I. Aspiration (Arthrocentesis) May confirm diagnosis and dictate treatment for suspected causes of joint, tendon sheath, or bursal lesions or poorly defined forms of arthritis Removal of fluid from a tense joint provides fast, effective pain relief and improved joint function Blood and pus within the synovial compartment are damaging to the synovial membrane and joint cartilage. Permanent sequellae can result if left untreated Aspiration and joint injection can be performed for diagnostic and therapeutic reasons. Diagnostically, they are mandatory if septic arthritis is suspected, strongly advised if crystal arthritis or hemarthrosis suspected. They help in the differentiation of inflammatory from noninflammatory arthritis. They are also useful as imaging studies through arthroscopy and arthrography. The therapeutic value of injections include removal of tense effusions (relieve pain and improve function), to remove blood or pus from a joint, for tidal lavage of joints and for injection of steroids and other intra-articular therapies. Other Tests (when appropriate): Gram stain and culture Cell count (especially, WBC) AFB stain and Culture Viral Culture Fungal Culture Complement (C 3, C 4 ) Relative contraindications to intra-articular injections include severe immunodeficiency, anticoagulant therapy, poor response to prior injection, multiple prior injections (? more than three) and uncontrolled diabetes. Absolute contraindications for aspiration and joint injection include skin infection overlying site to aspirate, septicemia/bacteremia (steroid injection), coagulopathy, unstable joint, septic effusion (steroid injection), presence of fracture or tumor, prosthetic joint and an inaccessible joint. NOTE: Intra-articular steroids have been used for may years in the treatment of inflammation, tendinitis and bursitis. Despite its ubiquitous use in medicine, there remains controversy regarding mechanism of action, efficacy, etc. 1
A comparison for synovial fluid analysis is below: Fluid Type Viscosity Appearance Microscopic Differential Normal High Clear, Transparent Non-Inflammatory High Clear-Yellow, Transparent Inflammatory Low Yellow Transparent- Opaque Crystalline Low Yellow Cloudy Septic Low Opaque, Yellow Cloudy WBC < 200 PMN <25% WBC 200-10K PMN < 50% mostly lymphs WBC 2K-50K PMN > 50% WBC > 2K - 20K PMN > 50% + Crystals (-Gout; +CPPD) WBC > 50K PMN > 60% + Gram stain/culture Traumatic Arthritis OA OCD Early or late Inflammatory Arthritis Arthritis R.A. Reiters Synd. IBD TB/Fungal Arthritis Viral Arthritis Crystal Induced Bacterial Infection Neisseria Staph. Hemorrhagic Variable Bloody Variable (approach serum values) Adapted from Emergency Orthopedics, The Extremities; Third Edition, 1995, p. 25-38. Trauma Bleeding Diatheses Thrombocytopenia Neoplasm II. Steroid Injections Utilized to provide relief of persistent localized inflammation. Exact mechanism of action of corticosteroids still uncertain. Corticosteroids block the arachidonic pathway, thereby decreasing prostaglandins and leukotrienes. Primarily used after other modalities (NSAIDS, Rehab) have failed or as alternative 2
therapy for patients who cannot tolerate other forms of treatment (NSAID s) Most authors agree to limit injections to no more than 3 injections per joint per year (especially in weight bearing joints). Exact evidence for this recommendation is unclear. After injection, it is generally helpful to massage the area and move the joint through its full range of motion to distribute the medication Allow 3-6 weeks to determine whether an injection is effective. Activity of the injected joint should be modified/limited for several days - weeks after injection depending on the site. If patient cannot rest the affected joint following, reconsider giving the injection. Range of motion exercises are OK, avoid resistance exercises during one to two weeks after injection. Pain at the site of injection is not uncommon, and can sometimes last for several days. If pain does not resolve (usually within 72 hrs), concern is raised for infection. NEVER inject against resistance; this may indicate incorrect position of the needle. Misplaced joint injections can be avoided if synovial fluid is aspirated prior to delivery of steroid. If a joint effusion is present, it is advisable to remove as much of this fluid as possible prior to administration of steroid. When injecting a tendinitis, the steroid should be placed adjacent to the tendon. Avoid injecting directly into a tendon since an injured tendon is more prone to rupture. STERILE technique for steroid administration is recommended. Follow universal precautions with all injections. GENERAL GUIDELINES Palpate bony landmarks of the joint/site to be injected Determine site for injection and mark the skin by applying pressure with needle cap or stick end of the Betadine swabs Prep the skin appropriately Mix steroid and anesthetic solutions Spray the skin with ethyl chloride (skin refrigerant) immediately before performing the injection Insert needle slowly and steadily When assured of the correct placement, inject solution 3
