UNASSIGNED: To analyze the effectiveness of external fixator combined with Kirschner wire (EF-KW) fixation in the treatment of oblique and comminuted distal humeral metaphyseal-diaphyseal junction (DHMDJ) fractures in children.
UNASSIGNED: A clinical data of 22 children with DHMDJ fractures who met the selection criteria between April 2021 and December 2023 was retrospectively analyzed. All patients were treated with EF-KW fixation. There were 14 boys and 8 girls with an average age of 6.8 years (range, 1.5-12.0 years). The time from injury to operation was 14-38 hours (mean, 24.2 hours). There were 18 cases of comminuted fractures and 4 cases of oblique fractures; and 1 case of median nerve injury and 1 case of radial nerve injury before operation. The occurrence of postoperative complications was recorded. At last follow-up, the function of the affected elbow joint was evaluated according to the Mayo elbow joint function score, and the Baumann\'s angle (BA) and humero-capitellar angle (HCA) of the affected and healthy sides were recorded and compared.
UNASSIGNED: All fractures were successfully treated with closed reduction and no complications such as nerve injury occurred. Superficial infection occurred in 4 cases after operation and healed after symptomatic treatment. The incisions of other patients healed by first intention. All patients were followed up 9-24 months (mean, 13.8 months). At last follow-up, according to the Mayo elbow joint function score, the elbow joint function was rated as excellent in 15 cases, good in 6 cases, and fair in 1 case, with an excellent and good rate of 95.5%. The neurologic injury before operation recovered gradually. X-ray films reexamination showed that all fractures healed, and the healing time of fractures ranged from 29 to 61 days, with an average of 35.6 days. At last follow-up, there was no significant difference in BA and HCA between the healthy side and the affected side ( P>0.05). During follow-up, 1 case developed mild cubitus varus, while the other patients had no serious complications.
UNASSIGNED: EF-KW fixation for oblique and comminuted DHMDJ fractures in children has the advantages of less trauma, simple operation, easy reduction, good stability after reduction, low incidence of serious complications, and good elbow functional recovery.
UNASSIGNED: 探讨外固定架联合克氏针固定治疗儿童倾斜型和粉碎型肱骨远端干-骺交界区（distal humeral metaphyseal-diaphyseal junction，DHMDJ）骨折的疗效。.
UNASSIGNED: 回顾性分析2021年4月—2023年12月收治且符合选择标准的22例儿童DHMDJ骨折临床资料，均行外固定架联合克氏针固定治疗。其中男14例，女8例；年龄1.5～12.0岁，平均6.8岁。受伤至手术时间14～38 h，平均24.2 h。骨折类型：粉碎型18例，倾斜型4例。术前合并正中神经损伤1例、桡神经损伤1例。记录术后并发症发生情况；末次随访时，采用Mayo评分标准评估患侧肘关节功能，测量健、患侧肘关节活动度并基于X线片测量健、患侧鲍曼角、髁干角，比较健患侧差异。.
UNASSIGNED: 术中骨折均闭合复位成功，手术顺利完成，无神经损伤等并发症发生。术后4例发生浅表感染，对症处理后愈合；其余切口均Ⅰ期愈合。患儿均获随访，随访时间9～24个月，平均13.8个月。末次随访时，肘关节功能根据Mayo标准获优15例、良6例、可1例，优良率95.5%。术前合并神经损伤者均逐渐自行恢复。X线片复查示骨折均愈合，愈合时间29～61 d，平均35.6 d；末次随访时，健、患侧鲍曼角和髁干角差异均无统计学意义（ P>0.05）。随访期间1例出现轻度肘内翻畸形，其余患儿均无严重并发症发生。.
UNASSIGNED: 对于儿童倾斜型和粉碎型DHMDJ骨折，采用外固定架联合克氏针固定具有创伤小、操作简便，骨折易于复位且复位后稳定性好，严重并发症发生率低、术后功能恢复好等优势。.

