Clinical analysis of 1301 children with hand and foot fractures and growth plate injuries.

BACKGROUND: Fractures of hands and feet are common in children, but relevant epidemiological studies are currently lacking. We aim to study the epidemiological characteristics of hand and foot fractures and growth plate injuries in children and provide a theoretical basis for their prevention, diagnosis, and treatment. METHODS: We retrospectively analyzed the data of children with hand and foot fractures who were hospitalized at Shenzhen Children's Hospital between July 2015 and December 2020. Data on demographic characteristics, fracture site, treatment method, etiology of injury, and accompanying injuries were collected. The children were divided into four age groups: infants, preschool children, school children, and adolescents. The fracture sites were classified as first-level (the first-fifth finger/toe, metacarpal, metatarsal, carpal, and tarsal) and second-level (the first-fifth: proximal phalanx, middle phalanx, distal phalanx, metacarpal, and metatarsal) sites. The changing trends in fracture locations and injury causes among children in each age group were analyzed. RESULTS: Overall, 1301 children (1561 fractures; 835 boys and 466 girls) were included. The largest number of fractures occurred in preschool children (n = 549, 42.20%), with the distal phalanx of the third finger being the most common site (n = 73, 15.57%). The number of fractures in adolescents was the lowest (n = 158, 12.14%), and the most common fracture site was the proximal phalanx of the fifth finger (n = 45, 29.61%). Of the 1561 fractures, 1143 occurred in the hands and 418 in the feet. The most and least common first-level fracture sites among hand fractures were the fifth (n = 300, 26.25%) and first (n = 138, 12.07%) fingers, respectively. The most and least common first-level foot fracture locations were the first (n = 83, 19.86%) and fourth (n = 26, 6.22%) toes, respectively. The most common first-level and second level etiologies were life related injuries (n = 1128, 86.70%) and clipping injuries (n = 428, 32.90%), respectively. The incidence of sports injuries gradually increased with age, accounting for the highest proportion in adolescents (26.58%). Hand and foot fractures had many accompanying injuries, with the top three being nail bed injuries (570 cases, 36.52%), growth plate injuries (296 cases, 18.96%), and distal severed fracture (167 cases, 10.70%). Among the 296 growth plate injuries, 246 occurred on the hands and 50 on the feet. CONCLUSIONS: In contrast to previous epidemiological studies on pediatric hand and foot fractures, we mapped the locations of these fractures, including proximal, shaft, distal, and epiphyseal plate injuries. We analyzed the changing trends in fracture sites and injury etiologies with age. Hand and foot fractures have many accompanying injuries that require attention during diagnosis and treatment. Doctors should formulate accident protection measures for children of different ages, strengthen safety education, and reduce the occurrence of accidental injuries.

The regenerative treatment of costal osteochondral graft implantation for partial growth arrest using a rabbit model.

PURPOSE: To investigate the feasibility of cylindrical costal osteochondral graft transplantation as a novel regenerative treatment in growth arrest. METHODS: The medial portion of the proximal tibial growth plate of 6-week-old male New Zealand White rabbits was resected to establish an experimental model of partial growth plate injury. The rabbits were divided into four groups: no-treatment, bone wax transplantation, costal chondral graft, and costal osteochondral graft groups. Radiographic and micro-computed tomography scan results were analyzed to evaluate angular deformity of the tibia and bony bridge formation at the injury site. In addition, repair of the injured growth plate cartilage was assessed histologically at 4, 8, and 12 weeks postoperatively. RESULTS: Radiographic examination revealed that bone wax transplantation continuously decreased the medial proximal tibial angle (MPTA) while the costal chondral graft implantation reduced the decrease of MPTA at 12 weeks postoperatively. The costal osteochondral graft implantation recovered the MPTA, close to the normal. Histologically, the costal osteochondral grafts retained the MPTA in the injured site compared to costal chondral grafts. Additionally, hypertrophic chondrocytes were observed at the graft site in the costal osteochondral graft group at 12 weeks, suggesting that endochondral ossification may occur at the graft site similar to normal ossification. The fluorescence in situ hybridization analysis of osteochondral grafts transplanted from male to female rabbits indicated that they were replaced by cells of host origin. CONCLUSION: The costal osteochondral graft can achieve regeneration without bony bridge formation in partial growth plate injury.

Physeal Fractures of the Distal Ulna: Incidence and Risk Factors for Premature Growth Arrest.

