Distal Clavicle Osteolysis

Summary

  • Uncommon injury of the ACJ that results from repetitive degeneration of the joint
  • Characterised by osteolysis of the distal clavicle, ACJ widening and pain
  • Management typically non operative, ACJ excision management option

Aetiology

  • The pathophysiology for this disease is thought to be predominantly due to a combination of repetitive trauma resulting in microfractures and fissuring of the cartilage leading to increased osteoblastic activity.
  • It is also thought that there is synovial invasion into the subchondral bone which leads to the osteolysis.

Epidemiology

  • Young athletes who perform repetitive overhead activities e.g weightlifters
    • Typically young male however increasingly common with women due to rise of popularity of extreme athletics and weightlifting in females
  • Also found post fixation/reconstruction for previous ACJ injuries

History

  • Pain
    • Insidious vague shoulder girdle pain
    • Nocturnal pain
    • No obvious history of trauma
    • History of above shoulder exercises e.g bench press, chest flies and push ups
    • Relieved with activity modification/decrease activity

Examination

  • Tenderness on palpation
  • May radiate to trapezius or deltoid region
  • Provocative tests
    • Cross body adduction

Investigations

X-ray

  • AP and lateral shoulder
  • Zanca view
    • Loss of subchondral bone in distal clavicle
    • Cystic changes
    • Widening of ACJ
    • Osteopenia of the distal clavicle

Bone Scan

  • Increase uptake in the distal clavicle

MRI

  • Increased signal intensity on fat-suppressed T2-weighted and short-tau inversion recovery images
  • Bone marrow oedema at the distal clavicle

Lignocaine Injection

  • Diagnostic and potentially therapeutic
    • Pain relief (temporary or not) will identify ACJ as source of pathology and is predictive of success with surgical outcome

Treatment

Principles

  • Non-operative care for several months before surgery
  • Diagnosis confirmed by pain relief from AC joint injection
  • Surgery when symptoms persist despite activity modification
  • Preserve the superior and posterior AC capsule to avoid instability
  • Resect enough clavicle to prevent abutment without excess resection

Non-operative

  • Activity modification (decrease or stop offending activity)
  • Physical therapy
  • Corticosteroid injection
  • Analgesia and nonsteroidal anti-inflammatory

Operative

  • Distal clavicle excision
    • Open
      • Incision overlying ACJ
      • Subperiosteal dissection to expose distal clavicle
      • Resection should not exceed 10mm with saw or burr (concern of compromise deltoid insertion and superior AC ligament, and leading to increased instability of the ACJ and potential posterior subluxation).
    • Arthroscopic
      • Direct or indirect approaches to the ACJ described with a burr used for excision
    • Post operative care
      • Sling use temporary with gradual decrease
      • Physical therapy for ROM and strengthening
      • Return to full activity as tolerated

Prognosis

  • Good prognosis with activity modification and limitation
    • Due to population it affects this is not always possible
  • 93% success in those who received lidocaine injection however concern is this may not last
  • There are multiple studies that look at both open and arthroscopic distal clavicle resection with both groups reporting good symptom relief. There is a paucity of high level studies comparing open and arthroscopic results.

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.