I. Diagnostic use--synovial fluid analysis
- Bloody vs. amber
- Clear vs. turbid
- Cell count
- Cx & sensitivity
- Crystals
II. Therapeutic use--relieve pain
- Remove exudate
- Inject lidocaine, saline, and/or steroid provides symptomatic relief and assists rehab
- Lido/marcaine 1:1 mix plus steroid works well
III. Conditions shown to improve with local steroid injection:
- Articular disease:
- Rheumatoid arthritis
- Seronegative arthropathies including ankylosing spondylitis, IBD, psoriasis, Reiter's
- Crystal-induced arthritis (gout, pseudogout)
- Nonarticular
- Fibrositis
- Bursitis (subacromial, trochanteric, prepatellar, pes anserinus, etc.)
- Tendonitis/synovitis
- DeQuervain's, trigger finger, biceps tendonitis, plantar fasciitis, epicondylitis, etc.
- Neuritis/entrapment
- CTS, tarsal tunnel, cubital tunnel, meralgia paresthetia, costochondritis, etc.
IV. Contraindications
- Cellulitis over inj. site
- Septic periarticular bursa
- Suspected bacteremia (unless joint is suspected as source)
- Coagulopathy (e.g. on coumadin)
- >3 injections of wt bearing joint in last 12mos
- Lack of response to 2-3 previous injections
- Unstable joints (for steroid injections)
- Joint prostheses (refer if infection is suspected)
V. Risks:
- Postinjection flare in 2-5%
- Asymptomatic pericapsular calcification in 40%
- Tendon rupture in <1%
- Can traumatize cartilage & nerves
- Injection .001-.072%
- Skin atrophy/depigmentation <1%
- Inj. of artery/vein; hypersens. rxn; transient paresis distally; facial flushing (all rare)
VI. Equipment
- Iodine wipes
- Sterile gloves & drape
- 22-25g 1.5" needle for inj
- 18-20g 1.5" needle for aspiration
- Bupivacaine or 1% lido (single dose vials good; lack preservative); steroid if applicable
- Hemostat, if plan to aspirate/inject with same needle
- Tubes for lab work
VII. Technique
- Informed consent
- Identify path of least risk; mark entry site with thumbnail
- Prep; local anesth although not required (don?t do if doing cx); position pt. supine
- Insert needle gently to avoid cartilagenous damage
- Aspirate before injection
- Can do asp. then injection with 2 syringes; changing them with hemostat
- Inject slowly. Stop & reposition needle if sig. resistnce or c/o paresthesia
- May inject in >1 place
- Cover with bandaid for 12h; advise of signs of inf; NSAIDS x 2-3d; rest; rehab
- Can repeat up to 3x/yr in wt-bearing joints; 4x/yr in smaller joints