Radiologic assessment of glenohumeral relationship: reliability and reproducibility of lateral humeral offset

Abstract

Background: It has been shown that anatomical reconstruction is an important step in achieving good function after shoulder arthroplasty. It is essential to reconstruct the distance between the coracoid process and greater tubercle as this relates to the moment arm of the deltoid and rotator cuff muscles. This study evaluated the reliability of measurement of the lateral humeral offset (LHO) on plain radiographs and on computed tomography (CT).

Methods: Four independent observers performed measurements of LHO on radiographs and CT from 26 patients awaiting shoulder reconstruction. The interobserver reliability and intraobserver reproducibility were assessed.

Results: Interobserver reliability and intraobserver reproducibility of LHO in axial CT scans were excellent. Plain radiography showed fair to excellent interobserver reliability and variable intraobserver reproducibility.

Conclusion: CT is a reliable tool to measure LHO supporting its use in preoperative planning. When AP radiography is used for preoperative planning the examiner should be aware of its limitations and standardisation protocols should be considered.