Office Procedures

11	OFFICE PROCEDURES Kenneth A. Egol

I. INJECTION

An injection may be indicated for either diagnostic or therapeutic purposes such as: rheumatoid arthritis in medium or large joints, osteoarthritis in large weight-bearing joints or the first carpometacarpal joint, other inflammatory arthritis, rotator cuff tendonitis or subdeltoid bursitis, trochanteric bursitis, carpal tunnel syndrome, De Quervain’s tendonitis, trigger finger, lateral epicondylitis, trigger point pain, etc.¹

Common injectable agents:

■ Steroids^2,3:

■ Glucocorticoids: Methylprednisolone

• Large joints (knee, ankle, shoulder): 20 to 80 mg

• Medium joints (elbow, wrist): 10 to 40 mg

• Small joints (MCP, IP, SC, AC joints): 4 to 10 mg

■ Corticosteroids: Triamcinolone acetonide (maximum dose/treatment including polyarticular injection 80 mg) 40 mg = 1 mL

• Larger joints: 5 to 15 mg for the initial injection and up to 40 mg for subsequent injections

• Smaller joints: 2.5 to 5 mg for the initial injection and up to 10 mg for subsequent injections

■ Local anesthetics:

■ Lidocaine: Onset of action: 1 to 2 minutes, duration: 1 hour, dose: maximum 4.5 mg/kg/dose not to exceed 300 mg; do not repeat within 2 hours, usually between 3 and 8 mL for large–medium joint injections, 0.5 mL for tendon sheath injections

■ Bupivacaine: Onset of action: 30 minutes, duration: 8 hours

Frequency of Injection

Potential Complications

Cellulitis, septic joint, and local muscle inflammation. There is controversial evidence regarding the systemic effect of intra-articular glucocorticoids on bone metabolism, patients on therapeutic anticoagulation, tendon rupture (decreased when glucocorticoid is mixed with local anesthetic), nerve atrophy/necrosis, skin atrophy, hypopigmentation (especially in patients with darker pigmentation).

Procedure

Gloves are required. As this is a sterile procedure, a sterile field is required. Examine and palpate the site, then mark the site of injection with marker or by making an impression. Next prepare the skin with several concentric outward spirals of either a chlorhexidine or an iodine prep. Once the skin is prepped, do not touch the site of injection again with unsterile finger as skin will need to be prepared again. Next apply local anesthetic if indicated. Ethyl chloride spray or a subcutaneous wheel of lidocaine (use a 22-gauge needle) may be administered to reduce injection site pain. Anesthetic may also be mixed with the glucocorticoid injection. For intra-articular injections, drawback on your syringe before injection to confirm you are not intravascular. Administer the medication, remove the needle following sharps safety guidelines, and apply gentle pressure to site with gauze. Apply a Band-Aid or dressing over the site of injection.

Patient Education

Advise patients to decrease weight bearing and strenuous activities for 48 hours. Patients may apply ice to the injected joint and should be instructed to observe the area for any significant rebound swelling, erythema, warmth, fever, worsening pain, and drainage from the injection site. Ice may be beneficial in the period between inactivity of local anesthetic and onset of steroid action.1

II. ASPIRATION (ARTHROCENTESIS)

Indications

An aspiration, or arthrocentesis, may be indicated for either diagnostic or therapeutic purposes. Arthrocentesis and/or analysis of synovial fluid (to rule out a septic joint or diagnose gout), to relieve pressure, and cyst aspiration (ganglion, Baker’s).

Needle Size

An 18- to 20-gauge needle is recommended for most large joint aspirations. For smaller joints, such as the wrist or IP joints, a smaller needle, such as a 22- to 24-gauge needle, is recommended.

Syringe Size

For obviously large joint effusions, a 20 mL syringe is recommended, otherwise a 10 to 12 mL syringe should be adequate for shoulder and knee aspirations, or a 5 mL syringe for smaller joints or ganglion cysts. Have additional syringes available in the situation where your syringe fills.

III. COMMON APPROACHES TO INJECTION OR ARTHROCENTESIS

The key to all procedures is to avoid bone and neurovascular bundles. Mark and prepare the site as described earlier. Following injection or aspiration, apply gentle pressure to site and affix a dressing in place.

Posterior Glenohumeral Approach

Externally rotate the shoulder. Mark two finger breadths distal to the scapular spine and two finger breadths medial to the acromial edge. In this “soft spot” direct the needle anteriorly and medially until you puncture the posterior shoulder capsule (Figure 11-1).

Subacromial Approach

Palpate and mark the posterolateral corner of the acromion process. Next palpate the edge of the bone and mark as the injection site. Direct the needle perpendicular to the skin through the deltoid muscle just under the acromion aiming toward the AC joint (Figure 11-2).

Lateral Elbow

Flex the elbow to 90 degrees. Draw a triangle from the radial head, lateral epicondyle, and tip of the olecranon. Direct the needle perpendicular to the skin into the center of the triangle about 2 to 2.5 cm deep (Figure 11-3).