It's already been summed up quite nicely:
http://cmsadmin.mercola.com/1999/archive/paradox_of_osteopathy.htm
The Paradox Of Osteopathy
The New England Journal of Medicine November 4, 1999;341:1426-1431, 1465-1467.
In the spring of 1864, Andrew Taylor Still, a rural Kansas practitioner, watched helplessly as the best medications then available failed to save his three children from spinal meningitis. Bitterly disappointed, Still set out to devise an alternative healing practice. He eventually based his new system on the idea that manipulation of the spine could improve blood flow and thus improve health by allowing the body to heal itself. His philosophy included a healthy dose of moralism; patients were forbidden to consume any liquor and, as part of the break from existing practices, were also forbidden to take any medicine. Still founded a school to teach his new system of osteopathy in Kirksville, Missouri, in 1892.
Osteopathy was not the only system of spinal manipulation to be created in the late 19th century. Chiropractic, established in 1895 by Daniel David Palmer, aimed to relieve obstruction in the nerves rather than in the blood vessels. Osteopathy and chiropractic initially shared several characteristics. Both were founded when Americans freely chose from many systems of healing. Both were homegrown American systems created at about the same time by messianic Midwesterners. Both systems were seen by many Midwesterners as preferable to the reductionist European model of laboratory-based medicine, which was established most firmly on the eastern seaboard and was fast becoming the standard.
Over the course of the 20th century, medicine as practiced by M.D.'s (sometimes called allopathy) has come to dominate U.S. health care. Chiropractic and osteopathy, initially parts of a pluralistic medical system, have taken very different paths. Chiropractors have generally remained focused on spinal manipulation for a limited set of conditions, particularly those that are often resistant to allopathic therapy, such as back pain. Osteopaths, on the other hand, have worked hard to employ the entire therapeutic armamentarium of the modern physician, and in so doing they have moved closer to allopathy. )
The move toward assimilation became explicit in California in the early 1960s, when the California Medical Association and the California Osteopathic Association merged in what has been called the osteopathic profession's darkest hour. By attending a short seminar and paying $65, a doctor of osteopathy (D.O.) could obtain an M.D. degree; 86 percent of the D.O.'s in the state (out of a total of about 2000) chose to do so. The College of Osteopathic Physicians and Surgeons became the University of California College of Medicine, Irvine. Many osteopaths feared that the California merger was the wave of the future and that the profession would not survive. But it did, and in so doing it may have become even stronger. D.O.'s are now licensed in all 50 states to prescribe drugs, deliver babies, and perform surgery -- in short, to do anything that M.D.'s can do. Despite national recognition, osteopathy is still a regional phenomenon in ways that mirror its historical origin. The ratio of D.O.'s to the population varies by a factor of almost 3, from a low of 7.7 per 100,000 population in the West to a high of 20.4 per 100,000 in the Midwest; the number is 8.5 per 100,000 in the South and 18.3 per 100,000 in the Northeast. M.D.'s are far more evenly distributed throughout the country.
Osteopathy was originally created as a radical alternative to what was seen as a failing medical system. Its success at moving into the mainstream may have come at a cost -- the loss of identity. Most people -- including physicians -- know very little about the field (most people know more about chiropractic). Many people -- even osteopaths -- question what osteopathy has to offer that is distinctive.
Those who claim that osteopathy remains a unique system usually base their argument on two tenets. One is the holistic or patient-centered approach, with a focus on preventive care that they say characterizes osteopathy. That claim to uniqueness is hard to defend in the light of the increasing interest paid to this approach within general internal medicine and other areas of allopathic medicine. The other, potentially more robust, claim to uniqueness is the use of osteopathic manipulation as part of the overall therapeutic approach. In osteopathic manipulation, the bones, muscles, and tendons are manipulated to promote blood flow through tissues and thus enhance the body's own healing powers. The technique, based on the idea of a myofascial continuity that links every part of the body with every other part, involves the "skillful and dexterous use of the hands" to treat what was once called the osteopathic lesion but is now referred to as somatic dysfunction. Osteopathic manipulation is not well known (or practiced) by allopathic physicians, but for decades it has stood as the core therapeutic method of osteopathic medicine.
