DOCTORAATSTHESIS Matthijs JACXSENS

The 3D scapulohumeral & glenohumeral evaluation in healthy shoulders & shoulders with primary osteoarthritis

Promotoren : Prof. dr. Lieven De Wilde en Prof. Dr. Alexander Van Tongel

Venue : Anatomisch Theater - Muziekcentrum De Bijloke Gent
Registration : //matthijs.jacxsens@gmail.com">matthijs.jacxsens@gmail.com
Live stream : https://teams.live.com/meet/9448077563734

As 3D technology has proven to be superior to 2D to address the pathoanatomy of the shoulder and loosening of the glenoid component, still considered the weakest link in aTSA, has been associated to these pathoanatomic features, the general goal of this doctoral thesis was to analyze the 3D pathoanatomy in primary OA with a focus on humeral head alignment in relation to the glenoid and scapula. Hereby, it was aimed to investigate several morphology types, measurement techniques, imaging modalities, and the relation to outcomes following aTSA.

The first article evaluates the 3D scapulohumeral relationship in healthy shoulders and shoulders with primary OA. The second study focuses on the glenohumeral relationship by means of 3D subluxation of the humeral head in relation to the native glenoid in the same study cohort. These studies in combination characterized primary OA in terms of humeral head alignment with posterior decentering, medialization, and a tendency toward an inferior orientation. Posterior decentering was a common feature seen in most types of wear patterns. Because the scapulohumeral and glenohumeral relationships behaved differently, they are most likely distinct entities. The third study evaluates anterior-posterior humeral head subluxation in relation to different reference planes (scapula vs glenoid) and imaging modalities within a normal population. Normative values and thresholds were introduced accordingly. The fourth study is a clinical study evaluating anatomical and surgical factors in relation to clinical and radiographic outcomes. The relation between humeral head recentering and glenoid version correction with an additional soft-tissue release was refined. Humeral head decentering and glenoid version had in important influence on radiographic outcomes, while clinical outcome was only influenced by the premorbid inclination of the glenoid.

The studies presented in this doctoral thesis add to current understanding of the pathophysiology of primary OA and its relation to outcome, and provides a foundation for 3D planning of aTSA. Surgeons should be aware of the differences seen between scapulohumeral and glenohumeral evaluation, the differences between several imaging modalities, and the factors influencing outcomes.