BACKGROUND: The aim of this study is to assess the rate of distal ulnar growth arrest following physeal fracture and to identify specific risk factors for premature physeal closure. METHODS: A retrospective review of patients with a distal ulnar physeal fracture was performed at a single United States children's hospital. Patients without 6-month follow-up were excluded. Patient demographics, injury characteristics, treatment, and outcomes were abstracted. Fractures were classified by the Salter-Harris (SH) system. All follow-up radiographs were reviewed for changes in ulnar variance or signs of premature physeal arrest. RESULTS: Fifty-six children with distal ulnar physeal fracture at a mean age of 10.7±3.3 years were included with a mean follow-up of 1.9 years. The most common fracture pattern was a SH II (52.7%), versus SH I (29.1%), SH III (9.1%), and SH IV (9.1%). Of displaced fractures (41.1%), the mean translation was 40.2±38.3% the and mean angulation was 24.8±20.9 degrees. Eleven fractures (19.6%) demonstrated radiographic signs of growth disturbance, including 3 patients (5.4%) with growth disturbance but continued longitudinal growth and 8 patients (14.3%) with complete growth arrest. The average ulnar variance was -3.4 mm. Three patients underwent subsequent surgical reconstruction including ulnar lengthening with an external fixator, distal ulna completion epiphysiodesis with distal radius epiphysiodesis, and ulnar corrective osteotomy. Patients with displaced fractures and SH III/IV fractures were more likely to develop a growth disturbance (34.8% vs. 3.2%, P =0.003; 50.0% vs. 11.1%, P =0.012, respectively). Children with less than 2 years of skeletal growth remaining at the time of injury had a higher risk of growth disturbance (46.2% vs. 9.5%, P =0.007). CONCLUSIONS: SH III and IV fractures are more common injury patterns in the distal ulna compared with the distal radius. Growth disturbance or growth arrest occurs in ~20% of distal ulnar physeal fractures. Displaced fractures, intra-articular fractures, fractures requiring open reduction, and older children are at increased risk of distal ulnar growth arrest and should be followed more closely. LEVEL OF EVIDENCE: Level IV--case series.

Physeal Closure and Fracture Pattern in Adolescent Transitional Distal Radius Fractures.

PURPOSE: To show a correlation between grade of physeal closure and fracture pattern in adolescent transitional distal radius fractures. METHODS: A retrospective chart review was performed of 490 distal radius fractures, ages 14 to 18, at a single institution between 2007 and 2020. A board-certified orthopaedic hand surgeon reviewed all images. Thirty-six distal-radius fractures were considered adolescent transitional fractures. The review included Salter-Harris classification, fracture fragments, and grade of physeal closure. RESULTS: Distal radial physeal closure is 50 times more likely to be of a higher grade in the presence of Salter-Harris type IV fractures ( P <0.001). Closure of the physis is also 7.37 and 13.08 times more likely to be of higher grade in the absence of a dorsal metaphyseal fracture and in the presence of an ulnar corner fracture, respectively ( P =0.011 and 0.021). CONCLUSION: Adolescent transitional fractures of the distal radius occur when the growth plate has a partial closure. The closure pattern of the distal radial physis begins centrally, with subsequent ulnar and then radial closure. In this cohort, there is a correlation between grade of physeal closure and fracture pattern in adolescent transitional distal radius fractures. LEVEL OF EVIDENCE: Level IV-diagnostic.

Physeal Bar Formation After Pediatric Medial Malleolus Fractures.

Pediatric medial malleolus fractures are commonly Salter-Harris (SH) type III or IV fractures of the distal tibia and are associated with a risk of physeal bar formation and subsequent growth disturbance. The purpose of this study was to determine the incidence of physeal bar formation following pediatric medial malleolus fracture and evaluate for patient and fracture characteristics predictive of physeal bar formation. Seventy-eight consecutive pediatric patients during a 6-year period who had either an isolated medial malleolar or a bimalleolar ankle fracture were retrospectively reviewed. Forty-one of 78 patients had greater than 3 months of radiographic follow-up and comprised the study population. Medical records were reviewed for demographic information, mechanism of injury, treatment, and need for further surgery. Radiographs were reviewed to assess for initial fracture displacement, adequacy of fracture reduction, SH type, percentage of the physeal disruption from the fracture, and physeal bar formation. Twenty-two of 41 patients (53.7%) developed a physeal bar. The mean time to diagnosis of physeal bar was 4.9 months (range, 1.6-11.8 months). Twenty-seven percent (6 of 22) of bars were diagnosed at greater than 6 months from injury. Adequacy of reduction was predictive of physeal bar formation, although all patients were reduced to within 2 mm. The mean residual displacement of patients with a bar was 1.2 mm compared with 0.8 mm for those without a bar (P=.03). Because the bar formation rate is greater than 50% on radiographs, routine radiographic assessment of all pediatric medial malleolar fractures should continue for at least 12 months after injury. [Orthopedics. 2024;47(1):e33-e37.].

