Types of shoulder AC separation include:
- Type 1 AC shoulder separation:
- Injury to the capsule that surrounds the AC joint
- No tears to the AC ligaments
- Mainly pain, but bones are in normal position
- Type 2 AC shoulder separation:
- Injury to capsule
- Partial tears of the coracoclavicular ligament which support the AC joint
- Small bump may be seen on shoulder
- Type 3 AC shoulder separation:
- Injury to capsule
- More substantial tearing of the coracoclavicular ligament which support the AC joint
- Large bump may be seen on shoulder
- Type 4 AC shoulder separation:
- Unusual injury
- Injury to capsule and acromioclavicular ligament
- End of clavicle is pushed behind the AC joint
- May need surgery
- Type 5 AC shoulder separation:
- This is a severe form of the type 3 injury
- The muscle that overlies the AC joint gets punctured by the end of the clavicle, causing a large bump over the injury
- Surgery is likely
- Type 6 AC shoulder separation:
- Very rare
- Clavicle is pushed downwards and becomes trapped below the coracoid process (a part of the scapula)
- Surgery is required
