Intra-articular punctures and injections are performed routinely on patients with injuries to and chronic diseases of joints, to release an effusion or haemarthrosis, or to inject drugs. The purpose of this study was to investigate the accuracy of placement of the needle during this procedure.A total of 76 cadaver acromioclavicular joints were injected with a solution containing methyl blue and subsequently dissected to distinguish intra-from peri-articular injection. In order to assess the importance of experience in achieving accurate placement, half of the injections were performed by an inexperienced resident and half by a skilled specialist. The specialist injected a further 20 cadaver acromioclavicular joints with the aid of an image intensifier. The overall frequency of peri-articular injection was much higher than expected at 43% (33 of 76) overall, with 42% (16 of 38) by the specialist and 45% (17 of 38) by the resident. The specialist entered the joint in all 20 cases when using the image intensifier.Correct positioning of the needle in the joint should be facilitated by fluoroscopy, thereby guaranteeing an intra-articular injection.Intra-articular aspirations and injections are performed routinely on patients with acute injuries and chronic conditions of their joints to aspirate an effusion or haemarthrosis, or to inject drugs. Corticosteroids, hyaluronic acid, local anaesthetics and miscellaneous agents are frequently injected into joints to alleviate pain caused by acute injuries or chronic diseases.1-3 Serious complications following unintentional periarticular injection of corticosteroid are well documented as far as major joints and those of the fingers are concerned.4-6 However, only a few reports exist regarding the frequency of unintentional peri-articular injections in acromioclavicular joint. 7,8 The objectives of this study were to estimate the overall frequency of peri-articular injections using a cadaver model, to investigate the degree to which experience contributes to successful injection of the joint and to compare the results using an image intensifier.
Materials and MethodsThere were 76 acromioclavicular joints (38 left, 38 right) from 38 cadaver specimens (20 male, 18 female) with a mean age of 74.8 years (59 to 98) at the time of death. The cadavers were preserved using the method of Thiel. 9 In the image-guided control study the specialist injected 20 acromioclavicular joints (ten left, ten right) in a further ten cadaver specimens. This special embalming technique, which was developed over a period of 30 years, preserves the original colour, consistency and degree of transparency of the tissue, with a full range of passive movement of the joints.9 Joints with advanced arthritis, evidence of trauma or other pathological changes detected by radiography were excluded from the study. An inexperienced resident (SG) in his first year of training and a skilled specialist surgeon (WG) with 15 years of experience were chosen to perform the injections. Each punctured a total of 38 joints,...