Injection therapy involves using a needle and syringe to relieve pain by injecting various substances (e.g., anesthetic, corticosteroid, opioid medication) into a person’s back, neck or other body areas. It typically is used only when less invasive forms of treatment fail to relieve a patient’s symptoms.

During these treatments, medication is injected into the soft tissues, joints and other areas in and around the source of a patient’s pain. Various types of injection therapy are available, including:

• Facet joint injections. Anesthetics or corticosteroids are injected into the facet joints, which are located between the vertebrae.
  
  
• Nerve root blocks. Anesthetics or corticosteroids are injected into a portion of a nerve that is inflamed or compressed.
  
  
• Prolotherapy. A sugar solution or other irritating substance is injected into trigger points (areas where pain is felt) in the fibrous tissue that covers bones. This is believed to trigger inflammation, which causes fibrous tissue growth that can strengthen the area.
  
  
• Trigger point injections. Anesthetic is injected directly into areas of the body where pain is present.

Examples of conditions that may be treated with injection therapy include carpal tunnel syndrome, sciatica, arthritis, bursitis, tendinitis and tennis elbow.

In preparation for injection therapy, imaging tests such as a CAT scan or MRI may be performed to look at various structures inside the body.  Prior to the procedure, the patient may be asked to follow a number of preparatory steps, including altering medication and dietary regimens.

In most cases, injection therapy is an outpatient procedure using a local anesthetic. A fluoroscopic x-ray may be performed to help the physician guide the needle to the right spot. Patients often are able to resume their daily activities within a brief period of time following the procedure.

Injection therapy is usually a safe procedure. However, side effects sometimes occur. These may include pain, bleeding or infection at the injection site. There is a risk of infection any time a needle is inserted into the body. Infections to joints can destroy a joint’s function. There is also a small risk of damage to spinal nerves that could result in additional complications.

Controversy remains over the effectiveness of injection therapy. Though some experts recommend them, studies have not conclusively shown injection therapy to be effective in treating certain types of pain.