- Discussing prison education at Harvard
- Transforming the ‘coastal squeeze’ over climate change
- New origin story for moon in Harvard-led research
- Experts in Harvard forum examine gender differences in disease
- Echoes from U.S. history in current animosity toward minorities, immigrants, Harvard panelists say
- Harvard surgeon publishes “Vanishing Bone: Conquering a Stealth Disease Caused by Total Hip Replacements”
Posted: 02 Mar 2018 03:20 PM PST
Harvard is hosting a conference on prison education, bringing to campus for the first time formerly incarcerated students and activists to discuss the University's long relationship with correctional facilities.
"Beyond The Gates: The Past and Future of Prison Education at Harvard," which begins Monday, will also convene a capstone event chaired by Danielle Allen, the James Bryant Conant University Professor and director of the Edmond J. Safra Center for Ethics, featuring Michelle Jones of New York University and the Indiana Women's Prison Higher Education Program and Kaia Stern, co-founder of the Harvard Prison Studies Project.
As part of the conference, a documentary titled "The Past and Future of Prison Education at Harvard," which traces the University's connections to prison education, will premiere Tuesday night at 6 p.m. in Sanders Theatre. (Admission is free, and tickets are available in person and online through the Harvard University box office.)
"Education is a basic human right that is, all too often, systematically denied to people in prisons across the country. We have an opportunity for Harvard in its mission to train students to be 21st-century leaders who engage practical learning that makes a difference in the world. Prison is a place that embodies the nexus of race, class, and gender," said Stern, who organized the conference with Elizabeth Hinton, assistant professor of history and of African and African American Studies, and Garrett Felber, a visiting scholar at the Charles Warren Center.
"By creating opportunities for Harvard students to learn with and from students in prison, we demonstrate a commitment to transformative education, education that is rigorous and reckons with questions of justice and equity," Stern said.
Stern has been working to bring students from Harvard into the Norfolk and Framingham correctional facilities, which respectively house men and women, to learn alongside students from Boston University's Prison Education Program since 2008, when she co-founded the Prison Studies Project with Bruce Western, formerly a Harvard professor of sociology. Now housed at the Warren Center, the project created the first nationwide directory of higher education programs in U.S. prisons and received a Harvard Initiative for Learning and Teaching grant in 2012. The last Harvard class taught in the prison was in 2013.
Stern hopes the conference will formalize efforts to reintroduce and sustain integrated classrooms in local prisons as part of a curriculum for college credit, which, she believes, is an ingredient to reduce mass incarceration.
"The first time I visited Norfolk prison was in 2007, on behalf of [Harvard Law School Professor] Charles Ogletree, who had been invited by some of the incarcerated men to come in and teach. People who live and work in prisons know that education changes culture, reduces institutional violence, and interrupts intergenerational cycles of incarceration. I often think of the game we teach our children: musical chairs. We are teaching scarcity and competition. There are not enough resources for everyone to enjoy. Well, there really are enough. In fact, you can see the abundance of chairs piled in the corner of the room. You just can't have access to them."
Claudine Gay, dean of social science, last year launched the Faculty of Arts and Sciences Inequality in America Initiative, which is co-sponsoring the conference. She said she welcomes the "groundbreaking" conference.
"The carceral state is deeply implicated in rising inequality," she said.
Felber, who founded Liberation Literacy with community members and incarcerated students at Columbia River Correctional Institution in Oregon in 2016, said these kinds of programs are equally beneficial to both groups.
"It's so valuable for everyone to work through that dynamic. It's not like it's not messy, but there are all kinds of ways that learning happens that it doesn't in a traditional classroom. Here it's often intergenerational. Liberation Literacy students are ages 18 to 60. We had debates all the time on prison abolition, and those conversations sharpen everyone's analysis. We do peer editing and film nights. We publish a newsletter of co-authored pieces. Everyone's getting something really important out of it."
