AC joint Flashcards Preview

OCS Exam > AC joint > Flashcards

Flashcards in AC joint Deck (93)
Loading 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?



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