Artificial intelligence-based detection of paediatric appendicular skeletal fractures: performance and limitations for common fracture types and locations.

BACKGROUND: Research into artificial intelligence (AI)-based fracture detection in children is scarce and has disregarded the detection of indirect fracture signs and dislocations. OBJECTIVE: To assess the diagnostic accuracy of an existing AI-tool for the detection of fractures, indirect fracture signs, and dislocations. MATERIALS AND METHODS: An AI software, BoneView (Gleamer, Paris, France), was assessed for diagnostic accuracy of fracture detection using paediatric radiology consensus diagnoses as reference. Radiographs from a single emergency department were enrolled retrospectively going back from December 2021, limited to 1,000 radiographs per body part. Enrolment criteria were as follows: suspected fractures of the forearm, lower leg, or elbow; age 0-18 years; and radiographs in at least two projections. RESULTS: Lower leg radiographs showed 607 fractures. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were high (87.5%, 87.5%, 98.3%, 98.3%, respectively). Detection rate was low for toddler's fractures, trampoline fractures, and proximal tibial Salter-Harris-II fractures. Forearm radiographs showed 1,137 fractures. Sensitivity, specificity, PPV, and NPV were high (92.9%, 98.1%, 98.4%, 91.7%, respectively). Radial and ulnar bowing fractures were not reliably detected (one out of 11 radial bowing fractures and zero out of seven ulnar bowing fractures were correctly detected). Detection rate was low for styloid process avulsions, proximal radial buckle, and complete olecranon fractures. Elbow radiographs showed 517 fractures. Sensitivity and NPV were moderate (80.5%, 84.7%, respectively). Specificity and PPV were high (94.9%, 93.3%, respectively). For joint effusion, sensitivity, specificity, PPV, and NPV were moderate (85.1%, 85.7%, 89.5%, 80%, respectively). For elbow dislocations, sensitivity and PPV were low (65.8%, 50%, respectively). Specificity and NPV were high (97.7%, 98.8%, respectively). CONCLUSIONS: The diagnostic performance of BoneView is promising for forearm and lower leg fractures. However, improvement is mandatory before clinicians can rely solely on AI-based paediatric fracture detection using this software.

THE INCIDENCE OF SPORTS INJURIES AMONG SCHOOL-AGED CHILDREN AND ADOLESCENTS.

It is estimated that approximately one in ten school-aged children experience sports-related injuries annually. These injuries are most common at 12 years of age. Boys are more likely to get injured and more likely to get seriously injured than girls. The probability of injury is greater in contact or high-impact sports, with American soccer accounting for the largest number of injuries, followed by wrestling, basketball, soccer, and baseball. In certain sports, such as horseback riding, women are four times more likely to sustain injuries. The presented literature review details the incidence of various sports-related injuries in adolescents. Sports-related injuries observed in children under the age of 10 are nonspecific and include contusions, mild sprains, and fractures of the extremities, most commonly Salter-Harris fractures (growth plate fractures) or plastic fractures. In young athletes, sports-related injuries of the ligaments or muscles, as well as spinal or head injuries, are rare. This is particularly true during puberty, where growth plate fractures and musculoskeletal injuries occur more frequently.

Variations in the Management of Closed Salter-Harris II Distal Tibia Fractures.

