IntroductionCannulated screws are widely used in pediatric orthopedic fixation. However, traditional screw removal requires preoperative x-ray positioning, leading to exposure to ionizing radiation. Sometimes, a larger incision is required, and trauma is a significant cause of x-ray positioning, which cannot be accurately marked on the skin. In this study, we aimed to evaluate the practicability of rapid removal of cannulated screws through a guide needle and small incision using ultrasound (US) guidance to locate the position of the screws accurately.MethodsA retrospective analysis was performed on patients who underwent removal of internal fixation after proximal tibial fracture surgery at our hospital between January 2019 and March 2024. Patients were divided into Group A and Group B based on the different cannulated screw removal techniques. In Group A, the cannulated screws were removed under US guidance, while in Group B, they were removed under direct visualization using a traditional incision. The operative time, blood loss, success rate of removal, radiation frequency, and incision length were statistically analyzed. Knee function was evaluated using the Knee Society Score.Results53 patients aged 15.3 ± 0.1 years were included in this study. Group A showed 50% shorter incision length (1.5 vs. 3.0 cm, p = 0.005) and average screw incisions (0.5 vs. 1.0 cm, p = 0.007), along with complete elimination of preoperative radiation exposure (0 vs. 2 times, p < 0.001) and dose (0 vs. 0.102 mGy, p < 0.001) compared to Group B. Participants in Group A had no postoperative complications, whereas one patient in Group B had an incision infection; however, no significant difference was observed between the groups.DiscussionUS-guided cannulated screw removal can be used in children with proximal tibial fractures, significantly reducing the preoperative radiation time and dose while minimizing the incisional length.Level of evidenceIII

AbstractObjectiveThere is a need today for favorable biomarkers to follow up on the disease progression and therapeutic response in patients with Duchenne muscular dystrophy (DMD). This study evaluates whether quantitative muscle ultrasound (QMUS) or magnetic resonance imaging (MRI) is more suitable for the assessment of DMD in China.MethodsThirty‐six boys with DMD, who were treated with prednisone from baseline to month 12, were enrolled in this longitudinal, observational cohort study. Muscle thickness and echo intensity on QMUS and T1‐weighted MRI grading were measured in the right rectus femoris.ResultsScores for muscle thickness and echo intensity in QMUS and T1‐weighted MRI grading showed significant correlations with the clinical characteristics of muscle strength, timed testing, and quality of life (p < 0.05). Scores for muscle thickness and echo intensity on QMUS also showed good correlations with T1‐weighted MRI grading (p < 0.05). However, 15 of 36 boys with DMD did not undergo MRI examinations for various reasons.ConclusionsQMUS and MRI can be used as biomarkers for tracking DMD to some extent. Both have strengths and weaknesses and the specific needs and goals of the clinical or research project are what make one preferable to the other.

Background To summarize and analyze the epidemiological characteristics, treatment and corresponding curative effect of triradiate cartilage injury(TCI) in children after trauma, to provide a theoretical basis for early diagnosis and improvement of treatment. Methods The TCI was classified according to Bucholz classification, and the final curative effect was evaluated with Harris Hip Score and imaging examination during follow-up. Finally, a comprehensive analysis was made by reviewing the cases in the literature combined with the patients in our hospital. Results A total of 15 cases (18 hips) of triradiate cartilage injuries were collected in our hospital. There was 1 hip with type I injury, nine hips with type II injury, two hips with type IV injury, one hip with type V injury and five hips with type VI injury. Among the 12 cases with complete follow-up, the bone bridge was found in or around the triradiate cartilage in 8 cases, early fusion of triradiate cartilage occurred in 5 patients, 3 cases had hip dysplasia, 4 cases had a subluxation of the femoral head, and HHS was excellent in 8 cases and good in 4 cases. Conclusion The early diagnosis of TCI is still a difficult problem. Conservative treatment is often the first choice. The overall prognosis of acetabular fractures involving triradiate cartilage is poor. The formation of the bone bridge in triradiate cartilage usually indicates the possibility of premature closure, which may lead to severe complications of post-traumatic acetabular dysplasia and subluxation of the femoral head.

Background: The application of external femoral fixation techniques often causes complications of knee flexion dysfunction. We report on technical modifications in the complications of external femoral fixation leading to knee flexion disorders. Methods: We flexed the knee joint 90 degrees during the operation, and then placed the external fixation nail. A retrospective review was performed for all patients undergoing repair by this technique. Results: A total of 52 children with femoral shaft fractures were included, the flexion of the knee joint measured at the time of discharge was 80 degrees (70-90 degrees) on average; when the external fixation is removed, the knee flexion can reach an average of 95 degrees (90-115 degrees), no children have stiff knees. Conclusion: This technique is simple and easy to implement, and it is worthy of popularization and application in clinical practice.

