joint injections

		Joint injections
		The use of injections is a highly effective way to produce symptomatic and therapeutic benefit in the management of arthritis related disease. The use applies in particular to the patient who has inflammed joints out of phase with the rest of the body. It has however - limitations. If there are several swollen joints, the activity of the underlying process must be addressed through proper disease modifying therapy. The joint injection should be a relatively LOW pain procedure. It is a fallacy that joint injections are extremely painful. Large joint injections - especially the knee should not be painful, but small joint injections in the hands may be tender, due to the narrowness of the joint space and also because the hands are designed physiologically to be sensitive to painful stimuli. However, very rarely an acute flare in inflammation from a response by the body to the crystal structure of the steroid in the injection. This is called a crystal flare. It usually lasts 24-36 hours.
		The injection usually contains corticosteroid plus local anesthetic, mixed in a syringe and given in an aseptic environment. The skin is marked at the local site of insertion of the needle. The skin is then cleaned with iodine or a concentrated 70% alcohol solution. Insertion of the needle is then done using a non-touch technique. After infusion of the contents of the syringe, the needle site is sealed ideally with a plastic spray and a light bandage. The patient should then be encouraged to rest the joint / tendon, for a 36-48 hour period. The needle site should be kept out of water for about 12 hours, to reduce infection risks. Types of corticosteroid in order of strength, include: Triamcinolone hexacetonide: 20mg for large joints and 5-10mg for smaller joints. Methyl prednisolone Betamethasone acetate
		Significant problems / complications of the injection include: Flushing Allergy - very rare (especially to the local anesthetic Pain usually mild but rarely more severe (crystal flare) Infection - fortunately very rare.
		Virtually any joint can be injected by knowing the landmarks for entry in the joint / tendon. The volume of fluid depends on the joint itself. The frequency of injections is also joint dependent. This applies especially for weight bearing joints. Excessive injections may result in deleterious effect on the joint.
		The response to injections are variable, but are especially satisfactory when the joint is inflammed. i.e. warmth and swelling in the joint. My recommendation for large / weight bearing joints ie knee or ankle is to restrict to 2-3 times maximal per year. For non-weight bearing joints i.e. shoulder / elbow / tendon, restriction to 4 per year. Failure of response after repeat injections, should be recognized as such, and ulterior methods used to address the problem.
		There are other types of joint injection than steroids. This includes Hyaluronan injections, i.e. Synvisc, or Hyalgan. These are not really in my opinion offering any particular advantage over corticosteroid itself and are extremely costly. Intraarticular ablative therapy to achieve synovectomy can be attempted by use of Yttrium-90 radioactive injection, or even mustine. However, these are difficult to use in the office environment and are largely replaced by arthroscopic synovectomy now.