AC Joint Sprain

Description

An AC joint(acromio-clavicular joint) sprain is a sprain to the ligaments and joint capsule that stabilise the AC joint.
AC joint sprains are a common injury to people:

  • Who fall on to the point of their shoulder and fall on to their hand with their arm out stretched.
  • Running in to a solid object and hitting it with your shoulder.
  • Bicycle crashes, car accidents, contact sports and in falls.

Because the ligaments hold the bones in place, if the injury is severe enough, you will see bony displacement under the skin.

There are 6 grades of ac joint sprain:

  1. Sprain of the capsule of the joint. Characterised by local tenderness and pain on movement.
  2. Complete tear of the AC joint ligaments and a sprain of the coracoclavicular ligaments. Characterised by localised tenderness and a palpable step deformity.
  3. Complete tear to the AC joint ligaments, coracoclavicular ligaments, conoid and trapezoid ligaments. Characterised by local tenderness, 25-100% greater coraco clavicular distance than the uninjured side.
  4. Complete tear to the AC joint ligaments, coracoclavicular ligaments, conoid and trapezoid ligaments. Characterised by much greater soft tissue injury, including damage to muscle, fascia and occasionally to skin. The coraco clavicular distance is 3-5x greater than the uninjured side and involves posterior displacement. Surgery indicated.
  5. Complete tear to the AC joint ligaments, coracoclavicular ligaments, conoid and trapezoid ligaments. Characterised by much greater soft tissue injury, including damage to muscle, fascia and occasionally to skin. The coraco clavicular distance is 3-5x greater than the uninjured side and involves superior displacement. Surgery indicated.
  6. Complete tear to the AC joint ligaments, coracoclavicular ligaments, conoid and trapezoid ligaments. Characterised by much greater soft tissue injury, including damage to muscle, fascia and occasionally to skin. The coraco clavicular distance is 3-5x greater than the uninjured side and involves inferior displacement. Surgery indicated.

Symptoms

Common symptoms include:

  • Pain on top of the shoulder.
  • Increase in pain when lying on affected side.
  • Pain with general movements of the shoulder especially reaching across body.
  • Possible palpable step deformity.

Treatment

Grade 1-3 AC joint sprains are indicated for physiotherapy treatments. Grade 4-6 are indicated for surgery.

Physiotherapy treatment for grade 1-3 AC joint sprains consists of:

Acute stage:

  • Rest.
  • Ice.
  • Immobilisation of the joint for 2-3 days for type 1, up to 6 weeks for type 3 to allow healing of injured ligaments.
  • Restrict from aggravating activities and carrying heavy loads.

Rehab:

  • Active movement of the shoulder outside of pain to prevent stiffness.
  • Mobilisation of AC joint to prevent adhesions.
  • Shoulder stability exercises.
  • Shoulder strengthening exercises.
  • Postural education.
  • Taping pre sport.