The one-stage procedure for treatment of older developmental dislocation of the hip (DDH) is used widely. However, the best age group for this operation is still unknown. The aims of our study were to evaluate middle-term outcomes of one-stage surgical treatment of a large number of patients with late-diagnosed DDH, and to explore the best age group for treatment. We retrospectively reviewed 652 patients with a total of 864 hip joints with DDH, all aged >18 months. All the hip joints were treated with one-stage procedures including open reduction, pelvic osteotomy, and femoral shortening. The patients were divided into three groups according to age at surgery: Group I: 1.5–2.5 years; Group II: 2.5–8 years; and Group III: >8 years. The latest clinical and radiographic outcomes, complications and avascular necrosis (AVN) of the femoral head were evaluated and compared among the three groups. The mean age at surgery was 5.8 years (range: 1.5–13.2 years). The average time of follow-up was 6.2 years (range: 3.2–8.9 years). A total of 79.4% of good or excellent outcomes were obtained for clinical functional evaluation according to the McKay classification. For radiographic outcomes, 732 hips (84.7%) were classified as good or excellent according to the Severin classification. A total of 27.4% of all hips had a poor outcome according to the Kalamchi and MacEwen classification for AVN. The poorest outcomes were observed for clinical, radiographic and AVN results in Group III (p < 0.001). Compared with Group I, the better results for clinical and AVN outcomes were found in Group II (p < 0.001). However, similar clinical outcomes were observed between Groups I and II (p > 0.05). A significantly higher incidence of redislocation and residual acetabular dysplasia was observed in Tonnis grade II and III hip dislocation (p < 0.001). One-stage treatment of late-diagnosed DDH had a good outcome in young and middle group. Younger patients achieved better results than older patients. However, the best age group was 2.5–8 years. Tonnis grade II and III DDH is a risk factor for redislocation and residual acetabular dysplasia after the one-stage operation.

Background: Ulnar lengthening is a consensus treatment for hereditary multiple exostoses with radial head dislocation in pediatric patients; however, the optimal amount of ulnar lengthening remains unclear. It is necessary to look for a parameter to decide the amount of ulnar lengthening that will avoid recurrence and complications. The purpose of the present study was to confirm that proportional ulnar length (ulnar length/radial length) can be used as a scale for ulnar lengthening in pediatric patients. Methods: The normal lengths of the ulna and radius in the pediatric population were measured in different age groups. The proportional ulnar length was calculated as ulnar length/radial length in each group. Thirty forearms in 26 patients with radial head dislocation were treated with ulnar lengthening and deformity correction. The goal of ulnar lengthening was to recover the normal proportional ulnar length. The function of the forearm was evaluated at the time of the latest follow-up. The preoperative and postoperative values for radial bowing, radioarticular angle, ulnar variance, and carpal slip were also compared. Results: The value of proportional ulnar length in the normal population consistently averaged approximately 1.1. In all cases, proportional ulnar length recovered to the normal value of 1.1. Reduction of the dislocated radial head was achieved in 28 forearms (93%); in 16 of these forearms, good-quality reduction was achieved and no recurrence of radial head dislocation was observed during follow-up. The function of the forearm improved markedly (p < 0.001). Ulnar variance improved from 2.51 to −0.79 cm (p < 0.001). Radial deformities improved according to measurements of radial bowing and the radioarticular angle (p < 0.001). All parents were satisfied with the postoperative appearance and function of the forearm. Conclusions: Proportional ulnar length could be used as a scale to decide the amount of ulnar lengthening for radial head dislocation in pediatric patients with hereditary multiple exostoses. Ulnar lengthening according to proportional ulnar length and deformity correction can prevent recurrence of ulnar variance and avoid impingement of the wrist. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: The treatment of congenital pseudarthrosis of the tibia (CPT) remains a challenge because of the difficulties of achieving and maintaining bone union, as well as complications of joint deformity and limb-length discrepancy. The purpose of this study was to evaluate the efficacy of cross-union of the tibia and fibula in achieving union and preventing refracture for patients with refractory CPT as a complementary approach to improve upon conventional surgical treatments. Methods: A retrospective study including patients with refractory CPT who attended our department between June 2014 and August 2020. Eighteen CPT patients, who had sustained refracture that required cast immobilization or secondary surgery, and were managed by pseudarthrosis resection, cross-union of the tibia and fibula, bone morphogenetic protein-2 and autogenous iliac bone grafting, were included. Clinical outcomes of the bone union rate and the frequency of refracture after performing cross-union of the tibia and fibula were assessed during the follow-up period. Results: The mean follow-up period was 4.3 years (range: 1.5 to 6.25 y). The mean age of the patients at surgery was 5.4 years (range: 2.6 to 10 y), and all 18 (100%) of the 18 patients had final healing at the site of pseudarthrosis. The average time spent to achieve radiologic bone union of the pseudarthrosis after operation was 2.96 months (range: 2.2 to 4.1 mo). Two (11.1%) patients had an average 2.5 cm limb-length discrepancy, none (0%) sustained refracture which needed cast immobilization or secondary surgery. Patients were all pain-free and move actively. Conclusions: Cross-union of the tibia and fibula is a promising complementary procedure for treating refractory CPT patients. Level of Evidence: Level IV—case series.

