural and logical. What one society eats may seem extraordinary to another. The same is true of what was eaten long ago in history as food tastes, menu items and meal periods have changed greatly over time. For example, the word supper means bread and soup[4] (from the German word sop- soup or stew over bread[5]).

In general, during the Middle Ages the main meal for almost everyone took place late in the morning, after several hours of work, when there was no need for artificial lighting. During the 17th and 18th centuries, this meal, called dinner, was gradually pushed back into the evening, creating a greater time gap between breakfast and dinner. A meal called lunch came to fill the gap.[6] A formal evening meal, artificially lit by candles, sometimes with entertainment, was a supper party as late as the Regency era.

Up until the early 19th century, luncheon was generally reserved for the ladies, who would often have lunch with one another when their husbands were out. As late as 1945, Emily Post wrote in the magazine Etiquette that luncheon is "generally given by and for women, but it is not unusual, especially in summer places or in town on Saturday or Sunday, to include an equal number of men" – hence the mildly disparaging phrase, "the ladies who lunch". Lunch was a ladies' light meal; when the Prince of Wales stopped to eat a dainty luncheon with lady friends, he was laughed at for this effeminacy.[6]

Beginning in the 1840s, afternoon tea supplemented this luncheon at four o'clock.[6] Mrs Beeton's Book of Household Management (1861) – a guide to all aspects of running a household in Victorian Britain, edited by Isabella Beeton – had much less to explain about luncheon than about dinners or ball suppers:

The remains of cold joints, nicely garnished, a few sweets, or a little hashed meat, poultry or game, are the usual articles placed on the table for luncheon, with bread and cheese, biscuits, butter, etc. If a substantial meal is desired, rump-steaks or mutton chops may be served, as also veal cutlets, kidneys... In families where there is a nursery, the mistress of the house often partakes of the meal with the children, and makes it her luncheon. In the summer, a few dishes of fresh fruit should be added to the luncheon, or, instead of this, a compote of fruit or fruit tart, or pudding.[7]

With the onset of industrialisation in the 19th century, male workers began to work long shifts at the factory, severely disrupting the age-old eating habits of rural life. Initially, workers were sent home for a brief dinner provided by their wives, but as the workplace was moved farther from the home, working men took to providing themselves with something portable to eat during a break in the middle of the day.

The lunch meal slowly became institutionalised in England when workers with long and fixed hour jobs at the factory were eventually given an hour off work to eat lunch and thus gain strength for the afternoon shift. Stalls and later chop houses near the factories began to provide mass-produced food for the working class, and the meal soon became an established part of the daily routine, remaining so to this day.[8]

In many countries and regions lunch is the dinner or main meal.[9] Prescribed lunchtimes allow workers to return to their homes to eat with their families. Consequently, where lunch is the customary main meal of the day, businesses close during lunchtime. Lunch also becomes dinner on special days, such as holidays or special events, including, for example, Christmas dinner and harvest dinners such as Thanksgiving; on these special days, dinner is usually served in early afternoon. Among Christians, the main meal on Sunday, whether at a restaurant or at home, is called "Sunday dinner", and is served after morning church services.[citation needed]

A traditional Bengali lunch is a seven-course meal. Bengali cuisine is a culinary style originating in Bengal, a region in the eastern part of the Indian subcontinent, which is now divided between Bangladesh and West Bengal. The first course is shukto, which is a mix of vegetables cooked with few spices and topped with a coconut sauce. The second course consists of rice, dal, and a vegetable curry. The third course consists of rice and fish curry. The fourth course is that of rice and meat curry (generally chevon, mutton, chicken or lamb). The fifth course contains sweet preparations like rasgulla, pantua, rajbhog, sandesh, etc. The sixth course consists of payesh or mishti doi (sweet yogurt). The seventh course is that of paan, which acts as a mouth freshener.

In China today, lunch is not nearly as complicated as it was before industrialisation. Rice, noodles and other mixed hot foods are often eaten, either at a restaurant or brought in a container. Western cuisine is not uncommon. It is called 午餐 or 午饭 in most areas.

Lunch in Denmark, referred to as frokost,[10] is a light meal. Often it includes rye bread with different toppings such as liver pâté, herring, and cheese.[11][12][13] Smørrebrød is a Danish lunch delicacy that is often used for business meetings or special events.

