L4 Shoulder Conditions Flashcards
Type 3 Acromial shape
more common in patients with impingement and full thickness RC tears
Tensile overload
repetitve intrinsic tension
Macrotrauma Tendon failure
traumatic injury reulsting in tearing of one or more RC tendons
may have history of tendonosis that predisposed tendon to failure during traumatic event
RC integrity
0 = normal
1 = some fat
2 = more muscle than fat
3 = equal fat to muscle
4 = more fat than muscle
Size classification of RCT
Small <1 cm
Medium 1-3 cm
Large 3-5 cm
Massive >5 cm
Full thickness tear
complete defect in the tendon, extending from teh articular surface completely through to the bursal surface
Partial Thickeness Tear
based on portion of tendon that is torn
Articular, Bursal, Interstitial
Different shapes of RCT
Crescent
Longitudinal: L or U shaped
Massive
Arthopathy
RCT Arthropathy
small tears over time
leads to reverese total shoulder
combination of massive chronic tear, cartilage destruction, osteoprosis, humeral head collapse
Static restraints of GHJ
ligaments
labrum
articular
vacuum effect
Dynamic restraints of GHJ
RC
biceps
periscapular
proprioception
Traumatic anterior instability
Hx: traumatic event, feeling of instability, shoulder pain caused by dislocation
MOI of anterior instability
posteriorly directed force on the arm when shoulder is in abd and ER
TUBS
traumatic, unidirectional w/bankart lesion requiring surgery
gross instability, common shoulder injury
those who are younger have a higher reoccurence
80% of TUBS are older than 60
Bankart lesion
avulsion of the anterior labrum and anterior band of IGHL from anterior inferior glenoid
present in 80-90% of those with anterior dislocation
Bony bakart lesion
fracture of anterior inferior glenoid
present in up to 49% of patients with recurrent dislocations
higher risk of failure in surgery
Hill sachs defect
chondral impaction injury in posteriorsuperior humeral head, secondary to contact with the glenoid rim
present in 80% of traumatic dislocations and 25% of traumatic subluxations
Dislocation and nerve injury
axillary is the most commonly injured
increased age, vascular injury, and delayed reduction increase risk
Humeral fracture and nerve injury
very frequent in displaced fractures
presence of fracture in dislocation doubles risk of nerve injury
Posterior Dislocations
less common than anterior
50% go undiagnosed in ED
risk factors: laxity of ligaments, glenoid retroversion
MOI: elbow ext, IR, contact with ground
common in older adults w/fall risk
Associated injuries w/Posterior instability
fx of anatomical neck or lesser tuberosity
Microtrauma and Posterior instability
may lead to labral tear, labral avulsion, or erosion of posterior labrum.
instability leads to gradual stretching of capsule
present in weightlifters, lineman, overhead athletes
Observation of Posterior dislocation
prominent posterior shoulder and coracoid
limited ER
shoulder locked in IR
Inferior Dislocation
very rare, has greatest risk of neurovascular injury
MOI: arm forced into elevation w/distraction
Exam: presents w/arm overhead with shoulder in abduction and elbow flexed
Atraumatic Instability S/S
pain, weakness, paresthesia, crepitus, shoulder instability during sleep
Signs of generalized hypermobility
patella hypermobility
genu recurvatus
elbow hyerpextension
MCP hyperextension
thumb abduction to forearm
knee and elbow hyperextension
Pathoanatomy of atraumatic instability
rotator interval deficiency
reverse bankart lesion
spread widely apart inferior capsule
AMBRI
atraumatic multidirectional bilateral rehab inferior capsular shift
peaks in 20s to 30s
pathophys of AMBRI
microtrauma from overhead overuse
general ligamentous laxity
Translation Classification
0 = normal GH translation
1 = humeral head translation up to glenoid rip
2 = over glenoid rip with reduction once force is withdrawn
3 = over glenoid rim w/locking
Normal values of GH translation
Posterior: 3-20 mm
Inferior = 5-15 mm
Anterior = 2-13 mm
Anterior labrum
anchors IGHL
link that leads to bankart lesion
Superior labrum
anchors biceps tendon
leads to SLAP lesion
Glenoid labrum
blocks subluxation
creates cavity-compression and 50% of glenoid socket depth
SLAP tear
may occur on own or with internal impingement, RCT, instability
MOI of SLAP
overhead
fall on outstretched arm with tensed biceps
traction on arm
Pathophys of SLAP
tightness of posterior IGHL shifts GH anterior/superior and increases shear force on superior labrum
lesion increases strain on anterior band of IGHL and compromises stabilty of shoulder
S/S of SLAP
vague, deep shoulder pain
popping and clicking
weakness, easy fatigue, decreased athletic performance
SLAP classification
1 = anchor intact, fraying labrum and biceps
2 = labral fraying, biceps detached
3 = bucket handle tear w/attached biceps
4 = bucket handle tear w/detached biceps
