Open Reduction of Supracondylar Fractures of the Humerus
Open Reduction of Supracondylar Fractures of the Humerus
DEFINITION
A supracondylar fracture that requires open reduction is one that cannot be treated with closed reduction and percutaneous pinning.
ANATOMY
The neurovascular anatomy to consider for an open reduction includes the following:
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 and are often immediately subcutaneous anteriorly because of fracture displacement, putting them at risk during the skin incision.
PATIENT HISTORY AND PHYSICAL FINDINGS
The patient history is the same for supracondylar fractures being treated by closed methods. A careful neurovascular examination must also be performed.
SURGICAL MANAGEMENT
Indications for open treatment of a supracondylar fracture include an open fracture, a fracture that proves irreducible by closed techniques, and a compromised vascular supply to the hand that does not reconstitute with closed reduction.
The timing for surgical intervention has been a matter of debate. Many surgeons believe that prompt reduction is optimal. Other studies show no significant increase in complication rates with delayed treatment.2,3
Preoperative Planning
For children with a severe, potentially irreducible fracture, it is helpful to make a provisional attempt at fracture reduction immediately after the induction of anesthesia.
After milking the fracture from its entrapment in the brachialis muscle, standard reduction maneuvers are performed to reduce the distal fragment into generally good alignment.
Although time should not be spent perfecting the reduction (which will likely be lost during prepping and draping), this provisional reduction of severe fractures after induction can alert the surgical team that open reduction may be necessary, allowing time to gather equipment (such as a sterile tourniquet) and to obtain and place a radiolucent table to facilitate open reduction.
Positioning
The patient is placed supine on the operating table. A hand table attachment is valuable when open reduction is needed.
A sterile tourniquet is placed on the child's arm after preparation and draping.
The surgeon should make sure that the portable image intensifier can be moved easily into and out of the operative field to assist with pinning of the fracture.
Approach
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 extensile exposure to explore these structures.
An inability to reduce the fracture may indicate that the proximal fragment has buttonholed through the brachialis muscle. Again, an anterior approach provides the most useful exposure to reduce this deformity.
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TECHNIQUES
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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). Care must be taken in dissecting, as the neurovascular bundle may be in a nonanatomic location—typically immediately subcutaneous and at risk for damage during the initial dissection (TECH FIG 1B).
Dissection proceeds until the metaphyseal spike is encountered. It is often 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 identified, they should be retracted out of the field.
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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.
Fracture Reduction
Defining the outline of the distal fragment can be the most challenging aspect of the procedure. It is usually 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 to help 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.
Three divergent, lateral entry pins are placed as described in Chapter 5.
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TECH FIG 2 • A. Proximal fragment is retracted to expose distal fragment. B. Sagittal view of fracture with proximal fragment shown buttonholing muscle and periosteum.
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.
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Indications
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The primary indications for an open reduction are interposed tissue in the
fracture site preventing closed reduction and vascular compromise that does not improve with closed reduction and percutaneous pinning.
Neurovascular ▪ The neurovascular bundle can be located anywhere within the operative field
structures and must be identified even if there is no suspicion of compromise.
Reduction of
the fracture
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The distal fragment often can be palpated but not seen, as it is hidden by the
overlying periosteum. The surgeon should expand the buttonhole through the periosteum for better visualization.
Fracture
pinning
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Pins should be maximally separated at the fracture site if three lateral pins are
used. Convergent pins are not stable. If medial and lateral pins are used, the surgeon should engage the medial and lateral columns of the distal fragment.
PEARLS AND PITFALLS
POSTOPERATIVE CARE
Sterile dressings are applied over the incision.
A strip of Xeroform dressing is wrapped around the pins, followed by soft 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.
Supracondylar fractures in children reliably heal in 3 weeks, but when open reduction is used, healing may be delayed by an additional week. It is wise to get an x-ray with the cast off but the pins still in at 3 weeks after injury. If the fracture is not completely healed, cast protection for an additional week is recommended.
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.4,5
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, 65 of which were treated with open reduction, found 55% excellent results, 24% good results, 9% fair results, and 12% poor results 5.8 months after injury in those
treated with open reduction.6
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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 compartment syndrome in the setting of a median nerve injury often do not complain of 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 varus 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
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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.
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Leet AI, Frisancho J, Ebramzadeh E. Delayed treatment of type 3 supracondylar humerus fractures in children. J Pediatr Orthop 2002;22: 203-207.
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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;83-A(3): 323-327.
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Morrisy RT, Weinstein SL. Open reduction of supracondylar fractures of the humerus. In: Atlas of Pediatric Orthopaedic Surgery, ed 3. Philadelphia: Lippincott Williams & Wilkins, 2001:63-67.
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Otsuka NY, Kasser JR. Supracondylar fractures of the humerus in children. J Am Acad Orthop Surg 1997;5:19-26.
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Reitman RD, Waters P, Millis M. Open reduction and internal fixation for supracondylar humerus fractures in children. J Pediatr Orthop 2001;21:157-161.
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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;89(4):713-717.