Background: Lateral humeral condyle fractures are the second most common elbow fracture in children. Displaced and rotated fractures require stabilization and reduction. Kirschner wires (K-wires) are most commonly used in the fixation of these fractures. Here, we introduce a new fixation method that uses an absorbable screw. We aim to determine if it is feasible to treat lateral humeral condyle fractures with an absorbable screw by comparing functional outcomes following absorbable screw fixation vs. K-wire fixation. Methods: Between May 2007 and September 2010, 86 patients were treated with absorbable screws (43 patients) or K-wire (43 patients). All patients had been diagnosed with lateral condyle fractures that were classified as either Jacob type II (unstable) or III. One absorbable screw (3.5 mm-diameter) was used for fixation in 1 group, while two 1.6 to 1.8mm K-wires were used in the other group. Patients were followed 6 months about the elbow function according to Broberg and Morrey standard. On 5-7 years, the patients were followed about the carrying angle (valgus deformities and varus deformities), range of motion (flexion loss and extension loss), prominent lateral condyle, symptomatic implants, and fishtail deformity. Results: Anatomic reduction was achieved in all patients. Each group had one radial nerve injury that were present preoperatively. Nerve function recovered spontaneously within 3 to 4 weeks of surgery in both patients. No patient developed necrosis of the capitulum in both groups. Nine patients in K-wires group and 2 in absorbable screw group developed symptomatic implants (P=.048). On the sixth month, there was no significant difference on elbow function according to Broberg and Morrey standard. On 5 to 7 years (average, 6.7 +/- 1.3 years), valgus deformities was 6.8 +/- 1.2 vs 5.7 +/- 0.8, varus deformities was 7.2 +/- 1.5 vs 5.1 +/- 1.9, flexion loss was 12.4 +/- 2.2 vs 9.5 +/- 3.1, extension loss was 11.1 +/- 3.1 vs 10.2 +/- 2.7, prominent lateral condyle was 27.9% vs 37.2%, fishtail deformity was 7.3% vs 4.9%, no significant difference between these groups. Conclusions: Open reduction with absorbable screw fixation is feasible and safe for the treatment of lateral condyle fractures of the humerus in children.

Introduction: In this study we aimed to determine the influence of daily prednisone treatment in Duchenne muscular dystrophy (DMD) by performing a prospective, randomized, placebo-controlled trial in southwestern China. Methods: Sixty-six children with DMD (4-12 years of age) were divided randomly into prednisone and placebo groups. Efficacy and safety of daily prednisone at 0.75 mg/kg/day were evaluated over 12 months by muscle strength and function, quality of life (QoL), quantitative muscle ultrasound (QMUS), and side effects. Results: Significant improvements in muscle strength and function, QoL, and QMUS were observed in the prednisone group compared with the placebo-treated group (P < 0.05). Changes in body weight, height, body mass index, and diastolic blood pressure were similar in both groups (P > 0.05). Conclusions: This pilot study in southwestern China found that daily prednisone at 0.75 mg/kg/day is suitable for children with DMD. It slowed disease progression and improved QoL and QMUS. Moderate side effects were generally well tolerated.

Purpose To evaluate the effectiveness of methylene blue staining during ganglion resection in children, to assess ganglion resection and minimize recurrence.Methods From August 2007 to March 2011, 36 children with dorsal or volar wrist ganglions with an average size of 2 cm (range, 1-4 cm), including 5 recurrent cases, underwent resection performed with intraoperative methylene blue marking of the cyst wall.Results We found recurrence in one patient after 2 years; no obvious complications were observed in any patient.Conclusions Methylene blue staining of the ganglion during resection may be helpful for achieving complete resection. Copyright (C) 2015 by the American Society for Surgery of the Hand. All rights reserved.

Case: A seven-year-old girl presented to the emergency department with severe neck pain and restricted movement of sudden onset. A basic neurological examination supplemented by radiography showed calcification within the intervertebral disc at the C6-C7 level. Computed tomography and magnetic resonance imaging of the spine confirmed the diagnosis and revealed additional calcification within the spine at the C3-C4, C7-T1, T1-T2, T4-T5, and T5-T6 levels. Conclusion: Idiopathic intervertebral disc calcification is a rare condition in children, and its etiology remains unclear. In this report, we present a rare case of idiopathic intervertebral disc calcification at numerous levels in a seven-year-old girl. The clinical and radiographic findings, laboratory examination, and follow-up are discussed.

