Table 1.

Classification of instability following reverse shoulder arthroplasty [10••]

Loss of compression	Undersized implants
	Loss of deltoid contour
	Loss of humeral height
	Subscapularis deficiency
	Acromial/scapular fracture
	Deltoid dysfunction
Loss of containment	Mechanical failure
	Alteration of depth/radius ratio
Impingement	Soft tissue or bony impingement
	Prosthetic malalignment
	Body habitus