Capitellar Osteochondritis Dissecans

Presentation by Dr Nathan Donovan

Definition

Focal lesion of the subchondral bone of the humeral capitellum with overlying articular cartilage involvement, in the adolescent or young adult elbow. Progresses to fragment separation, loose body formation and radiocapitellar arthrosis.

Anatomy

  • Capitellum supplied by end arteries entering posteriorly from the radial recurrent and interosseous recurrent arteries.
  • No metaphyseal collateral supply to the ossific nucleus until skeletal maturity.
  • Lesion characteristically anterolateral – the area loaded in radiocapitellar compression.
  • Lateral column of the capitellum buttresses the radial head; lateral wall involvement changes treatment and prognosis.

Aetiology

  • Repetitive valgus loading with radiocapitellar compression
  • Subchondral microtrauma and local ischaemia in a watershed blood supply
  • Overuse injury: throwing athletes, gymnasts, racquet sports

Epidemiology

  • Typically 12–17 years
  • Dominant arm
  • Male predominance in throwers, female in gymnasts
  • Bilateral in a minority

Pathology

  • Subchondral bone fails first; cartilage intact early
  • Fibrous or fluid interface develops between fragment and bed
  • Fragment destabilises, then detaches as a loose body

Stable vs Unstable

  • Stable – open capitellar physis, flattening or lucency only, intact cartilage, good range
  • Unstable – fragmentation or displacement, fluid rim on MRI, closed physis, mechanical symptoms, restricted range

Differential: Panner’s Disease

  • Younger child, 7–12 years
  • Involves the entire capitellar ossific nucleus
  • Self-limiting osteochondrosis; resolves with rest, joint remains normal

Classification

Minami (radiographic)

GradeDescription
ITranslucent shadow in mid capitellum
IIClear zone between lesion and adjacent bone
IIILoose body
  • ICRS / Baumgarten (arthroscopic), cartilage integrity and fragment stability
  • Practically, stable or unstable, which decides treatment

History

  • Insidious lateral elbow pain in an adolescent athlete; worse with activity, relieved by rest
  • Flexion contracture of 15–20° common at presentation
  • Catching, locking or giving way suggests an unstable lesion or loose body
  • Training history: sport, position, volume, pitch counts

Examination

  • Tenderness over the radiocapitellar joint, elbow flexed and forearm rotated
  • Loss of terminal extension; measure both sides
  • Active radiocapitellar compression test – pronation / supination with the elbow extended
  • Assess medial collateral ligament and ulnar nerve in throwers

Investigations

  • Radiographs – AP, lateral, and AP in 45° flexion which profiles the anterior capitellum. Easily missed on standard views.
  • MRI – investigation of choice. Defines size, cartilage integrity, stability. High T2 signal rim or fluid beneath the fragment indicates instability.
  • CT – bony detail and graft planning

Treatment

Non-operative

  • Treatment of choice for stable lesions with an open physis
  • Cessation of throwing or loading 3–6 months, then graduated return
  • Return to sport at least equal to surgery for stable lesions in systematic review

Indications for Surgery

  • Unstable lesion
  • Loose body or mechanical symptoms
  • Failure of an adequate non-operative trial

Operative Options

  • Debridement and marrow stimulation (microfracture or drilling) – smaller contained lesions, intact lateral wall
  • Fragment fixation – large fragment with good subchondral bone
  • Osteochondral autograft transfer (OATS) – large lesions, lateral column involvement; superior to marrow stimulation for lateral wall lesions
  • Osteochondral allograft – salvage of large defects, avoids donor site morbidity

Outcome

  • All surgical modalities improve range and elbow scores; no clear superiority between techniques at a given grade
  • Surgery superior to non-operative treatment only for higher grade lesions
  • Poor prognostic factors: lateral wall involvement, closed physis, large lesion size

References

  1. Sayani J, et al. Treatment strategies and outcomes for osteochondritis dissecans of the capitellum: a systematic review. Am J Sports Med 2021. PubMed 33886390
  2. Treatment and early outcomes of capitellar osteochondritis dissecans. Am J Sports Med 2024. PubMed 39547213
  3. Diagnosis and treatment of osteochondritis dissecans of the humeral capitellum. J Orthop Sci 2018. PubMed 29276039
  4. Osteochondral reconstruction of the capitellum. Orthop Clin North Am 2020. PubMed 31739884
  5. Outcomes of arthroscopic treatment of osteochondritis dissecans of the capitellum. J Shoulder Elbow Surg 2015. PubMed 26234666
  6. Capitellum osteochondral allograft transplantation for osteochondritis dissecans of the elbow. J Hand Surg Am 2023. PubMed 36967310

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