Ant-Post instabilites Flashcards
define instability
when laxity produces symptoms
how does instability occur
if the net GH joint reaction force is directed outside the glenoid arc
define subluxation
translation beyond normal physiological limits but maintain glenoid contact
define dislocation
translation with complete dissocation of articular surfaces
what are the components of shoulder stability
- bony congruency: enhanced by the labrum
- negative pressure: at side and rest
- muscles and tendons: static and dynamic
- ligaments and capsule
what is anterior instability
90%
FOOSH
-unidirectional w traumatic onset
-combine position of ABD and ER
-may have anteroinferior labral disruption
what is post instability
-unidirectional with repetivie loading (bench press)
-sport and trauma specific
-combine position of ADD and ER
-may have posterior labral disruption
what is MDI
-not typically from trauma
-congential or acquired laxity
-most common in young
talk about MDI
-symptomatic GH instability in multiple directions
-common in young women with hypermobility and athletes patients <40 years old
-some have symptoms that mimic subaccromial pain syndrome
-significant ligamentous and capsule laxity
-recurrent dislocations/sublux
-congenital like in ehlers-danlos
-muscle imbalance/coordination
-often no associated trauma or MOI
-RC pain often first presenting symptom
what is the rotator interval
-interval between superior aspect of the subscap tendon and anterior most portion of supraspinatus tendon
-research shows that the size of this is related to stability
what is the cluster for MDI
-sulcus sign
-load and shift
-arc of pain
-history/coomplaints
in the load and shift what shows laxity?
more than 50% migration
what are the protocols for rotator interval closure surgery
avoid early supraspinatus and subscap contraction for the first 4-5 weeks
