Determining the development stage of the ossification centers around the elbow may aid in deciding whether to use ESIN or not in adolescents' forearm shaft fractures

Abstract

Background and purpose - Elastic stable intramedullary nailing (ESIN) is the preferred method of operative stabilization of unstable pediatric forearm shaft fractures. However, the decision whether to use ESIN or open reduction and internal fixation (ORIF) in older children or teenagers is not always straightforward. We hypothesized that the development stage of the elbow would aid in evaluating the eligibility of the patient for ESIN.Patients and methods - All eligible children, aged <16 years who were treated with ESIN in Oulu University Hospital, during 2010-2019 were included (N = 70). The development stages of 4 ossification centers were assessed according to the Sauvegrain and Diméglio scoring. The proportion of impaired union vs. union was analyzed according to bone maturity, by using the optimal cutoff-points determined with receiver operating characteristics (ROC).Results - Development stage ≥ 6 in the olecranon was associated with impaired union in 20% of patients, compared with none in stages 1-5 (95% CI of difference 8% to 24%). Trochlear ossification center ≥ 4 was associated with impaired union in 17% of patients (CI of difference 7% to 36%) and lateral condyle ≥ 6 in 13% of patients (CI of difference 3.4% to 30%). Proximal radial head ≥ 5.5 was associated with impaired union in 18% of patients (CI of difference 7% to 39%).Interpretation - Recognizing the rectangular or fused olecranon ossification center, referring to stage ≥ 6, was in particular associated with impaired fracture healing. This finding may aid clinicians to consider between ESIN and plating, when treating forearm shaft fracture of an older child or teenager.

Figure 1.

Modified illustration of the Sauvegrain and Dimйglio classification of maturation of the secondary ossification centers around the elbow. This staging was used in this research to find the optimal cutoff-point for (A) olecranon, (B) proximal radial head, (C) lateral condyle of the humerus, and (D) trochlea of the humerus.

Figure 2.

The elbow has been captured on the lateral view of the forearm radiograph and the secondary ossification center of the olecranon has been marked with a border (dotted line). The patient is a male aged 12. According to the Sauvegrain and Dimйglio method the olecranon ossification stage with a rectangular shape is 6. This stage was found to be a cutoff point in association with disturbed bone union after ESIN of forearm shaft fracture.

Figure 3.

Optimal cutoff points (lines) of Sauvegrain and Dimйglio stages, according to area under receiver operating curve (ROC). Green dots are the fractures that united and red dots are the fractures that showed impaired union.