This technique reduces the risk of corticosteroid-induced fat atrophy, because the only medication that passes through fat tissue is anesthetic. A single syringe containing anesthetic and corticosteroid is used. The needle is introduced under sterile conditions into the skin at an orientation that would miss the target by 0.5 to 1.0 cm. At the target site, the medications are delivered and then the needle is withdrawn. Creating a discontinuous entry path reduces the risk of fistulous tract formation.
Most injections are well tolerated.
Physicians can decrease the odds of adverse effects by advising patients to follow a few post-injection instructions. First, patients should be instructed to rest, avoiding vigorous activity that involves the injection site for 48 hours. Patients may return to activity as their condition allows. This problem is self-limiting and believed to be caused by the precipitation of crystals within the tissue fluids. Summary Successful joint and soft-tissue aspiration and injection rely on the physician's understanding of the indications, contraindications, and general techniques involved in these procedures.