Evidence-based reviews of injection procedures have not established their efficacy but practice experience supports its effectiveness1 leading to their vast applications. Diagnostic and therapeutic aspiration of major joints has been an accepted practice in pediatric age group. On the other hand therapeutic injections of joint and soft tissue are rarely indicated or necessary for most sport-related musculoskeletal conditions in children and adolescents. This section provides a short introduction to the topic.
General indications for joint and soft tissue injection and aspiration are twofold: diagnostic and therapeutic.1,2 Aspirating a joint for synovial fluid analysis is a useful diagnostic tool to differentiate an infectious versus an inflammatory etiology. Presence of fat globules in a fresh aspirate may confirm a suspected occult fracture not easily seen on initial plain radiographic studies. Symptomatic relief after injecting a local anesthetic may delineate local from referred pain. A common therapeutic indication is to alleviate the patient's pain and improve range of motion like in a large tense knee effusion. Another indication is to deliver the appropriate pharmacologic agents that usually include a local anesthetic and a form of corticosteroid. Examples of some specific conditions for which these procedures may be called for are listed in Table B-1.
Table B-1. Indications for Injection ||Download (.pdf)
Table B-1. Indications for Injection
Effusion of unknown origin
Any procedure has absolute and relative contraindications.1,3 Absolute contraindications include joint sepsis, local cellulitis, fracture, bacteremia, prosthesis, tendinous sites with high risk or rupture, joint prosthesis and allergy for the drugs being used. Relative contraindications are joint instability, coagulopathy, anticoagulation therapy, poor response to previous injections, anatomically inaccessible joints, and uncontrolled diabetes mellitus. All the aforementioned refer to therapeutic injections. An exception is the presence of a septic joint which in itself is an indication for aspiration but a contraindication for therapeutic injection.1,3
These procedures are generally safe and complications are rare.4 These can be broken into two categories: those attributed to the procedure itself and those from the medication being delivered. Bleeding, infection, and joint injury comprise the first category. A big concern with corticosteroid injection is the risk of tendon rupture. The risk is extremely low but because of the potential adverse outcome, it is one of the important things that need to be included in discussing risks and benefits when obtaining informed consent. Local complications are accelerating a septic joint, subcutaneous fat atrophy, skin depigmentation, steroid flare, cartilage damage, fistulous tract formation, and transient paresis of involved extremity. Facial flushing, gastrointestinal effects, mood alterations, fluid retention, menstrual irregularities, hypothalamic-pituitary axis suppression,5 and allergic reactions are some of the systemic adverse effects reported.
Certain general guidelines need to be followed when performing joint aspiration ...