AC joint Flashcards
What are the typical mechanisms of AC injury?
Direct force to the tip of the shoulder with the arm adducted against the body, the acromion is driven downward or inferiorly; A secondary MOI is indirect force with a FOOSH which generates an impact load at the acrominion through the humeral headtypically results in only disruption of the AC capsule and ligaments
Function of the AC joint?
Serves as a crankshaft keeping the arm in a functional position in relationship to the body; rotates early and late in elevation
What are the ligaments of the AC joint?
Acromioclavicular, conoid, and trapezoid ligaments
Coracoclavicular ligaments = conoid and trapezoid
A/C ligaments controls horizontal
Coracoclavicular controls vertical
Describe the acute presentation of a patient with an AC injury?
Holding their arm into their side supporting the elbow with the opposite hand
How are AC injuries classified?
Grade I: sprain of the AC ligaments all ligaments intact; general movement pain free and tender to palpation
Grade II: complete disruption of the AC ligaments, sprain of the CC ligaments; TTP, mod-severe pain with ROM; slight elevation of the clavicle
Grade III: complete disruption of the AC and CC ligaments with 25-100% increase in CC space
Grade IV: superior and posterior displacement
Grade V: 100-300% of CC interspace vs opposite arm
Grade VI: inferior displacement to coracoid
What weight lifting movements tend to aggravate a pt s/p A/C injury?
Wide grip bench press, anterior flys secondary to provocation of horizontal adduction, dips; some patients will benefit from pre and post ice
What athletes are prone to AC problems?
Racquet and throwing athletes may exhibit symptoms on follow through motions as arm goes into adduction; change wide grip activities, decrease effort on throwing and decrease range on aggravating exercises (flys)
What surgery is done for an arthritic AC joint?
Mumford procedure = distal clavicle resection
What is the role of AC joint mobilization?
Helps when patients who have limited horizontal add and elevation; performed giving clavicle anterior glide from behind on the distal clavicle
What is the typical MOI for SC injuries?
Direct trauma to the clavicle or indirect with someone forceful rolled when laying on their side;
What is the role of the scapula in GH movement?
Mobile base for humeral motions; transmits force from the trunk and LE to arm during throwing; bony attachment for most of the upper quarter proximal muscles
What muscular force couples act on the scapula during arm elevation?
Upper trap, lower trap, and serratus anterior are involved in upward rotation of the scapular during UE elevation
Can abnormal scapular movement be associate with rotator cuff impingement?
Yes, diminished scapular movement, particularly posterior tilting and superior translation has been associated with rotator cuff impingement symptoms
Define scapular dyskinesia?
Abnormal or atypical movement of the scapula during normal active movements such as reaching or elevation; similar terms: abnormal scapulohumeral rhythm, scapular winging, and scapular dysrhythmia
How common is scapular dyskinesia?
Warner estimated it at 64% of pt’s with unstable GH joint, while impingement pt’s also demonstrate some type of dyskinesia
What populations are more at risk for scapular pathology?
Overhead athletes or patient who presents with pain in the shoulder region
Cause of scapular dyskinesis?
May be primary or secondary to shoulder pathology; deficient scapular muscles with serratus anterior and trapezius being most often involved; may be weakness, tightness, or compensatory; scoliosis or Sprengel’s deformity can also cause it
What is Sprengel’s deformity?
Elevation of the scapula and failure for it to descend during development; scapula may be malrotated and abnormally shaped with limited abd
What is “SICK” scapula syndrome?
S- scapular malposition
How to treat scapular dyskensis?
Strengthen weak muscles, stretch tight muscles; scapular protractors (serratus anterior) and minimizing upper trap use, educate on posture; biofeedback; focus on rhomboids, trap, serratus ant, and rotator cuff
Best exercise for serratus ant?
Pushup with a plus
Best exercise for lower trap?
Prone flexion
Best exercise for middle and upper trap?
Rows
Difference between scapular dyskensis and winging?
Winging is associated with long thoracic nerve palsy; winging is noted when the patient leans into a wall or when resistance is applied secondary to a deficient serratus anterior
What is the standard of Tx for long thoracic nerve palsy?
EMG to confirm Dx and track progress; strengthen of serratus ant should be delayed until EMG indicates regeration; restrict heavy pushing and overhead lifting;
A patients symptoms include severe shoulder and neck pain and a drooped shoulder after cervical lymph node resection. What do you suspect is the cause?
One complication s/p lymph node or beign tumor removal is iatrogenic injury to the spinal accessory nerve involving the trapezius and often sparing the SCM. Presents with an inability to raise arm above the horizontal and has a drooped posture. Pain and a sensation of heaviness, also feeling as if the arm was getting pulled from its socket.
