1. OVERVIEW AND DESCRIPTION
Joint injections are valuable procedures for managing musculoskeletal conditions, both for diagnostic and therapeutic purposes. The purpose of therapeutic joint injections is to relieve pain, reduce inflammation, and improve mobility. Local anesthetics may be injected with corticosteroids to provide additional, rapid pain relief.
As with any procedure, success depends on knowing the correct diagnosis (who to inject), performing the right procedure (how to inject), and using the most appropriate pharmacologic agent (what to inject).1
Joint arthrocentesis (aspirations) play a critical role in the diagnosis of inflammatory arthropathies. They are required for the diagnosis and management of the acute “hot red joint,” which is a medical emergency because of the morbidity and mortality related to septic arthritis. This largely relates to presentation with acute monoarthritis but is also relevant to the patient with pre-existing chronic polyarthritis, such as rheumatoid arthritis (RA), who develops a “flare” limited to one joint. By aspirating synovial fluid an accurate diagnosis can be done for joint sepsis or crystal-associated synovitis (gout or pseudogout).2
Aspiration of synovial fluid from a swollen joint, due to synovitis or hemarthrosis, may quickly relieve severe pain by reducing intra-articular pressure. If septic arthritis is highly suspected, steroid injection should be deferred after exclusion of sepsis by joint fluid culture. Corticosteroid injection may avoid the requirement for additional systemic treatment or provide quick relief while slow disease-modifying drugs take effect. In the circumstance of inflammatory monoarthritis, intra-articular treatment is most appropriate.2
2. RELEVANCE TO CLINICAL PRACTICE
As for any musculoskeletal complaint, it is imperative to obtain a careful history and thorough physical examination. Red flags concerning issues such as infection and malignancy should be ruled out. A functional assessment of the patient should be obtained. Judicious use of imaging studies and laboratory tests should be ordered when appropriate. Once a diagnosis is established, an outlined treatment plan should be given. Joint injections can be done for diagnostic and/or therapeutic purposes to aid with the rehabilitation program.
Joint injections can be done with or without image guidance. Among image guidance the most common types are with the use of fluoroscopy or ultrasound. Some studies support the use of image guidance to inject the joint, as it improves accuracy and efficacy. 3,4
As with any procedure, informed consent must be obtained from the patient. For documentation purposes, this should be done in a written format. Risks, benefits, and expectation from the proposed procedure should be explained and the patient should have adequate opportunity to ask questions.
Selection of steroids for injections depends on the practice and level of comfort of the physician. The clinical effects of steroids result from several different mechanisms of action. Intra-articular corticosteroids work by reducing synovial blood flow,5 lowering the local leukocyte and inflammatory modulator response,6 and altering local collagen synthesis.7 The combination of these effects reduces pain and inflammation. Hydrocortisone esters are more effective in producing these effects than their parent compounds. Solubility is reduced when there is a branched esterification of the corticosteroid, allowing them to remain at the injection site longer.5 Clinically, insoluble steroids have a longer duration of action and a higher incidence of cutaneous side effects. Triamcinolone hexacetonide is the least soluble of the commonly used injectable steroids and has a longer duration of action, followed by triamcinolone acetonide. Betamethasone has a high solubility, shorter duration of action, and fewer cutaneous side effects.
Local anesthetics are often used in combination with corticosteroids for intra-articular injection. Local anesthetics relieve pain and can be used diagnostically to differentiate between local and referred pain.8,9,10
The injectable lidocaine maximum dose is 300mg or 4.5mg/kg.30 For example 2% lidocaine = 2g/100mL or 20mg/mL, therefore to inject 100mg = 5mL of 2%. There have been no randomized controlled trials to show the best dose of steroids for peripheral joints.
Bupivicaine and lidocaine have been shown to be chondrocytotoxic, though toxicity is based on amount of time the chrondrocytes are exposed and the dose of local anesthetic. 31,32 This research was more aimed at studying post-op bupivacaine pain pumps which the dose and time are much greater than performing a single joint injection.33
As with the choice of corticosteroids, the choice of local anesthetic for injection is based on clinical preference. When both the corticosteroids and local anesthetics are used together, many patients will experience relatively rapid relief of symptoms immediately following the injection. This is the initial action of the local anesthetic. However, patients then often experience a transient increase in pain as the local anesthetic wears off.
