AC pathology Flashcards
Acromium-clavicular injuries- separation distal clavicle osteolysis ac arthritis
1
Q
What is the epidemioogy of AC separation ?
A
- Common Injury making up 9% shoulder girdle
- More common in males
- mechansim
- direct blow to the shoulder
2
Q
What is the presentation of ac separation?
A
- Pain
- palpable lateral clavicle and ACJ tenderness
- ap stability assess ac ligament
- vertical stability assess Coracoclavicular ligament
3
Q
What is seen on radiographs of AC separation?
A
-
Bilateral AP
- measure from top of coracoid to bottom of clavicle
-
axillary lateral
- to dx type iv
-
zanca view
- tilt beam 10-15o towards cephalic direction adn use only 50% of standard shoulder ap penetration strength
4
Q
Describe the classification of AC joint separation?
A
- Rockwood
Type1- sprain AC normal CC no displacment = sling
Type 2- Torn AC/sprain CC-slight increase in CC = sling
Type 3- Torn AC/CC- cc distance 25-100%= contraversial tx
Type 4- torn AC/CC- lateral end clav displ post= surgery
Type 5- torn AC/CC- CC distance >100%= surgery
Type 6- torn AC/CC- displaced inferior= surgery
5
Q
What is the tx for ac separation injury?
A
-
Type 1-2 , 3 most individuals
- ice, rest , sling 3/52
- early rom
- regain functional motion 6/52
- return to normal activity 12 weeks
- complx
- acj arthritis
- chronic subluxation & instability
-
Type 3 labourers/elite athletes types 4-6
- ORIF or ligament reconstruction
- sling immobilisation without abduction 6/52
- no shoulder rom 6/52
- general return to full activity 6/12
6
Q
Describe the types of surgical orif fixation?
A
-
ORIF w CC screw fixation
- prox aspect of anterolateral approach to shoulder
- superior to inferior screw from distal clavicle to coracoid
- rigid internal fixation, danger of screw being too long & damage critical structure below
- Complx: hardware irriation or failure
-
ORIF w CC suture fixation- endobutton
- suture thru clavicle or around adn arounn base of coracoid
- no risk of hardware failure or migration
- suture not as strong as screw fixation
- complx suture erosion
-
ORIF w hook plate
- exposure of distal & middle clavicle
- use of standard hook plate over superior distal clavicle
- rigid fixation, usually requires 2nd surgery for plate removal
- high rate of acromial erosion
7
Q
describe the types of ligament reconstruction for acj separation?
A
- CC ligament reconstruction= modified Weaver -Dunn
-
http://www.shoulderdoc.co.uk/article.asp?article=666
- proximal aspect of anterolateral approach to the shoulder
- arthroscopic also
- distal clavicle excised
- transfer of coracoacromial ligament to distal clavicle to recreate CC ligament
- combined with internal fixation
- coracoacromial lig only 20% as strong as normal CC ligament
- lack of internal fixation risks failure of soft tissue repair
- CC ligament reconstruction w free tendon graft- semitendinosus
- http://www.orthobullets.com/video/view?id=484
- figure of 8 passage of graft from distal clavicle to coracoid
- graft reconstruction more closely recreates the strength of native cc ligament
- standard risks of allograft use or autograft harvest
- lack of internal fixation risks failure of soft tissue repair
8
Q
What approach would you use to gain access to acj ?
A
- anterolateral Incision- from ACJ /lateral edge of clavicle towards coracoid- see pic
- No internervous plane
- Thru deltoid superifical fascia
- acromial branch of thoracromial artery must be ligated when encountered deep to deltoid, ne ACJ
- Split thru deltoid, prox to axillary nerve- no internervous plane
- detach coracoacromial ligament close off acromium
9
Q
Describe distal clavicle osteolysis?
A
- Commonly seen in weight lifters
- hx of traumatic injuries
- caused by repetitive micro-fx in distal clavicle which leads osteopenia
10
Q
Describe the ostetology of clavicle?
A
- S shpaed clavicle
- last bone to ossify
- medial growth plate fuses early 20s
11
Q
Describe the symptoms of clavicle osteolysis?
A
- Pain at distal clavicle
O/E
- tenderness at distal end of clavicle
12
Q
What is seen on imaging of distal clavicle osteolysis?
A
- Ap clavicle
- cysts at distal end of clavicle
- osteopenia
- tapering of distal clavicle
13
Q
What is the tx of distal clavicle osteolysis?
A
- Nonoperative
-
Activity modification, corticosteriod injections, NSAIDS
- first line
- quit weight lifitng or move arms further apart
-
Activity modification, corticosteriod injections, NSAIDS
- Operative
- Open or arthroscopic distal clavicle excision
- failed non op tx
- only resect 0.5-1cm distal clavicle- preserve ligaments
- leave space that fills with scar tissue
- arthroscopic adv allowing evaluation of GH joint
- gd result w arthroscopic
- open proceedure require meticulous repair of deltoid-trapezial fascia
14
Q
Can you describe AC arthritis?
A
- Caused by transmission of large loads through a small contact area
- more common with age but seen in 20 yrs
- risk factors
- Prior AC separation
- weightlifters/ overhead throwing athletes
- Assoc conditions
- distal clavicle osteolysis
15
Q
Dsecribe the role of AC joint?
A
- articulates scapula to clavicle
- contains fibrocartilaginous disc
-
Ac ligaments
- provide ant-post stability
- posterior and superior AC igaments most important for stability
-
Coracoclavicular ligaments
- provide superior-inferior stability
16
Q
What is the presentation of AC arthritis?
A
- Activity related pain
- overhead activity
- arm adducted
O/E
- Pain with direct palpation of ACJ
- pain with cross body adduction
17
Q
What is seen on imaging for AC arthritis?
A
- Xray
- Zanca view best- 15o cephalic tilt
- osteophytes and jointspace narrowing
- distal clavicle osteolysis
- imaging findings don’t always correlate with symptoms
- MRI
- Increae signal and oedema of ACJ
