The infiltration of the AC joint performed by one specialist: ultrasound versus palpation a prospective randomized pilot study.

The acromio-clavicular (AC) joint is very susceptible to degenerative processes that result in pain and functional impairment. One common modality of treatment has been local infiltration of the joint space. Although this procedure has produced notable positive results, needle misplacement occurs frequently. The aim of this investigation is to evaluate the effects of an intra articular infiltration by comparing precise needle placement into the joint space using high-resolution-ultrasound with the conventional palpation technique.This prospective and randomized pilot study analysed 20 patients who were assigned either to the "ultrasound" or the "palpation" group. Clinical examinations were performed before treatment and at 1h, 1 week and 3 weeks after a single infiltration of local anaesthetic and corticoid carried out by one specialist.In both groups significant improvement in pain and function was obtained up to one-week post injection. Function remained significantly improved until the last follow-up and did not differ between the two groups. The agent was administered in all patients into the joint space in the ultrasound group.Ultrasound guided infiltration of the AC joint is an easily achieved procedure without any complications. However, clinical follow-up did not differ between free-hand and ultrasound-guided AC joint space infiltration.