BACKGROUND: There are no formal practice guidelines for the surgical management of closed, Salter-Harris (SH) II distal tibia fractures. The purpose of this study was to survey the indications for operative and nonoperative management of this injury across pediatric tertiary care centers. METHODS: We surveyed pediatric orthopedic surgeons at 20 tertiary care level-1 pediatric trauma centers. Surgeons were provided with 16 clinical scenarios that varied based on patient age and sex, and highlighted the following surgical indications: translation <3 mm, translation ≥3 mm, sagittal plane angulation >5 degrees, and coronal plane angulation >5 degrees. Each case's scenario and radiographs after closed reduction were presented in a randomized manner. Consensus was defined as 80% agreement, and descriptive statistics were used to summarize the results. RESULTS: In total, 33 of 37 surgeons completed the survey (89% response rate). All surgeons took trauma call at a level-1 pediatric trauma center and had an average of 8.8 years (SD: 6.5 y) of experience. Consensus was reached in 4 of 16 scenarios. Specifically, nonoperative management was recommended for all scenarios showing <3 mm of translation after closed reduction. The majority of surgeons recommended operative management in scenarios showing coronal plane angulation after closed reduction, but none of these scenarios reached consensus. There was a near-equal split in operative and nonoperative management in 8 of 16 scenarios. These scenarios showed ≥3 mm translation after closed reduction and sagittal plane angulation after closed reduction. Surgeons with 6 to 10 years in practice were the most likely to recommend surgery, especially in the case of >5 degrees coronal plane angulation postreduction ( P <0.05). CONCLUSIONS: There is considerable variation regarding the indications for operative and nonoperative management of closed, SHII distal tibia fractures. Consensus was reached for nonoperative management in patients with <3 mm of translation after closed reduction; however, with greater deformity consensus regarding optimal treatment was unable to be achieved. The variation in the management of distal tibia SHII fractures is significant, suggesting that perhaps clinical equipoise exists between operative and nonoperative management. LEVEL OF EVIDENCE: V.

Epidemiology and risk factors for premature physeal closure in distal femur fractures.

BACKGROUND AND PURPOSE: Premature physeal closure (PPC) is a common and concerning complication to distal femoral fractures as the distal growth plate accounts for 70% of the growth of the femur. The literature is not unanimous in determining the risk factors of PPC, and the epidemiological characterization of these fractures is limited. Our aim was to calculate the population-based incidence and investigate risk factors for PPC in these fractures. PATIENTS AND METHODS: In this register-based study, between 2014 and 2021, 70 children with distal femoral physeal fractures presented to our hospital. Demographic data, and fracture- and treatment-related details were collected using the Kids' Fracture Tool. A directed acyclic graph (DAG) was constructed to determine confounding factors used in the risk analysis. RESULTS: Physeal fractures of the distal femur occurred with an annual incidence of 6/105 children, and a resulting PPC occurred in 16/70 (23%) with an annual incidence of 1.3/105 children. In multivariable analysis, dislocation exceeding 10 mm was a risk factor for PPC (OR 6.3, CI 1.4-22). CONCLUSION: One-fourth of distal femoral physeal fractures developed PPC. Greater dislocation and higher injury energy were significant risk factors, whereas choice of fracture treatment was not an independent risk factor. All patients with PPC belonged in the age group 11-16 years.

Disruption of Endochondral Ossification and Extracellular Matrix Maturation in an Ex Vivo Rat Femur Organotypic Slice Model Due to Growth Plate Injury.

Postnatal bone fractures of the growth plate (GP) are often associated with regenerative complications such as growth impairment. In order to understand the underlying processes of trauma-associated growth impairment within postnatal bone, an ex vivo rat femur slice model was developed. To achieve this, a 2 mm horizontal cut was made through the GP of rat femur prior to the organotypic culture being cultivated for 15 days in vitro. Histological analysis showed disrupted endochondral ossification, including disordered architecture, increased chondrocyte metabolic activity, and a loss of hypertrophic zone throughout the distal femur. Furthermore, altered expression patterns of Col2α1, Acan, and ColX, and increased chondrocyte metabolic activity in the TZ and MZ at day 7 and day 15 postinjury were observed. STEM revealed the presence of stem cells, fibroblasts, and chondrocytes within the injury site at day 7. In summary, the findings of this study suggest that the ex vivo organotypic GP injury model could be a valuable tool for investigating the underlying mechanisms of GP regeneration post-trauma, as well as other tissue engineering and disease studies.

A More Conservative Approach in the Surgical Management of Pediatric Physeal Ankle Fractures Should be Preferred: Mid to Long-term Functional Outcomes of Three Different Surgical Techniques for Salter-Harris Type II and Triplane Distal Tibial Fractures.

