miR-143 is implicated in growth plate injury by targeting IHH in precartilaginous stem cells.

Precartilaginous stem cells (PCSCs) are able to initiate chondrocyte and bone development. The present study aimed to investigate the role of miR-143 and the underlying mechanisms involved in PCSC proliferation. In a rat growth plate injury model, tissue from the injury site was collected and the expression of miR-143 and its potential targets was determined. PCSCs were isolated from the rabbits' distal epiphyseal growth plate. Cell viability, DNA synthesis, and apoptosis were determined with MTT, BrdU, and flow cytometric analysis, respectively. Real time PCR and western blot were performed to detect the mRNA and protein expression of the indicated genes. Indian hedgehog (IHH) was identified as a target gene for miR-143 with luciferase reporter assay. Decreased expression of miR-143 and increased expression of IHH gene were observed in the growth plate after injury. miR-143 mimics decreased cell viability and DNA synthesis and promoted apoptosis of PCSCs. Conversely, siRNA-mediated inhibition of miR-143 led to increased growth and suppressed apoptosis of PCSCs. Transfection of miR-143 decreased luciferase activity of wild-type IHH but had no effect when the 3'-UTR of IHH was mutated. Furthermore, the effect of miR-143 overexpression was neutralized by overexpression of IHH. Our study showed that miR-143 is involved in growth plate behavior and regulates PCSC growth by targeting IHH, suggesting that miR-143 may serve as a novel target for PCSC-related diseases.

Pediatric Seymour Fractures of the Toe.

BACKGROUND: Seymour fractures of the toe are physeal fractures with often occult concomitant nail bed injuries and thus are open fractures. They are uncommon injuries that without proper treatment can result in osteomyelitis. The literature has sparse information regarding the clinical outcomes for these injuries. METHODS: A single-center retrospective review included juxta-epiphyseal fractures or Salter-Harris I/II fracture of the toe with documented concomitant nail bed injury or laceration. Clinical and radiographic data were recorded for consecutive fractures. The primary outcome was the incidence of osteomyelitis. Secondary outcomes included premature physeal arrest, development of nail dystrophy, and functionality of the toe. RESULTS: Between 2006 and 2019, 19 patients were treated for this injury by the pediatric orthopaedic division. Complications included osteomyelitis (n=6), physeal arrest (n=4), and nail dystrophy (n=1). Days from injury to definitive treatment were significantly greater in patients who developed osteomyelitis compared with those who did not (P<0.01). Patients were significantly more likely to develop osteomyelitis if they did not receive acute definitive treatment (<48 h) (P<0.001; likelihood ratio, 17.9). CONCLUSIONS: Prompt definitive treatment of Seymour fractures of the toe was associated with a lower incidence of osteomyelitis. Greater awareness for these seemingly innocuous injuries is needed to provide an early treatment that may reduce the rate of osteomyelitis. LEVEL OF EVIDENCE: Level IV-case series.

Clinical Outcomes of Triplane Fractures Based on Imaging Modality Utilization and Management: A Systematic Review and Meta-analysis.

BACKGROUND: Because of the complex nature and relatively rare prevalence of triplane fractures, ideal imaging and optimal treatment remain controversial. The purpose of this investigation was to systematically review and compare clinical outcomes in skeletally immature patients with triplane fractures on the basis of imaging modalities [radiography alone vs. radiography+computed tomography (CT)] and fracture management (operative vs. nonoperative). METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement using a PRISMA checklist. All the literature related to skeletally immature patients with triplane fractures published from January 1988 to March 2020 were identified. Inclusion criteria consisted of skeletally immature patients with triplane fractures with reported imaging modality performed during diagnosis, fracture management, and postoperative outcomes on the basis of functional scores and the incidence of any complications. RESULTS: A total of 11 articles met inclusion criteria, comprising a total of 203 skeletally immature patients with 203 documented triplane fractures. Male individuals were significantly older at the time of injury (14.2±0.6 y) when compared with female individuals (12.6±0.9 y) (P=0.006). Fracture diagnosis and management were evaluated using radiography+CT in 63% (128/203) of patients, whereas 37% (75/203) underwent radiography only. No significant differences in good/excellent Modified Weber Protocol scores were reported in patients treated nonoperatively versus those undergoing operative treatment (P=0.78), whereas Modified Weber Protocol scores were significantly higher in patients using radiography alone (P=0.02). No significant difference in complication incidence was reported on the basis of management type (nonoperative, 16%; operative, 15%; P=0.47). CONCLUSIONS: Patients undergoing operative management of triplane fractures achieved comparable functional outcomes scores without an increased incidence of complications when compared with patients undergoing nonoperative treatment. Further investigations analyzing outcomes at middle and long-term follow-up are necessary to determine the clinical utility of CT and various treatment modalities for the management of triplane fractures. LEVEL OF EVIDENCE: Level IV-Systematic review.

