Overview
Definition:
A supracondylar humerus fracture is a break in the bone just above the elbow joint, specifically in the distal humerus, proximal to the condyles
It is the most common type of elbow fracture in children, typically occurring in the humerus between the epiphysis and diaphysis.
Epidemiology:
Accounts for approximately 60-70% of all pediatric elbow fractures
Peak incidence is between 3-10 years of age, with a male predominance
Often caused by a fall on an outstretched hand (FOOSH) with the elbow in hyperextension.
Clinical Significance:
Critical to recognize and manage promptly due to the proximity of vital neurovascular structures (median nerve, radial nerve, ulnar nerve, brachial artery)
Potential for severe complications like compartment syndrome and Volkmann's ischemic contracture necessitates careful assessment and timely intervention for optimal functional outcomes.
Clinical Presentation
Symptoms:
Significant elbow pain
Swelling around the elbow
Inability to move the elbow
Deformity of the elbow (often posteromedial displacement)
Possible history of a fall
Parents may report the child holding the arm in a characteristic flexed and pronated position due to pain and swelling.
Signs:
Visible deformity (e.g., "sail sign" on lateral radiograph due to fat pad displacement, or "tenting" of the skin anteriorly with posterior displacement)
Tenderness over the distal humerus
Limited range of motion of the elbow
Swelling and ecchymosis
Palpable radial pulse
Assessment of distal sensation and motor function.
Diagnostic Criteria:
Diagnosis is primarily based on clinical examination and radiographic findings
Radiographs should include anteroposterior (AP) and lateral views of the elbow
In younger children (<6 years), assessment of the humerocondylar angle on the lateral view is crucial for identifying occult fractures or assessing displacement
The presence of an anterior and posterior fat pad sign on lateral radiographs indicates intra-articular effusion, highly suggestive of a fracture.
Diagnostic Approach
History Taking:
Mechanism of injury: Fall on an outstretched hand with hyperextended elbow is classic
Type of fall: direct blow vs
indirect force
Time of injury
Any associated symptoms like numbness or tingling in the hand
Previous elbow trauma or congenital abnormalities
Allergies and medications.
Physical Examination:
Systematic assessment of the injured limb: Inspection for deformity, swelling, ecchymosis, and skin integrity
Palpation for tenderness and crepitus
Assessment of range of motion (active and passive), noting pain provocation
Crucial neurovascular assessment: Assess median, radial, and ulnar nerve function (motor and sensory) distal to the fracture
Palpate radial pulse for presence, quality, and capillary refill time in digits
Assess for signs of compartment syndrome (pain out of proportion, tense swelling, pain with passive stretch).
Investigations:
Radiographs: Standard AP and lateral views of the elbow
Oblique views may be necessary
Identify fracture line, displacement, angulation, and rotation
Assess for fat pad signs (anterior and posterior)
If fracture is not evident but suspicion is high, a posterior fat pad sign is indicative of an intra-articular fracture
Ultrasound can be useful in equivocal cases
CT scan is rarely indicated for initial management but may be useful for complex fractures or pre-operative planning.
Differential Diagnosis:
Radial head fracture
Olecranon fracture
Elbow dislocation
Ligamentous injury
Pediatric supracondylar humerus fracture is usually a diagnosis of exclusion based on imaging and clinical presentation
The characteristic mechanism and radiographic findings are usually definitive.
Management
Initial Management:
Prompt assessment of neurovascular status is paramount
Neurovascularly intact fractures with minimal displacement may be managed non-operatively with a long arm splint and sling, with close follow-up
Fractures with significant displacement or neurovascular compromise require urgent reduction and stabilization.
Surgical Management:
Indications for surgery include: Open fractures
Open reduction and internal fixation (ORIF) for irreducible or unstable fractures
Fractures with associated vascular injury
Compartment syndrome
Most significantly displaced supracondylar fractures (Gartland type II and III) are treated with closed reduction and percutaneous pinning (CRPP)
The goal is anatomical reduction and stable fixation to allow early mobilization and prevent complications.
Pinning Technique:
Closed reduction is performed under general anesthesia or procedural sedation
The elbow is reduced using axial traction and manipulation of the distal fragment (flexion and pronation for posterior displacement)
After successful reduction (confirmed by fluoroscopy and restoration of neurovascular function), percutaneous K-wires are inserted through the medial and/or lateral epicondyles into the distal humerus
Standard technique involves two crossed K-wires from the medial side, or one K-wire from the medial and one from the lateral side
Adequate wire placement is crucial to avoid iatrogenic nerve injury.
Postoperative Care:
Post-operative immobilization in a long arm cast or splint with the elbow at 90 degrees of flexion
Regular neurovascular checks are essential
Pain management with analgesics
Prophylactic antibiotics may be considered for open fractures or surgical procedures
K-wires are typically removed between 3-4 weeks
Mobilization of the elbow is initiated gradually following K-wire removal.
Complications
Early Complications:
Neurovascular injury: Median nerve palsy is most common (2-15%), followed by radial nerve palsy
Brachial artery injury leading to compartment syndrome and Volkmann's ischemic contracture is a surgical emergency
Compartment syndrome: A serious complication characterized by increased pressure within a fascial compartment, leading to muscle and nerve ischemia
It requires emergent fasciotomy
Pin migration or breakage
Infection.
Late Complications:
Stiffness and loss of range of motion
Cubitus varus or valgus deformity
Heterotopic ossification
Malunion or nonunion (rare)
Residual nerve deficits
Growth disturbance of the distal humerus.
Prevention Strategies:
Meticulous neurovascular assessment before and after reduction/pinning
Adequate reduction and stable fixation
Early recognition and management of compartment syndrome (fasciotomy if suspected)
Careful K-wire placement to avoid iatrogenic injuries
Appropriate post-operative care and follow-up
Gradual rehabilitation to regain range of motion.
Prognosis
Factors Affecting Prognosis:
The severity of the initial fracture displacement
Promptness and quality of reduction and fixation
Presence and severity of initial neurovascular injury
Development of complications like compartment syndrome
Age of the child.
Outcomes:
With timely and appropriate management, the prognosis for supracondylar humerus fractures is generally excellent, with most children regaining good to excellent functional outcomes and range of motion
Early neurovascular deficits usually resolve with appropriate management
Severe complications like ischemic contracture can lead to permanent functional impairment.
Follow Up:
Regular follow-up appointments are necessary to monitor radiographic healing, regain range of motion, and assess for any developing deformities or late complications
Follow-up typically involves clinic visits at 1 week (for cast check/pin removal), 4-6 weeks, and then as needed
Physiotherapy is often initiated to aid in restoring full elbow function.
Key Points
Exam Focus:
Gartland classification of supracondylar fractures (Type I, II, III, IV) is crucial for management decisions
Neurovascular status is the most critical factor in management, especially median nerve and brachial artery
Volkmann's ischemic contracture is a dreaded complication of vascular compromise
Closed reduction and percutaneous pinning (CRPP) is the gold standard for displaced fractures.
Clinical Pearls:
Always document baseline neurovascular status meticulously before any intervention
Be wary of pain out of proportion and tense swelling as signs of compartment syndrome
Inability to achieve full elbow extension during reduction attempts may indicate tenting of the brachial artery
Two crossed medial pins provide the most stable fixation.
Common Mistakes:
Inadequate neurovascular assessment
Delay in reduction and pinning of displaced fractures
Over-aggressive reduction attempts that can worsen neurovascular compromise
Improper K-wire placement leading to iatrogenic nerve or vessel injury
Premature mobilization before adequate healing, leading to loss of reduction.