**5. Conclusions**

The investigated postero-inferior approach with subdeltoidal access and posterior dislocation of the humeral head through an internervous split between the infraspinatus and the teres minor with a medial T-shaped incision of the capsule allows for sufficient exposure and orientation to perform rotator-cuff sparing anatomical total shoulder arthroplasty with acceptable implant sizing and positioning in cadaveric specimens. This approach tends to medialize the COR that needs to be taken into account when performing aTSA. Further research should focus on the radiological and clinical outcomes of the PI approach in daily practice.

**Author Contributions:** Conceptualization, D.A. and P.M.; methodology, D.A. and L.L.; formal analysis, P.M. and M.M.; data curation, D.A. and K.K.; writing—original draft preparation, D.A. and L.L.; writing—review and editing, F.U., S.D.S., M.M., M.v.d.M. and P.M.; supervision, P.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** Funding was received from Arthrex Inc. in terms of material sources.

**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board (or Ethics Committee) of Charite Universitätsmedizin (EA1/026/21).

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data available on request due to restrictions, e.g., privacy or ethical.

**Conflicts of Interest:** Author P.M. receives royalties from Arthrex Inc. and consultant payments from Arthrex Inc., Medacta and Depuy/Synthes. Authors F.U., S.S. and M.W. are employed by Arthrex Inc. The authors D.A., M.M., L.L. and K.K. declare they have no financial interests.