Osteosarcoma is the commonest malignant bone tumour in children, with a poor prognosis due to limited treatment options. Antibody–drug conjugates (ADCs) offer targeted therapeutic potential but are limited by the low expression of specific antigens like disialoganglioside (GD2) on osteosarcoma cells. This study aimed to enhance the efficacy of an anti-GD2 ADC by combining it with the enhancer of zeste homolog 2 (EZH2) inhibitor tazemetostat to upregulate GD2 expression and improve treatment outcomes. We constructed an ADC by conjugating naxitamab to mertansine (DM1) via an SMCC linker. Human osteosarcoma cell lines (U2OS and 143B) were treated with tazemetostat to increase GD2 expression. In vitro experiments included apoptosis assays, gene expression analysis, and flow cytometry. We evaluated in vivo efficacy in mouse xenograft models by measuring tumour growth and pulmonary metastases. Tazemetostat treatment significantly increased GD2 expression in U2OS and 143B cell lines. The anti-GD2 ADC induced apoptosis via the mitochondrial pathway, as shown by increased expression of apoptosis-related genes and higher apoptosis rates. In vivo, the ADC significantly inhibited tumour growth and reduced pulmonary metastasis. These therapeutic effects were further enhanced when the ADC was combined with tazemetostat. Combining anti-GD2 ADC therapy with EZH2 inhibition effectively improves targeted treatment for osteosarcoma. Tazemetostat upregulates GD2 expression, enhancing the ADC’s efficacy. This dual-approach strategy demonstrates the potential of integrating epigenetic modulation with targeted drug delivery, offering a promising path for improving outcomes in hard-to-treat cancers.

Objective: This study aimed to compare limited open reduction and transepiphyseal intramedullary fixation with Kirschner wire (LOR-TIKW) versus open reduction and internal fixation with plate and screw (ORIF-PS) for treatment of irreducible distal radius diaphyseal–metaphyseal junction (DMJ) fracture in older children.Methods: Data of children (aged 10–14 years) treated in our hospital for distal radius DMJ fractures with LOR-TIKW or ORIF-PS from January 2018 to December 2019 were retrospectively analyzed. Follow-up was until radiographic union. Demographic, clinical, and radiographic data; treatment cost; healing time; functional outcome (by Price criteria); complications; and postoperative angulation and displacement were compared between children treated by the two methods. Statistical analysis was performed with alpha set at P < 0.05.Results: A total of 26 children were included: 14 treated with LOR-TIKW and 12 with ORIF-PS. Operation time was less (22.1 min vs. 46.7 min, P < 0.0001), surgical incision smaller (2.43 cm vs. 5.00 cm, P < 0.0001), cost of internal fixation lower (US$, 40.6 vs. 2020, P < 0.0001), and healing time shorter (4.79 weeks vs. 5.64 weeks, P = 0.03) with LOR-TIKW; however, postoperative fracture angulation was slightly larger (1.07° vs. 0.83°, P = 0.85) and displacement slightly more (0.86 mm vs. 0.58 mm, P = 0.44) in the LOR-TIKW group. Rate of union, functional outcome, and complications were not significantly different between the groups.Conclusion: For irreducible DMJ fracture of distal radius in older children, LOR-TIKW appears to be a promising method with several advantages over ORIF-PS.

Pediatric desmoid tumor (PDT) is rare and has a high local recurrence rate. The purpose of the present study was to analyze clinical risk factors of local recurrence in PDT patients. We reviewed clinical data of 66 PDT patients from 2004 to 2015. All patients underwent macroscopically complete resection, and some recurrent tumors were prescribed radiotherapy. Factors such as sex, age at presentation, location, and proximity to nerves or vasculature were analyzed. The local recurrence rate and recurrence-free survival were analyzed with these factors. All patients in the present study were children and had extra-abdominal tumors. The median follow-up time was 6.6 years. Thirty-six (55%) patients had local recurrence. Age, sex, tumor site, tumor size, and proximity to nerves/vasculature had a significant impact on prognosis in univariate analysis. Radiotherapy decreased the local recurrence rate. In multivariate analysis, younger age, tumor location in buttocks, larger tumor, and proximity to important nerves/vasculature were independent risk factors for poor prognosis. Favorable therapeutic strategies could be selected according to the preoperative prognostic risk factors. Radiotherapy should be considered for local recurrence of PDT.