Anatomically-Guided Glenohumeral Joint Injections Using the Glenohumeral Acromioclavicular Portal Technique: A Pilot Study.

Research

Objectives: To test hypotheses that the Glenohumeral Acromioclavicular Portal (GAP) injection technique is non-inferior, and superior in accuracy, to other anatomically guided techniques for glenohumeral joint (GHJ) injections, and can be effectively taught to resident physicians.

Design: Experimental/Pilot studySetting: Anatomy LaboratoryParticipants: Bilateral shoulders of 12 donor bodies (n=24)Interventions: Glenohumeral Acromioclavicular Portal (GAP) injections and relevant anatomic landmarks were described to a physiatry resident (trainee) by a sports medicine-trained physiatrist (specialist). The specialist and trainee then independently injected 24 donor shoulders with 3 mL of separate food coloring dyes. Martinez-Silvestrini’s GAP injection procedure was followed: a 25 gauge 1.5 inch needle was placed in the midpoint between the acromion and coracoid process, and advanced with a ~45° cephalocaudal and ~45° mediolateral angulation until bony contact was observed. An anatomist and trained assistant then dissected each shoulder, exposing the GHJ.Main Outcome Measures: The success of GAP injections was determined by direct visualization of dye in the GHJ as follows: blue = specialist, yellow = trainee, green (mixed dyes) = specialist and trainee, no coloring = neither specialist nor trainee (unsuccessful injection).

Results: Of 48 injections, inspection of dissected shoulders revealed the following: the specialist successfully injected 22/24 shoulders (91.67%); the trainee successfully injected 20/24 (83.33%) shoulders. Combined accuracy was 42/48 (87.5%); 19/24 (79.2%) of shoulders were jointly injected by both the trainee and specialist; Both specialist and trainee were unsuccessful at injecting one of the shoulders which was grossly deformed.

Conclusions: The GAP technique was shown to have high accuracy when performed on 24 donor body shoulders. Our data suggest that the GAP technique is non-inferior, and potentially superior, in accuracy to traditional methods of anatomically guided intra-articular shoulder injections (26.8-40% accuracy). Additionally, GAP injections can be taught effectively to resident trainees. Further investigation appears warranted.Author(s) Disclosures: No Disclosures.