In Finland, lunch is a full hot meal,[b] served as one course, sometimes with small salads and desserts. Dishes are diverse, ranging from meat or fish courses to soups that are heavy enough to constitute a meal.[15]

In France, the midday meal is taken between noon and 2:00Â pm.[16]

In Germany lunch is the main meal of the day.[c] It is traditionally a substantial hot meal, sometimes with additional courses like soup and dessert. It is usually a savoury dish, consisting of protein (e.g., meat), starchy foods (e.g., potatoes) and vegetables or salad. Casseroles and stews are popular as well. There are a few sweet dishes like Germknödel or rice pudding that can serve as a main course, too. Lunch is called Mittagessen – literally, "midday's food".

In the Netherlands, Belgium and Norway, it is common to eat sandwiches for lunch: slices of bread that people usually carry to work or school and eat in the canteen. The slices of bread are usually filled with sweet or savoury foodstuffs such as chocolate sprinkles (vlokken), apple syrup, peanut butter, slices of meat, cheese or kroket. The meal typically includes coffee, milk or juice, and sometimes yogurt, some fruit or soup. It is eaten around noon, during a lunch break.

In Portugal, lunch (almoço in Portuguese) consists of a full hot meal, similar to dinner, normally with soup, a meat or fish course, and dessert. It is served between noon and 2:00 pm. It is the main meal of the day throughout the country with the exceptions of the Metropolitan areas of Lisbon and Porto, where lighter meals or snacks are not uncommon. The Portuguese word lanches derives from the English word "lunch", but it refers to a lighter meal or snack taken during the afternoon (around 5 pm) due to the fact that, traditionally, Portuguese dinner is served at a later hour than in English-speaking countries.

In Spain, the midday meal, "lunch" takes place between 1:00 pm and 3:00 pm and is effectively dinner, (the main meal of the day); in contrast, supper does not usually begin until between 8:30 pm and 10:00 pm. Being the main meal of the day everywhere, it usually consists of a three-course meal: the first course usually consists of an appetizer; the main course of a more elaborate dish, usually meat- or fish-based; the dessert of something sweet, often accompanied by a coffee or small amounts of spirits. Most places of work have a complete restaurant with a lunch break of a least an hour. Spanish schools have a complete restaurant as well, and students have a one-hour break. Three courses are common practice at home, workplace, and schools. Most small shops close for between two and four hours – usually between 1:30 pm to 4:30 pm – to allow to go home for a full lunch.

In Sweden, lunch is usually a full hot meal, much as in Finland.[b]

In the United Kingdom, lunch is often a small meal, designed to stave off hunger until returning home from work and eating dinner. It is usually eaten early in the afternoon.[18] Lunch is often purveyed and consumed in pubs.[19] Pub lunch dishes include fish and chips, ploughman's lunch and others.[18]

In Hungary, lunch is traditionally the main meal of the day,[20] following a leves (soup).

In Poland the main meal of the day (called obiad) is traditionally eaten between 1:00 pm and 5:00 pm,[d] and consists of a soup and a main dish. Most Poles equate the English word "lunch" with "obiad" because it is the second of the three main meals of the day; śniadanie (breakfast), obiad (lunch/dinner) and kolacja (dinner/supper). There is another meal eaten by some called drugie śniadanie, which means "second breakfast". Drugie śniadanie is eaten around 10:00 am and is a light snack, usually consisting of sandwiches, salad or a thin soup.

In Russia, the midday meal is taken in the afternoon. Usually, lunch is the biggest meal[e] and consists of a first course, usually a soup, and a second course which would be meat and a garnish. Tea is standard.

In Bosnia and Herzegovina, lunch is the main meal of the day. It is traditionally a substantial hot meal, sometimes with additional courses like soup and dessert. It is usually a savoury dish, consisting of protein (such as meat), starchy foods (such as potatoes), and a vegetable or salad. It is usually eaten around 2:00Â pm.

In Romania, lunch (prânz in Romanian) is the main hot meal of the day.[23] It is usually eaten at 12:00, but never later than 3:00 pm. Lunch normally consists of two dishes: usually, the first course is a light soup and the second course, the main course, often consists of meat accompanied by potato, rice or pasta (garnitură)[citation needed] Traditionally, people used to bake and eat desserts, but nowadays it is less common. On Sundays, the lunch is more consistent and is usually accompanied by an appetiser or salad.

