Indications

Contraindications

Equipment

In the past, joint injections were frequently performed without gloves with only an alcohol wipe. In contrast, some physicians still use an extensive sterile draping procedure. Although the former is most likely inadequate, the latter is probably unnecessary unless the patient is immunosuppressed, diabetic, or at high risk of infection. Most injections are administered after an alcohol or povidone–iodine wipe. Gloves (sterile or nonsterile) should be used. When a culture is anticipated, sterile gloves are more customary. Masks are unnecessary.

Required equipment includes the following:

• 22– to 27-gauge, -inch needle for injections

• 18- to 21-gauge, -inch needle for aspirations

• 30-gauge, -inch needle, if skin anesthesia is to be given (usually not needed)

NOTE: There are two reasons to use single-dose vials. First, no allergic reaction to lidocaine (an amide) has ever been reported. Although rare, reactions do occur to the preservative (parabens) that is used in multidose vials. Local anesthetics with an ester base (e.g., procaine [Novocain]) can cause allergic reactions. So, using a single-dose vial of lidocaine makes it highly unlikely that there will be a reaction. Second, many steroids will precipitate when mixed with the parabens preservatives. This leads to uneven distribution in the syringe as well as the injection of small crystals into the site, and these crystals themselves could cause an inflammatory process (Fig. 192-1). Theoretically, a homogeneous solution would be more efficacious, although no studies have looked at the issue and many feel it is a moot point and of little concern. Certain manufacturers, however, do not recommend injecting precipitated steroids.

Figure 192-1 A, Example of precipitation of steroid (Celestone Soluspan) when mixed with lidocaine solution from a multidose vial. B, Steroid in solution (Celestone Soluspan) when mixed with lidocaine from a single-dose vial. It is preferable to have the steroid in solution rather than in precipitated form.

(Courtesy of The Medical Procedures Center, PC, John L. Pfenninger, MD.)

Many practitioners will use a longer-acting local anesthetic such as bupivacaine (Marcaine). Although this addition in most cases will not have any untoward effects, it should be noted that there have been instances of myotoxicity associated with bupivicaine, and given that it is only intended to provide short- to medium-term relief of symptoms, one might question its regular use.

TABLE 192-1 Relative Potency of Corticosteroids

TABLE 192-2 Common Corticosteroids and Recommended Dosages for Various Joint Injections

A reasonable rule of thumb is that the greater the water solubility of the corticosteroid, the more rapid the onset of action, and the shorter the duration of effect. Thus, steroids with a lower degree of water solubility would in general be more effective in a chronic disease process, such as OA, whereas an acute inflammatory process might be more responsive to a shorter-acting preparation (Table 192-3).

TABLE 192-3 Steroid Solubility

NOTE: It is best to pick out one or two preparations and learn them well. It is not necessary to be familiar with all the drugs listed. There is no consensus in the literature as to the “best” drug or the optimal dosages. Table 192-2 offers our recommendations for appropriate dosing.

Preprocedure Patient Preparation

Inform the patient of the risks, benefits, and possible complications of injection therapy. This information is especially important if steroids are used. Rarely is there ever a complication from the use of lidocaine alone. However, with steroids, and especially with repeated injections, there are some adverse consequences (see the “Complications” section and) Table 192-4. Inform the patient that there is always a possibility for infection with the injection, although this is extremely rare. Bleeding into a joint can occur, but this generally does not happen unless the patient has a coagulopathy. The injection may actually cause more pain during the first 24 to 36 hours. This reaction is called steroid flare. If the pain lasts for more than 72 hours, evaluate the patient for the possibility of a septic joint. Warn the patient of a possible failure to obtain relief, and that a second or even a third injection may be needed. Whether or not steroids have significant adverse effects on the cartilage and bone itself when steroids are injected into the joint space, and the degree of this reaction, is controversial. However, the effects would appear to be minimal, especially when used appropriately. Allergic reactions are very rare. Tendon ruptures should be avoidable if the injection is placed peritendinously instead of within the tendon itself. However, rupture is always a possibility. As a final precaution, warn the patient that a steroid placed too close to the surface of the skin occasionally causes atrophy (Fig. 192-2). This reaction may leave the patient with depigmentation and a slight indentation in the skin.

TABLE 192-4 Adverse Effects of Local Corticosteroid Therapy

Figure 192-2 Fatty atrophy. This patient received a steroid injection for lateral epicondylosis approximately 11 months before this photo was taken, showing an example of steroid fatty atrophy and hypopigmentation. Such changes may take up to a year to resolve, and some can be permanent changes.

For diabetics, rapidly absorbed steroids can interfere with glucose metabolism. Therefore, glucose levels need to be followed more closely in the first 24 hours.

Pneumothorax has been reported after injection of trigger points and other conditions around the thorax. The following Technique section explains how to avoid this problem.

