Needle Length Requirement for Glenohumeral Joint Injection Using the Neviaser Approach.

Intra-articular glenohumeral joint injections are commonly performed in the clinical setting for diagnostic and therapeutic purposes. Multiple approaches are described, including the anterior and posterior approaches and the less studied superomedial (Neviaser) approach. The purpose of this study was to determine the length of needle required to enter the shoulder joint via the Neviaser approach by radiography and magnetic resonance imaging (MRI) measurements. Additionally, the authors sought to identify any correlation between needle length and body mass index (BMI). They performed a retrospective review of 101 consecutive patients evaluated by one faculty member at their institution. Inclusion criteria were age older than 50 years, no previous shoulder surgery, no history of acromioclavicular joint injury, and having a true anteroposterior radiograph and MRI within 1 year of each other. Using a digital imaging system, the Neviaser approach needle path was drawn for both images, and the lengths were measured. Correlation coefficients for needle length and BMI were calculated. The images of 58 (57.4%) male patients and 43 (42.6%) female patients were evaluated (average BMI, 31.2 kg/m). The average needle length measurement was 4.27 cm on radiograph and 3.9 cm on MRI. Correlation coefficients were r=0.36 (P=.0002) using radiographs and r=0.53 (P<.0001) using MRIs. When using the Neviaser approach, there is a moderate positive correlation between BMI and the measured distance between skin and the glenohumeral joint when assessed on MRI, and a weak positive correlation on radiographs. The authors conclude that an injection needle of 2 inches or greater is required to reliably access the shoulder joint, and this length may increase with increasing BMI. [Orthopedics. 2020;43(4):e215-e218.].