In the Middle East and in most Arab countries, lunch is eaten between 1:00 pm and 4:00 pm and is the main meal of the day. It usually consists of meat, rice, vegetables and sauces and is sometimes but not always followed by dessert. Lunch is also eaten as a light meal at times in the Middle East, such as when children arrive at home from school while the parents are still out working.[24] Water is commonly served, which may be iced, and other beverages such as soft drinks or yogurt drinks are also consumed.[24]

In the United States and Canada, lunch is usually a moderately sized meal generally eaten around noon. During the work week, North Americans generally eat a quick lunch that often includes some type of sandwich, soup, or leftovers from the previous night's dinner (e.g., rice or pasta). Children often bring packed lunches to school, which might consist of a sandwich such as bologna (or other cold cut) and cheese, tuna, chicken, or peanut butter and jelly, or, in Canada, savoury pie, as well as some fruit, chips, dessert and a drink such as juice, milk, or water. Adults may leave work to go out for a quick lunch, which might include some type of hot or cold sandwich such as a hamburger or "sub" sandwich. Salads and soups are also common, as well as a soup and sandwich, tacos, burritos, sushi, bento boxes, and pizza. Some individuals may pack leftovers for lunch. Lunch may be consumed at various types of restaurants, such as formal, fast casual and fast food restaurants. Canadians and Americans generally do not go home for lunch, and lunch rarely lasts more than an hour except for business lunches, which may last longer. In the United States the three-martini lunch – so called because the meal extends to the amount of time it takes to drink three martinis – has been making a comeback since 2010.[25] Businesses can deduct 80% of the cost of these lunches.[26] Children generally are given a break in the middle of the school day to eat lunch. Public schools often have a cafeteria where children can buy lunch or eat a packed lunch. Boarding schools and private schools, including universities, often have a cafeteria where lunch is served.

In Mexico, lunch (Comida) is usually the main meal of the day and normally takes place between 2:00 pm and 4:00 pm. It usually includes three or four courses: the first is an entrée of rice, noodles or pasta, but also may include a soup or salad. The second consists of a main dish, called a guisado, served with one or two side dishes such as refried beans, cooked vegetables, rice or salad. The main dish is accompanied by tortillas or a bread called bolillo. The third course is a combination of a traditional dessert or sweet, café de olla, and a digestif. During the meal, it is usual to drink aguas frescas, although soft drinks have gained ground in recent years.

In Australia, a light meal eaten in the period between 10:30Â am and noon is considered brunch; an actual lunch will be eaten between 12 and 2PM.[citation needed] While usually consisting of fruit or a cereal product, a typical Australian brunch may include other foods as well such as burgers, sandwiches, other light food items, and hot dishes[citation needed]. Sometimes a meal during the late afternoon is referred to as "afternoon tea"[citation needed], a meal in which food portions are usually significantly smaller than at lunch, sometimes consisting of nothing more than coffee or other beverages[citation needed].

In Argentina, lunch is usually the main meal of the day, and normally takes place between noon and 2:00Â p.m. People usually eat a wide variety of foods,[27][f] such as chicken, beef, pasta, salads, and a drink like water, soda or wine, and some dessert. Although at work, people usually take a fast meal which can consist of a sandwich brought from home or bought as fast food.

In Brazil, lunch is the main meal of the day,[g] taking place between 11:30 a.m. and 2:00 p.m. Brazilians basically eat rice with beans, salad, french fries, some kind of meat or pasta dishes. But the kind of food may vary from region to region.

Since lunch typically falls in the early-middle of the working day, it can either be eaten on a break from work, or as part of the workday.  The difference between those who work through lunch and those who take it off could be a matter of cultural, social class, bargaining power, or the nature of the work. Also, to simplify matters, some cultures refer to meal breaks at work as "lunch" no matter when they occur – even in the middle of the night. This is especially true for jobs that have employees that rotate shifts.

Lunch foods at a Japanese restaurant in Hong Kong

Japanese cuisine: An udon lunch set

A typical South Indian lunch served in a plate

Typical Indian "thali" lunch

Vietnamese phở, commonly served as lunch

A typical Swedish school lunch

A Swedish outdoor picnic

A cheeseburger at a pub in London

Farmworkers taking a lunch break at Nieuw-Scheemda, Oldambt, Groningen, Netherlands, c.â€‰1955

US President Barack Obama and Canadian Prime Minister Stephen Harper with aides during a working luncheon in the Canadian Parliament in Ottawa, Ontario, in 2009

A Polish Easter lunch