Jennifer J. Winell and John M. Flynn
DEFINITION
A supracondylar fracture that requires open reduction is one that cannot be treated with closed reduction and percutaneous pinning.
ANATOMY
A very thin area of bone connects the medial and lateral columns of the distal humerus. This makes the area prone to fracture. The coronoid fossa is located anteriorly and the olecranon fossa is located posteriorly.
The neurovascular anatomy to consider for an open reduction includes:
The ulnar nerve passes behind the medial epicondyle.
The radial nerve courses from posterior to anterior just above the olecranon fossa.
The brachial artery and median nerve pass through the antecubital fossa.
PATIENT HISTORY AND PHYSICAL FINDINGS
The patient history is the same for supracondylar fractures being treated by closed methods.
Tenting of the skin may indicate an open reduction is needed. This may represent buttonholing of the proximal fragment through the periosteum and brachialis muscle, making closed reduction difficult.
A careful neurovascular examination must also be performed.
SURGICAL MANAGEMENT
Indications for open treatment of a supracondylar fracture include an open fracture, an irreducible fracture, and a compromised vascular supply to the hand that does not reconstitute with reduction by closed means.
The timing for surgical intervention has been a matter of debate. Many surgeons believe that prompt pinning or open reduction is optimal. Some newer articles have been published finding no significant increase in complication rates with delayed treatment.2,3
Preoperative Planning
During preoperative planning, the surgeon must consider the reasons why an open procedure is necessary. This will help guide the approach.
Other factors for consideration include the pin size for maintaining the reduction once the fracture is reduced. In general, 0.062-mm wires are used for all but the oldest children. More importantly, at least three pins should be used for type III fractures if they are going to be pinned with lateral entry pinning.
Positioning
The patient is placed supine on the operating table. A hand table attachment is valuable. A sterile tourniquet is placed on the child's arm after preparation and draping. The surgeon should make sure that the fluoroscope can be moved easily into and out of the operative field to assist with pinning of the fracture.
Approach
The first factor to consider in determining the approach is the direction of displacement of the distal fragment. This helps guide placement of the incision.
In general, a transverse anterior incision through the antecubital fossa is the most useful and cosmetic.
If more visualization is needed, this incision can be extended medially or laterally based on displacement, but this is rarely necessary.
Extension of the incision on the opposite side of the displacement of the distal fragment allows for removal of soft tissue obstacles to reduction.
If there is a suspicion of neurovascular compromise, the anterior approach provides the best exposure.
An inability to reduce the fracture may indicate that the proximal fragment has buttonholed through the brachialis muscle. Again, an anterior approach is the most useful exposure to reduce this deformity.
Some surgeons have advocated a posterior approach for severely comminuted fractures.4 However, other surgeons strongly believe that a posterior approach risks compromising the blood supply to the distal fragment and should be avoided.5
TECHNIQUES
OPEN REDUCTION THROUGH AN ANTERIOR APPROACH
Incision and Dissection
Once the patient has been prepared and draped, the tourniquet is inflated.
A transverse incision is made across the antecubital fossa (TECH FIG 1A).
Blunt dissection continues through the subcutaneous and fatty tissue. Care must be taken in dissecting as the neurovascular bundle may be located in a nonanatomic place; it may be immediately in the subcutaneous tissue and at risk for damage during initial dissection (TECH FIG 1B).
Dissection proceeds until the metaphyseal spike is encountered. It is covered by a small amount of tissue and parts of the brachialis muscle that may be torn (TECH FIG 1C).
It is at this point that the neurovascular bundle should be located, if it has not yet been identified. This usually involves dissecting across the anterior aspect of the metaphyseal spike. This step should not be omitted even if there is no vascular compromise. Once the vessels are indentified, they should be retracted out of the field.
Fracture Reduction
Defining the outline of the distal fragment can be the most challenging aspect of the procedure. It is posterior and lateral and the periosteum is folded over its surface (TECH FIG 2).
Reduction is obtained by reaching into the fracture site with a hemostat and getting hold of the cut edge of the periosteum. This cut edge is extended with scissors to increase the size of the buttonhole and helps to free up the distal fragment. The distal fragment is then brought anteriorly and reduced to the shaft fragment, which is maneuvered back through the buttonhole into its resting position posterior to the brachialis muscle.
Alternatively, the surgeon can hold his or her thumb on the proximal fragment and push downward while an assistant applies traction to the forearm with the elbow flexed at 90 degrees.1 A periosteal elevator can be used as a lever to assist the reduction.