Sonya Karabel, a Harvard junior studying social studies and African and African American Studies, said helping plan the conference makes her "excited to be part of something that has a real chance of making a real change.
"Sometimes it feels like student activism is symbolic and broad, but this is something concrete," said Karabel, who serves on the board of the student-run Harvard Organization for Prison Education and Reform (HOPE), which tutors in local correctional facilities. "I came to College knowing this was what I wanted to do. It's the ultimate example of wanting a diverse community of learners on this campus. You can come face-to-face with people you learn about in the abstract and see they are people as smart as us who have not had all the life chances we've had."
The three-day conference is also co-sponsored by the Mahindra Humanities Center's Mellon Seminar on Violence and Non-Violence and the Hutchins Center for African & African American Studies, and will culminate with a recorded debate between the Norfolk Prison Debating Society and the Harvard College Debating Union.
Harvard's involvement with prisons dates back to 1833, when Divinity School students tutored prisoners at Charlestown State Prison in Boston. An alumnus named Howard Belding Gill, 1913, M.B.A. 1914, designed Norfolk Prison to look like a college campus in order to foster a sense of community. HOPE, which was founded by the Phillips Brooks House Association in the 1950s, tutors men, women, and juveniles at minimum- and medium-security facilities every week, and awards scholarships for college and post-college degree classes.
Hinton said some of what "Beyond the Gates" proposes "is a rich part of Harvard's history" and matches up well with the pioneering work that's been done at Norfolk and Framingham.
"What Norfolk looked like in the 1920s through the 1950s is a model, really. The prison had a jazz orchestra, a newspaper. Framingham as well — there was a sewing club, and the women put on plays. These were meaningful activities to do," she said.
Hinton visited one of Liberation Literacy's first meetings to discuss her book "From the War on Poverty to the War on Crime," and has supported the group ever since. Her passion for the conference is both academic and personal.
"Historians were really late to the study of mass incarceration, and I had to convince some people why the issue of crime control is an important historical question. I came to this topic, in part, based on my own experience, my family, and visiting people who were incarcerated," she said. "I was born in the crack era and saw how unemployment and poverty led some members of my family to drug abuse and incarceration. I witnessed that cycle firsthand, and its impact on generations of Hintons."
Stern, who has been a student or teacher in prisons for more than two decades, sees the conference as an opportunity to catalyze sustained action that students are eager to join.
She said she and the Rev. Jonathan Walton, Plummer Professor of Christian Morals and Pusey Minister in the Memorial Church and professor of religion and society, called an early morning meeting in the basement of Memorial Church during exam week in the winter of 2014.
"We were working to discern student interest in prison students. More than 50 people came from across the University: HBS, FAS, HMS, HLS, GSD, HGSE, HDS, and HSPH. It is clear that there is student hunger to be make connections about prisons and justice — to be part of education that truly meets the goals of diversity, inclusion, and belonging."
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Posted: 02 Mar 2018 01:43 PM PST
Analysts call it "the coastal squeeze," but for plant and animal communities bordering urban and suburban seashores, another word could apply: extinction.
Though the Earth's seas have risen and fallen many times over the planet's lifetime, the man-made changes occurring now and the larger ones anticipated in the near future are different, says Steven Handel, a visiting professor in landscape architecture at Harvard's Graduate School of Design.
The reason, he says, is because humans have built roads and houses and other hard, immutable structures along the coasts. And what people may view as scenic coastal roadways, the natural communities of plants and animals may experience as terminal barriers, blocking their migratory response to rising seas.
"Can these [natural] zones migrate when behind these zones is us — our sidewalks, roads, homes, factories, power stations, and yuppies jogging?" Handel said. "There's no open land here, no open soil for these higher [ecosystem] zones to move to. This is civilization. We call this problem the coastal squeeze."
