English to French Medical Medical: Instruments shoulder surgery (rotator

This is a technical medical document on Affinis inverse shoulder operations.

Context:
Baseplate Fixation
The modification of the baseplate design resulted from the conflict of goals with the conventional baseplate with one peg and an inferior screw.
On the one hand, the baseplate has to be positioned as inferiorly as possible to prevent notching. On the other hand—in this inferior position—the inclined inferior screw is difficult to place in the scapular neck and there is a systematic potential of implant-implant notching between the screw and the humeral inlay.

I understand the meaning mostly but am not sure where/how notching would occur between the screw itself and the inlay?
Also the term implant-implant means between one implant and another but am not sure how to convey this in good French.

This is my attempt of the last sentence:
D'autre part, dans cette position basse - il est difficile de fixer la vis inférieure inclinée dans le col de l’omoplate et il y a un potentiel systématique d’encoche implant-implant entre la vis et l’implant (insert) huméral.

I would appreciate the input of medical experts in the field. Especially an improvement in the style...