Weaver Dunn Procedure

Aims

  • To reduce & fix dislocated AC joint

Indications

  • Treatment of grades III, IV & V AC joint dislocation, without significant AC joint osteoarthritis

Options

  • AO Hook Plate
  • Synthetic reconstruction

Position

  • Place a suitably prepared patient on the operating table, under appropriate anaesthesia
  • Supine & gentle beach chair positions can be used
  • Prepare the skin & drape the shoulder with the upper extremity free

Landmarks

  • AC joint, acromion, clavicle, coracoid process

Incision

  • Make a transverse skin incision (Langer lines) approximately 5cm in length, centred on the AC joint

Internervous Plane

  • nil

Superficial Dissection

  • Dissect deep tissue in this line, exposing the distal clavicle by subperiosteal dissection

Procedure

  • Resect the most lateral 1-1.5cm of the clavicle.
    • Taper the bone cut from superolateral to inferomedial, leaving it angled
  • Sharply divide the coracoacromial ligament from its acromial attachment.
    • A described variant is to take a sliver of bone with the ligament
  • Weave a heavy non-absorbable suture through the ligament
  • Drill two small holes from the superior aspect of the clavicle to emerge through the bevelled end of the clavicle
  • Pass the suture ends through these holes
  • Push the clavicle down into its reduced position & tie the suture
  • Shorten or lengthen ligament as necessary
    • Shorten
      • It may be necessary to shorten the ligament prior to tying it
    • Lengthen
      • gain extra length by detaching the anterior fasciculus off the waist of the coracoid
      • Another way to achieve extra length is to take a bone block off the acromion with the ligament
  • Adjuvant fixation
    • Weaver & Dunne did not describe any adjuvant fixation to hold the clavicle reduced while the ligament heals
    • Options
      • Bosworth screw
      • Hook plate

Postop / Rehab

  • If adjuvant fixation has been used, the patient is allowed to use the arm for ADLs, below the shoulder
  • At 12/52, the screw is removed & overhead activities are allowed

Complications / Dangers

Perioperative

General
  • Anaesthetic
Local
  • Damage to supraclavicular nerves/neuroma formation

Postoperative

Early
  • Infection
  • Haematoma
  • Anaesthesia
  • Scar formation
  • Recurrence of deformity
  • Breakage of fixation
  • Erosion or fracture of clavicle
  • Post-op pain & limitation of motion
  • Second procedure required to remove metal
Late
  • Osteoarthritis
  • Soft tissue calcification