Supracondylar Humerus Fracture
synonyms: supracondylar fracture, supracondylar humerus fracture
Pediatric Supracondylar Humerus Fx ICD-9
- 812.41 = closed
- 812.51 = open
Pediatric Supracondylar Humerus Fx Etiology / Epidemiology / Natural History
- most common elbow fx in children, @60%
- most common in children <10, peak incidence=5-8y/o
- most commonly peak in children who are around age 7 years. This is often a period of maximum ligamentous laxity; therefore, the elbow hyperextends when the child tries to catch himself or herself during a fall. During the hyperextension process, the olecranon process is forced against the weaker, immature metaphyseal bone of the distal humerus, producing the typical extension-type supracondylar fracture.
Pediatric Supracondylar Humerus Fx Anatomy
- the olecranon fossa and coronoid fossa of the distal humerus create a very thin area of bone between the medial and lateral columns of the elbow. This makes supracondylar humerus fractures very unstable and prone to angular deformity.
Pediatric Supracondylar Humerus Fx Clinical Evaluation
- detailed NV exam, especially note AIN function.
- r/o compartment syndrome
- Assess soft tissues, especially note if fracture is open or closed.
Pediatric Supracondylar Humerus Fx Xray / Diagnositc Tests
- A/P and lateral elbow films
- proximal radius points to capitellum in all views
- long axis of ulna lines up or slightly medial to long axis of humerus on true AP
- Anterior humeral line passes through the middle 1/3 of the capitellum. In children <4yrs old it passes equally through the middle 1/3 and anterior 1/3. (Herman MJ, JBJS 2009;91A:2188).
- humeral-capitellar (Baumann's) angle; normal =75 degrees, best to compare to uninjured side. As Baumann angle increases the carrying angle decreases. 5degree change in Baumann angle = 2 degree change in carrying angle. (Worlock, JBJS 68B:755, 1986. If measuring from a perpendicular to humeral axis normal = 9-26 degrees
- posterior fat pad = 76% incidence of occult fracture
- Jones view=a/p view of distal humerus with elbow maximally flexed, difficult to interpret.
Pediatric Supracondylar Humerus Fx Classification / Treatment
- Extension(90-98%) caused by fall on an outstretched hand with the elbow hyperextended
- Flexion(rare)caused by falling on flexed elbow
- Gartland's Classification
- Type I= nondisplaced=LAC x 3-4weeks. Restore ant hum line, Baumanns angle <9, cast with elbow at 90 degrees and forearm in neutral
- Type II=ant. Gapping, intact post. hinge. Rx=CRPP. Reduce by flexing elbow and pronating forearm
- Type III=no cortex in continuity=CRPP/ORPP
- Pirone JBJS 70A:641, 1988 established CRPP as best treatment option in retrospective review of 230pts treated with CRPP/ORIF/traction/cast
- Treatment options=casting, skin/skeletal traction(takes 2-3wks, costs more), CRPP, ORIF
- see Supracondylar Humerus CRPP Technique.
- Nerve Palsy: anterior interosseous nerve palsy is most common followed by radial nerve. Nearly all nerve palsies are neuropraxia and resolve spontaneously. Initial treatment = treatment of fracture and observation of nerve palsy.
Pediatric Supracondylar Humerus Fx Associated Injuries / Differential Diagnosis
- distal forearm fx(common)
- ipsilateral humerus fx(rare)
- Nerve injury-7-15.5%, AIN most common: posterolateral displacement=median n, posteromedial=radial n, ulnar nerve(uncommon) Cramer KE, Green NE, Devito DP: Incidence of anterior interosseous nerve palsy in supracondylar humerus fractures in children. J Pediatr Orthop 1993;13:502-505. Dormans JP, Squillante R, Sharf H: Acute neurovascular complications with supracondylar humerus fractures in children. J Hand Surg 1995;20A:1-4.
- Vascular injury<1%, brachial artery is protected by brachialis muscle
Pediatric Supracondylar Humerus Fx Complications
- Cubitus varus: most common complication, due to malreduction (mild extension and rotation of distal fragment), not growth disturbance, sequela is largly cosmitec, but also associated with lateral condyle fractures, posterolateral rotatory elbow instability, ulnar neuropathy. Treatment = distal humerus osteotomy (Pankaj A, JPO 2006;26:61).
- Compartment syndrome
- 5-19% nerve injury(JAAOS), If no improvement either clinically or by EMG at 5 months exploration recommended.(Culp,JBJS 72A:1211, 1990)
- Vascular injury 5-12%
- Volkmanns Ischemic contracture <1%
- angular deformity-most commonly cubitus varus-primarily a cosmetic only deformity-remodeling potential is limited as distal humerus contributes only 20% of humeral growth.
- Malunion- Atign'a has shown that completely displaced supracondylar fractures that become sufficiently rigid with new callous formation cannot be adequately manipulated approximately 7 days following the injury. The treatment of choice at this time is to apply a new cast and let the fracture heal. This should be followed by reassessment of the appearance and function of the fracture to determine if a corrective osteotomy is necessary. Delayed open reduction carries a risk of producing myositis ossificans in 85% of patients with this injury. Atign'a JEO: Conservative management of supracondylar fractures of the humerus in Eastern Provincial General Hospital. East Afr Med J 1984;61:557-560. Malunion may lead to ulnar neuropathy, increased risk of late lateral condyle fractures, posterolateral rotatory instability and active extension loss.
Pediatric Supracondylar Humerus Fx Follow-up Care
- if CRPP splint at 70°, overwrap to LAC at f/u, remove K-wires in 3-4 wks
- physical therapy is generally not needed.
Pediatric Supracondylar Humerus Fx Review References
- Lal GM, Bhan S: Delayed open reduction for supracondylar fractures of the humerus. Int Orthop 1991;15:189-191.