Chiropractic care primarily focuses on the spine and the musculoskeletal system. The technique that often prompts public safety questions is spinal manipulative therapy (SMT), which involves applying a controlled, sudden force to a joint. These high-velocity, low-amplitude thrusts are used to restore joint mobility and alleviate pain. Concerns about potential harm from this physical intervention are legitimate, and this article examines the safety profile of chiropractic SMT.
Expected Reactions After Treatment
Following spinal manipulative therapy, it is common for patients to experience mild reactions as the body adjusts to the treatment. The most frequently reported reaction is localized soreness or stiffness in the muscles and joints around the area that was treated. This discomfort is often likened to the feeling of muscle fatigue after a physical workout. These effects can also include a transient headache, which is more common after a neck adjustment, or a general sense of fatigue. These symptoms usually begin shortly after the appointment and resolve within 24 to 48 hours.
Assessing the Risk of Severe Complications
While the common reactions are mild, public concern often focuses on severe adverse events, particularly those associated with cervical spine manipulation. The most serious complication is a cerebrovascular accident (CVA), or stroke, which can be triggered by a vertebral artery dissection (VAD). A dissection involves a tear in the inner lining of the vertebral artery, which supplies blood to the brainstem and cerebellum. Evidence suggests that the risk of a VAD leading to stroke following cervical manipulation is extremely rare, with estimates ranging from approximately one case per 1 million to one case per 5.85 million cervical manipulations. It is challenging to distinguish whether the manipulation caused the dissection or whether the patient was already experiencing an impending dissection before the adjustment. Patients often seek care for neck pain or headache, which are also early symptoms of an existing VAD. The manipulation may act as a mechanical trigger in patients who already have a weakened or compromised artery wall. Other severe complications, such as the aggravation of a pre-existing disc herniation or cauda equina syndrome, occur with exceptional infrequency.
When Chiropractic Care Should Be Avoided
Manipulation is unsafe for a small number of patients due to pre-existing medical conditions, categorized as absolute or relative contraindications. Absolute contraindications are conditions where spinal manipulation should never be performed because the risk of serious harm is elevated.
Absolute Contraindications
- Acute fractures, spinal cord compression, and active infections such as osteomyelitis or discitis.
- Advanced spinal osteoporosis, tumors in the spine, or known spinal instability (due to risk of fracture).
- Certain vascular conditions, like an unstable aneurysm or vertebrobasilar insufficiency (for neck manipulation).
Relative contraindications are conditions where the procedure may be modified, such as using low-force techniques instead of high-velocity thrusts. These include moderate osteoporosis, severe degenerative joint disease, and certain blood-clotting disorders or the use of strong anticoagulant medications. The practitioner must weigh the potential benefit against the acceptable level of risk. Acute inflammatory arthritis during a flare-up may also require avoidance of manipulation in the affected area.
How Practitioners Minimize Patient Risk
Practitioners use a screening process to identify and mitigate potential risks before beginning any treatment. This process starts with patient intake and history taking to uncover pre-existing conditions and known contraindications. The practitioner asks detailed questions about past surgeries, recent trauma, medication use, and any neurological symptoms, often referred to as “red flags.”
Following the history, a comprehensive physical examination is performed, including orthopedic and neurological testing. This examination helps to assess the structural integrity of the spine and the function of the nervous system. If a practitioner identifies signs of a serious underlying pathology or a condition that falls outside their scope of practice, they must refer the patient to a specialist for further testing or consultation.
This referral process, along with the requirement for informed consent, is part of professional risk management. All licensed practitioners adhere to professional standards of care that dictate when SMT is appropriate and when it should be avoided or modified.