Reliability of Radiographic Union Score and correlation of clinical outcomes in children operated for supracondylar humerus fracture: A prospective study

To the editor,

The study was conducted at a university hospital and included patients from all surrounding areas, both near and far. The fact that the median follow-up appointments were slightly longer than the nominal 2- and 4-week periods reflects real-life factors, such as personal reasons affecting families’ hospital visit dates, transportation difficulties for patients coming from distant regions, and challenges in patient follow-up during the pandemic at the end of the study. Because prospective studies may require extended follow-up, it is important to minimize loss to follow-up. These patients were included to minimize loss to follow-up, but our average follow-up periods are clearly stated in our article. K-wire removal was performed on average day 34, and the fact that this period was slightly later than our recommendation was explained in the discussion section. Nevertheless, it is consistent with the recommended times in the literature and clinical practice. Of course, age can affect the union process. However, the primary purpose of this study was not to produce estimates based on age, but to evaluate the reliability of the Radiographic Union Score for Tibial Fracture (RUST) score. We believe that subgrouped analyses by age will add value to future studies. The postoperative protocol for pediatric supracondylar humerus fractures remains controversial and may involve some variation. ¹ In our protocol, we ensure adequate intraoperative fixation and perform postoperative radiographic checks. We also use a long-arm splint to reduce loss of reduction. We recommend dressing changes every other day and recommend follow-up visits if wound problems are noted. At the 2-week follow-up, we temporarily remove the splint, perform radiographic checks, and evaluate RUST scores. We also remove sutures from patients who underwent open surgery.

Bernthal et al. report that lateral condylar fractures have a slower rate of elbow motion recovery compared to supracondylar humerus fractures. ² The differences in mechanical properties, etiology, and healing potential between supracondylar humerus fractures and lateral condylar fractures, as well as the intra-articular nature of lateral condylar fractures, are hypothesized to play a role in the slower recovery of elbow motion. In their study examining the recovery of elbow motion in children after supracondylar humerus fractures, Spencer et al. reported that the absolute arc of motion reached 90% at 9 weeks. ³ In our study, at the third follow-up, the mean ROM was 120% in closed surgery patients and 110% in open surgery patients, which is consistent with the literature.

Our study used the full version of the Modified Gartland classification, which also includes type 4 fractures.^4,5 There was no methodological confusion in this regard. The Johns Hopkins classification provides a detailed description of fracture morphology. However, the widely used Modified Gartland classification, which has high observer agreement, was preferred in our study.

Our aim is not to present a specific RUST–ROM correlation, but to demonstrate the parallel recovery trend in both parameters. The RUST score was used to evaluate union radiologically, and the Flynn criteria were used to evaluate union functionally. In the editorial letter, it was claimed that the Flynn score distribution in our study was inconsistent with the normative Range of Motion (ROM) data published by McKay et al. (2017). ⁶ However, this comparison lacks context and is misleading. The McKay study reports the muscle strength and range of motion of 1000 healthy individuals who had not undergone trauma or surgery. Our study, however, evaluates postoperative recovery in children who underwent surgery for supracondylar humerus fractures.

The Flynn criteria are a reliable and clinically validated scale used for years to assess functional and cosmetic outcomes in pediatric orthopedics. This scoring focuses on the patient’s return to activities of daily living and the degree of functional gain. However, McKay’s references represent “maximum physiological values” for a completely healthy population.

In the vast majority of our patients, ROM gains were observed at the expected level for postoperative recovery within 2 months, as evaluated in accordance with the Flynn scores. Expecting 130°–140° of flexion during post-traumatic recovery is unrealistic, and achieving this degree in clinical practice can take months. Therefore, a one-to-one comparison of Flynn scores with McKay’s healthy population data is scientifically and methodologically inappropriate.

The purpose of this study was to demonstrate the intraobserver and interobserver reliability of the RUST score in the radiological healing of supracondylar humerus fractures. Our results demonstrate the utility of the RUST score in this patient group. Larger sample sizes and multicenter studies are necessary for the development of clinical algorithms.

Supplemental Material

sj-pdf-1-cho-10.1177_18632521251370879 – Supplemental material for Reliability of Radiographic Union Score and correlation of clinical outcomes in children operated for supracondylar humerus fracture: A prospective study

Supplemental material, sj-pdf-1-cho-10.1177_18632521251370879 for Reliability of Radiographic Union Score and correlation of clinical outcomes in children operated for supracondylar humerus fracture: A prospective study by Uğur Yüzügüldü, Murat Yeşil, Özal Özcan, Gökhan Maralcan and Mehmet Nuri Konya in Journal of Children's Orthopaedics