BACKGROUND:The treatment of radial neck fractures with complete displacement or severe displacement and an angle of >30 degrees is controversial. The currently used methods, including the Metaizeau technique, are associated with drawbacks such as imperfect reduction, epiphyseal damage, and delayed functional recovery. To overcome these drawbacks, we used absorbable rod fixation followed by early functional training for the treatment of displaced radial neck fractures in children.METHODS:In this study, 68 patients (age, 4 to 12 y; average, 8.4 y; average angle, 58 degrees; average displacement, 53%) with radial neck fractures with Salter-Harris grades II to IV underwent lateral elbow open reduction and absorbable rod fixation. At 3 weeks postoperatively, the patients' plaster casts were removed, and functional training was started.RESULTS:Anatomic reduction was achieved in all patients. We followed-up 68 patients for 6 months to 4 years (average, 41 mo). No cases of radial nerve injury, radial bone necrosis, myositis ossificans, and postoperative infection were observed. The functional recovery was "excellent" in 43 patients, "good" in 13 patients, "average" in 12 patients, and "bad" in 0 patients, according to the Morrey evaluation standard.CONCLUSION:Open reduction with absorbable rod fixation for the treatment of displaced radial neck fractures in children was feasible and was a choice in children.LEVEL OF EVIDENCE:Therapeutic II.

Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and play a critical role in skeletal development, bone formation and stem cell differentiation. Disruptions in BMP signaling result in a variety of skeletal and extraskeletal anomalies. BMP9 is a poorly characterized member of the BMP family and is among the most osteogenic BMPs, promoting osteoblastic differentiation of mesenchymal stem cells (MSCs) both in vitro and in vivo. Recent findings from various in vivo and molecular studies strongly suggest that the mechanisms governing BMP9-mediated osteoinduction differ from other osteogenic BMPs. Many signaling pathways with diverse functions have been found to play a role in BMP9-mediated osteogenesis. Several of these pathways are also critical in the differentiation of other cell lineages, including adipocytes and chondrocytes. While BMP9 is known to be a potent osteogenic factor, it also influences several other pathways including cancer development, angiogenesis and myogenesis. Although BMP9 has been demonstrated as one of the most osteogenic BMPs, relatively little is known about the specific mechanisms responsible for these effects. BMP9 has demonstrated efficacy in promoting spinal fusion and bony non-union repair in animal models, demonstrating great translational promise. This review aims to summarize our current knowledge of BMP9-mediated osteogenesis by presenting recently completed work which may help us to further elucidate these pathways.

Mesenchymal stem cells (MSCs) are multipotent progenitors, which give rise to several lineages, including bone, cartilage and fat. Epidermal growth factor (EGF) stimulates cell growth, proliferation and differentiation. EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface and stimulating the intrinsic protein tyrosine kinase activity of its receptor, which initiates a signal transduction cascade causing a variety of biochemical changes within the cell and regulating cell proliferation and differentiation. We have identified BMP9 as one of the most osteogenic BMPs in MSCs. In this study, we investigate if EGF signalling cross-talks with BMP9 and regulates BMP9-induced osteogenic differentiation. We find that EGF potentiates BMP9-induced early and late osteogenic markers of MSCs in vitro, which can be effectively blunted by EGFR inhibitors Gefitinib and Erlotinib or receptor tyrosine kinase inhibitors AG-1478 and AG-494 in a dose- and time-dependent manner. Furthermore, EGF significantly augments BMP9-induced bone formation in the cultured mouse foetal limb explants. In vivo stem cell implantation experiment reveals that exogenous expression of EGF in MSCs can effectively potentiate BMP9-induced ectopic bone formation, yielding larger and more mature bone masses. Interestingly, we find that, while EGF can induce BMP9 expression in MSCs, EGFR expression is directly up-regulated by BMP9 through Smad1/5/8 signalling pathway. Thus, the cross-talk between EGF and BMP9 signalling pathways in MSCs may underline their important roles in regulating osteogenic differentiation. Harnessing the synergy between BMP9 and EGF should be beneficial for enhancing osteogenesis in regenerative medicine.

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OSdirected therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

OBJECTIVE:To investigate an effective therapeutic method for the secondary deformity after the correction of the Wassel type IV thumb duplication.METHODS:9 cases of Wassel W-D Complex thumb deformities in children with postoperative secondary deformity, including 6 males and 3 female, were treated. The age ranged from 2.0 to 14 years old with an average of 5.3 years old. During the operation, the anatomical structure was dissected to observe the structure and alignment of the flexor tendon as well as anatomical structure of the joint. In the meantime, the flexor pollicis longus tendon was shifted, A2 pulley was reconstructed, joint capsule was released and contracted, the end point of thenar was shifted. Kirschner wires fixation were used for about 4-5 weeks, the brace fixation for about 3 months.RESULTS:All the patients had radial side skin contracture of the interphalangeal joint, radial deviation of the thumb tip, radial side contracture and ulnar relaxation of the joint capsule. Flexor hallucis longus tendon was located in front of the radial side of the proximal phalanx, with no wrapped sheath or A2 pulley. Flexor hallucis longus tendon was attached to the thumb tip substrate, of which 1/3 was located in the center and 2/3 in the radial side. The thumb tip rotated about 10 degrees-15 degrees to the radial side. The patients were followed up for 6-38 months, with an average of 24 months. We adopted Tada standard to evaluate the follow-up results as excellent in 7 cases, good in 1 case, poor in 1 case.CONCLUSIONS:Soft tissue reconstruction for the secondary deformity after the correction of the Wassel type IV-D thumb duplication is an effective method. Application of the brace after removal of Kirschner wires has an important role in preventing the secondary deformity.