BACKGROUND: Pediatric physeal ankle fractures carry a high risk of complications. This study aimed to (1) investigate the effect of anatomic reduction of the physis on mid to long-term functional outcomes in Salter-Harris type II and triplane distal tibial physeal fractures (DTPFs) and (2) compare the outcomes of 3 different surgical techniques applied in these fractures. METHODS: The database of a single level-I trauma center was retrospectively reviewed for DTPFs between 2012 and 2022. A total of 39 eligible patients with operative Salter-Harris type II and triplane fractures between 2012 and 2022 were included. Surgical treatment methods were closed reduction-percutaneous fixation (CR-PF), open reduction-screw fixation, or open reduction-plate fixation. Patients were further divided into subgroups for fractures reduced anatomically (<1 mm) or nonanatomically (1 to 3 mm). The primary outcome measures were the American Orthopaedic Foot and Ankle Society Score, ankle range of motion, presence of premature physeal closure and angular deformities, and Takakura ankle osteoarthritis grade. RESULTS: A total of 39 patients were included, with an average age of 12.9 ± 2.2 years. The mean follow-up time was 68.9±38.0 months. The CR-PF group had higher postoperative fracture displacement ( P = 0.011). American Orthopaedic Foot and Ankle Society scores were excellent in all groups, statistically similar between surgical techniques, and similar between anatomic and nonanatomic reduction groups. The CR-PF group ( P =0.030) and nonanatomic reduction ( P = 0.030) provided a significantly lower ankle osteoarthritis rate. All 4 patients with premature physeal closure were observed in patients treated with open techniques. CONCLUSIONS: CR-PF for the treatment of DTPFs should be preferred in suitable cases as it is less invasive and provides satisfactory mid to long-term functional outcomes without increasing complications compared with anatomic reduction and open techniques. LEVEL OF EVIDENCE: Level III.

Delayed open surgery for distal radius epiphyseal plate fracture in children.

OBJECTIVES: This study assessed the feasibility of open surgery and determined outcome predictors for late management of epiphyseal plate fracture of the distal radius in children. METHODS: This retrospective study included 25 patients (22 male, 3 female) who underwent open surgery for late management of epiphyseal plate fracture of the distal radius. Wrist function was evaluated on Cooney score. Potential predictors comprised age, gender, fracture type, days after injury (DAI), degree of violence (DOV), and dorsal angulation before surgery (DABS). RESULTS: Overall, wrist function after surgery was classified as excellent for 16 patients (64%), good for 6 (24%), and fair for 3 (12%). The rate of excellent wrist function was 86.7% (13/15) in children older than 10 years but only 40% (4/10) for those aged under 10 years (p = 0.0280). Cooney score correlated positively with age, but there was no correlation with gender, fracture type, DAI, DOV or DABS. CONCLUSION: Open reduction surgery for late management of distal radius epiphyseal fracture yielded good results in patients aged over 10 years. LEVEL OF EVIDENCE: III.

Displaced distal tibial Salter-Harris II fractures.

Salter-Harris II fractures of the distal tibia affect children frequently, and when they are displaced present a treatment dilemma. Treatment primarily aims to restore alignment and prevent premature physeal closure, as this can lead to angular deformity, limb length difference, or both. Current literature is of poor methodological quality and is contradictory as to whether conservative or surgical management is superior in avoiding complications and adverse outcomes. A state of clinical equipoise exists regarding whether displaced distal tibial Salter-Harris II fractures in children should be treated with surgery to achieve anatomical reduction, or whether cast treatment alone will lead to a satisfactory outcome. Systematic review and meta-analysis has concluded that high-quality prospective multicentre research is needed to answer this question. The Outcomes of Displaced Distal tibial fractures: Surgery Or Casts in KidS (ODD SOCKS) trial, funded by the National Institute for Health and Care Research, aims to provide this high-quality research in order to answer this question, which has been identified as a top-five research priority by the British Society for Children's Orthopaedic Surgery.

Child Fractures: Are We Getting More Surgical? / Fraturas na criança: Estamos ficando mais cirúrgicos?

