Extension Type Supracondylar Fractures



- Discussion:
    - extension type accounts for 95% of cases, & is caused by a fall on outstretched hand with hyperextension of the elbow;
    - anterior periosteum is torn;
    - there may be a significant amount of local bleeding and swelling;
    - nerves & blood vessels are contused, compressed, or lacerated  by bone fragments & blood that infiltrates the antecubital fossa;

- Gartland Classification:
       - Type I:   undisplaced;
       - Type II:  displaced with intact posterior cortex;
       - Type III: displaced with no cortical contact;

- Fracture Anatomy:
    - distal fragment is posteiorly displaced;
    - in the sagittal plane, the fx line traverses obliquely upward and backward, and the frontal plane, it is frequently transverse;
          - older pt, more oblique frx line tends to be in frontal plane;
          - transverse fractures are more stable than oblique fractures;
          - frx is usually complete, but occassionaly green stick frx occurs;
    - distal fragment is displaced proximally & posteriorly;
           - it is often tilted laterally or medially and rotated medially;
    - lower end of proximal frag projects anteriorly, pierces periosteum, & forces its way into brachialis anticus & biceps brachii;
          - periosteum is stripped from anterior surface of  lower fragment and posterior surface of the upper fragment;
          - degree of displacement of the fracture fragments is limited by the extent of periosteal stripping;
    - most displaced frxs (Type III) are of extension type (97%);
    - fractures of the extension type are associated with the most serious complications and the highest rate of residual cosmetic deformity;

- Physical Exam

- Treatment:
      - Extension-type supracondylar fractures are initially splinted in  20 degrees of elbow flexion pending evaluation and treatment;
      - Reduction
             - intact posterior periosteum provides stability to the fracture and assists w/ reduction;
             - position of maximum stability for reduction is full flexion and pronation;
      - Non-displaced fractures are initially treated w/ immobilization in long arm splint with the elbow flexed;
              - in non-displaced frx, the elbow should not be flexed > 90 deg;
              - flexion of upto 120 deg renders frx more stable but also increases risk of neurovascular compromise;
              - if neurovascular compromise has occurred, elbow must be gradually extended until neurovascular status of limb returns to normal;
    - Percutaneous Pin Fixation  
    - Type III Supracondylar Frx



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, January 4, 2013 11:38 am