Some claim that osteopathic physicians are more parsimonious in their use of medical technology. Thus, they can provide more cost-effective medical care and reduce the need for medications, which, although effective, can have serious side effects. The specific mechanism that would account for any improvement in back pain directly related to osteopathic manipulation is unclear, but the most important studies will be those that test whether the technique works in clinical practice. Part of the success of osteopathic manipulation for patients with back pain may come from the fact that physicians who use osteopathic manipulation touch their patients.
Osteopathic manual therapy is claimed to be useful for treating a wide range of conditions, from pancreatitis to Parkinson's disease, sinusitis, and asthma. Some leading osteopaths say that manual therapy should be part of almost every visit to an osteopathic physician. A recent president of the American Osteopathic Association claimed that he "almost always turned to [osteopathic manipulation] before considering any other modality," and he asserted that 90 percent of his patients got better with osteopathic manipulation alone. Such claims underscore a raging debate within osteopathy and a disconnection between its theories and its practice. A 1995 survey of 1055 osteopathic family physicians found that they used manual therapy only occasionally; only 6.2 percent used osteopathic manipulation for more than half of their patients, and almost a third used it for fewer than 5 percent. The more recent their graduation from medical school, the less likely practitioners were to use osteopathic manipulation, a finding consistent with the view that osteopathic practice is moving closer to allopathic practice. A decreasing interest in osteopathic manipulation may also indicate that more physicians enter osteopathic medical school not as a result of a deeply held belief in the osteopathic philosophy but after failing to be admitted to allopathic medical schools. The osteopathic physicians who are more committed to osteopathic manipulation tend to be more likely than their colleagues to have a fundamentalist religious orientation.
With or without manipulation therapy, osteopathic medicine seems to be undergoing resurgence. Although the number of allopathic medical schools in the United States has remained stable since 1980, at about 125, the number of osteopathic medical schools has increased from 14 to 19. The number of graduates each year has increased at an even more disproportionate rate. The number of graduates of allopathic medical schools has increased only slightly, from 15,135 in 1980 to 15,923 in 1997, whereas the number of graduates of osteopathic medical schools has almost doubled, from 1059 to 2009, over the same period. Osteopathic medical schools have not done as well as allopathic medical schools in recruiting underrepresented minorities and women, and students entering osteopathic medical schools have somewhat lower grade-point averages and lower scores on the Medical College Admission Test. On the other hand, the ratio of applicants to those admitted is higher for osteopathic medical schools, 3.5 applicants for each person admitted, as compared with 2.4 for allopathic medical schools.
Overall, osteopathic medical schools have come to resemble allopathic medical schools in most respects; some students even share classes. Graduates of osteopathic medical schools more often than not go on to residency training in allopathic programs. An evaluation of performance on the certifying examination of the American Board of Internal Medicine in the 1980s noted that although physicians from osteopathic medical schools did not do as well as those from allopathic programs, overall they "did well" and could be an "untapped reservoir of talented physicians" for internal medicine.
Although they constitute only about 5 percent of U.S. physicians, osteopaths may be disproportionately important for the health care system by virtue of their distribution in terms of specialty and location: 60 percent of graduates of osteopathic medical schools select generalist fields. Because osteopathic education is more community-based than allopathic education, and because osteopathic schools are smaller, osteopathic education may be able to adapt more quickly to new approaches to health care delivery. Many more osteopaths than allopaths (18.1 percent vs. 11.5 percent) select rural areas in which to practice. One osteopathic medical school found that 20 percent of its graduates were practicing in underserved communities.
At the end of the century, osteopathy continues its uneasy dance with allopathy, but only one partner is really paying attention. The resurgence in the numbers of osteopaths should not mask the precarious position of osteopathy. At its birth, osteopathy was a radical concept, rejecting much of what allopathic medicine claimed was new and useful.
Today, osteopathic medicine has moved close to the mainstream -- close enough that in general it is no longer considered alternative medicine. The long-term survival of osteopathic medicine will depend on its ability to define itself as distinct from and yet still equivalent to allopathic medicine. That argument may best be articulated not in theoretical terms, but by demonstrating treatment outcomes. The paradox is this: if osteopathy has become the functional equivalent of allopathy, what is the justification for its continued existence? And if there is value in therapy that is uniquely osteopathic -- that is, based on osteopathic manipulation or other techniques -- why should its use be limited to osteopaths?
Joel D. Howell, M.D., Ph.D. University of Michigan Ann Arbor, MI 48109-0604
