Chronic instabilities may be traumatic or atraumatic, unidirectional or mul
tidirectional. It is important to distinguish between symptomatic instabili
ty and asymptomatic hyperlaxity. Posttraumatic. unidirectional anterior ins
tability without hyperlaxity is the most common form of instability. The pa
tient presents apprehension, the sulcus-sign is negative. Posttraumatic. un
idirectional instability with hyperlaxity is due to an adequate trauma, bot
h the apprehension test and the sulcus sign are positive. The treatment of
traumatic instability is surgically with respect to the underlying patholog
y of the ligaments, labrum and capsule. The "golden standard" is the recons
truction of the capsulolabral complex. The repetitive microtraumatic instab
ility is seen in overhead athletes with elongation or disruption of the cap
sule. The typical patient presents with painful subluxations. the instabili
ty may be unidirectional or multidirectional. The treatment is conservative
ly. Multidirectional instability with hyperlaxity is defined as symptomatic
instability in at least two directions of instability with multidimensiona
l hyperlaxity. These individuals will also report on pain rather than insta
bility. The apprehension test is positive in at least two directions, the s
ulcus sign is positive as well. The patients are responsive to an intensive
rehabilitation program for 6-12 months. Open capsular shift or thermal cap
sular shrinkage may be successful after failed conservative treatment. Mult
idirectional instability without hyperlaxity is extremely rare and is due t
o more than one adaquate trauma with traumatic instability in different dir
ections. The apprehension test is positive, the sulcus sign negative. The t
reatment is surgically. The fixed dislocation is posterior in most of the c
ases and frequently being missed primarily. It is seen in unconscious, mult
iple-injured patients or after grand mal or electroshock seizures. The redu
ction may be either closed or open depending on the interval between trauma
and diagnosis. Voluntary instability represents a subset of individuals wi
th atraumatic instability. The patients can dislocate and reduce their shou
lder, have no pain and do not develop arthritis. They do not require a spec
ial therapy.