Low Energy, Lateral Ankle Injuries in Pediatric and Adolescent Patients: A Systematic Review of Ankle Sprains and Nondisplaced Distal Fibula Fractures.

BACKGROUND: Lateral ankle injuries are one of the most common musculoskeletal injuries sustained by pediatric and adolescent athletes. These injuries can result in significant time lost from competition, affect performance when returning to play, and represent a significant burden on the health care system as a whole. The purpose of this study was to systematically review the literature on the diagnosis, treatment, and prevention of acute lateral ankle injuries and their chronic effects in pediatric and adolescent athletes (younger than 19 y). METHODS: This systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) guidelines between September and December 2018. PubMed and Google Scholar were systematically searched using the search terms: ("distal fibula fracture" OR "ankle sprain") AND ("youth" OR "pediatric" OR "adolescent"). All authors participated in article review (N=172) for relevance and age restrictions in which 30 met the inclusion criteria. RESULTS: Thirty articles met inclusion criteria [Levels of Evidence I to IV (I: n=4, II: n=16, III: n=9, and IV: n=1)] including distal fibula fracture diagnosis and treatment, and risk factors, prevention, and chronic sequela of lateral ankle injuries in pediatric and adolescent patients. CONCLUSIONS: Low-energy, lateral ankle injuries are common in pediatric and adolescent patients, yet underrepresented in the medical literature. There is a lack of high-quality literature on diagnosis, treatment, and outcomes after Salter-Harris I distal fibula fractures. Available literature, however, suggests that there remains over diagnosis and over treatment of presumed Salter-Harris I distal fibula fractures. Adolescent ankle sprains dominate the available literature likely due to the high recurrence rate. Youth athletes and coaches should address risk factors and engage in injury prevention programs to prevent and minimize the effect of acute lateral ankle injuries. LEVELS OF EVIDENCE: Level III-Systematic review.

Comparison of mesenchymal stem cell sheets and chondrocyte sheets in a rabbit growth plate injury model

Background/aim: The treatment of posttraumatic deformities and differences in length between the extremities resulting from physeal injury remains controversial. The aims of this study were to compare the efficacy of tissue-engineered, monolayer, and allogeneic mesenchymal stem cell sheets and chondrocyte sheets for physeal arrest treatment and to investigate cell sheet technology as a novel method for cell transplantation in physeal cartilage repair. Materials and methods: A proximal tibial physeal injury was induced in New Zealand rabbits. Allogeneic mesenchymal stem cells (MSCs) and chondrocytes were cultured in temperature-responsive culture dishes and applied to the iatrogenic partial growth plate defects in single-sheet grafts (cell sheets). Treatment efficacy was determined using radiological measurements, as well as histological and immunohistochemical staining. Results: Treatment with MSCs and chondrocytes prevented endochondral ossification in the physeal plate, and bone growth resumed after treatment in both the MSC and chondrocyte cell groups. We found significant differences in radiological evaluations between pre- and posttreatment measurements in both MSC and chondrocyte groups. Transplanted cells were observed in the damaged area in both of the groups, which differentiated in the direction of growth plate cartilage. Conclusion: Our results support the hypothesis that MSC or chondrocyte transplantation using the cell-sheet technique described in the present study aids in the regeneration of cartilage tissue during physeal arrest after growth plate damage.

Salter-Harris type II fractures of the distal tibia: Residual postreduction displacement and outcomes-a STROBE compliant study.