Contraindications to intra-articular injection include: 8,11,12
- Broken skin at injection site
- Known hypersensitivity to intra-articular agent
- Osteochondral/intra-articular fracture
- Prosthetic joint (relative contraindication)
- Severe joint destruction
- Skin infection overlying injection site
There has been debate on whether to discontinue anticoagulation prior to giving a peripheral joint injection. A review of the current literature shows that there is likely more risk in discontinuing anticoagulation than continuing anticoagulation while performing peripheral joint injection.25-28 ASRA (American Society for Regional Anesthesia) classifies peripheral joint injections as low risk for bleeding. 29
Single intra-articular steroid injections have little effect on glycemic control.16 Soft tissue or peritendinous injections can cause elevation of blood glucose that persist from 5 – 21 days.16
If the underlying diagnosis is unknown, aspiration and synovial fluid analysis should be performed for diagnostic purposes, including: crystals, Gram stain, glucose, uric acid, and/or total protein. Although ultrasound imaging can be used to direct or confirm injection location,12 the use of standard anatomic landmarks results in correct needle placement in most uncomplicated cases.13,14
The most common complications of intra-articular injection are: 14,15,16
- Postinjection flare of pain (2 to 10%)
- This risk can be reduced by taking a one-time oral NSAID after the injection
- Skin atrophy (1%)
- Fat atrophy (1%)
- Facial flushing (less than 1 to 12 percent)
- Iatrogenic infection (risk of 1 in 1,000)
Also, systemic side effects can occur as well. The most common include:
- Vasovagal reaction (10 to 20%)
- Facial flushing (less than 1%)
- Hypersensitivity reaction (less than 1%)
Common Joint Injections and Techniques16
|Glenohumeral (shoulder) Joint||Posterior Approach – The needle should be inserted 2-3 cm inferior to the posterolateral corner of the acromion and directed anteriorly towards the coracoid process.|
|Acromioclavicular(AC) Joint||Affected arm should rest comfortably at the patientâ€™s side. Palpate the clavicle distally to its termination, at which point a slight depression will be felt at the joint articulation. The needle is inserted from the superior and anterior approach into the AC joint and directed inferiorly|
|Elbow Joint||The patient should be in a supine position with the elbow flexed to 45 degrees and the hand in a neutral position resting on the patient’s thigh. Important structures that should be identified prior to performing this injection are the soft tissue at the center of the triangle formed by the lateral olecranon, the head of the radius, and the lateral epicondyle. The elbow joint is injected from a lateral approach, thereby avoiding the ulnar nerve. The needle is inserted into the soft tissue within the triangle described and directed to the opposite (medial) epicondyle.|
|Carpometacarpal (CMC) Joint||Identify the space between the trapezium and the first metacarpal. The needle should enter proximal to the first metacarpal on the extensor surface. Care must be taken to avoid the radial artery and the extensor pollicis tendons. The needle should enter toward the dorsal (ulnar) side of the extensor pollicis brevis tendon. Traction can be applied to the thumb to further open the joint space.|
|Knee Joint||Several approaches described (lateral, medial, superolateral). The patient is in the supine position with the knee slightly flexed with a pillow or rolled towel in the popliteal space.|
Lateral approach: Lines are drawn along the lateral and proximal borders of the patella. The needle is inserted into the soft tissue between the patella and femur near the intersection point of the lines, and directed at a 45-degree angle toward the middle of the medial side of the joint.