But Handel, a plant ecologist who is visiting Harvard from Rutgers University, where he is distinguished professor of ecology and evolution, said all doesn't have to be lost. Incorporating understanding of plant characteristics with smart design can produce alternatives that preserve natural communities and human use of a landscape endangered by sea-level rise that Handel said could — under pessimistic scenarios — top 31 inches by mid-century.
About a dozen years ago, Handel became interested in how natural processes could be harnessed to improve degraded, damaged, and abandoned sites dotting city landscapes.
He teamed up with landscape architects to transform the Fresh Kills Landfill in Staten Island and an all-but-abandoned former commercial port area near the Brooklyn Bridge. Both areas have been restored to their natural state and are habitats where native plants attract birds and other wildlife. And humans by the thousands also come to enjoy the park-like settings.
Other projects Handel has been involved in include a site in Beijing that was restored in preparation for the 2008 Summer Olympics, and California's Orange County Great Park, fashioned from a decommissioned Marine Corps air station.
Handel spoke Tuesday evening at Harvard's Geological Lecture Hall at an event sponsored by the Harvard Museum of Natural History (HMNH) and co-sponsored by the Association to Preserve Cape Cod. The talk was introduced by Jane Pickering, executive director of the Harvard Museums of Science and Culture, of which the HMNH is part, and by the association's executive director, Andrew Gottlieb.
Handel used several projects as examples of how smart design can transform landscapes. Some buttress existing sites against coming changes even as they incorporate natural features, by encouraging sand dunes on previously flat beaches, and planting native, salt-tolerant trees and grasses. Other plans concede that the sea is likely to reclaim certain areas, such as barrier islands and some coastal homes, and recommend moving residents inland and converting the endangered sites to day and recreational uses.
The approach Handel described begins with accepting that the seas will rise. It takes projections for how sea levels will change familiar landscapes and moves forward from there, looking for opportunities such as inland water bodies and waterways that may soon be brackish, making them potential sites for future salt marshes. Newly engineered marshes can replace those drowned by the rising tide, buffer storms, and provide breeding grounds for fish and birds. Other opportunities lie in brownfields and abandoned sites that could be rehabilitated into places where communities meet the sea and around which fresh development can grow.
Homeowners living near the coast can help as well, Handel said, by substituting traditional landscape plantings and mown lawns with natural coastal plantings, like beach plum and other species selected both for their beauty and because they're native.
"We want to tell people, 'You're 10 blocks from the bay, you're part of the bay ecosystem,'" Handel said.
Unfortunately, everything can't be saved. Though in the past it's been possible to rebuild coastal homes wrecked by storms, rising seas and stronger storms will make those projects less practical, forcing some homeowners to move. Even natural communities not bounded by human development may not be able to disperse seeds and adapt inland as fast as the seas come up.
On Cape Cod, Handel pointed out that early maps show the land around its tip, near Provincetown, shifting even without the powerful forces unleashed by climate change, so that's one place where more change can be expected. In addition, the Cape's characteristic sand dunes will become even more vulnerable to erosion from the powerful surf.
How those and other changes will unfurl is uncertain, but the fact that change is coming isn't, he said.
"The past is not prologue," Handel said. "What we know from our youth and from today will not remain. That's the one thing that we know for sure."
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Posted: 02 Mar 2018 12:00 PM PST
Simon Lock wants to change the way you think about the moon.
A graduate student in Harvard's Department of Earth and Planetary Sciences, Lock is the lead author of research that challenges mainstream thought by suggesting that the moon emerged from a massive, doughnut-shaped cloud of vaporized rock called a synestia. The study was published this week in the Journal of Geophysical Research: Planets.
"The commonly accepted theory as to how the moon was formed is that a Mars-size body collided with the proto-Earth and spun material into orbit," Lock said. "That mass settled into a disk and later accreted to form the moon. The body that was left after the impact was the Earth. This has been the canonical model for about 20 years."
It's a compelling story, Lock said, but probably wrong.
