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Shoulder

Acromioclavicular Joint Reconstruction

Aims

  • Anatomic reconstructionof chronic AC joint dislocation

Indications

  • Symptomatic Type III AC dislocation
    • labourers, throwers, overhead athletes
  • Instability after distal clavicle excision

Contradications

  • painless, functional Grade III separation
  • regional pain syndrome
  • unclear diagnosis
  • adhesive capsulitis

Principles

  • Prerequisites
    • reasonable expectations from patient
    • compliant patient
  • Surgical Steps
    • EUA shoulder
    • Harvest Semitendinosus
    • Exposure shoulder
    • Passing under the coracoid
    • Clavicular tunnels
    • Graft preparation
    • Graft passage
    • Biotenodesis fixation
    • AC joint capsular ligament repair
    • Closure
  • Postop sling for 6 weeks

Options

  • Weaver Dunn
  • AO Hook Plate

Position

  • beach chair
  • small towel bump placed on the medial scapular edge to elevate the coracoid anterior
  • Drape
    • wide to expose sternoclavicular joint and posterior clavicle
    • Arm drape free

Landmarks

  • Clavicle, Acromion, Coracoid process

EUA

  • ACJ
    • AP translation
    • Superior - inferior translation
  • Glenohumeral Joint
    • Motion
    • Stability

Incision

  • 6 cm longitudinal incision
    • centered over coracoid

Internervous Plane

  • nil

Superficial Dissection

  • Incise directly over clavicle until AC joint
  • Expose distal clavicle
    • Excise distal 5 mm with microsaw
  • Expose Coracoid
    • Cobb elevator
    • Beware of Musculocutaneous Nerve (medially)

Dangers

  • Musculocutaneous Nerve

Procedure

  • Harvest Semitendinosus
    • Prepare graft so that it fits through a 5.5mm tunnel
    • Whip stitch the ends with No. 2 FibreWire
  • Tunnels
    • Clavicular Tunnels
      • Location
        • 4.5cm medial to intact lateral distal  clavicular edge
        • along posterior superior cortex
        • directed 30 degrees anteriorly towards coracoid
    • Trapezoid Tunnel
      • Location
        • 1.5 cm medial to clavicular tunnel
        • central on clavicle
        • directed 30 degrees anteriorly towards coracoid
    • Reaming
      • Guide wire
      • Ream 5.5mm
        • Tip - remove reamer by hand (not power) to avoid tunnel widening
  • Graft Passage
    • Pass Fibrewire around Coracoid as a shuttle
    • Pass the ends into the tunnels
  • Fixation
    • Over-reduce ACJ
      • with downward pressure (Cobb elevator)
      • with upward pressure on humerus
    • 5.5 X 8 mm PEEK (polyetheretherketone) tenodesis screw
    • Additional fixation
      • Tie FibreWire to each other
      • Suture graft ends to each other
  • Superior AC joint Capsular Ligament Repair
    • No 2 FibreWire
      • Pants over Vest configuration
      • gives additional AP stablity
  • Closure
    • 2.0 Vicryl
    • 3.0 Monocryl
    • bupivacaine (Marcaine)

Postop / Rehab

  • 1 Week : Sutures out
  • 6 weeks: Broad Arm sling
  • Physio
    • Immediate
      • pendulum exercises
      • passive ER < 30 degrees
      • passive FF < 90 degrees
    • 8 weeks
      • active ROM
    • 12 weeks
      • strengthening
    • 16 weeks
      • sports
    • 6 months
      • heavy labour

Complications / Dangers

Perioperative

General
  • Anaesthetic
Local
  • Nerve injury

Postoperative

Early
  • Infection
  • Sterile abscess from Fibrewire or PEEK screw reaction
Late
  • Clavicle fracture
  • Construct failure
  • Persistent Pain

Results

  • Load to failure
    • Native Coracoclavicular ligament
      • 560 - 815 N
    • Anatomic Reconstruction
      • 400 - 700 N
    • Coracoacromial Transfer (Weaver Dunn)
      • 150 - 483
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