GH Dislocation & Instability Flashcards
What structures and mechanisms act as passive stabilizers of the GH joint?
Superior, middle, and inferior GH ligaments and joint capsule
Glenoid labrum
Negative intra-articular pressure (Vacuum effect)
What anatomical structure provides stability to a joint at the extreme ranges of motion?
Ligaments
Ligaments provide stability to a joint at the ____ ranges of motion in the glenohumeral joint?
Extreme
What is the function of the glenoid labrum?
Increases depth and contact area of the glenoid fossa
What is glenohumeral instability?
Excessive symptomatic displacement of the humeral head in the glenoid fossa
What are the three types of GH instability?
Dislocation
Medical subluxation
Microinstability
What is the most common cause of GH instability?
Trauma
What are the major causes of GH instability?
Trauma
Congenital ligament laxity
Trauma results in ____ instability of joints?
Uni-directional
What is uni-directional instability?
Instability of the joint in the direction of the trauma
Uni-directional instability occurs in the (Same/Opposite) direction of the trauma?
Same
What are the grades of joint instability from stable to the worst scenario?
Stable ——> Microinstability ——> Subluxation ——> Dislocation
What is a common cause(s) of congenital ligament laxity?
Connective tissue disorder such as Ehler’s Danlos and Marfan’s syndrome
Congenital ligament laxity results in ____ instability
Multi-directional
What is a glenohumeral dislocation?
When the humeral head slips out of the glenoid fossa
What is the most common direction of dislocation of the GH joint?
Anterior-inferior
What is the major or most common cause of first time GH dislocation?
Trauma
What are two mechanisms for how an anterior-inferior GH joint dislocation occurs?
Combination of forced ABduction, Extension, and External Rotation
P-A blow to posterior shoulder
What is the most common mechanism for an anterior-inferior GH joint dislocation?
Combination of forced ABduction, Extension, and External Rotation
What tissues are commonly injured in an anterior-inferior GH dislocation?
Anterior aspect of the Inferior GH ligament
Anterior-inferior labrum
RC muscles
How will a patient present to your office if they suffer an acute anterior-inferior GH dislocation?
Arm held slightly ABducted and supported by other arm with intense pain
If it seems obvious that a patient has a GH dislocation you must perform orthopedic testing to confirm your diagnosis (TRUE/FALSE)?
False
How will a patient present upon physical examination of the area surrounding an anterior-inferior GH joint dislocation?
Sharp deltoid contour
Prominent acromion
Palpable fullness below coracoid process
For neurovascular testing of a patient with a GH joint dislocation, you must perform both pre and post reduction exams (TRUE/FALSE)?
t
What artery must be checked for a patient with an anterior-inferior GH dislocation?
Axillary artery
What rotator cuff muscle is most commonly torn in an anterior-inferior GH dislocation?
Subscapularis
What is the most frequently injured nerve in an anterior-inferior GJ joint dislocation?
Axillary nerve
What is the purpose of a radiograph for a patient with a GH joint dislocation?
Rule out fracture and confirm direction of dislocation
What is a Hill-Sacks lesion?
Posterior humeral head fracture
What is a Bankart lesion?
Anterior-inferior rim of glenoid fossa fracture
Reduction of a first time dislocation is controversial without X-rays (TRUE/FALSE)?
t
Reduction of a RECURRENT dislocation is not very controversial without X-rays (TRUE/FALSE)?
t
In a young athlete, an athletic trainer will reduce a shoulder dislocation immediately on the spot if trauma is known (TRUE/FALSE)?
t
What are the most common fractures of the humeral head during a dislocation?
Greater tuberosity
Posterior humeral head (Hill-Sacks)
Anterior-inferior rim of glenoid fossa (Bankart)
Why is an immediate reduction often done on athletes?
Because waiting too long allows the muscles to spasm up and makes reducing harder without sedation
If a doctor chooses not to immediately reduce a dislocation and the patient is sent to the emergency room, what will likely be required in order to reduce this persons shoulder?
