Changes in Management Based on X-rays after Pinning of Supracondylar Humerus Fractures: Rare, but More Common in Complex Injuries.

Purpose: Clinical practice, including utilization of postoperative x-rays, may vary after pinning of supracondylar humerus fractures in children. The purposes of this study were to: (1) evaluate the frequency at which postoperative radiography resulted in management changes and (2) determine risk factors for such changes, as previous studies may be underpowered for such analyses.

Methods

This retrospective cohort study included skeletally immature patients that underwent pinning of a supracondylar humerus fracture at four tertiary children's hospitals. Skeletally mature patients or those requiring fixation with implants other than pins were excluded. Pre-, intra-, and postoperative data was collected, with attention to the frequency of postoperative x-rays as well as management changes based on such imaging. Statistical analysis included independent samples t-tests, chi-square tests, or Fisher exact tests, as appropriate.

Results

A total of 6151 postoperative x-rays were obtained in 2929 patients (mean 2.1±0.9 per patient). Specifically, 1523 (52.0%) patients had imaging taken at a visit prior to the date of pin removal, 2814 (96.1%) on the date of pin removal, and 1416 (48.3%) after the date of pin removal. Eighteen patients experienced 28 changes in clinical management based on postoperative films: 15/2929 (0.5%) on early imaging prior to pin removal, 11 (0.4%) at the time of pin removal, and 2 (0.1%) after pin removal. Compared to those that did not experience a management change based on x-ray, patients with an altered clinical course more frequently had an ipsilateral proximal/diaphyseal forearm fracture (11.5% vs. 0.5%, p<0.001); preoperative deficit of the ulnar (3.8%), posterior interosseous (5.0%), or complete median nerve (2.2% vs. 0.5 %, p=0.04); and more mean total pins placed (3.0±0.3 vs. 2.6±0.6, p<0.001). Similar results were found when evaluating risk factors for imaging-based management changes at specific time periods (before, during, and after pin removal).

Conclusion

Plain radiography is obtained frequently after pinning of pediatric supracondylar humerus fractures. This results in management changes 0.5% of the time or less, calling into question the utility of postoperative x-rays when weighed against time, cost, and radiation risk. Patients that experienced imaging-based management changes were more likely to have an ipsilateral forearm fracture, uncommon nerve palsy, or received more pins, suggesting a more complex initial injury in these children. Significance: This large, multicenter study found the rate of management changes based on postoperative x-rays to be 0.5% or less in children with supracondylar humerus fractures. Such alterations were more likely to occur in patients with complex injuries. For uncomplicated fractures, surgeons should consider the implications of postoperative x-rays on cost, radiation, and resource utilization.