Acute Shoulder Flashcards
1
Q
Acromioclavicular joint sprain
1. Rockwood classification of ACJ injury
2. Mechanisms of injury
3. Cause of pain
4. Observations
A
- grade 1 minor dmg to AC lig and capsule but maintain high struc integrity; grade 2 tear through AC and capsule, some dmg to CC lig, some elevation of clavicle forming slight step deformity but still have overlap; grade 3 tear through AC lig and capsule and CC lig, disruption of fascia blending delts and upper traps into AC joint, complete elevation of clavicle no overlap
- falling on outstretched hand humerus pushes acromion up and away from clavicle; falling on lateral shoulder against acromion
- any sig motion to shoulder girdle (all shoulder motion except GH rotation) or weight bearing
- bruising inf to clavicle, step deformity grade >=2, specific point pain, swelling
2
Q
Clavicle fractures
1. Location of fracture
2. Clinical presentation
3. Aggravates
4. Testing
A
- middle of clavicle most common (80%) since bone is thinnest there; lat end is less common and complex since it involves AC joint; med end is also complex and rare since it near sternoclavicular joint, internal jugular vein, and resp tract; any fracture to clavicle can dmg brachial plexus and apex of lung as they run under clavicle
- bump on clavicle, sound or sensation of crack or snap, point specific pain, displacement of the ends and if severe then open fracture, swelling and bruising on upper anterior chest wall
- painful to hang arm at side use sling or support for relief, crossflexion
- pinching from furthest pt from pain can trigger pain to localize fracture and use gold standard X-ray
3
Q
fracture healing process
A
- hematoma; first 72 hours, blood from bone and periosteum pool and clot to connect broken ends in framework
- soft callus; fibroblasts form fibrocartilage layer holding 2 ends together; angiogenesis to promote healing
- hard callous; 6-12 weeks after soft callus, fibroblasts differentiate into osteoblasts, calcification of the callus, resorb cartilage, greatly increase structural integrity with over growth
- remodelling; several months after hard callous, osteoblasts and clasts reshape overgrowth into final shape
4
Q
GH joint dislocation: focus on anterior dislocation
1. dislocation risk and reccurence
2. mechanism of injury
3. clinical presentation
A
- 75-95% anterior dislocation, easy to dislocate since low bony congruency (humeral head is x4 SA of glenoid fossa); 39% recurrence in first year and high risk of recurrent instability when <40 y/o
- pos of vulnerability when ext rot (stress all GH lig) and abducted 90 deg (stress inf GHL) with outstretched hand min contact with glenoid fossa?
- pain depending on struc injured but abduction and ext rot always, bruising and swelling in shoulder, arm, and pec regions, deep shoulder pain no specific point, upper traps, subscap, and infraspinatus pain or tight by compensating and holding humerus in place
5
Q
structures damaged during GH joint dislocation: focus on ant dislocation
1. ligaments
2. muscles
3. GH labrum
4. Hill-Sachs lesion
A
- GHL reinforce loose GHJ capsule (loose allows mobility) ant and inf; GH lig limit ext rot of humerus, sup GHL limit most <45 deg abduct, middle limit most 45-90 deg, inf limit most >90 deg; ant dislocation assoc with inf GHL dmg since mechanism of inj is most likely >90 deg abduct
- subscapularis support GH joint closest to GHLs, supraspinatus from sup GHJ, infraspinatus on post GHJ, and teres minor on inf post GHJ; dislocation of humerus tear these tendons attached to it
- deepens socket to increase contact area of joint, cartilagenous with low BF slow healing, Bankart lesion 33% (dmg to labrum in ant inf 4:00-6:00 location) and SLAP 25% ( tear labrum on superior aspect from ant to post 10:00-1:00) occurrence with first time dislocation; GH labrum integrate with tendon of biceps brachii, if SLAP then peel away in sup ant GHJ when BB tendon pull on it; can sig decrease stability when torn and often req surgical repair
- ant and inf dislocation can cause compression fracture when ant aspect of glenoid fossa fractures posterolateral aspect of humeral head; cause deep post shoulder pain
6
Q
joint stability spectrum
A
- typical function: zero displacement, max contact between bones
- subluxation: partial displacement
- dislocation: full displacement
7
Q
sensitivity vs. specificity
A
- sensitivity is how likely test going to test for injury, specificity is how good is it for testing for that injured struc/injury
- varyijng deg of sensitivity and specificity therefore use battery of test
8
Q
AC joint injury:
1. to sling or not to sling?
2. typical recovery guidelines
A
- sling shifts load from ligaments for pain management for up to 10 days support, but comfortable without no need to use
- RW I 2-4 weeks, RW II 4-6 weeks, RW III 6-12 weeks
9
Q
GH joint injury
1. immobilization
2. surgery
A
- ER v. IR immoblization recurrance rate RR = 0.56, 15 deg of ext rotation more effective
- 6% operative and 47% non-operative redislocate humerus
