Soft tissues, particularly surrounding joints, may be injected with therapeutic medicines to relieve symptoms and to speed healing of an injury. A common site is the shoulder where injuries to the tendons ("rotator cuff") and nearby structures are treated with an injection of a mixture of a local anaesthetic and an insoluble steroid. After a diagnostic scan has confirmed a soft tissue injury is the cause of symptoms (e.g. tendonitis and/or bursitis) and has determined that surgery is not warranted, an immediate or delayed follow-up procedure is performed using live ultrasound imaging to guide an injection using a fine needle to the precise point in the body where treatment is required. This will often dramatically shorten the recovery time after trauma. The procedure has been shown to be very safe with a very low incidence of complications. No side effects are anticipated because the drugs used are designed to remain at the site of injection and have a local therapeutic effect, rather than passing throughout the body and causing unwanted effects elsewhere. As a rule, an injection may be safely repeated at the same injured site up to a maximum of 3 doses in a 12 month period (repeat injections are occasionally required for incomplete response to the first dose, or if symptoms recur after some months).
Some literature refers to this procedure as HCLA (hydrocortisone local anaesthetic). In current practice, however, hydrocortisone is rarely used, and a suspension of a longer acting steroid such as triamcinolone acetonide (Kenacort) is used.
A similar technique may be used to treat many conditions where tendonitis or bursitis is the underlying problem, including trigger finger/thumb, tennis elbow, housemaid's knee etc.
A therapeutic aspiration may be performed when, often following trauma, a collection of fluid e.g. haematoma has accumulated and is of such a volume or in such a location that it will delay recovery and could lead to complications including infection. Ultrasound is used to guide the needle safely into the fluid which is drawn up ("aspirated") into a syringe and may be analysed at a laboratory where appropriate. A ganglion (joint cyst) may also be so treated.