Chiropractic for back pain. (Alternative Medicine).

* Many patients with back pain experience at least short-term benefits with chiropractic treatments.

* A very small but real risk of injury exists with cervical spinal adjustment.

History of Use

Spinal manipulation has been used in medical practice at least since the time of Hippocrates, but chiropractic--from the Greek cheiros (hand) and praktos (done by)--is said to officially have begun on Sept 18, 1895, when Iowa lay magnetic healer Daniel David Palmer performed his first spinal "adjustment" on a deaf patient, reportedly restoring the man's hearing.

Palmer, his son, and other followers developed a system of healing based on the concept of the body's inherent capacity for self-healing, or "innate intelligence." Central was the belief that "dis-ease" resulted from impingement of nerves in the spine, and that manipulation removed this interference and healed the patient.

Despite chiropractic's popularity among patients-today, about 15% of the population consults chiropractors each year-efforts to achieve recognition as a medical specialty have been met with considerable resistance. The American Medical Association fought against acceptance of chiropractic until 1987, when a U.S. District Court judge ruled that the organization was guilty of conspiracy "to contain and eliminate the chiropractic profession," in violation of the Sherman Antitrust Act.

Increasing acceptance of chiropractic in recent years was reflected in the establishment in 1997 of a research center at the Palmer College of Chiropractic in Davenport, Iowa, under the aegis of the National Center for Complementary and Alternative Medicine of the National Institutes of Health. This center is conducting clinical and basic science studies on the effects of applying forces and loads to spinal tissues and joints. Researchers at the center also are looking at the effects of manipulative procedures on pain sensation.

"It's clear that mobility is enhanced and pain is mitigated by various types of manual, mechanical procedures," William Meeker, D.C., director of the Palmer Center for Chiropractic Research, told this newspaper. We don't know if there are common pathways that would explain the effects of massage, acupuncture, spinal manipulation, and chiropractic adjustments, but it has been hypothesized that there might be."

Chiropractic Practice Today

Spinal adjustment is said to help maintain the integrity of the joint cartilage, improve the metabolism of the intervertebral disk, and prevent premature degenerative changes (Neurol. Clin. 17[1]:91-111, 1999). The spinal abnormality is referred to as a subluxation.

Most chiropractors also offer wellness advice in areas such as exercise, smoking cessation, and relaxation. But some have been criticized as being hostile to public immunization programs. In a survey of 1% of U.S. chiropractors, one-third agreed that "there is no scientific proof that immunization prevents disease" (Vaccine 20[suppl. 1]:S90-S93, 2001). The American Chiropractic Association has no position on immunization, stating only that both sides of the issue should be considered. The Chiropractic Health Care Section of the American Public Health Association supports APHA's proimmunization stance.

The Evidence

A recent review noted that the English language literature contains at least 73 randomized clinical trials involving spinal manipulation, 43 of which focused on acute, subacute, or chronic back pain (Am. Intern. Med. 136[3]:216-27, 2002). Many modalities were used for comparison, including analgesics, massage, and exercise. Of the 43 studies, 30 found evidence favoring chiropractic and 13 did nor. No trial found spinal manipulation to be inferior to the comparison treatment. The authors of the review, led by Dr. Meeker, wrote, "In most of the randomized, controlled trials of manipulation for musculoskeletal pain, the positive effect sizes appear to be clinically and statistically significant but not dramatic."

The review prompted a series of critical letters. "The chiropractic theory of vertebral subluxation and spinal manipulative adjustments ... is just as false today as when it was formulated more than a century ago, one said (Ann. Intern. Med. 137[8]:701-02, 2002). "Where is the 'basic science' of chiropractic?" another asked. "Biased interpretation," charged a third. "Chiropractic ... has made many advances in education, ethics, practice, and theory" Dr. Meeker responded, describing it as "a profession at the crossroads between mainstream and alternative medicine."

Safety Concerns

Short-term, minor adverse events associated with spinal manipulation include mild transient muscle and joint soreness. Serious but reversible events include sternocostal cartilage separation, rib fracture, and transient ischemic attacks. Irreversible events--which are very rare but have led to cases of paralysis and death--include cauda equina syndrome, which sometimes can be reversed with prompt surgery and vascular injury primarily to the verrebrobasilar arteries.

The rate of serious cerebrovascular complication after cervical manipulation has been estimated at 1 per million manipulations in "Principles and Practice of Chiropractic" (East Norwalk, Conn.: Appleton and Lange, 1991). The risk of irreversible cauda equina syndrome after lumbar manipulation has been estimated at 1 in 100 million (Spine 17[12]:1469-73, 1992).

Risks should be evaluated with respect to benefits, Dr. Meeker said. "While no expert will deny that there are some risks associated with spinal manipulation, there are risks associated with all treatment procedures. The risk rate and actual numbers of hospitalizations and deaths from the use of nonsteroidal anti-inflammatory drugs, which are routinely used for the same conditions that chiropractors treat, are much higher than for spinal manipulation."