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Capitellum Fracture

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Other Names

  • Elbow Fracture
  • Capitellum fractures
  • Capitellar Fracture


  • This page refers to a fracture of the articular part of the distal Humerus, known as the Capitellum



  • Uncommon
  • Represents 1% of all elbow fractures[1]
  • 4-6% of all distal humerus fractures[2]


  • General
    • Typically involves fall on outstretched hand, often from standing
    • Elbow is semi-flexed
    • Axial transmitted to capitellum by the radial head
    • Affects the Radiocapitallar Joint

Associated Conditions

Risk Factors

  • Unknown

Differential Diagnosis

Clinical Features

  • History
    • History of trauma
    • Patient self reports pain, swelling, deformity
    • Inability to fully extend or flex the elbow
  • Physical: Physical Exam Forearm
    • Ecchymosis, swelling
    • Tenderness
    • Loss of range of motion


Lateral xray showing a capitellum fracture. Note the semilunar fragment displaced anterosuperiorly consisting of both the capitellum and lateral half of the trochlea. This is referred to as “Mckee’s double arc sign”. Note the joint effusion as well.[3]


  • Standard Radiographs Elbow
    • Best viewed laterally
    • May be missed if fracture fragment is small
    • Osteochondral lesions may be missed if fragment is occult
    • McKee's 'double arc sign' two seperately visible arcs represent displaced capitellum, trochlea[4]


  • Can be helpful to clarify fracture pattern, classification


Bryan and Morrey Classification (with McKee modification)

  • Type I: Large osseous piece of the capitellum involved in coronal plane, may involve trochlea
  • Type II: Kocher-Lorenz fracture, shear fracture of articular cartilage, articular cartilage separation with very little subchondral bone attached
  • Type III: Broberg-Morrey fracture, severe comminution
  • Type IV: McKee modification, coronal shear fracture that includes the capitellum and trochlea


  • In general, displaced fractures lead to poor clinical outcomes if left untreated, most often requiring surgery


  • Indications
    • Nondisplaced type I, II with <2 mm displacement
  • Splint: Posterior Long Arm Splint for 2-3 weeks
  • Transition to pre-fab for early range of motion exercises


  • Indications
    • Displaced type I, II, III fractures >2 mm
    • Type IV fractures
  • Technique
    • ORIF (can be open or arthroscopic)
    • Fragment excision
    • Arthroplasty

Rehab and Return to Play


  • Highly variable
  • Discretion of orthopedic surgeon

Return to Play/ Work

Complications and Prognosis



See Also


  1. Bryan RS, Morrey BF. Fractures of the distal humerus. Philadelphia: WB Saunders; 1985.
  2. Khalili M, Wong RJ. Underserved Does Not Mean Undeserved: Unfurling the HCV Care in the Safety Net. Dig Dis Sci. 2018 Dec;63(12):3250-3252. doi: 10.1007/s10620-018-5316-9.
  3. Case courtesy of Dr Samir Benoudina, Radiopaedia.org, rID: 67687
  4. Coronal Shear Fractures of the Distal End of the Humerus*. (1996) The Journal of Bone and Joint Surgery-american Volume. 78 (1): 49. doi:10.2106/00004623-199601000-00007
Created by:
John Kiel on 18 June 2019 01:12:34
Last edited:
13 October 2022 13:23:53
Trauma | Elbow | Upper Extremity | Fractures | Acute