Analysis of factors leading to open surgery in pediatric supracondylar humeral fractures: A retrospective study

INTRODUCTION

A supracondylar humeral fracture (SHF) constitutes a fracture of the distal humerus proximal to the elbow joint. It represents one of the most prevalent types of elbow fractures in the pediatric population, accounting for approximately 17% of all childhood fractures.^[1] The highest incidence is observed in children aged 5–6 years.^[2] These injuries typically result from a fall onto an outstretched hand with the elbow maintained in full extension.^[3] Fracture characteristics, including type and displacement severity, are systematically classified using the Modified Gartland Classification system.^[4]

The primary surgical approaches for managing displaced pediatric SHF are closed reduction with percutaneous pinning (CRPP) and open reduction with internal fixation (ORIF). Current literature supports CRPP as the initial intervention, reserving ORIF for cases in which closed reduction proves unsuccessful or when the fracture is complex.^[5-8] The choice of operative method significantly impacts functional outcomes, complication rates, and rehabilitation timelines. Open reduction is predominantly indicated in cases exhibiting severe displacement (Gartland type IV), obesity, concomitant nerve and vascular injuries, failed closed reduction attempts, or certain fracture patterns such as flexion-type fractures, coronal displacement exceeding 4 mm, or anterior spikes.^[5–7,9,10] While open reduction is typically employed for complex or irreducible fractures, current evidence suggests that its application does not appreciably escalate the incidence of major complications. Nevertheless, it may be associated with longer hospital stays and higher healthcare costs.^[9]

This study aimed to systematically collect and analyze data on pediatric SHF cases classified as types III and IV according to the Modified Gartland system in a tertiary-care setting in an urban area. The primary objective is to identify patient- and fracture-specific risk factors associated with unsuccessful closed reduction, which subsequently necessitate open reduction. The findings were intended to enhance clinical decision-making and serve as a valuable predictive resource for orthopedic surgery residents, particularly those with limited experience in managing these injuries.

MATERIALS AND METHODS

This study analyzed data extracted from the electronic medical records of patients younger than 15 years diagnosed with SHF and treated with pin fixation at our institution between January 2012 and December 2023. As the primary tertiary referral center in Bangkok, Thailand, our hospital offers comprehensive orthopedic care to a diverse pediatric population. The exclusion criteria included patients with open fractures, those requiring urgent open surgical intervention, such as cases complicated by vascular compromise or neurovascular injury after initial reduction, and patients whose radiographs were non-diagnostic due to poor image quality.

The collected data comprised demographic variables (age, sex, affected side, body weight, and body mass index [BMI]); injury-related details (mechanism of injury and time from injury to surgery); and surgical information (operating surgeon, operative reports, and type of reduction performed). A high-energy mechanism of injury was defined as trauma resulting from events such as falls from playground structures, bicycle or skateboard accidents, traffic collisions, or falls from a substantial height. Conversely, a low-energy mechanism of injury was defined as trauma sustained from ground-level falls (e.g., tripping while standing or walking) or minor falls from low surfaces, such as chairs or short tables. We performed a closed reduction under general anesthesia with fluoroscopic guidance, then applied longitudinal traction to correct the coronal translation of the distal fragments. Then, we flexed the elbow under anterior force to correct the sagittal deformity. An open lateral approach was used for direct reduction when closed reduction was inadequate. Two divergence K-wires via lateral entry were used for fixation; if the fracture was still unstable, a third K-wire via medial entry was placed. The procedures were performed by senior orthopedic residents or consultant surgeons at our institution. Each consultant has a distinct subspecialty within orthopedics, and case assignments were made based on their clinical duties and areas of expertise.

Additionally, radiographic parameters recorded included the degree and direction of displacement, fracture morphology, and whether the fracture line occurred distal to the medial and lateral epicondyle lines. Displacement severity was classified according to the Modified Gartland system, with particular emphasis on type III fractures, which involve disruption of the posterior hinge. These fractures display a wide range of displacement, from minimal to severe. Severe displacement was defined as the anterior cortex of the distal fragment being displaced beyond the posterior cortex of the proximal fragment [Figure 1]. Statistical analyses were conducted using STATA (StataCorp LLC, College Station, TX, USA) version 13. Continuous variables were compared between two groups: patients who achieved successful closed reduction and those who required open reduction, using independent t-tests. Logistic regression analysis was used to identify variables significantly associated with the need for open reduction. An initial univariate analysis assessed each potential risk factor separately, using a significance threshold of P < 0.10 to select variables for further analysis. Those variables meeting this criterion were then included in a multivariate logistic regression model. A P < 0.05 was considered statistically significant. Results are reported as odds ratios (ORs) with 95% confidence intervals (CIs), providing a measure of the strength and precision of each association.

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Figure 1:

Both pictures were diagnosed as a supracondylar fracture, Gartland’s type III. Picture (A) has significant displacement that distal fragments displace beyond the line of the posterior cortex of the shaft of the humerus, but picture (B) shows less displacement of distal fragments.

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RESULTS

A total of 139 patients diagnosed with SHF were managed with K-wire fixation. Among these, 92 patients were classified as Gartland type III or IV based on initial radiographic assessment, comprising 85 type III cases and 7 type IV cases. A successful CRPP was achieved in 66 patients (72%). However, 22 type III fractures and 4 type IV fractures required open reduction, corresponding to rates of 25.88% and 57.14%, respectively. Regarding age-related trends, among the 64 patients younger than 8 years, 22 necessitated open reduction. Conversely, in the cohort aged 8 years or older (n = 28), only 4 required open reduction. Notably, six patients presented with a pucker sign, and four ultimately underwent open reduction (4 of 6 cases).