Abstract Historically, surgeries on the immature skeleton were reserved for open or articular fractures. In recent years, the improvement in the quality and safety of anesthesia, new imaging equipment, implants designed especially for pediatric fractures, associated with the possibility of shorter hospitalization time and rapid return to social life has demonstrated a new tendency to evaluate and treat fractures in children. The purpose of this update article is to answer the following questions: (1) Are we really turning more surgical in addressing fractures in children? (2) If this is true, is this surgical conduct based on scientific evidence? In fact, in recent decades, the medical literature demonstrates articles that support better evolution of fractures in children with surgical treatment. In the upper limbs, this is very evident in the systematization of the reduction and percutaneous fixation of supracondylar fractures of the humerus and fractures of the forearm bones. In the lower limbs, the same occurs with diaphyseal fractures of the femur and tibia. However, there are gaps in the literature. The available published studies show low scientific evidence. Thus, it can be inferred that, even though the surgical approach is more present, the treatment of pediatric fractures should always be individualized and conducted according to the knowledge and experience of the professional physician, taking into account the presence of technological resources available for the care of the small patient. All possibilities, non-surgical and/or surgical, should be included, always instituting actions based on science and in agreement with the family's wishes.

Resumo Historicamente, as cirurgias no esqueleto imaturo eram reservadas às fraturas expostas ou articulares. Nos últimos anos, a melhora na qualidade e segurança das anestesias, novos equipamentos de imagem, implantes desenhados especialmente para fraturas pediátricas, associados à possibilidade de menor tempo de hospitalização e rápido retorno ao convívio social vêm demonstrando uma nova tendência de avaliar e tratar fraturas na criança. O objetivo deste artigo de atualização é responder às seguintes questões: (1) estamos realmente ficando mais cirúrgicos na abordagem das fraturas em crianças? (2) Caso isto seja verdadeiro, esta conduta cirúrgica está baseada em evidências científicas? De fato, nas últimas décadas, a literatura médica demonstra artigos que suportam melhor evolução das fraturas na criança com o tratamento cirúrgico. Nos membros superiores, isto fica muito evidente na sistematização da redução e fixação percutânea das fraturas supracondilianas do úmero e das fraturas de ossos do antebraço. Nos membros inferiores, o mesmo ocorre com fraturas diafisárias do fêmur e tíbia. No entanto, há lacunas na literatura. Os estudos publicados são geralmente com baixa evidência científica. Assim, pode-se deduzir que, mesmo sendo a abordagem cirúrgica mais presente, o tratamento de fraturas pediátricas deve ser sempre individualizado e conduzido de acordo com o conhecimento e experiência do médico profissional, levando em conta a presença de recursos tecnológicos disponíveis para o atendimento do pequeno paciente. Deve-se incluir todas as possibilidades, não cirúrgicas e/ou cirúrgicas, sempre instituindo ações baseadas na ciência e em concordância com os anseios da família.

MRI findings of growth plate fractures of the knee: are there age- and fracture-dependent differences?

OBJECTIVE: To investigate MRI findings in children with physeal fractures of the knee with respect to age, location, and articular involvement. METHODS: Children with physeal fractures who underwent knee MRI between 2008 and 2021 were included. Two radiologists retrospectively reviewed all examinations to determine articular involvement, findings of physeal instability (perichondral disruption, periosteal entrapment), and internal derangement (cruciate ligament injury, meniscal tear, chondromalacia). Independent samples t, Mann-Whitney U, Pearson's chi-square, and Fisher's exact tests were used to compare findings. RESULTS: Fifty-six patients (37 boys, 19 girls; mean age: 12.2 ± 2.5 years; 32 distal femur, 24 proximal tibial fractures) included 24(43%) intraarticular fractures. Fractures were more common in the tibia than the femur (67% versus 25%, p = 0.004) and intraarticular fractures were more common in older than younger children (13.1 ± 2.0 versus 11.5 ± 2.7 years, p = 0.01), to associate with chondromalacia (46% versus 12%, p = 0.02) and undergo surgery (33% versus 10%, p = 0.04) when compared to extraarticular fractures. Perichondral disruption (n = 44, 79%) and periosteal entrapment (n = 13, 23%) did not significantly differ based on location or articular involvement (p > 0.05). At a median follow-up of 17.5 months (interquartile range: 1.25-34), 3 patients (2 intraarticular, 1 extraarticular fractures) developed osteoarthritis, osteochondral lesion, and leg-length discrepancy from growth arrest, which required additional surgery. CONCLUSION: Intraarticular physeal fractures were more common with older children, associate with chondromalacia, and underdo surgical intervention when compared to extraarticular fractures of the knee. While MRI findings of physeal instability were common, no significant differences were found between fractures based on anatomic location or fracture pattern.

KLF2 reduces dexamethasone-induced injury to growth plate chondrocytes by inhibiting the Runx2-mediated PI3K/AKT and ERK signalling pathways.

