Abstract
Introduction
Reverse Total Shoulder Arthroplasty (rTSA) is an efficient treatment, to relieve from pain and to increase function. However, scapular notching remains a serious issue and post-operative range of motion (ROM) presents many variations. No study compared implant positioning, different implant combinations, different implant sizes on different types of patient representative to undergo for rTSA, on glenohumeral ROM in every degree of freedom.
Material and Methods
From a CT-scan database classified by a senior surgeon, CT-exams were analysed by a custom software Glenosys® (Imascap®, Brest, France). Different glenoid implants types and positioning were combined to different humerus implant types. Range of motion was automatically computed. Patients with an impingement in initialisation position were excluded from the statistical analysis. To validate those measures, a validation bench was printed in 3D to analyse different configurations.
Results
25 patients were included; 50 configurations were realised per patient. The validation bench on 5 configurations retrieved an error of 1,5° ± 0,88°. The impingement rate and ROM were improved using lateralised glenoid implant types, inferior positioning glenoid implant types, 42mm glenospheres, decreased Neck Shaft Angles for humerus implants and humerus inset.
Conclusion
Impingement in resting arm at side position and ROM can be maximised with an adequate implant choice. A surgical planning software could assist the surgeon to choose the best configuration for each patient to maximise the post-operative outcome (scapular notching and global range of motion).