Sedation to reduce pain and spasm
Under the current scope of practice, chiropractors are able to perform closed reductions of a shoulder dislocation in the US (TRUE/FALSE)?
Depends on state (must check scope of practice)
What is the standard of care after a closed reduction for a first time dislocation?
4-6 weeks of immobilization only removing the arm for treatment
What is the recommended treatment for a 1st time shoulder dislocation in a young active person after reduction?
Surgery
What is the recommended treatment for a shoulder dislocation in an older individual?
Conservative treatment
Patients under 25 have a (Low/High) chance of re-dislocation if non-surgical treatment is opted for?
High
Older individuals over 45 have a (Low/High) chance of re-dislocation if non-surgical treatment is opted for?
Low
What are examples of closed reduction techniques for an anterior-inferior dislocation?
Milch
Hippocratic
Traction-Counter Traction
Stimson
Kocher
What is implicated in an open reduction of the shoulder?
Surgery
What is a medical subluxation of the GH joint?
Humeral head moves to the edge but does NOT leave the glenoid fossa
What is the most common direction of a GH joint subluxation?
Anterior-inferior
What are the two major causes of a medical subluxation of the GH joint?
Acute trauma
Chronic repetitive trauma
What is the most common mechanism of injury for a medical subluxation of the GH joint?
Combination of forced ABduction, Extension, and External Rotation
What is an apprehension test for the shoulder?
Test for anterior instability of the GH joint that may indicate a medical subluxation. Performed by bracing the arm and slowly moving it into external rotation
What should be tested for on a physical exam of a patient with a suspected GH joint subluxation?
Generalized ligament laxity
What is an example of a test for assessing generalized GH joint ligament laxity and hypermobility?
Beighton Score
What is a Beighton Score?
Assessment of joint HYPERmobility scored from 0-9 with one point allocated for each of the tests performed
What is a positive Beighton Score for an adult?
Adult 5/9
Joint mobilization is the only answer for GH joint instability (TRUE/FALSE)?
False
A low-grade mobilization DOES NOT stress tissues (TRUE/FALSE)?
t
What is a positive Beighton Score for a child?
6/9
What may be evident in a patient’s history if they have a medical subluxation of the GH joint?
Pain
Unstable sensation
Hx of prior dislocation
During an anterior inferior dislocation of the GH joint what two PASSIVE structures are frequently injured and play a major role in allowing recurrent dislocations or subluxations?
A. Middle GH ligament
B. Anterior aspect of the inferior glenohumeral ligament
C. Inferior aspect of the infraspinatus
D. Anterior-inferior aspect of the GH labrum
B and D
What is microinstability of the GH joint?
A subtle form of instability that is usually only seen in athletes involved in intense repetitive overhead sports
What is the most common direction if microinstability in the GH joint?
Anterior-inferior
What is the major cause of microinstability of the GH joint?
Chronic repetitive trauma
What is the mechanism of injury of microinstability of the GH joint?
Combination of forced ABduction, Extension, and External Rotation
When does a patient experience symptoms with GH microinstability?
Extreme repetitive demands usually during a sporting activity
You should NOT mobilize or manipulate a joint into the direction of instability (TRUE/FALSE)?
t
What type of mobilization is good for early treatment of anterior-inferior GH joint instability?
Low grade lateral distraction mobilizations
What are the objectives of low grade lateral distraction mobilizations for anterior-inferior GH joint instability?
Decrease pain
Move synovial fluid
Maintain joint play
What type of mobilization can be used in later stages of an anterior-Inferior GH joint instability?
A-P glide to treat a tight posterior capsule
What mobilizations should NOT be used for an anterior-inferior GH joint instability issue?
P-A glides and external rotation with ABduction (You’re pushing the thing out of place)
With a tight posterior capsule in the GH joint, the humeral head translates ____
Anterior and superior