Dexamethasone (Dex) is a type of glucocorticoid drug. Long term use can induce growth plate chondrocytes (GPCs) apoptosis, impair differentiation, and inhibit cell proliferation and bone growth. It has been reported that Krüppel-like factor 2 (KLF2) inhibits osteoblast damage induced by Dex, but the role in Dex-induced GPCs remains unclear. Dex was used to construct a model of growth plate injury in vitro. CCK-8 and TUNEL kits were used to determine cell viability and apoptosis. A model of growth plate injury was established by intraperitoneal injection of Dex. Immunohistochemistry was used to investigate the expression of KLF2 in rats. The results showed that KLF2 expression of rat tibial GPCs was down-regulated after Dex stimulation. Overexpression of KLF2 promoted cell viability and cell cycle, while inhibited apoptosis of growth plate Dex-induced chondrocytes. Moreover, KLF2 inhibited Runx2-mediated PI3K/AKT and ERK signalling pathways. And PI3K/AKT and ERK signalling pathways, which were involved in the regulation of KLF2 on GPCs. Further studies showed that KLF2 alleviated growth plate injury in vivo. In conclusion, our study found that KLF2 promoted proliferation and inhibited apoptosis of Dex-induced GPCs by targeting the Runx2-mediated PI3K/AKT and ERK signalling pathways.

A New Method for Modeling Rabbit Growth Plate Injury for the Study of Tissue Engineering Scaffolds.

Establishing a suitable animal model of growth plate injury is necessary to evaluate the effect of tissue engineering scaffolds on repairing the injured growth plate. However, the currently used animal models have limitations. Therefore in this study, we reported and evaluated a new modeling method termed the longitudinal disruption method, which is to make a longitudinal defect in the region of growth plate. To compare this new method with the traditional transverse disruption method, we constructed the models by both methods, respectively. To observe whether bone bridges were formed, histological sections were analyzed by hematoxylin-eosin (HE) and Masson staining at 3 weeks after modeling. The HE and Masson staining results showed the formation of bone bridges in both groups, implying that the two methods successfully injured the growth plate. However, it was unclear whether the exact injury to growth plate caused by both methods was consistent. Therefore, to evaluate the accuracy and precision of modeling method, the X-ray and micro-computed tomography (CT) were performed immediately after modeling. The percentages of accurate defect position in the longitudinal and transverse modeling groups were 88.89% and 55.56%, respectively. The micro-CT results revealed irregularly shaped defect cross sections in the transverse modeling group, whereas the defects in the longitudinal modeling group had regular shapes. The mean defect areas were 10.06 ± 0.86 and 12.30 ± 2.13 mm2 in the longitudinal and transverse modeling groups, respectively, while the difference between the actual area and the expected area were -1.94 ± 0.86 and -7.70 ± 2.13 mm2, respectively, showing the high precision of this new method. Altogether, we successfully demonstrated a new method for establishing a rabbit model of growth plate injury, which provides a simple and rapid modeling process, good modeling effect, high modeling accuracy, and convenient scaffold implantation. The new method provides an effective animal model for tissue engineering research on the repair and regeneration of injured growth plate. Impact Statement In recent years, an increasing number of studies have used tissue engineering scaffolds in the repair and regeneration of growth plate. However, the currently used animal models have certain limitations in the study of tissue engineering scaffold for growth plate. In this study, a new method is presented to establish a rabbit model of growth plate injury. This method is characterized by simple and rapid modeling process, good modeling effect, high modeling accuracy, and convenient scaffold implantation, which is suitable for the study of the repair effects of tissue engineering scaffolds. Altogether, this method provides an effective animal model for tissue engineering research on growth plate and facilitates the development of tissue engineering research on the repair and regeneration of injured growth plate.

Polyelectrolyte Complex Hydrogels with Controlled Mechanics Affect Mesenchymal Stem Cell Differentiation Relevant to Growth Plate Injuries.

