Purpose: Intra-articular glenohumeral injections are an important part of orthopaedic practices, and the therapeutic benefit and diagnostic information of certain injections is based on the premise of the injection reaching its desired target. This study assessed the accuracy of an anterior intra-articular injection in awake subjects without radiologic assistance.
Type of study: Case control study.
Methods: Forty-one patients scheduled for magnetic resonance imaging arthrography underwent anterior placement of a spinal needle using a location just lateral to the coracoid as the anterior landmark for injection, without radiographic assistance. After the needle was placed and clinically estimated to be intra-articular, 1 mL of gadolinium was injected into the joint to determine accuracy of position. The presence of intra-articular contrast was judged as an accurate injection.
Results: Only 26.8% (11 of 41) of injections placed anteriorly were actually intra-articular. The remaining were extra-articular, the most common location of error being either too medial or too superficial in the deltoid muscle.
Conclusions: Based on our cadaveric study, we believed that an unassisted anterior injection to the glenohumeral joint would be accurately placed. However, this study shows that without some form of radiologic guidance, it is unlikely that an anteriorly placed intra-articular glenohumeral injection will be accurately placed in awake patients, and we do not recommend this technique.
Level of evidence: Level IV.