Pinning
Once a reduction has been obtained, the fracture is fixed with smooth Kirschner wires. This is accomplished in the same manner as closed reduction with percutaneous pinning.
TECH FIG 1 • A. Placement of a transverse incision for treatment of supracondylar fracture. B. Incision through subcutaneous tissue and fat. C. Deepening of incision with fracture site exposed.
TECH FIG 2 • A. Proximal fragment retracted to try to expose distal fragment. B. Sagittal view of fracture with proximal fragment shown buttonholing though muscle and periosteum.
Three divergent, lateral entry pins are placed as described in Chapter PE-5.
Alternatively, a cross-pinning strategy can be used with medial and lateral entry pins. Ideally, both the medial and lateral pins should cross proximal to the fracture site. The surgeon must be sure to engage both the medial and lateral columns of the distal fragment.
The surgeon checks pin placement and reduction with fluoroscopy. If acceptable, the pins are bent, cut, and left out of the skin. Once healed, they can easily be removed in the office.
The incision is closed with absorbable sutures.
POSTOPERATIVE CARE
Sterile dressings are applied over the incision.
A strip of Xeroform dressing can be wrapped around the pins, followed by fluff dressings.
The elbow is splinted in 60 to 90 degrees of flexion with a neutral forearm.
The patient is admitted overnight for observation. Often a long-arm cast can be placed safely the next day, with the arm flexed about 80 degrees. This cast can be maintained until the pins are removed 3 or 4 weeks after surgery.
The patient can then be placed back into a sling and started on gentle range-of-motion exercises out of the sling for another 2 weeks.
The child can then start to use the arm normally.
Formal physical therapy is usually not necessary.
OUTCOMES
It is generally agreed that prompt attention to reduction and stabilization of supracondylar fractures results in better outcomes and fewer complications.
Postoperative loss of reduction is uncommon.7 However, children with supracondylar fractures that have been treated with open reduction generally take longer to regain their elbow motion than children treated with closed pinning. Families should be advised about this longer period of elbow stiffness in the immediate postoperative period.
A 2001 study of 862 supracondylar fractures treated with open reduction found 55% excellent results, 24% good results, 9% fair results, and 12% poor results 5.8 months after injury.6
COMPLICATIONS
Complications can result from the injury itself or from surgery.
The risk of infection is decreased with the use of perioperative antibiotics.
Iatrogenic neurovascular injury
Identification of neurovascular structures is crucial.
The ulnar nerve is susceptible to injury if a medial pin is used.
Compartment syndrome
The child should be kept overnight for observation and the surgeon should make sure that serial neurovascular examinations are performed.
The first sign of compartment syndrome in a child is usually increased pain, or increased pain medication requirements.
The children most at risk are those who had compromised blood flow to the hand immediately after injury.
Children who have a median nerve injury often do not complain of the pain because of the sensory deficit.
Loss of motion
Although rare, some loss of full extension has been reported.
If there is excessive posterior angulation at the time of healing, some loss of full flexion can occur.
Cubitus valgus and cubitus varu.
Varus angulation is mostly cosmetic.
Valgus deformity can cause loss of full elbow extension and can result in tardy ulnar nerve palsy.
Myositis ossificans is rare and should resolve in 1 to 2 years.
REFERENCES
1. Ay S, Akinci M, Kamiloglu S, et al. Open reduction of displaced supracondylar humeral fractures through the anterior cubital approach. J Pediatr Orthop 2005;25:149–153.
2. Leet AI, Frisancho J, Ebramzadeh E. Delayed treatment of type 3 supracondylar humerus fractures in children. J Pediatr Orthop 2002;22:203–207.
3. Mehlman CT, Strub WM, Roy DR, et al. The effect of surgical timing on the perioperative complications of treatment of supracondylar humeral fractures in children. J Bone Joint Surg Am 2001;83A: 323–327.
4. Open reduction of supracondylar fractures of the humerus. In: Morrisey RT, Weinstein SL, eds. Atlas of Pediatric Orthopaedic Surgery, ed 3. Philadelphia: Lippincott Williams & Wilkins, 2001:63–67.
5. Otsuka NY, Kasser JR. Supracondylar fractures of the humerus in children. J Am Acad Orthop Surg 1997;5:19–26.
6. Reitman RD, Waters P, Millis M. Open reduction and internal fixation for supracondylar humerus fractures in children. J Pediatr Orthop 2001;21:157–161.
7. Sankar WN, Hebela NM, Skaggs DL, et al. Loss of pin fixation in displaced supracondylar humeral fractures in children: causes and prevention. J Bone Joint Surg Am 2007;89A:713–717.