The Integrity of Cartilage Hinge in Song 2/3 Lateral Humeral Condylar Fractures in Children: A Retrospective Radiological Study in Two Centers. Issue 8 (22nd June 2022)

• Record Type: Journal Article
• Authors: Zhu, Tong; Jia, Guoqiang; Jin, Bin; Liu, Tianjing; Ma, Shuyu; Chen, Jiayuan; Wang, Enbo
• Is Part Of: Orthopaedic surgery. Volume 14:Issue 8(2022)
• Page Start: 1656
• Page End: 1662
• Publication Date: 2022-06-22
• Subjects: Cartilage hinge -- Humerus -- Lateral condylar fracture -- Magnetic resonance imaging -- Stability; Orthopedic surgery -- Periodicals; Orthopedics -- Periodicals; Musculoskeletal system -- Wounds and injuries -- Periodicals; 617.47005
• DOI: 10.1111/os.13371
• Languages: English
• ISSNs: 1757-7853

Abstract

Abstract : Objective: For pediatric lateral condylar fractures (LCFs) of the humerus, it is often hard to determine the stability of the fracture based on the Song classification, especially for those categorized as Song stages 2 and 3. This study aims to define the characteristics of cartilage injury and assess the stability of LCFs classified as Song stages 2 and 3 on post‐traumatic magnetic resonance imaging (MRI). Methods: This was a retrospective study based on imaging data, conducted with a short follow‐up period. From January 2016 to May 2019, data of all patients with Song 2 and Song 3 LCFs treated at two institutions were collected. Based on the inclusion criteria, a total of 62 patients with Song stage 2/3 LCF were included. All radiographs were selected for observation and classification for comparison by two observers, both experienced pediatric orthopedic surgeons. MRIs scans for comparison were analyzed in three consecutive coronal sections and cross‐sections. Patients were treated conservatively with casting or surgically with closed reduction and percutaneous pinning (CRPP). Results: Altogether 62 cases between 1.5 to 9 years old were included. Reliability analysis revealed poor, moderate, or good agreement between the two observers (range, 0.149–0.633). Both observers showed moderate or good consistency (range, 0.413–0.611). Among the 62 patients diagnosed with Song stages 2 and 3 fractures on initial radiographs, only two patients (3%) had complete fractures with complete disruption of the cartilage hinge as seen on MRI. The hinge was generally located in the posterior‐inferior region of the distal humeral cartilage as indicated on MRI. There was no significant difference between Song stages 2 and 3 with regard to ratio of hinge to total values in any cross‐sections, nor was there any significant difference in the completeness of the coronal sections ( P > 0.05). Of the 62 patients treated, 50 were managed conservatively with casting and 12 underwent CRPP. Forty‐nine of the remaining 60 patients (97%) with incomplete fractures were managed conservatively, while the remaining 11 patients were managed with CRPP. All patients with incomplete fractures showed bone healing and no evidence of lateral condyle displacement on follow‐up radiographs. Conclusions: The Song stage 2 or 3 classification is not entirely accurate and is inadequate at guiding treatment outcomes. The cartilage hinge was most likely located posteroinferiorly within the distal humeral epiphysis. According to our findings, conservative treatment with an effective cast or splint may be sufficient for bone healing in case of incomplete cartilage fractures. Abstract : Pediatric surgeons often find it difficult to tell whether a humeral lateral condylar fracture is stable or not according to radiographic findings, especially those classified as Song types 2 and 3. The purpose of this study was to describe magnetic resonance imaging(MRI) manifestations of Stage2/3 fractures of Song classification in lateral condylar fracture (LCF) in children. Altogether 62 such cases were included in this study. The inter‐ and intra‐observer reliability was moderate. The integrity of cartilage, as seen in MRI, was not related to the Song classification. The cartilage hinge that stabilized the distal fragment generally located in the posterior‐inferior region of the distal humeral cartilage. For cases with incomplete cartilage fractures, conservative treatment with an effective cast or splint would be probably sufficient for bone healing of LCFs. While for cases with complete cartilage fractures, displacement may happen when mis‐diagnosed as stable LCF and timely healing cannot be guaranteed.