We assessed factors associated with premature physeal closure (PPC) and outcomes after closed reduction of Salter-Harris type II (SH-II) fractures of the distal tibia. We reviewed patients with SH-II fractures of the distal tibia treated at our center from 2010 to 2015 with closed reduction and a non-weightbearing long-leg cast. Patients were categorized by immediate postreduction displacement: minimal, <2 mm; moderate, 2 to 4 mm; or severe, >4 mm. Demographic data, radiographic data, and Lower Extremity Functional Scale (LEFS) scores were recorded.Fifty-nine patients (27 girls, 31 right ankles, 26 concomitant fibula fractures) were included, with a mean (±SD) age at injury of 12.0 ±â€Š2.2 years. Mean maximum fracture displacements were 6.6 ±â€Š6.5 mm initially, 2.7 ±â€Š2.0 mm postreduction, and 0.4 ±â€Š0.7 mm at final follow-up. After reduction, displacement was minimal in 23 patients, moderate in 21, and severe in 15. Fourteen patients developed PPC, with no significant differences between postreduction displacement groups. Patients with high-grade injury mechanisms and/or initial displacement ≥4 mm had 12-fold and 14-fold greater odds, respectively, of PPC. Eighteen patients responded to the LEFS survey (mean 4.0 ±â€Š2.1 years after injury). LEFS scores did not differ significantly between postreduction displacement groups (P = .61).The PPC rate in this series of SH-II distal tibia fractures was 24% and did not differ by postreduction displacement. Initial fracture displacement and high-grade mechanisms of injury were associated with PPC. LEFS scores did not differ significantly by postreduction displacement.Level of Evidence: Level IV, case series.

Hand and Wrist Injuries in the Pediatric Athlete.

This article examines the most common problematic hand and wrist injuries in the pediatric athlete. Hand and wrist injuries in the growing skeleton pose a different diagnostic and therapeutic challenge than in the mature skeleton. Ligaments are stronger than bone, and unossified cartilaginous sections of the skeleton are yet more susceptible to injury than bone. Although remodeling can correct for even moderate deformities if sufficient growth potential exists, remodeling cannot return the child to normal anatomy in many cases. Remodeling depends on intact periosteum, a nearby growing physis, and competent ligaments to direct remodeling via Hueter-Volkmann and Wolff's laws.

Treatment and outcomes of distal tibia salter harris II fractures.

BACKGROUND: Distal Salter-Harris (SH) II fractures of the tibia are common injuries in the pediatric population. The purpose of this study is to evaluate our treatment and outcomes of SH II fractures of the distal tibia. METHODS: The study was approved by the medical school's institutional review board (IRB). Fifty-one distal tibia SH type II fractures were treated from 2003 to 2017. We performed a retrospective review of all patients. Patients with displacement less than 3 mm, on x-ray, were treated with a cast. Patients with displacement greater than or equal to 3 mm displacement were initially treated with closed reduction in the emergency department with conscious sedation. Patients were also categorized based on the mechanism of injury and complications were noted. Patients were followed for an average of 4 months (range, 4 weeks-28 months). RESULTS: Fifty-one patients, 28 females and 23 males, were included in the study, with a mean age of 9.4 years (range, 13 months-13 years) at presentation. The most common mechanism of injury was participation in sports (43%). Out of the 51 patients, 45 were minimally displaced and treated with cast. Six displaced fractures were treated with closed reduction. The mean displacement in the closed reduction group at presentation was 5.7 (range, 3- 8.8) mm. Five out of 6 patients had reduction to less than 3 mm. The overall complication rate was 1 out of 51 patients, 2%. When examining displaced fractures, the complication rate was 1 out of 6 patients, 17%. CONCLUSION: Most SH II fractures of the distal tibia are minimally displaced and do not need a reduction. 6/51 cases (12%) in the current study were displaced and were indicated for a reduction. Displacement greater than or equal to 3 mm can be treated with closed reduction followed by a cast; if closed reduction fails, open reduction is indicated. Displaced fractures have a small risk of growth arrest.

Rabbit Model of Physeal Injury for the Evaluation of Regenerative Medicine Approaches.

Physeal injuries can lead to bony repair tissue formation, known as a bony bar. This can result in growth arrest or angular deformity, which is devastating for children who have not yet reached their full height. Current clinical treatment involves resecting the bony bar and replacing it with a fat graft to prevent further bone formation and growth disturbance, but these treatments frequently fail to do so and require additional interventions. Novel treatments that could prevent bone formation but also regenerate the injured physeal cartilage and restore normal bone elongation are warranted. To test the efficacy of these treatments, animal models that emulate human physeal injury are necessary. The rabbit model of physeal injury quickly establishes a bony bar, which can then be resected to test new treatments. Although numerous rabbit models have been reported, they vary in terms of size and location of the injury, tools used to create the injury, and methods to assess the repair tissue, making comparisons between studies difficult. The study presented here provides a detailed method to create a rabbit model of proximal tibia physeal injury using a two-stage procedure. The first procedure involves unilateral removal of 25% of the physis in a 6-week-old New Zealand white rabbit. This consistently leads to a bony bar, significant limb length discrepancy, and angular deformity within 3 weeks. The second surgical procedure involves bony bar resection and treatment. In this study, we tested the implantation of a fat graft and a photopolymerizable hydrogel as a proof of concept that injectable materials could be delivered into this type of injury. At 8 weeks post-treatment, we measured limb length, tibial angle, and performed imaging and histology of the repair tissue. By providing a detailed, easy to reproduce methodology to perform the physeal injury and test novel treatments after bony bar resection, comparisons between studies can be made and facilitate translation of promising therapies toward clinical use. Impact Statement This study provides details to create a rabbit model of physeal injury that can facilitate comparisons between studies and test novel regenerative medicine approaches. Furthermore, this model mimics the human, clinical situation that requires a bony bar resection followed by treatment. In addition, identification of a suitable treatment can be seen in the correction of the growth deformity, allowing this model to facilitate the development of novel physeal cartilage regenerative medicine approaches.

