AC joint stabilisation


The term 'AC Joint' is an abbreviation for the acromioclavicular joint which is where the acromion – the outer edge of the shoulder blade (the scapula) – connects to the collarbone (the clavicle). This joint can be damaged and 'separate', also causing damage to the ligaments, when subject to a sudden force, such as when someone falls and their shoulder is the first thing to hit the ground. It's a fairly common sports injury in some sports (rugby, football, hockey) and activities such as horse-riding where a rider falls. People who are involved in these sports are at higher risk of damaging the AC joint.

AC joint separations are classified by their level of severity into 6 different groups – the less severe (levels 1-3) can be treated without recourse to surgery and the more severe (levels 4-6) generally need surgical treatment.

Preoperative Instructions

  • Existing medication(s) – some medications can impact surgery, especially any anti-coagulant medication and medicine for diabetes; we will advise if any of your medication needs to be stopped (and when) well ahead of the day of surgery. Any other medication should be taken the morning of surgery with a little water (half a cup maximum).
  • You should not shave (or wax) skin near where any surgical incisions will be made.
  • No solid foods (cow's milk and drinks containing cow's milk are considered food) should be consumed within 6 hours of surgery; clear fluids (e.g. water, cordial) may be consumed until 3 hours before surgery and then nil by mouth from that point.
  • Please advise us if you have a cold or fever, a cough or any other injuries or infections (e.g. urinary tract infection or cuts/tears to the skin) – your procedure may need to be postponed as any of these may make anaesthesia or surgery unsafe.
  • Please bring all imaging (e.g. x-rays / CT scans / MRI scans) with you to hospital.
  • Please come to hospital at least one hour before your planned surgery, unless we advise you otherwise.

In very general terms make sure you follow a healthy and balanced diet before surgery and continue any regular physical activity up until the day of the procedure. If you smoke, you should ideally stop smoking at least four weeks before the procedure and otherwise as a minimum at least one week before.


There are two different primary surgical approaches to stabilisation of the AC joint- Distal clavical excision / resection and Weaver-Dunn procedure:

Distal clavical excision / resection

Also referred to as a Mumford procedure, this involves the excision of the end of the clavicle and can be performed as open surgery or as a minimally invasive (arthroscopic) procedure.

Weaver-Dunn procedure

Suitable for more severe separations, the excision of the clavicle takes place as in the Mumford procedure and then a ligament from underneath the acromion is used to replace ligaments torn in the injury. A modified version of this procedure uses screws and/or a loop suture to stabilise the joint.

An alternative to using the patient's existing ligament is to use artificial ligaments (called 'LARS ligaments') or to use an 'allograft', which is a donor graft ligament.

Postoperative instructions

After the procedure a rehabilitation program would normally start about a month afterwards, initially with passive exercises that move the joint but do not involve exercising the muscles and then incorporating active exercises involving the muscles 2-4 weeks later. More details on the rehabilitation program will be given to you after surgery.

After the procedure the shoulder and arm must be kept in a sling for at least 2-4 days.


As with any surgery, there is always a risk of:

  • Pain.
  • Bleeding.
  • Scarring.
  • Infection (of the incision site, or in the chest).
  • Blood clot (leg or lung).
  • Stroke.
  • Heart attack.

Some specific risks of AC joint stabilisation include:

  • Continued pain / stiffness.
  • Re-tearing of ligaments.
  • Bone fracture.
  • Requirement for revision surgery.

Post-operative guidelines

  • Elbow must be supported for 6 weeks post op.
  • No lifting or arm dangling for 6 weeks post-op.
  • Use sling but not swathe. Swathe may pull arm inferiorly.

Physiotherapy Post-op Protocol

Weeks 1-4

  • Patient is allowed passive range of motion in all directions. Forward flexion and abduction limited to 90 degrees in the first instance and isometrics for deltoid exercises are permitted.
  • Patients then progress to resisted internal and external rotation as tolerated with elbow supported at all times.
  • Wounds may be wet after 2 weeks when stitches are removed.

Week 4

  • Patients are permitted to start active forward flexion and abduction to 90 degrees. Gentle resistance is also permitted at this time if tolerated.
  • Driving is permitted at this stage of your recovery if able.

Week 6

  • Range of motion is expected to increase at this time and resistance exercises are initiated to strengthen the girdle. Scapula movements, range of motion and strengthening will be encouraged by your physiotherapy.

Weeks 10-12

  • Weight training may begin under the guidance of your physiotherapist.

6 Months

  • Full unrestricted activities and return to normal function with order from Dr Moopanar.

Related Information

Shoulder trauma