V. Steroid Preparations Corticosteroid Short Acting Relative Antiinflammatory Potency Approximate Equivalent Dose (mg) Cortisone 0.8 25 Hydrocortisone 1 20 Intermediate Acting Prednisone (Deltasone) 3.5 5 Prednisolone terbutate (Hydeltra-TBA) Triamcinolone (Aristocort, Aristospan, Kenalog) Methylprednisolone (Depo-Medrol) 4 5 5 4 5 4 Long Acting Dexamethasone (Decadron-LA) 25 0.6 Betamethasone (Celestone Soluspan) 25 0.6 Adapted from Leversee JH, Aspiration of Joints and Soft Tissue Injections, Prim Care, 13:572, 1986 Note: The preservative in some anesthetics will tend to precipitate steroid solutions.there is speculation that when this precipitate is injected the is greater risk for steroid flare. Single dose lidocaine, methyl parabens-free (MPF) lidocaine and bupivacaine do not contain the preservatives that result in precipitation. 4
IV. Materials- Equipment Required for Joint and Soft Tissue Injections Skin Preparation Local Anesthetics Needles Syringes Antiseptic Solution (Betadine, Chlorhexidine); Alcohol 4x4 Gauze pads Adhesive bandages 1-2% Lidocaine (without Epinephrine) Ethyl Chloride Spray 23-25 Gauge needles for local anesthetic 19 Gauge needles for moderate to large size joints 23 Gauge needle for small joints 3 or 5 ml syringe for anesthetic/steroid injection 10-60 ml syringe for fluid aspiration Miscellaneous Adapted from Practical Rheumatology, John Klippel, 1995, p. 111-20. Sterile gloves Forceps for removing needles from syringe (aspiration then injection) Specimen tubes for cultures and fluid studies Other corticosteroid preparations may be substituted, but dosages may differ. Consult full product prescribing information for use. Adapted from Pfenninger John, Injections of Joints and Soft tissue: Part II. Guidelines for Specific Joints, American Family Physician, Vol. 44(5), November 1991, p. 1690-1701. III. Risks/Complications A. Skin atrophy B. Altered skin pigmentation C. Fat atrophy D. Infection- septic arthritis (1 per15,000-50,000 procedures) E. Bleeding F. Nerve damage G. Systemic Reaction H. Steroid Flare- transient increased inflammation at the site of injection prior to therapeutic response (onset usually 6-12 hours after injection with resolution by 72 5
Dept of Family and Community Medicine hours). Treatment includes ice packs and NSAIDS I. Leakage of injected substance into surrounding soft tissue J. Misplaced Injection K. Asymptomatic pericapsular calcification L. Steroid Arthropathy- Theoretical increased risk of accelerated cartilage attrition (softening of cartilage especially in weight bearing joints). Limited studies in primate have shown no serious long term deleterious effects on cartilage Complication Incidence (%) Skin atrophy < 1 Altered skin pigmentation < 1 Iatrogenic infectious arthritis 0.001-0.072 Post Injection Flare 2-5 Tendon rupture < 1 Facial flushing < 1 Steroid Arthropathy 0.8 Transient paresis Hypersensitivity reaction Asymptomatic pericapsular calcification Rare Rare Unknown Acceleration of Cartilage attrition Unknown Adapted from Gray RG, Gottlieb NL, Intra-articular corticosteroids; an updated assessment. Clin Orthop 1983; 177;253-63 6
Dept of Family and Community Medicine REFERENCES Blair B, Rokito AS, Cuomo F. Efficacy of injections of corticosteroids for subacromial impingement syndrome. J Bone Joint Surg. 78A(11):1685-9, 1996. Dickson J. Corticosteroid injection: how to avoid the risks. The Practitioner. 225: 370-9,1995. Hochberg MC, Altman RD, Brandt KD. Guidelines for the medical management of osteoarthritis. Arthritis and Rheumatism. 38(11):1541-6, 1995. Larson HM, O Connor FG, Nirschl RP. Shoulder pain: the role of diagnostic injections. AFP. 53(5):1637-43, 1996. Nelson KH, Briner W, Cummins J. Corticosteroid injection therapy for overuse injuries. AFP. 52(6):1811-6, 1995. Office Orthopedics for Primary Care, Bruce Anderson, 1995. Pfenninger J. Injections of joints and soft tissue: part I. General guideline. AFP. 44(4): 1196-1202, 1991. Pfenninger J. Injections of joints and soft tissue: part II. Guidelines for specific joints. AFP. 44(5): 1690-170, 1991. Practical Rheumatology, John Klippel, 1995, p. 111-20. Stahl S, Kaufman T. The efficacy of an injection of steroids for medial epicondylitis: a prospective study of sixty elbows. J Bone Joint Surg. 79A(11):1648-52, 1997. 7