|Ankle Joint||Place the patient in the supine position with the ankle relaxed. Identify the space between the anterior border of the medial malleolus and the medial border of the tibialis anterior tendon and palpate this space for the articulation of the talus and tibia. The needle is inserted into the identified space and directed posterolaterally. Reduced resistance will be felt on entering the joint space.|
Hyaluronic acid (HA) can be used as well. It appears to have a slower onset of action than intra-articular steroids, but the effect seems to last longer.17 HA not only relieves the symptoms of osteoarthritis (OA) but also modifies the structure of the diseased joint and the rate of OA disease progression, at least early in the evolution of the disease process.18
Viscosupplementation has been shown to be an effective treatment for OA of the knee with beneficial effects on pain, function, and patient global assessment at different post-injection periods but especially at the 5- to 13-week post-injection period, with a effect on the reduction of NSAIDs monthly consumption.18
3. CUTTING EDGE/UNIQUE CONCEPTS/EMERGING ISSUES
The use of ultrasound has gained more popularity over the last decade. Berkoff demonstrated in a review article that ultrasound guidance improves injection accuracy to statistically significant in the target intra-articular joint space of large joints, including the knee, compared to clinical anatomical guidance.19 A study from Patel demonstrated that ultrasound-guided injections are more accurate at reaching the glenohumeral joint than blind injections. However, ultrasound-guided injections took substantially longer to administer.3 Cunnington performed a randomized, double-blind, controlled study of ultrasound-guided corticosteroid injection into the joint of patients with inflammatory arthritis and it was found that ultrasound- guidance significantly improves the accuracy of joint injection, but did not improve the short-term outcome of joint injection.20
4. GAPS IN KNOWLEDGE/EVIDENCE BASE
Platelet-rich protein (PRP) joint injections have been used in certain studies, but none are prospective randomized-controlled trials. Two studies for knee osteoarthritis showed good improvement at follow-up at 5 months and 1 year, respectively. 21.22
Stem cell injections have gained popularity, with promising results. Cell therapy by implanting autologous chondrocytes has been used to regenerate local defects in the cartilage for years. Mesenchymal stromal cells (MSC) have chondrogenic potential, that it is enhanced by co-culture of chondrocytes. They possess two potentials: the ability to differentiate into skeletal cell lineage, and the capacity to self-renew for a relatively long period of time. MSC can be accessed from several sources, including bone marrow aspirates.23 Orozco and colleagues conducted a pilot study with chronic knee osteoarthritis and found the MSC therapy can be considered as a valid alternative treatment for chronic knee osteoarthritis. They even found that it is a simple intervention that does not require surgery, providing pain relief and improving the cartilage quality.24
Emadedin and colleagues injected MSC in six patients that required total knee replacements due to advanced osteoarthritis. During a one-year follow-up, no local or systemic side effects were noted. There was a statistical improvement in the reduction of pain, functional status of the knee and walking distance. MRI was compared at baseline and six-month following the injection and an increase in the cartilage thickness and extension of repair tissue over the subchondral bone were noted. Thus, this study highlights the benefits from MSC and its treatment for osteoarthritis.23
- Stephens MB, Beutler AI, O’Connor FG. Musculoskeletal injections: a review of the evidence. Am Fam Physician. 2008;78(8):971-976.
- Courtney P, Doherty M. Joint aspiration and injection. Best Pract Res Clin Rheumatol. 2005;19(3):345-369.
- Patel DN, Nayyar S, Hasan S, et al. Comparison of ultrasound-guided versus blind glenohumeral injections: a cadaveric study. J Shoulder Elbow Surg. 2012;21(12):1664-1668.
- Naredo E, Cabero F, Beneyto P, et al. A randomized comparative study of short term response to blind injection versus sonographic-guided injection of local corticosteroids in patients with painful shoulder. J Rheumatol. 2004;31(2):308-314.
- Caldwell JR. Intra-articular corticosteroids. Guide to selection and indications for use. Drugs. 1996;52(4):507â€“514.
- Lavelle W, Lavelle ED, Lavelle L. Intra-articular injection. Med Clin North Am. 2007;91(2):241â€“250.
- Wei AS, Callaci JJ, Juknelis D, et al. The effect of corticosteroid on collagen expression in injured rotator cuff tendon. J Bone Joint Surg Am. 2006;88(6):1331â€“1338.
- Tallia AF, Cardone DA. Diagnostic and therapeutic injection of the shoulder region. Am Fam Physician. 2003;67(6):1271â€“1278.
- Rifat SF, Moeller JL. Injection and aspiration techniques for the primary care physician. Compr Ther. 2002;28(4):222â€“229.
- Tallia AF, Cardone DA. Diagnostic and therapeutic injection of the ankle and foot. Am Fam Physician. 2003;68(7):1356â€“1362.