Management of ankle fractures in children.

Ankle fractures are a common injury in children and adolescents - 1 in 1000 children will sustain an ankle fracture each year. Understanding the diagnosis and management of these injuries is vital for any doctor or clinician working in the emergency department, orthopaedics or providing community care. This review identifies the important features of high- and low-risk ankle fractures, how to prevent the use of unnecessary radiation and the management of these injuries. Fractures may be at high or low risk of instability and are managed accordingly. Many can be treated with conservative management in a cast, including unstable injuries following reduction. However, particular fracture patterns associated with the tibial growth plate need careful assessment of fracture reduction with cross-sectional imaging before committing to conservative management.

Salter-Harris Type III Fracture in a Football Player.

A 15-year-old high school football player sustained direct impact to his anteromedial left knee by a teammate's helmet during practice. The physician referred the athlete immediately to an after-hours clinic for imaging to rule out a fracture. Radiographs of the knee showed a nondisplaced Salter-Harris type II fracture. The treating physician also ordered magnetic resonance imaging, the results of which allowed for a more specific diagnosis of the fracture as a Salter-Harris type III fracture of the left femur.J Orthop Sports Phys Ther 2019;49(3):209. doi:10.2519/jospt.2019.7984.

Salter-Harris Fracture of the Proximal Humerus in an Adolescent Gymnast.

A 13-year-old male gymnast presented via direct access to physical therapy with a chief complaint of insidious-onset right anterolateral shoulder pain that occurred only when performing on the rings and high bar. Following physical examination, the patient was advised to avoid any gymnastic activities that might cause pain while completing stretching and neuromuscular training over the following 2 weeks. Due to continued symptoms, the patient was then referred to an orthopaedist. Radiographs were performed, followed by magnetic resonance imaging without contrast. The patient was diagnosed with a type 1 Salter-Harris fracture. J Orthop Sports Phys Ther 2018;48(9):729. doi:10.2519/jospt.2018.7296.

The heterogeneous management of pediatric ankle traumas: A retrospective descriptive study.

Frequent misdiagnosis of pediatric ankle traumas leads to inappropriate management, which may result in residual pain, instability, slower return to physical activity, and long-term degenerative changes. The purpose of this study was to evaluate the consistency of diagnosis, management, and the treatment of acute lateral pediatric ankle trauma in a tertiary care pediatric hospital. The hypothesis was that the initial diagnosis is often incorrect, and the treatment varies considerably amongst orthopedic surgeons.We conducted a retrospective study of all cases of ankle sprains and Salter-Harris one (SH1) fractures referred to our orthopedic surgery service between May and August 2014. Exclusion criteria included ankle fractures other than SH1 types, and cases where treatment was initially undertaken elsewhere before referral to our service. Primary outcome was the difference between initial and final diagnosis.Among 3047 cases reviewed, 31 matched our inclusion criteria. Initial diagnosis was 20 SH1 fractures, 8 acute ankle sprains, and 3 uncertain, with a change in diagnosis for 48.5% at follow-up.Accurate diagnosis can be difficult in pediatric ankle trauma, with case management and specific treatments varying considerably. This study reinforces the need to evaluate the safety of a general treatment algorithm for all lateral ankle trauma with normal radiographs.Level of evidence III.

Distal Femoral Physeal Fractures.

Physeal fractures of the distal femoral are rare injuries accounting for less than 2% of all physeal injuries, and tend to have a worse prognosis than similar injuries in other locations. This article reviews the evaluation (including imaging), classification, and treatment of these injuries, and discusses their most important complications and their management, including vascular injury and growth arrest.

Isolated Salter-Harris Type III Physeal Fracture of the Distal Ulna.

