Rationale

The gold standard in the treatment of displaced pediatric supracondylar humerus fractures is closed reduction with percutaneous pinning. However, there are supracondylar humerus fractures that necessitate an open reduction.

Clinical comment

An open reduction is indicated in the following situations:

• Unable to obtain an acceptable alignment of the fracture fragments using closed reduction.
• Open fracture.
• Compartment syndrome.
• Vascular injury
  • Hand is poorly perfused following reduction and fixation.
• Change in neurologic exam or vascular exam (for the worse) following closed reduction of a supracondylar fracture.

Findings

According to Holt et al., nationally 24% of children with supracondylar humerus fractures undergo surgery in the US. Among surgically treated supracondylar humerus fractures, there is a 12.7% rate of open reduction. They also found that, as displaced supracondylar fractures are more often being transferred to tertiary care facilities and being treated by fellowship‐trained pediatric orthopedic surgeons, the rates of performing open reductions are trending down.¹ In another study of pediatric closed type III supracondylar humerus fractures, there was a 9.4% rate of conversion following an attempted closed reduction to an open reduction,²,³ Novais et al. in their retrospective review found that the incidence of conversion from closed to open reduction was 7%. Among those treated with ORIF, the indication in the majority (93%) of cases to convert to open treatment was secondary to irreducibility of fracture fragments – 40% due to fracture instability, 36% secondary to brachialis interposition, 16% due to periosteal interposition, and 8% secondary to triceps interposition. In those children where the indication to convert to open reduction was secondary to change in vascular status after attempted closed reduction, neurovascular structures were entrapped at the fracture site.⁴

In a retrospective review of 236 surgically treated type III supracondylar fractures at a single institution, Pesenti et al. noted that the low‐volume surgeons (treating less than five type III supracondylar fractures/year) had a higher frequency of performing open reduction and had worse postoperative radiographic alignment than those fractures treated by higher volume surgeons. This same study also demonstrated that there is a learning curve of approximately 20 patients with supracondylar humerus fractures treated surgically (close or open reduction) to positively impact operative time and radiographic outcomes.⁵

The flexion type supracondylar humerus fracture is less common than extension type, approximately 5% of supracondylar humerus fractures. The ulnar nerve can be entrapped in the fracture site – causing nerve compromise and blocking reduction. Open reduction should be undertaken if there is a persistent gap at the fracture side or when the fracture gap closes down, but then springs back open: the rubbery reduction.⁶

A retrospective study done by Flynn et al. found that a flexion‐type injury had a 15.4‐fold increase in the odds of open reduction. They also found that if a flexion‐type supracondylar fracture presented with an ulnar nerve injury, there also was a 6.7‐fold additional higher risk of open reduction. This study brought to light the need to counsel patients and families preoperatively regarding the increased rate of performing an open reduction in these specific situations and to prepare the operating room appropriately.⁷

Based on the available evidence, the need for open versus closed reduction techniques is not a predictor of clinical outcome.² Studies have failed to demonstrate clinically significant differences in outcome when comparing open reduction to closed reduction of displaced supracondylar humerus fractures. Clinical outcome is most often assessed using Flynn’s criteria⁸ and are comparable in final radiographic alignment and range of motion.⁹,¹⁰ The only differences between the two approaches was a longer surgical time and a larger scar in those who underwent open reduction.⁹

Rationale

The “best” approach is controversial. For closed fractures, there is literature to support the use of anterior, medial, lateral, and posterior approaches.

Clinical comment

Open fractures, which account for 1% of supracondylar humerus fractures, obviate the decision of the preferred surgical approach.²,¹¹ The zone of injury allows for direct visualization and decompression of the fracture, often utilizing an extension of the traumatic wound.

Findings

A principle to keep in mind is that the incision for open reduction of supracondylar humerus fractures is dictated by the location of the distal metaphyseal spike of the proximal fragment. Make a direct approach that is centered over the prominent metaphyseal spike as this is where the overlying periosteum or muscle (most often brachialis) is most likely entrapped and blocking the reduction⁶,¹⁰ By choosing the incision based on the location of the metaphyseal spike, one avoids disruption of the remaining intact periosteum, which acts as a periosteal hinge. Otherwise, one risks further destabilization of the fracture fragment or interruption of blood supply to the distal fragment.¹⁰,¹² We believe that this surgical approach is logical when the indication for an open reduction is an inability to obtain an acceptable close reduction.