Late Breaking Research Poster 2237351| Volume 104, ISSUE 3, e11, March 2023

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

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      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.


      Experimental/Pilot study.


      Anatomy Laboratory.


      Bilateral shoulders of 12 donor bodies (n=24).


      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.


      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.

      Key Words

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