The growth plate is a complex cartilage structure in long bones that mediates growth in children. When injured, the formation of a "bony bar" can occur which impedes normal growth and can cause angular deformities or growth arrest. Current treatments for growth plate injuries are limited and result in poor patient outcomes, necessitating research toward novel treatments that can prevent bony bar formation and stimulate cartilage regeneration. This study investigates alginate-chitosan polyelectrolyte complex (PEC) hydrogels as an injectable biomaterial system to prevent bony bar formation. Biomaterial properties including stiffness and degradation are quantified, and the effect that material properties have on mesenchymal stem cell (MSC) fate is quantified in vitro. Specifically, this study aims to elucidate the effectiveness of biomaterial-based control over the differentiation behavior of MSCs toward osteogenic or chondrogenic lineages using biochemical metabolite assays and quantitative real time PCR. Further, the PEC hydrogels are employed in a rat growth plate injury model to determine their effectiveness in preventing bony bar formation in vivo. Results indicate that hydrogel composition and material properties affect the differentiation tendency of MSCs in vitro, and the PEC hydrogels show promise as an injectable biomaterial for growth plate injuries.

Pediatric Juxtaepiphyseal Phalangeal Fractures Are Distinct from Salter-Harris Type II Fractures and More Frequently Need Operative Fixation.

BACKGROUND: Salter-Harris type II fractures are the most common pediatric phalangeal fracture. A juxtaepiphyseal fracture is a distinct fracture pattern that, although similar in radiographic appearance, occurs 1 to 2 mm distal to the growth plate. Although subtle, there are important differences in the behavior and management of these fracture types. The purpose of this study was to compare these two fracture patterns in terms of clinical features and treatment. METHODS: An institutional review board-approved retrospective chart review was conducted of patients presenting to our tertiary care pediatric hospital. One hundred fifty-eight patients with either Salter-Harris type II or juxtaepiphyseal phalangeal fractures were identified. Primary outcomes analyzed included angulation at initial presentation, stability of reduction if attempted in the emergency department, and need for operative fixation with and without Kirschner wire fixation, with final angulation measurements. RESULTS: Salter-Harris type II fractures were more common than juxtaepiphyseal fractures (83 percent versus 17 percent, respectively). There was no significant difference between the two fracture types in the patient's age, sex, or mechanism of injury. Juxtaepiphyseal fractures were radiographically more angulated on presentation than Salter-Harris type II fractures (p = 0.02). Juxtaepiphyseal fractures required significantly more operative fixation by closed reduction and percutaneous pinning compared to Salter-Harris type II fractures (42.9 percent versus 10.8 percent, respectively; p = 0.002). There was no difference in final outcomes obtained between the two groups. CONCLUSIONS: Juxtaepiphyseal phalangeal fractures are a distinct entity from Salter-Harris type II fractures. Presenting with significantly more radiographic angulation and clinical instability, juxtaepiphyseal fractures more frequently required operative fixation. Recognizing the differences between these pediatric fracture types is important to help guide clinical management for successful healing. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Combining Salter-Harris and Dias-Tachdjian could be better at determining the prognosis of distal tibial physeal fractures.

OBJECTIVES: The aim of this study is determining the factors that affect prognosis of distal tibial physeal fractures (DTPF) and analyzing whether Salter-Harris (SH) or Dias-Tachdjian (DT) classification is more predictive for outcomes. METHODS: Patients treated for DTPF were retrospectively analyzed. Fracture patterns were classified according to SH and DT. Treatment methods and fracture characteristics were noted. Distal tibial angles and joint irregularities were analyzed on patient's final ankle radiographs followed by American Orthopedic Foot and Ankle Score questionnaire. RESULTS: 75 patients followed-up between 6 and 96 months meeting the inclusion criteria were evaluated. Joint irregularity was observed in 41.3% and partial premature physeal closure (PPC) in 34.7% of the patients. Lateral distal tibial angle (LDTA) and talocrural angle related deformity were detected in 20% and 14.7% of the patients, respectively. Partial PPC and joint irregularities that have been developed in pronation-eversion-external rotation and supination-inversion injuries (SH type 3, 4) were 62% and 50%, and 42% and 75%, respectively. On follow-ups of supination-external rotation injuries (SH type 2) joint irregularity has never been observed. Following supination-external rotation and supination-plantar flexion injuries, a low rate of partial PPC have been developed; LDTA related deformity was revealed at a high rate of 39.1% after supination-inversion injuries. There weren't any differences observed between the initial displacement, residual displacement or surgical technique and PPC, joint irregularity and angular deformities. Patients treated by ORIF technique had lower AOFAS scores than patients treated by other surgical techniques. CONCLUSIONS: In this study it was revealed that SH classification system is not sufficient alone to determine the prognosis of DTPF, the injury mechanisms causing SH types might be also significant in prediction of the prognosis of DTPF.