"Getting enough mass into orbit in the canonical scenario is actually very difficult, and there's a very narrow range of collisions that might be able to do it," he said. "There's only a couple-of-degree window of impact angles and a very narrow range of sizes … and even then some impacts still don't work."
"This new work explains features of the moon that are hard to resolve with current ideas," said co-author Sarah Stewart, a professor of Earth and planetary sciences at the University of California, Davis. "This is the first model that can match the pattern of the moon's composition."
Tests have shown that the isotopic "fingerprints" for both the Earth and moon are nearly identical, suggesting that both came from the same source, the researchers noted. But in the canonical story, the moon formed from the remnants of just one of the two colliding bodies.
It's not just similarities between the Earth and moon that raise questions about the conventional wisdom — their differences do as well.
Many volatile elements that are relatively common on Earth, such as potassium, sodium, and copper, are far less abundant on the moon.
"There hasn't been a good explanation for this," Lock said. "People have proposed various hypotheses for how the moon could have wound up with fewer volatiles, but no one has been able to quantitatively match the moon's composition."
The scenario outlined by Lock and colleagues still begins with a massive collision, but rather than creating a disc of rocky material, the impact creates the synestia.
"It's huge," Lock said. "It can be 10 times the size of the Earth, and because there's so much energy in the collision, maybe 10 percent of the rock of Earth is vaporized, and the rest is liquid … so the way you form the moon out of a synestia is very different."
The phenomenon includes a "seed" — a small amount of liquid rock that gathers just off the center of the doughnut-like structure. As the structure cools, vaporized rock condenses and rains down toward the center of the synestia. Some of the rain runs into the moon, causing it to grow.
"The rate of rainfall is about 10 times that of a hurricane on Earth," Lock said. "Over time, the whole structure shrinks, and the moon emerges from the vapor. Eventually, the whole synestia condenses and what's left is a ball of spinning liquid rock that eventually forms the Earth as we know it today."
The model addresses each of the problems with the canonical model for the moon's creation, Lock said. Since both the Earth and moon are created from the same cloud of vaporized rock, they naturally share similar isotope fingerprints. The lack of volatile elements on the moon, meanwhile, can be explained by it having formed surrounded by vapor and at 4,000‒6,000 degrees Fahrenheit.
"This is a dramatically different way of forming the moon," Lock said. "You just don't think of a satellite forming inside another body, but this is what appears to happen."
Lock was quick to note that the work is still taking shape.
"This is a basic model," he said. "We've done calculations of each of the processes that go into forming the moon and shown that the model could work, but there are various aspects of our theory that will need more interrogation.
"For example, when the moon is in this vapor, what does it do to that vapor? How does it perturb it? How does the vapor flow past the moon? These are all things we need to go back and examine in more detail."
Along with Lock and Stewart, researchers on the study were Matija Ćuk (SETI Institute), Stein Jacobsen (Harvard), Zoë Leinhardt (University of Bristol), Mia Mace (Bristol), and Michail Petaev (Harvard).
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Posted: 02 Mar 2018 10:00 AM PST
Much of how we attack serious illnesses like heart disease, depression, and Alzheimer's has been informed by studies of men. And that approach misses important gender differences in how the diseases look, progress, and respond to treatment, according to panelists at the Harvard T.H. Chan School of Public Health.
"[We need] education and awareness on every level, with every sector," said British Robinson, chief executive officer of the Women's Heart Alliance. "We have to take a whole-systems approach. That system includes our medical and clinical systems, hospitals systems. It includes our physicians, our nurses, our community health workers."
Differences between men and women are particularly salient in diseases of the heart and brain, panelists said, including heart attack and heart failure, major depression — which occurs at double the rate in women — and Alzheimer's disease, which strikes women more frequently than their longer average lifespans explain.
More women experience heart attacks that have atypical symptoms, including heartburn, back pain, anxiousness, and fatigue. In addition, women tend toward smoother arterial plaque, which can make heart disease harder to diagnose through catheterization, panelists said.
