Posterior intra-articular hip injections: a pilot study investigating a new approach.

Abstract

The purpose of this study was to investigate a novel posterior intra-articular hip injection approach while discussing the clinical pearls for methodology, accuracy, and associated adverse events. The goal was to investigate if this approach could potentially be used in those where the typical anterior access would be challenging. 10 adults (age > 18years) who were referred to a tertiary outpatient clinic for hip injection due to hip osteoarthritis or femoral acetabular impingement with labral tearing to a single academic sports medicine clinic. Patients were placed in prone position. Posterior structures were identified using a curvilinear transducer. A 22 gauge 3.5-6-inch spinal needle was advanced in-plane to the transducer towards the hip capsule at the head-neck junction of the femur from inferolateral to superomedial. A fluoroscopic arthrogram was obtained to evaluate needle placement accuracy. Location of the needle, direction of contrast flow, the rate of conversion to an anterior portal, and adverse events were analyzed. A fluoroscopic arthrogram was obtained after the first attempt in nine patients (90%). One patient (10%) was converted to the anterior approach due to inability to obtain the expected arthrogram. Two patients (20%) demonstrated mild adverse events. Ultrasound-guided posterior approach hip injection is accurate and without serious adverse events in our study. The posterior approach can be considered as an alternative approach for patients who cannot tolerate or may have technical difficulty with an anterior approach.