In all shoulder instabilities it is very important to classify the typ
e of instability precisely in order to choose the right form of therap
y and predict the results. The acronyms TUBS, which means traumatic in
stability, unidirectional, Bankart lesion, and good response to surger
y, and AMBRI, which means atraumatic aetiology, multidirectional, and
good for rehabilitation, represent the complete range of possible inst
abilities. We discuss the subtypes in the differentiation of various i
nstabilities and the different causes and pathologies for instability,
the clinical and radiological tests possible, and the different surgi
cal treatment options, as well as the results in the literature. A mod
ification of the Bankart procedure and the arthroscopic Caspari capsul
orrhaphy procedure for traumatic instabilities are described. The caps
ular T-shift by Neer and Foster is explained as a surgical treatment f
or multidirectional instability.