Define snapping scapula:
Attributed to friction between the mobile scapula with its attached soft tissues and thorax; Noise or grating sound is generally nonpathologic and occurs quite frequently in the normal population (70%); Grating, loud snapping, or popping associated with pain may be pathologic including a thickened bursa, bone spurs, luschka’s tubercle, osteochondroma
Differential diagnosis of snapping scapula?
Pain referred from the GH, cervical, or thoracic spine; tumors
How to treat snapping scapula:
NSAIDs, modalities, and exercises for lower trap and serratus ant; strapping or taping; injection may be referred for
What does wasting of the infraspinatus with sparing of the supraspinatus suggest?
Suprascapular nerve compression along the course through the spine of the scapula; a ganglion cyst may be present; spinoglenoid ligament may be causing compression; surgical release is the Tx if decreased nerve conduction and compression are present
What nerve is most frequently injured with a fracture of the clavicle?
Ulnar nerve as it passes between the first rib and the fractured clavicle
What nerve injuries are most commonly associated with proximal humeral fx?
Axillary and suprascapular nerves; may manifest with temporary weakness
Can proximal humerus fractures be treated non-op?
Yes, the majority can because they are minimally displaced.
What is the treatment of conservatively managed proximal humerus fx?
Immobilized but early motion is key; sling to reduced traction from weight of the arm, elbow wrist, and hand ROM immediately; pendulums as tolerated for stable fractures; ROM once humerus moves as a unit around 2-3 wks
Outcomes s/p humerus fx?
130-150 elevation, near symmetric ER, and only mild weakness
Indications for surgery with proximal humerus fx?
greater tuberosity displacement, greater than 45 degrees angulation or translation of the humeral shaft, lesser tuberosity displacement greater than 1cm, anatomic neck split fx, fx with dislocation
What nerve injury may occur with humeral shaft fx?
radial nerve
How is the spinal accessory nerve usually injured?
Tumor, surgery to the posterior triangle, stretch and whiplash injury
Common sites of entrapment of the suprascapular nerve?
Suprascapular notch beneath the transverse scapular ligament; mimics rotator cuff pathology;
Diagnostic test for suprascapular nerve injury?
EMG nerve conduction
What nerve is most commonly injured after ant dislocation?
axillary nerve
What is rucksack palsy?
Injury to the upper trunk of the brachial plexus or long thoracic nerve with individuals wearing heavy packs. Shoulder pain and isolated winging or global symptoms of the upper trunk may present. Return of function is good.
What are the common causes of brachial plexus injuries?
GSW, traction, fractures of the humerus, dislocations of the shoulder, tumors, metastatic breast cancer, and radiation therapy
Signs of an upper trunk lesion?
Suprascapular, musculocutaneous, and axillary nerves as well as parts of the median nerves – weakness of shoulder flexion, abduction, and ext as well as elbow flexion, supination, and pronation.. wrist flexion; numbness in lateral forearm and hand
Signs of an middle trunk lesion:
rare in isolation; radial nerve – triceps with sparing of brachioradialis
Signs of a lower trunk lesion:
ulnar nerve and C8 radial; lumbricales and thenar muscles; medial forearm numbness
Signs of a lateral cord lesion:
similar to upper trunk lesion with sparing of the suprascapular nerve and upper trunk contributions to the axillary and radial nerves – normal shoulder strength in flexion, ext, abd, ER; weakness in elbow fleixon, supination, pronation, and wrist flexion; numbness of lateral forearm
Signs of a medial cord lesion:
similar to lower trunk – sparing of C8 to the radial nerve; finger ext is normal
What is Thoracic Outlet Syndrome?
TOS refers to the compression of neurovascular structures between the neck and axilla – can be either neuro or vascular in nature
TOS tests: Adson manuver?
radial pulse monitored with arm in abd and ext with ER with head rotated to the same side while the patient takes a deep breath + = diminished pulse, suggests compression of the subclavian by the scalanes
TOS tests: Allen test
Abd in 90/90 position with head turned away, patient hold breath; radial pulse monitored
TOS tests: Roos
B 90/90 fingers opened and closed rapidly for 3 min + = dimished motor function of the hands ordecreased sensation
Wright test (hyper abduction)
Abd over the head with head rotated and ext away while taking a deep breath while palpating the pulse
TOS tests: Military brace
shoulder depressed and ext while monitoring the pulse
TOS tests: Provocation elevation test
Both arms elevated above the horizontal and rapidly opened and closed x15 + = fatigue, cramping, or tingling for vascular insufficiency
Which TOS and how many should be performed?
Three or more: adson, allen, and wright
What is a Pancost tumor?
compression of C8-T1 nerves from the apex of the lung, more common in smokers with no history of trauma; weakness of the 4th and 5th digits
What is a “burner”
A nerve injury that often occurs in football, generally thought to be from traction or compression of the upper trunk of the brachial plexus of c5-6; best way to prevent is with shoulder and cervical strengthening
What is inferior angle scapular dysfunction?