Severe displacement on the initial radiograph was associated with open reduction in 19 of the 33 cases (73.1%). Of these 33 patients, 27 were classified as type III and 6 as type IV. The mean fracture gap measured 21.23 mm in the open reduction cohort, compared to 9.97 mm in the closed reduction cohort. No statistically significant differences were observed between the groups regarding BMI proportions, nerve injury incidence, or surgeon experience level. The mean interval from injury to surgical intervention was 14.9 h in the open reduction group and 14.6 h in the closed reduction group. Additionally, no vascular injuries were reported, and none of the 3 patients with flexion-type fractures required open reduction [Supplementary Table 1], [Figure 2].

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Figure 2:

Percentage distribution of categorical variables between closed and open reduction groups. BMI: Body mass index

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Univariate regression analysis identified several potential predictors of closed reduction failure, including age <8 years (P = 0.057), high-energy injury mechanisms (P = 0.069), presence of the pucker sign (P = 0.051), posteromedial or posterolateral displacement (P = 0.004 and P = 0.025, respectively), and the severity of fracture displacement (P < 0.001). However, Gartland type IV was not identified as a potential risk factor for requiring open reduction (ORs = 3.81, P = 0.108). Multivariate logistic regression analysis demonstrated that two factors remained independently significant predictors of unsuccessful closed reduction: severe displacement on initial radiograph, which conferred a 9.12-fold increased risk of requiring open reduction (95% CI 2.37–35.14, P < 0.001), and age under 8 years, associated with a 6.36-fold increased risk (95% CI 1.25–32.31, P = 0.026) Supplementary Table 2. Although high-energy injury mechanisms, presence of the pucker sign, and displacement direction showed trends in univariate analyses, they did not attain statistical significance in the multivariate model. The primary reasons for failure of closed reduction included soft-tissue interposition, documented in four cases, which precluded adequate alignment; four of the seven Gartland type IV fractures underwent ORIF because the reduction could not be maintained; and other cases with undocumented etiologies that led to unacceptable joint alignment.

DISCUSSION

SHFs are common injuries in the pediatric population. Although most cases can be successfully managed with CRPP, a subset requires open reduction. At our institution, the proportion of cases requiring open reduction remains relatively high when compared with the reported worldwide rate of 4.2–16%.^[11] This higher rate may be attributed to several factors. First, as a tertiary referral center, our hospital receives many patients with complex or severely displaced fractures, including cases initially managed unsuccessfully elsewhere before referral. Second, the procedures were performed in an academic teaching hospital, where surgical cases are often undertaken by orthopedic residents under supervision. Orthopedic residents may have a lower threshold for converting to open reduction when closed reduction proves technically challenging or prolonged, to minimize anesthesia time and potential complications. Third, soft tissue swelling and delayed presentation, both common among referred patients, can further complicate fluoroscopic visualization and fragment manipulation, thereby increasing the likelihood of conversion to open reduction. These institutional and case-mix characteristics likely account for the higher proportion of open reductions observed in this series.

Our findings indicate that the most significant predictor of open reduction is severe displacement. Specifically, this refers to extension-type III or IV SHF in which the anterior cortex of the distal fragment is displaced beyond the line of the posterior cortex of the proximal fragment. The odds of requiring open reduction are increased more than ninefold in these cases. This aligns with prior research,^[7,8,10,12] which shows that severe displacement creates complex fracture patterns that are difficult to realign through closed methods. Contributing factors include fracture rotation, sharp angulation, significant translation, and soft-tissue interposition, all of which hinder the achievement and maintenance of proper alignment with minimally invasive techniques. Fragments that are rotated or sharply angulated are especially challenging to manipulate without direct visualization.^[6,7,10,13] Although type IV fractures generally represent a greater degree of instability than type III, in our series, 3 of the 7 type IV fractures were successfully managed with closed reduction, and univariate analysis did not identify type IV as a significant risk factor for requiring ORIF because only 7 cases were included, limiting the statistical power. This observation likely reflects case distribution and fractured behavior rather than classification severity alone. Specifically, the small number of type IV cases limited statistical power, whereas severely displaced type III fractures often exhibited rotational deformity or soft-tissue interposition, making closed reduction technically more difficult.

Additionally, multivariate analysis revealed that children under 8 years old have a more than sixfold increased risk of requiring open reduction. This finding contrasts with previous studies, including a large retrospective analysis of children aged 3–12 years, which reported that older children had a slightly higher risk, while an age <8 years was not identified as a significant factor.^[12] A recent meta-analysis supports the view that factors such as obesity, nerve injury, and severe displacement are the primary predictors of the need for open reduction, rather than age alone.^[9] The reason may be because of the small number of cases when compared to previous studies, or one possible explanation for this is that, in children under 8 years, ongoing skeletal development, characterized by more open growth plates and less ossified structures, may contribute to increased fracture complexity and instability. These intrinsic factors make closed reduction more technically challenging. Additionally, initial soft tissue swelling and injury can obscure fracture visualization, complicate stabilization and often necessitating surgical exposure for definitive repair.

CONCLUSION

This study identified severe displacement in SHF and age under 8 years as key predictors for the need for open reduction. Recognizing these factors can aid in preoperative planning and decision-making. Despite limitations related to its retrospective design and record completeness, the findings provide valuable insights to inform improved management strategies and resident training.