View source for Acromioclavicular joint injury

==Background==
[[File:Right shoulder with AC Ligaments.jpg|thumb|Right shoulder anatomy with AC Ligaments.]]
*Occurs via direct trauma to the adducted shoulder
*Accounts for 40% of all shoulder injuries and 10% of all injuries in collision sports (football, hockey, etc.)<ref>Sirin E, Aydin N, Mert Topkar O. Acromioclavicular joint injuries: diagnosis, classification and ligamentoplasty procedures. EFORT Open Rev. 2018;3(7):426-433. Published 2018 Jul 17. doi:10.1302/2058-5241.3.170027</ref>
*Acromioclavicular (AC) and coracoclavicular (CC) ligaments may be affected
*Routine use of stress radiographs is controversial (low yield)

==Clinical Features==
[[File:Luxation acromioclaviculaire.jpeg|thumb|Acromion-clavicle injury. Note that the left shoulder is lower and the "piano key"; Screws on the radiography are a former trauma repair and unrelated to present trauma.]]
*Tenderness directly over AC joint (with possible deformity)
*AC compression test
**Passively flex arm so It is parallel with ground; then passively adduct across body
***Pain suggests AC joint injury
*Ability to touch contralateral shoulder with injured arm suggests lack of [[shoulder dislocation]]

==Differential Diagnosis==
{{Shoulder DDX}}

==Evaluation==
===Workup===
[[File:AC Separation XRAY (enhanced).png|thumb|]]
[[File:AC Type III.JPG|thumb]]
*AP shoulder (highly consider comparison view)
**AC joint
***Normal width of AC joint in adults is 1-3mm
***By age 60 width is often less than 1mm 
***Children and adolescents have a slightly wider joint space
**CC joint
***Normal distance is 11-13mm
***Comparison to opposite CC joint space is more important 
****Increase in CC distance of 25-50% indicates complete CC ligament disruption
**Zanca view  (AP with 10-15 degree cephalic tilt)
***Consider if AP view is ambiguous, concern for type II injury or distal clavicle injury
**Axillary view
***Obtain if coracoid tenderness is present to rule-out associated coracoid fracture 
***Helps to confirm ant-post position of clavicle in injury types III-IV

===Diagnosis===
[[File:AC_Joint_Separation.jpg|thumb|AC joint separation]]
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Classification'''
| align="center" style="background:#f0f0f0;"|'''Anatomic Injury'''
| align="center" style="background:#f0f0f0;"|'''Exam'''
| align="center" style="background:#f0f0f0;"|'''X-ray'''
| align="center" style="background:#f0f0f0;"|'''Image'''
|-
| '''Type I'''||
*AC ligament sprain
*AC joint intact
||
*Mild swelling, no deformity 
*CC ligaments are nontender 
*Only distal-most 1-2cm of clavicle is tender 
*Active overhead and cross-body ROM are limited by pain
||
*Often no abnormality is seen on xray
*Slight widening of the AC joint may occur
||
[[File:Classification type 1 of AC separation.png|120px]]
|-
| '''Type II'''
||
*AC ligament torn
*Coracoclavicular (CC) ligament may be partially torn but is intact
||
*Prominent and tender AC joint with significant swelling 
*Minimal tenderness of CC ligaments reflecting lack of significant injury 
*May be instability of the distal clavicle in the horizontal plane
||
*Partial elevation of the distal clavicle with no or minimal widening of CC distance
||
[[File:Classification type 2 of AC separation.png|120px]]
|-
| '''Type III'''||
*AC and CC ligaments torn
*Complete dislocation of the joint
||
*Deformity of the AC joint is clearly visible 
*Marked tenderness of CC ligaments (helps distinguish Type 3 from type 2) 
*Palpable posterior fullness or deformity despite significant swelling
||
*Elevated distal clavicle and increased CC distance 
*Distal clavicle is positioned above the plane of the top of the acromion
||
[[File:Classification type 2 of AC separation.png|120px]]
|-
| '''Type IV'''||
*Complete dislocation with posterior displacement of distal clavicle in/through trapezius
||
*SC dislocation may be appreciated
||
*Axillary view required to visualize the posterior dislocation
||
[[File:Classification type 4 of AC separation.png|120px]]
|-
| '''Type V'''
||
*More severe form of type III injury 
*Superior dislocation of the joint of 1-3x the normal spacing 
*CC ligament distance is increased 2-3x normal *Disruption of the deltotrapezial fascia
||
*Shoulder appears to droop 
*Severe superior displacement of clavicle (may cause tenting, ischemia of skin) 
*Clavicle is perhced above the muscle and does not reduce when patient shrugs shoulder
||
*Clavicle is elevated above acromion approximately 1-3x width of the clavicle 
*CC distance is increased 2-3x normal range
||
[[File:Classification type 5 of AC separation.png|120px]]
|-
| '''Type VI'''
||
*Complete dislocation with clavicle displaced inferiorly
||
||
*Complete disruption of the AC and CC ligaments
||
[[File:Classification type 6 of AC separation.png|120px]]
|}

==Management==
===Type I===
*Rest, ice, [[sling]]
*ROM and strengthening exercises as soon as tolerated
*Return to sport or work is limited only by pain 

===Type II===
*Rest, ice, [[sling]] x 3-7 days
*ROM and strenghtnening exercises as soon as tolerated
*Return to sport or work once full ROM and strength are regained

===Type III===
*Rest, ice, [[sling]] x2-3 weeks
*ROM and strengthening exercises as soon as tolerated
*Return to sport or work 6-12 weeks following injury
*Ortho consultation within 1 week

===Types IV-VI===
*Require orthopedic evaluation; emergent if neurovascular compromise exists
*Generally operative

==Disposition==
*'''Admission Criteria'''
**Neurovascular compromise
**Open or unstable fractures
**Admission for operative repair may be needed for Types IV, V, and VI 
*'''Discharge Criteria'''
**Type I/Type II may be discharged with orthopedic follow-up 
**Type III may be discharged with urgent orthopedic follow-up

==See Also==
*[[Shoulder diagnoses]]

==References==
<references/>
[[Category:Orthopedics]]