We describe a case of isolated physeal fracture of ulna distal end in a 13-year-old boy. This fracture type is uncommon, especially Salter-Harris type III of this injury has not been reported. Plain radiographs showed a small vertical fracture line at the ulnar distal end and an enlargement of epiphyseal plate at the base of ulnar styloid process. The present case was successfully managed with conservative treatment because of its minimal displacement.

Distal radius nonunion after epiphyseal plate fracture in a 15 years old young rider.

BACKGROUND AND AIM OF THE WORK: Radius and ulna fractures are the most common long bone fractures in children and adolescents. The majority of these injuries involve the distal metaphyseal portion of the radius associated or not to physeal plate injuries. Because of the high remodelling potential of the distal radius in growing children most injuries heal without complication after closed reduction and immobilization in a long arm cast. Nonunions of closed distal radius fracture are an extremely rare occurrence especially in paediatric population. Methods: In this report, we describe a rare case of distal radius fracture nonunion in a 15-years old male rider treated conservatively with cast immobilization. Eight months later he underwent surgical closed reduction and fixation with kirschner wire and cannulated screw. Results: Follow-up at 2 years showed satisfying radiological and functional outcomes. The patient ultimately returned to ride 3 months following surgery. Conclusions: Nonunion is rarely seen in distal radius fractures in healthy children and adolescents, and there are few studies in the literature. Treatment of the nonunion must be individualized and the results are not entirely predictable.

Physeal fractures of the lower leg in children and adolescents: Therapeutic results, pitfalls and suggested management protocol - based on the experience of the authors and contemporary literature.

PURPOSE: Physeal fractures in children frequently give rise to concerns about the condition of the growth plate. Our observations have proven that the dysfunction of the growth plate is less frequent complication in those cases than misdiagnosed interposition of the periosteum. The aim of this paper is to familiarize the readers with the issue of treatment of physeal fractures of the distal tibia and fibula in the growing skeleton. MATERIALS AND METHODS: We analyzed the group of 75 patients - children and adolescents - with surgically treated physeal fractures of the lower leg. The analysis included age, sex, circumstances of trauma infliction, type of sustained damage, employed therapeutic technique, timing of surgical procedure, duration of hospitalization, complications, duration of follow-up, radiological and functional results according to the AOFAS scale. RESULTS: The group consisted of 23 girls and 52 boys. The mean age was 13.6 years. The most frequent cause of trauma was same-level fall, usually during sports activities (35 cases). The most common type of damage was Salter-Harris type II fracture (35 cases). Among the employed surgical techniques, open reduction and stabilization with K-wires was the most often used (52 cases). A group of four patients attracted our attention, in whom after a closed reduction, signs of periosteum interposition were noted. These patients required a second procedure. In one patient, the growth plate arrest occurred; it was directly caused by local osteomyelitis. CONCLUSIONS: With adequately conducted treatment of distal tibia and distal fibula physeal fractures, the results are good. Misdiagnosed periosteum interposition poses a more serious clinical problem as opposed to the commonly anxiety-provoking post-traumatic growth plate dysfunction.

Physeal Fractures in Foals.

Physeal fractures are common musculoskeletal injuries in foals and should be included as a differential diagnosis for the lame or nonweightbearing foal. Careful evaluation of the patient, including precise radiographic assessment, is paramount in determining the options for treatment. Prognosis mostly depends on the patient's age, weight, and fracture location and configuration.

Treatment of rabbit growth plate injuries with oriented ECM scaffold and autologous BMSCs.

Tissue-engineered technology has provided a promising method for the repair of growth plate injuries using biocompatible and biodegradable scaffolds and appropriate cells. The aim of this study was to fabricate oriented ECM scaffolds to imitate the material and structure of a natural growth plate and to investigate whether BMSCs in a scaffold could prevent the formation of bone bridges in an injured growth plate. We developed a natural, acellular and oriented scaffold derived from a growth plate. The oriented scaffold was fabricated using new freeze-drying technology and by cross-linking the microfilaments in the growth plate. From histological examination, the scaffold contained most of the ECM components including GAG and collagen II without cell DNA fragments, and SEM revealed that oriented scaffold had a uniform aperture in the transverse plane and columnar structure in length plane. Cytotoxicity testing with MTT showed no cytotoxic effect of the scaffold extracts on BMSCs. Autogenous BMSCs in oriented scaffolds promoted the regeneration of neogenetic growth plate when repairing an injured growth plate and prevent the formation of bone bridges to reduce the angular deformity and length discrepancy in the proximal tibia in rabbits. The well-characterized ECM-derived oriented growth plate scaffold shows potential for the repair of injured growth plates in young rabbits.