Inferior border of the scapular is very prominent resulting from anterior tipping of the scapula typically seen in rotator cuff impingement; ant tip causes acromion to be in more offending position
What is medial border scapular dysfunction?
Medial border is posteriorly displaced from the thoracic wall occurs from the IR of the scapula most often witnessed in patients with GH joint instability
What is superior scapular dysfunction?
Early and excessive supeiror scapular translation during elevationfo the arm; typically occurs in rotator cuff weakness and force couple imbalances
What is the SAT scapular assistance test?
inferior medial border is supported and rotation assistance is provided to the scapula during elevation; an increase in ROM or derease in pain is a postive for impingement type symptoms
What is the flip sign
Resisted ER at the side, if the medial border of the scapula tips then potential for loss of scapular stability
What is GIRD?
Glenohumeral Internal Rotation Deficit; common amoung overhead atheltes where there is an increase in ER and decrease in IR; may be caused from post cap tightness, ant humeral translation
Loss of what motion increases risk for GH impingement?
IR
Anterior translation and superior migration of the humeral head increase risk for what injury
Rotator cuff injury
Best MMT test for supraspinatus?
Empty can
Best MMT for infraspinatus?
ER at side with 45 IR; alt 90 abd with half max ER
Best MMT for teres minor?
Resisted ER at 90/90
Best MMT for subscap?
lift off test
Describe the Hawkins impingement sign:
Forced IR in the scapular plane
Describe the coracoid impingement test:
Forced IR in the coronal plane
Cross-arm adduction tests for:
impingement
Describe the Yocum test:
Active combination of elevation and IR provides info on ability to control superior humeral head translation during active movement
What are the different types of rotator cuff impingement?
Primary, secondary, and internal
Describe the Multidirectional instability sulcus test:
Sitting with arms resting in lap, examiner grasps the distal aspect of the humerus with a rapid traction looking for a visible sulcus sign; tests the superior glenohumeral ligament
Describe A-P G-H testing:
supine with A-P (anteromedial) or P-A (posteriorlateral) transitional in the plane of the G-H joint
Describe P-A G-H testing:
perform at 90 abd
Describe the relocation test:
Identifies anterior instability especially in the overhead throwing athlete; Arm taken to 90-90 while in supine max ER while an anterior-med force applied to the humeral, then the head is relocated with a posterior lateral force; + is reproduction of symptoms with subluxation or reduction of symptoms with relocation; could be instability with secondary or primary impingement or even suggest a SLAP lesion
What is the Beighton hypermobility scale /index:
A series of 9 tests (extremities B’ly) to assess general hypermobility: hyperext of the 5th MCP, passive thumb opposition to forearm, elbow, knee hyperext, standing flexion; + 4/9
What is a Bankart lesion?
Primarily occurs with patients with anterior dislocation with a torn labrum from about 2-6 o’clock on the R 6-10 on the L; anterior inferior detachment of the labrum
What is a SLAP lesion?
Superior labrum anterior to posterior lesion; often has biceps involvement; this can decrease the ability for the G-H to withstand rotational force and increase strain on the ant and inf band of GH ligaments
MOI for a SLAP lesion?
Throwing secondary to tensile failure at the biceps insertion; biceps decelerates the extending elbow during follow through with pitching coupled with the large distraction force present during the violent phase of throwing; secondary theory “peel back mechanism” torsional force with abd and max ER where the biceps peels back the labrum
Describe these general labral tests: Clunk, circumduction test, compression rotation, and crank test
Clunk: circumduction test: arm at 90 ER and cirumducted in to horizontal abd; compression rotation, and crank test: 135 degrees elevation humerus loaded and taken through IR/ER
Describe these SLAP tests:
O’Brien Active compression test: slight horizontal add resisted elevation with IR and then with ER; Mimori test; biceps load and ER supination: arm at 90/90 with resisted supination and elbow flexion;
Functional testing of UE: modified crossover pushup type maneuver
Tape placed 3 feet apart with hands just inside the tape and in a pushup postion; hands are alternating moved as quickly as possible to ea side in a windshield wiper motion; number of touches counted in 15s
Describe primary impingement:
A compressive impingement of the rotator cuff tendons between the humeral head and the overlying anterior third of the acromion, coracoacromial ligament, coracoid, or AC joint; in the subacromial space
Primary signs of impingment:
painful arc, positive neer impingement sign, and ER weakness
Continued impingement can lead to what?
Fibrosis and tendonitis leading to bone spurs and tendon rupture
What are the three types of acromion shapes, which is associated with rotator cuff tears?
Type I: flat; Type II: curved; Type III: hooked (high association with tears)
What is secondary impingement caused by?
Joint instability of the GH
Where is internal/undersurface impingement usually felt?
Ofter with overhead athletes posterior shoulder pain brought on by 90 abd 90 ER can impinge tendons on the post/sup portion of the glenoid lip