- Cardone DA, Tallia AF. Diagnostic and therapeutic injection of the hip and knee. Am Fam Physician. 2003;67(10):2147â€“2152.
- Denkler K. Helpful hints for injections of wrist and hand region. Am Fam Physician. 2003;68(10):1912.
- Hall S, Buchbinder R. Do imaging methods that guide needle placement improve outcome? Ann Rheum Dis. 2004;63(9):1007â€“1008.
- Courtney P, Doherty M. Joint aspiration and injection. Best Pract Res Clin Rheumatol. 2005;19(3):345â€“369.
- O’Connor FG. Common injections in sports medicine: general principles and specific techniques. In: O’Connor FG, ed. Sports Medicine: Just the Facts. New York, NY: McGraw-Hill Medical Pub. Division; 2005:426â€“433.
- Wang CT, Lin J, Chang CJ, et al. Therapeutic effects of hyaluronic acid on osteoarthritis of the knee. A meta-analysis of randomized controlled trials. J Bone Joint Surg Am. 2004;86-A:538â€“545.
- Ohkawara Y, Tamura G, Iwasaki T, et al. Activation and transforming growth factor beta production in eosiniphils by hyaluronan. Am J Respir Cell Mol Biol. 2000;23:444â€“451.
- Berkoff DJ, Miller LE, Block JE. Clinical utility of ultrasound guidance for intra-articular knee injections: a review. Clin Interv Aging. 2012;7:89-95.
- Cunnington J, Marshall N, Hide G, et al. A randomized, double-blind, controlled study of ultrasound-guided corticosteroid injection into the joint of patients with inflammatory arthritis. Arthritis Rheum. 2010;62(7):1862-1869.
- SÃ¡nchez M, Anitua E, Azofra J, et al. Intra-articular injection of an autologous preparation rich in growth factors for the treatment of knee OA: a retrospective cohort study. Clin Exp Rheumatol. 2008;26(5):910-913.
- Kon E, Buda R, Filardo G, et al. Platelet-rich plasma: intra-articular knee injections produced favorable results on degenerative cartilage lesions. Knee Surg Sports Traumatol Arthrosc. 2010;18(4):472-479.
- Emadedin M, Aghdami N, Taghiyar L, et al. Intra-articular injection of autologous mesenchymal stem cells in six patients with knee osteoarthritis. Arch Iran Med. 2012;15(7):422-428.
- Orozco L, Munar A, Soler R, et al. Treatment of knee osteoarthritis with autologous mesenchymal stem cells: a pilot study. Transplantation. 2013;15 Jun 27;95(12):1535-1541.
- Bashir MA, et al. Determination of a safe INR for joint injections in patients taking warfarin. Ann R Coll Surg Engl. 2015 Nov;97(8):589-91.
- Guillen A, et al. Is it safe to perform joint infiltrations or aspirations in patients anticoagulated with acenocoumarol? Reumatol Clin. 2015 Jan-Feb;11(1)9-11.
- Conway R, et al. Safety of joint and soft tissue injections in patients on warfarin anticoagulation. Clin Rheumatol. 2013 Dec;32(12):1811-4.
- Ahmed I, et al. Safety of arthrocentesis and joint injection in patients receiving anticoagulation at therapeutic levels. Am J Med. 2012 Mar;125(3):265-9.
- Rosenberg PH, et al. Maximum recommended doses of local anethetics; a multifactorial concept. Reg Anes Pain Med. 2004; 29:564-575.
- Gulihar A, et al. Articular cartilage and local anesthetic: A systematic review of the current literature. J Ortho. 2015 Oct 31:12(Suppl 2):S200-10
- Chu CR, et al. In vivo effects of single intra-articular injection of 0.5% bupivacaine on articular cartilage. J Bone Joint Surg Am. Mar 2010; 92: 599-608.
Original Version of the Topic
Jose Mena, MD, German Ojeda Correal, MD, Eddymé Danger, MD. Joint injections / aspiration. 09/20/2013
Casey Murphy, MD
Nothing to Disclose
Stephen Kishner, MD
Nothing to Disclose