AC Joint Injuries

Brian R. Wolf, MD

Univ. of Iowa Sports Medicine

12/1/05

Acromio-clavicular Sprain/Dislocation

]     Also referred to “shoulder separation”

]     Likely the most common sports related shoulder injury, especially contact sports

]     More common in males (5:1)

]     More often incomplete injury than complete (2:1)

 

 

Anatomy

]     Connects axial skeleton to upper extremity

]     Diarthrodial joint with articular cartilage, fibrocartilage disk

]     AC ligaments

]     Superior, inferior, anterior, posterior

]     Coracoclavicular ligaments

]     Conoid, trapezoid

 

Biomechanics of AC Joint

]     5-20 degrees of rotation

]     AC ligaments

]     AP stability

]     Axial distraction

 

 

]     CC ligaments

]     Vertical stability

]     Both ligaments must be disrupted for a complete dislocation

Mechanism of injury

]     Direct force from fall onto shoulder, or blow to shoulder (most common)

]     Indirect-fall on outstretched hand

]     AC ligaments tear first, then trapezoid, then conoid

Presentation and PE

]     Acute injury

]     Pain swelling at AC joint region

]     +/- deformity

]     Pain with FF and with cross body adduction

]     Tenderness at AC

 

Presentation and PE

]     Chronic AC injury

]     Same signs and symptoms

]     May c/o of crepitus  and popping with shoulder motion

]     Deformity may have increased with time.

 

Radiographs

]     AP shoulder

]     Axillary lateral

]     Zanca view

]     15 degree cephalad AP view

 

Classification

Classification

]     Type I: strain of AC ligs, CC ligaments intact

]     Tenderness, swelling

]     No deformity

]     Type II: rupture of AC ligs, CC ligaments intact

]     Tenderness, swelling

]     Mild deformity

Classification

]      Type III: rupture of AC and CC ligs.

]      sig. tenderness and swelling

]     Obvious deformity (25-100% increase in CC inter space)

 

]      Type IV: Same as III except clavicle displaced posteriorly into trapezius muscle (from more anterior force)

]     Rare

]     Signif. Deformity, clavicle can button hole into trapezius making reduction difficult

Classification

]     Type V: all ligaments torn, delto-trapezial fascia often disrupted

]     Severe deformity (>100% increase in CC interspace)

]     Pain, swelling

]     Type VI: displaced beneath coracoid and conjoined tendon

]     Rare

]     Secondary to severe trauma

 

Treatment

]      Type I and II: non-operative, immobilization in supportive sling)

]      Figure eight brace, Kenny Howard brace: must monitor for skin pressure

]      Type I: 1-2 weeks, gradually resume activities as tolerated

]      Type II: likely minimum of 3-6 weeks before return to activities

 

]      Not all Type I and II injuries do well:

]     Damage to meniscus or cartilage

]     Cox AJSM ‘81:

]     42% clicking, pain

]     23% limited participation

]     Mouhsine JSES ’03

]     26% AC pain, adduction pain

]     25% residual AP instability

]     22% activity related pain

]     27% surgery at 2.2 yrs

 

Treatment

]      Type III: controversial

]     Non-operative-return at 8-12 weeks

]     Operative

]    Acute: reduction and screw fixation

]    Chronic: distal clavicle excision and reduction / reconstruction of CC ligaments

]    Return in 4-6 months

Optimal Treatment???

]     Any series that has compared outcomes has not shown true difference in results

]     Recent survey of NFL team physicians—most would try non-operative first

]     Things to consider

]     What bridges do you burn with non-op trial?  With surgery?

]     Contact athlete—potential to fail again

]     Thrower?

Treatment

]     Type V: Operative fixation

]     Reduce AC joint

]     DCE if >4 wks.

]     Repair/reconstruct CC ligaments

]     2 months sling, PT at 4 weeks, strengthening at 8 weeks, return to sports 6 months.

Acromioclavicular joint arthrosis

]     More common than glenohumeral arthritis

]     Often can occur in conjunction with rotator cuff disorders

]     Etiology

]     Injury in past

]     idiopathic

Common scenarios

]     Weight lifters

]     Can get osteolysis of distal clavicle

]     Heavy laborers

]     Often comes bilaterally

 

AC joint pain

]     History

]     Pain with overhead activities

]     Reaching across chest

]     Point tenderness

AC joint

]     Exam: point tender over AC joint

]     Pain with adduction of shoulder across chest

]     Radiographs: spurs, OA at AC joint.

Treatment

]     Activity modification

]     Medication

]     Injection: steroid

]     Surgery: distal clavicle resection

]     Indications: failure of non-operative means, focal pain at ac joint, relief from injection

Arthroscopic distal clavicle resection

Distal clavicle resection

Thank you