"They're called 'atypical' because the 'typical' was defined on the male norm, and so when women present with burning or back pain or jaw pain they're often triaged in a different way in the emergency room," said Marjorie Jenkins, director of medical initiatives and scientific engagement for the Food and Drug Administration's Office of Women's Health. "So a woman comes in. She's anxious. She has heartburn. She has back pain. She's questioned. She tells the doctor she's tired. She's really nervous. So the doctor thinks she's having a panic attack or she's depressed and therefore she gets medication for that. Those medications will not treat a heart attack. She needs to be screened for heart disease."
Harvard Medical School Professor of Psychiatry and Medicine Jill Goldstein, who heads the Women, Heart and Brain Global Initiative at Massachusetts General Hospital, and Ana Langer, a professor of the practice of public health and director of the Women and Health Initiative at Harvard Chan School, also participated in the discussion on Wednesday, "Heart and Brain Disease in Women: Sex and Gender Connections."
One opportunity for raising awareness is in research, panelists said, noting that before recent gains, women were underrepresented for decades. Even when women are included, data isn't always analyzed by sex, missing an opportunity to tease out gender differences.
"If we don't get the data, we won't know the answers," Jenkins said.
To truly understand gender disparities, researchers should design trials in a way that accounts for factors such as the natural ebb and flow of hormones, which Goldstein cited as a possible driver of differences. Studies also need to account for the influence of life stages such as puberty, pregnancy, and menopause, panelists said.
The Food and Drug Administration has for years required new drug applications to include analysis of data by sex, Jenkins said, and the National Institutes of Health enacted a policy in 2016 that required research funded by NIH grants to consider the role of sex as a biological variable. Jenkins said that studies should also examine differences in age and racial and ethnic backgrounds to capture the true diversity that exists in the population.
"We need women of color, we need women of different backgrounds, we need women of different ages," Jenkins said. "We need to need to know those answers for all women, and all men. So that's why very it's important to participate so we can have those answers and treat patients to the highest level of care."
The problem is not restricted to the U.S., Langer noted. Women in developing nations face particular challenges because rates of smoking and obesity are increasing while health care systems are often weak.
Looking ahead, Goldstein urged that precision medicine, in which treatment is tailored to individual needs, aim for inclusiveness in clinical trials, analysis of results by sex, and heightened awareness among doctors and nurses of sex-based differences.
"[It's important to be] educating the next generation who are going into medicine and educating the public about the importance of the impact of sex on what we now are terming personalized, individualized, precision medicine," Goldstein said. "Because … what could be more personal than one's sex?"
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Posted: 02 Mar 2018 09:00 AM PST
Archon Fung opened the Institute of Politics forum "Trolls, Threats and Terror: Why Is Hate Rising and What Can We Do About It?" on Wednesday night with a warning.
"We're not going to be discussing a pleasant topic," said the Kennedy School dean.
Indeed, he observed in the panel's most sobering conclusion, things can always get much worse than they are now — and indeed, they have been.
Hate, Fung suggested, is a longstanding American tradition.
"It has always been a dark part of the American political experience, from lynchings and the rise of the Klan to mass shootings to attacks on children of the BGLTQ community," he said.
While the nation's history of 3,000 lynchings may be more frightening than anything happening in America today, the same anger and hate that fueled them may well be returning to the social forefront. Fung noted that one of the night's two panelists, Southern Poverty Law Center president Richard Cohen, traveled to Harvard with a security director. Cohen, who has litigated a variety of important Civil Rights actions, now has to worry about assassination threats. "Such are the times we live in," Fung said.
The other panelist, former NAACP president Cornell William Brooks, reminded the audience that the NAACP itself was formed in response to a 1908 race riot in which at least a dozen African-Americans were murdered. In response to a question from co-moderator Sarah Wald, senior policy advisor at HKS, he noted that the country is facing some of the same fears of immigration that fueled the Ku Klux Klan.