Mesenchymal stem cells (MSCs) are multipotent progenitors and can differentiate into osteogenic, chondrogenic, and adipogenic lineages. Bone morphogenetic proteins (BMPs) play important roles in stem cell proliferation and differentiation. We recently demonstrated that BMP9 is a potent but less understood osteogenic factor. We previously found that BMP9‐induced ectopic bone formation is not inhibited by BMP3. Here, we investigate the effect of BMP antagonist noggin on BMP9‐induced osteogenic differentiation. BMP antagonists noggin, chording, gremlin, follistatin, and BMP3 are highly expressed in MSCs, while noggin and follistatin are lowly expressed in more differentiated pre‐osteoblast C2C12 cells. BMP9‐induced osteogenic markers and matrix mineralization are not inhibited by noggin, while noggin blunts BMP2, BMP4, BMP6, and BMP7‐induced osteogenic markers and mineralization. Likewise, ectopic bone formation by MSCs transduced with BMP9, but not the other four BMPs, is resistant to noggin inhibition. BMP9‐induced nuclear translocation of Smad1/5/8 is not affected by noggin, while noggin blocks BMP2‐induced activation of Smad1/5/8 in MSCs. Noggin fails to inhibit BMP9‐induced expression of downstream targets in MSCs. Thus, our results strongly suggest that BMP9 may effectively overcome noggin inhibition, which should at least in part contribute to BMP9's potent osteogenic capability in MSCs. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1796–1803, 2013

Oral Diseases (2012) 18, 595–601Objective: The purpose of this study was to determine the bacterial profiles in saliva of the isolated children for studying caries etiology.Materials and methods: Samples were collected from isolated children from 6 to 8 years old including 20 caries‐free (dmfs = 0) (healthy) and 30 caries‐active individuals (dmfs > 8) (patients). 16S rRNA genes were amplified by PCR from bacterial DNA of saliva sample and labeled via incorporation of Cy3‐dCTP in second nested PCR. After hybridization of labeled amplicons on HOMIM, the microarray slides were scanned and original data acquired from professional software.Results: Collectively, 94 bacterial species or clusters representing six bacterial phyla and 30 genera were detected. A higher bacterial diversity was observed in patients than in healthy samples. Statistical analyses revealed eight species or clusters were detected more frequently in diseased patients than in healthy samples, while six different species were detected more frequently in healthy as compared to diseased patients.Conclusion: The diversity of microbe within saliva derived from isolated population increased in caries‐active status, and there are some bacteria in salivary flora can be as candidate biomarkers for caries prognosis in mixed dentition. The imbalances in the resident microflora may be the ultimate mechanism of dental caries.

ObjectiveThis study aimed to identify the oral microbial diversity of healthy Chinese Han children.MethodsDental plaques were sampled from the oral cavity of ten healthy Chinese Han children. The oral microbiome was examined using the 16S rRNA–based Human Oral Microbe Identification Microarray. The microbial diversity and similarity were analyzed using the Chao–Jaccard similarity index.ResultsA total of 112 species, which belonged to nine bacterial phyla and 41 genera, were detected. Each individual harbored an average of 54.1 microbial species (ranging from 37 to 69) and 26.2 genera (ranging from 21 to 31), with interindividual variations both at the species and genus level. Thirteen genera were conserved among all individuals. The Chao–Jaccard similarity index averages, at the genus and species level, were 0.642 (ranging from 0.485 to 0.871) and 0.506 (ranging from 0.338 to 0.676), respectively, suggesting that the healthy oral community was more conserved at the genus level than at the species level.ConclusionAlthough there was interindividual variation in the oral microflora, some bacterial genera were conserved among individuals, supporting the existence of a core microbiome in the oral cavity of healthy Chinese Han children.

1Department II of Orthopedics, Children's Hospital of Chongqing Medical University; Stem Cell Biology and Therapy Laboratory & Key Laboratory of Child Development and Disorders; Key Laboratory of Pediatrics in Chongqing (CSTC2009CA5002), Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China 2Department 8, Institute of Research Surgery, Daping Hospital, Third Military Medical University, Chongqing, China 3Department of Anesthesiology, General Hospital of Chengdu Military Command, Chengdu, China 4Traumatic Center, Institute of Research Surgery, Daping Hospital, Third Military Medical University, Chongqing, China These authors contributed equally to this study