Table 1.

Various risk factors having an effect on instability after reverse shoulder arthroplasty (RSA)

Author	Risk factor
	Comorbidities and demographic factors
Cheung et al82	Male gender
Padegimas et al104	Body mass index > 30
	Diagnosis
Cheung et al82	Previous open procedures, preoperative nonunion of proximal humerus or tuberosity
	Intraoperative factors
Tashjian et al83	Superior inclination of baseplate
Ohl et al105	Resection of tuberosities
Lädermann et al106	Deltoid insufficiency, intraoperative neurological palsy
Cheung et al and Edwards et al82,107	Lack of anterior restraints including subscapularis insufficiency (controversial, depend on prosthetic design)
Lädermann et al and Gallo et al81,108	Inability to restore humeral length
Edwards et al107	Conjoint tendon weakness and pectoralis major insufficiency
Favre et al62	Malpositioning of the components
Johnson et al109	Impingement
	Postoperative factors
Gallo et al108	Infection
Lädermann et al106	Deltoid insufficiency resulting from acromial fracture, polyethylene wear, stem subsidence