"America is becoming more black and brown, and more diverse in our religiosity," Brooks said. "What we're seeing now is not just a demographic backlash, but a post-Obama blacklash. This cannot be ducked, it's real. The rise of the Klan was driven by a toxic brew of anti-immigrant sentiment, a kind of faux patriotism, and a view of Christianity that is in fact antithetical to the Gospel. Today we see the same forces at work. And it's fueled by a president who is intentionally or unwittingly — and I would say intentionally — fanning the flames."
Though the panelists said they didn't intend to take political sides, they said they couldn't avoid talking about President Trump's collusion — not with Russia, but with white supremacists. Cohen said that Trump's general failure to denounce such groups brought the fringes closer to the center.
"This election was unusual in that white supremacists endorsed Trump. And after he was elected, Trump went on Alex Jones' radio show and said 'I hear you have a really fine reputation.' That about says it all," he said.
Brooks went a step further and suggested that Trump sometimes appeased such hate groups. "When you appoint Steve Bannon to high office, someone whose business model is propagating hate, then you have created a de facto office of legitimacy for the alt-right, i.e., white supremacy."
Wald challenged Cohen on one of his organization's more controversial positions: naming nonviolent organizations such as the conservative Christian lobbying group Family Research Council as hate groups. Cohen replied that haters who wear business suits are no less dangerous than those who wear white sheets.
"We don't require violence," he said. "[The Family Research Council] constantly demonizes the LBGT community and spreads propaganda against them. Some groups that we would consider hate groups have a foothold in the mainstream. And having that foothold makes them more dangerous."
Some members of the audience asked what individuals can do to oppose hate. While both panelists agreed that it can be useful to engage with haters in person and online, they said the real hope lies in larger organized efforts.
"We need to get law enforcement engaged," Brooks said. "We need to take these crises as organizational moments that build our resources, in the same way that the NAACP did."
But both panelists expressed some optimism for the future. Brooks found a source of inspiration in the community response to the church massacre in Charleston, S.C., and Cohen saw hope in Parkland, Fla., student Emma Gonzalez's recent campaign for gun-control laws.
"When she has more Twitter followers than the NRA in two weeks, something is happening," he said. "I see change in the young people of our country. I just wish they voted."
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Posted: 02 Mar 2018 08:00 AM PST
In 1957, British orthopedic surgeon John Charnley saw what William Harris today calls "the promised land."
That glimpse was the first total hip replacement, an operation that almost miraculously restored pain-free movement and active lives to patients whose hip-joint damage, often rooted in arthritis, had made even the simple act of walking across the room difficult.
Empowered by advances in materials, Charnley dispensed with the surgical half-measures of the past, removed the damaged joint entirely, and started over, replacing the cuplike hip socket with one made of Teflon, known for its slipperiness. He cut off the top of the thighbone and inserted the end of a rodlike metal implant into its center, cementing it in place. The round head of the implant — like the natural one at the top of the thighbone — fit into the Teflon hip socket.
The procedure seemed to work, but not for long. Within a year, complications arose. The routine movement of the balls in the sockets made the Teflon wear too quickly, loosening the implants. Charnley was forced to reoperate on nearly 300 patients after they developed what he described as an infection around the implant.
"The shining side of that unmitigated disaster was that he had seen the promised land," said Harris, who was 27 when Charnley performed the first operation. "These people were so good [after the operation]. He said, 'What we need is a better plastic.'"
Charnley filled that need with a more-resistant material called high-density polyethylene, which he began using in a new version of the artificial hip joint in 1962. Years passed, then a decade, with no sign of the accelerated wear that had doomed the Teflon socket.
By 1974, Harris was a noted orthopedic surgeon at Massachusetts General Hospital and clinical professor of surgery at Harvard Medical School. One day he saw a California lawyer, referred by doctors in San Francisco, who had undergone hip replacement surgery seven years earlier. The procedure had initially brought pain relief and renewed freedom of movement. But the hip pain had returned.
