Acromio-clavicular Joint Dislocation
Classification
Types
- Intra-articular damage of the acromio-clavicular joint alone without ligamentous instability either of the joint capsule or of the coraco-clavicular ligaments
- Dislocation of the acromio-clavicular joint and disruption of its capsule and ligaments without disruption of the coraco-clavicular ligaments
- Acromio-clavicular separation with disruption of the coraco-clavicular ligaments as well as the AC ligaments leaving the clavicle grossly unstable
- coracoclavicular interspace 25- 100% greater than normal side
- a type 3 with the distal clavicle displaced posteriorly into or through the trapezius
- a type 3 but with exaggeration of the vertical displacement of the clavicle from the scapula
- coracoclavicular interspace 100- 300% greater than the normal side
- a type 3 with the clavicle dislocated inferiorly either subcoracoid or subacromial
XRays
- Normal jt
- normal width is 1-3mm
more than 7mm in men and 6mm in women is abnormal
- AP view
- pt standing with arms hanging unsupported, both AC jts on one film
- Zanca view
- 10-15 deg cephalic tilt view
- Axillary view
- to see any post displacement of the clavicle
- Stress view
- AP XR with 10- 15 lb wghts hanging from both hands
Treatment
Type I and Type II injuries are treated conservatively and if ® acromio-clavicular arthritis should be treated by excision arthroplasty
- Supportive sling for 3 - 4 weeks ® mobilisation of the shoulder
Type III injuries ® also conservative treatment initially unless considered to be an at risk patient ® surgical repair (+/- excision outer end of clavicle)
Type IV, V and VI : surgical repair
Weaver and Dunn operation equally effective for both early and late cases therefore no indication to operate in the acute stage except in selected cases, patients who do heavy work and those whose daily work or recreational activities requires that the shoulder be held in an abducted position
ref: Weaver and Dunn " Treatment of AC injuries, especially complete AC separation"
JBJS 54A: 1187-1197, 1972
Late resection of the distal part of the clavicle ( = Mumford procedure) reliably produces significant clinical improvement if patients develop problems
- Other options
- screw fixation clavicle to coracoid ( Bosworth)
direct repair of coracoclavicular ligs
use of a sling to hold the clavicle down
imbrication of the deltoid and trapezius over the distal clavicle
Complications
1. of the acute injury
skeletal: fracture clavicle, acromion or coracoid
coracoclavicular calcification or ossification - common - does not affect late results
osteolysis of the distal clavicle - can follow acute injury or may occur in those that have recurrent stress on the shoulder eg weight lifters
2. of operative treatment
- Early
- infection
loss of reduction with recurrence of deformity
unsightly scar
- Late
- soft tissue calcification
AC OA
Implant - failure, erosion of bone, migration
necessity to remove