Technique

Before injection therapy, consider the differential diagnosis. If a tumor or fracture is possible, radiographs should be obtained. Many times, especially with trigger-point injection (see Chapter 197, Trigger-Point Injection), x-rays are unnecessary. Other diagnoses may also be fairly straightforward and not require a prior radiographic examination either. If the diagnosis is in question or if the patient is at risk for bone metastases (e.g., a history of breast or prostate cancer), the condition should be clarified before injection therapy.

Generally, the clinician injects a combination of lidocaine with the steroid of choice. Single-dose vials of lidocaine should be used to avoid the preservative/precipitation problems (see earlier comments and the “Complications” section). Using a rather large volume of lidocaine may be beneficial. Not only does it disperse the steroid in a less concentrated solution, the volume itself may have a therapeutic effect. In some instances, only a minimal amount of lidocaine can be used (e.g., ganglion cysts, trigger fingers). In other sites, larger amounts are recommended (e.g., lidocaine 5 to 10 mL in a shoulder or knee mixed with 0.5 to 1 mL of selected steroid). A good rule of thumb is to use more, not less, when it comes to lidocaine.

The recommended dosages of medications (Table 192-5) and the specific techniques for various injection sites (Figs. 192-3 to 192-25) are included in this chapter.

TABLE 192-5 Needle Size and Drug Dosage for Injection Therapy

Figure 192-3 Injecting finger and toe joints. A, Appropriate technique for injecting a finger joint. Tendons run over the dorsum of the finger, whereas nerves and vessels run laterally. Open the joint slightly by flexing it and then inject between the ligaments and the vascular structures as noted. The needle enters at a 45-degree angle to the joint. Any of the finger (B) and toe (C) joints may be aspirated or injected in the lateral or medial aspect. Slightly flex the joint to open the joint space. Direct the needle to enter just medial or lateral to the extensor tendon, avoiding too lateral or medial an approach where the nerve and vascular structures run. Use a 25-gauge, 1-inch needle with 0.5 to 1.0 mL 1% lidocaine and 4 to 10 mg of methylprednisolone acetate or equivalent (see Tables 192-2 and 192-5).

Figure 192-4 Trigger finger. A, The anatomy of a finger showing the annular pulleys, which maintain the flexor close to the bony structures. When the tendon becomes inflamed and enlarges, it catches on the pulleys, causing a snapping with extension or a “trigger finger.” B, Identify the flexor tendon involved. Insert the needle at the distal palmar crease. Attempt to position it peritendinously. When the needle is in position, the syringe will move with flexion of the finger. Use a 25-gauge, 1-inch needle with 0.25 to 0.5 mL 1% lidocaine and 4 to 10 mg of methylprednisolone acetate or equivalent (see Tables 192-2 and 192-5).

Figure 192-5 Wrist joint. A, Injection of the wrist joint. The hand is held in slight flexion, and the needle is inserted just distal to the radius in the “snuff box.” B, Flex the joint 20 degrees to open the joint spaces. The dorsal approach is generally used. Position the needle perpendicular to the skin surface. Enter at a site distal to the radial head and lateral to the extensor pollicis longus tendon (just ulnar to the anatomic “snuff box”). If the needle can be easily inserted to 1 or 2 cm, it is correctly positioned in the joint space. The intercarpal joints have interconnecting synovial spaces, and the contents of one correctly placed injection will disperse into the entire joint complex. Use an 18- to 20-gauge, 1- to -inch needle with 0.5 to 1.0 mL 1% lidocaine and 4 to 10 mg of methylprednisolone acetate or equivalent (see Tables 192-2 and 192-5).

Figure 192-6 A ganglion is a manifestation of joint inflammation. A, Frontal view. B, Side view. C, Example of an unusual ganglion cyst on the thenar eminence. D, Aspiration of the cyst. Hold the needle in position with the hemostat and remove the syringe. Attach the steroid-containing syringe and inject the contents. (Some have used fibrin sealants, hypertonic saline, and other irritants for attempts to “scar down” the cyst.) E, The contents are often thick, and there may only be minimal return of a gel-like material. F, Use an 18- to 20-gauge, 1- to -inch needle with 0.5 to 1.0 mL 1% lidocaine and 4 to 10 mg of methylprednisolone acetate or equivalent (see Tables 192-2 and 192-5).

(A–E, Courtesy of The Medical Procedures Center, PC, John L. Pfenninger, MD.)

Figure 192-7 De Quervain’s disease. Maximally abduct the thumb to accentuate and identify the tendon. Insert the needle parallel to (but not into) the tendon. Inject at the areas of greatest tenderness. Postinjection splinting may still be necessary. Use a 25-gauge, -inch needle with 3 to 4 mL 1% lidocaine and 10 to 20 mg of methylprednisolone acetate or equivalent (see Tables 192-2 and 192-5).

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