Harris was startled when he looked at his new patient's X-rays. Large portions of his thighbone had been eaten away. Cancer was the only thing Harris could think of that destroyed bone like that, but it also seemed unlikely. First, cancer had never been associated with hip replacement. And second, bone cancer wasn't typically found in the femurs of 55-year-old men.
Further tests brought good news, confirming that the patient was cancer-free. But those results were tempered by the fact that his doctor remained stumped.
Harris himself would see three similar cases that year and many more in the years to come. In time, the condition became so widespread — reaching over a million cases — that it was defined as a new disease, periprosthetic osteolysis.
The condition led not just to implant failures, but also to hip fractures, femur fractures, and complex reoperations to install new implants. It would take decades to devise a solution, in the form of a new material — highly crosslinked polyethylene — pioneered in the labs of Harris and his Massachusetts Institute of Technology collaborator, biomedical engineer Edward Merrill.
"In my clinical office, I often have the privilege of seeing one happy postoperative patient after another," Harris, now the Alan Gerry Clinical Professor of Orthopedic Surgery Emeritus, writes in his new book, "Vanishing Bone: Conquering a Stealth Disease Caused by Total Hip Replacements."
"It was one of the real pleasures of my work as a surgeon, to put an end to the deep, daily grief that patients often suffered by giving them total hip replacements. Their joy and gratitude afterwards was one of my greatest rewards. However, those with bone destruction were my worst nightmares."
As the book details, the journey of Harris, his patients, and multiple collaborators included promising leads and roads to nowhere, the development of a new hip simulation machine, at least one lab explosion, and too much time in a patent case. The adventure ultimately led to a new generation of hip implants and, possibly, the breakthrough that Charnley had glimpsed more than 60 years earlier.
A few years after Harris first described the condition, in 1976, a separate research effort traced its cause to tiny particles of the cement that secured the metal thigh implant inside the femur. Those particles caused a massive immune reaction that in turn triggered osteoclasts, the only cell in the body capable of destroying bone.
The discovery led to the condition being called "cement disease," prompting the development in the early 1980s of porous-metal implants that allowed the bone to grow into the implant and hold it in place in the thighbone.
But Harris was still seeing new cases in 1990, even among patients with cement-less implants. Further research showed that particles were still present, but of the polyethylene that made up the hip socket. Though the polyethylene was far more durable than Teflon, the regular motion of the ball in the socket still caused wear, producing particles that set off the same destructive immune reaction.
With that discovery, researchers finally understood what was happening in the body. It was not a cement disease, but a particle disease. With so many hip replacement surgeries continuing around the world, what was needed was a material even more durable than polyethylene.
The new answer came from studying the old one. Harris had asked patients to donate implants for study after they died, and he worked with lab members to examine them under a scanning electron microscope. The researchers noticed something interesting: The long, skinny molecules of high-density polyethylene, which normally curl haphazardly like spaghetti in a bowl, as Harris described it, had become aligned in the direction of the back-and-forth motion of the joint.
The surgeon wondered whether the team was seeing wear's signature and whether, if they connected the individual molecules to keep them in their original configuration, they could halt the damage.
"That was a light-bulb moment: 'Wow, I wonder if in fact that realignment is critical to the particular type of wear that leads to the tiny particles?'" Harris said.
Harris knew MIT's Merrill, a polymer scientist and noted pioneer in biomedical engineering, and asked him if it could be done. Merrill said it could, by irradiating the polyethylene into a new form: highly crosslinked polyethylene.
The idea worked. In 1998, the first artificial hips using highly crosslinked polyethylene were put in patients. Since then, across roughly 7 million cases worldwide, "there's not been one documented reoperation caused by the bone destruction, which used to be so common," Harris said. "That is huge progress."
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