MyPACS.net: Radiology Teaching Files > Case 34122209

previously visited OCCULT ELBOW FRACTURE WITH POSTERIOR FAT PAD
Contributed by: Rebecca Kessler, Resident, Brooke Army Medical Center, Texas, USA.
Patient: 20 year old male
History: 20 year old male: with right elbow pain after fall. Evaluate for fracture.
Images:[small]larger

Fig. 1

Fig. 2: Elevated posterior fat pad with mildly elevated anterior fat pad.

Fig. 3

Fig. 4: Coranoid Fracture.

Fig. 5: Coronoid fracture.

Fig. 6: Nondisplaced fracture of the anterior lateral aspect of the radial head.

Fig. 7: Nondisplaced fracture through the right coronoid process.
Findings:

x-ray: Elevated posterior fat pad with mild elevation of the anterior fat pad.  No definite fracture seen on x-ray.

CT: Nondisplaced fracture of the coronoid and anterior lateral aspect of the radial head.

Diagnosis: Nondisplaced fracture of the coronoid and anterior lateral aspect of the radial head.
Discussion:

Type I Radial Head Fracture (based on Mason classification)

 



- Discussion:
    - fissure or margin sector fracture w/ displacement less than 2 mm;
    - type I fractures may be difficult to identify;
    - fat pads are intracapsular but extrasynovial;
    - anterior fat pad is normally visible anterioir to coronoid fossa;
    - posterior fat pad sign is pathologic & should suggest need for further
            oblique views, including radial head capitellum view;
    - there is no mechanical block to motion;

- Radiographs:
    - type I frx are nondisplaced & may be missed on routine radiographs;
    - posterior fat pad sign is pathologic & should suggest further oblique views,
          including radial head-capitellum (RHC) view.

 

Discussion:
    - radial head frx is most common type of elbow fracture in adults (radial neck in kids)

    - Fall on outstretched hand.... head into capitulum
    - the high frequency of frx in the anterolateral aspect of radial head occurs as a result of lack of subchondral bone under anterolaterl aspect of the radial head;
     - because the anterolateral aspect of radial head does not articulate w/ sigmoid fossa, frx in the region are amenable to fixation w/ small screws;
    - associated injuries:
           - frx of the capitellum
           - distal radius frx
           - dislocation of the distal RU joint (Essex Lopresti Fracture)
           - valgus instability (MCL rupture)
                  - probably more common than is reported;
                  - indications for repair of the MCL will be determined based on stability of the elbow thru a functional range of motion;
           - rupture of the triceps tendon
           - elbow dislocation:
           - terrible triad: RHF + MCL + coronoid process frx;

 

Dx and Exam:
    - pain, effusion in the elbow, & tenderness on palpation directly over radial head are typical manifestations;
    - if frx is displaced, click or crepitus over radial head is detected w/ supination;
    - if elbow ROM is limited, then aspirate and inject several cc of lidocaine, and then re-examine;
           - check for blocks to flexion-extension as well as supination-pronation;  
    - wrist tenderness with ROM is common

 

Treatment: (based on Mason classification)
    - type I
    - type II
          - less than 30% of radial head;
          - more than 2 mm displacement
    - type III - entire radial head fractured A,B and C
          - ORIF of radial head fracture
          - excision of radial head
                  - Posterolateral Rotatory Instability of the Elbow Following Radial Head Resection.
                  - The Effect of Radial Head Excision and Arthroplasty on Elbow Kinematics and Stability. 
          - radial head implants:
          - references:
                 - Treatment of displaced segmental radial-head fractures. Long-term follow-up.
    - complex fractures
          - radial head frx & elbow dislocation :
          - radial head frx & MCL instability :
          - Essex Lopresti Fracture
          - reference:
                - Radial head fractures and their effect on the distal radioulnar joint. A rationale for treatment.
                - Radial head fracture. A potentially complex injury.
                - Radial head fractures with acute distal radioulnar dislocation.

References: http://www.wheelessonline.com/ortho/radial_head_frx
Comments:
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Additional Details:

Case Number: 34122209Last Updated: 01-21-2010
Anatomy: Skeletal System   Pathology: Trauma
Modality: CT, Conventional RadiographAccess Level: Readable by all users
Keywords: fat pads, elbow fracture

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