暂无摘要。

BACKGROUND: Several methods have been used for the treatment of pediatric distal femoral fractures, such as elastic stable intramedullary nail (ESIN), external fixator (EF) and plate osteosynthesis, but there has been no consensus about the optimal method. The purpose of this study was to compare the clinical outcome between EF and ESIN techniques used in metaphyseal-diaphyseal junction (MDJ) fractures of the pediatric distal femur.
METHODS: We retrospectively analyzed operatively treated MDJ fractures of pediatric distal femur between January 2015 and January 2022. Patient charts were reviewed for demographics, injury and data of radiography. All of the patients were divided into EF and ESIN groups according to the operation techniques. Malalignment was defined as more than 5 degrees of angular deformity in either plane. Clinical outcomes were measured by Flynn scoring system.
RESULTS: Thirty-eight patients were included in this study, among which, 23 were treated with EF, and 15 with ESIN. The mean follow-up time was 18 months (12-24 months). At the final follow-up, all of the fractures were healed. Although there were no statistical differences between the two groups in demographic data, length of stay, estimated blood loss (EBL), rate of open reduction, time to fracture healing and Flynn score, the EF was superior to ESIN in operative time, fluoroscopic exposure and time to partial weight-bearing. The EF group had a significantly higher rate of skin irritation, while the ESIN had a significantly higher rate of malalignment.
CONCLUSIONS: EF and ESIN are both effective methods in the treatment of MDJ fractures of the pediatric distal femur. ESIN is associated with lower rates of skin irritation. However, EF technique has the advantages of shorter operative time, reduced fluoroscopic exposure, and shorter time to partial weight-bearing, as well as lower incidence of malalignment.
METHODS: Level III.

To compare the biomechanical properties of several anterior pelvic ring external fixators with two new configurations in the treatment of Tile C pelvic fractures, in order to evaluate the effectiveness of the new configurations and provide a reference for their clinical application. A finite element model of a Tile C pelvic ring injury (unilateral longitudinal sacral fracture and ipsilateral pubic fracture) was constructed. The pelvis was fixed with iliac crest external fixator (IC), anterior inferior iliac spine external fixator (AIIS), combination of IC and AIIS, combination of anterior superior iliac spine external fixator (ASIS) and AIIS, and S1 sacroiliac screw in 5 types of models. The stability indices of the anterior and posterior pelvic rings under vertical longitudinal load, left-right compression load and anterior-posterior shear load were quantified and compared. In the simulated bipedal standing position, the results of the vertical displacement of the midpoint on the upper surface of the sacrum are consistent with the displacement of the posterior rotation angle, and the order from largest to smallest is IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. The longitudinal displacement of IC is greater than that of the other models. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter is smaller. In the simulated semi-recumbent position, the vertical displacement and posterior rotation angle displacement of the midpoint on the upper surface of the sacrum are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Under the simulated left-right compression load state, the lateral displacements of the highest point of the lateral sacral fracture end are consistent with the highest point of the lateral pubic fracture end, and the order from large to small is S1 screw, IC, AIIS, ASIS + AIIS and IC + AIIS, among which the displacements of S1 screw and IC are larger, and the displacements of ASIS + AIIS and IC + AIIS are similar and smaller than those of other models. The displacements of IC + AIIS are smaller than those of ASIS + AIIS. Under the simulated anterior-posterior shear load condition, the posterior displacements of the highest point of the lateral sacral fracture end and the highest point of the lateral pubic fracture end are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Among them, the displacements of IC and AIIS are larger. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter are smaller. For the unstable pelvic injury represented by Tile C pelvic fracture, the biomechanical various stabilities of the combination of IC and AIIS are superior to those of the external fixators of conventional configurations. The biomechanical stabilities of the combination of ASIS and AIIS are also better than those of the external fixators of conventional configurations, and slightly worse than those of the combination of IC and AIIS. Compared with sacroiliac screw and conventional external fixators, the lateral stabilities of IC + AIIS and ASIS + AIIS are particularly prominent.

BACKGROUND: The purpose of the study was to assess and compare the clinical efficacy of bone transport with either circular or unilateral external fixators over an intramedullary nail in the treatment of tibial bone defects caused by infection.
METHODS: Between May 2010 and January 2019, clinical and radiographic data were collected and analyzed for patients with bone defects caused by infection. Thirteen patients underwent bone transport using a unilateral external fixator over an intramedullary nail (Group A), while 12 patients were treated with a circular external fixator over an intramedullary nail (Group B). The bone and functional outcomes of both groups were assessed and compared using the Association for the Study and Application of the Method of the Ilizarov criteria, and postoperative complications were evaluated according to the Paley classification.
RESULTS: A total of 25 patients were successfully treated with bone transport using external fixators over an intramedullary nail, with a mean follow-up time of 31.63 ± 5.88 months. There were no significant statistical differences in age, gender, previous surgery per patient, duration of infection, defect size, and follow-up time between Group A and Group B (P > 0.05). However, statistically significant differences were observed in operation time (187.13 ± 21.88 min vs. 255.76 ± 36.42 min, P = 0.002), intraoperative blood loss (39.26 ± 7.33 mL vs. 53.74 ± 10.69 mL, P < 0.001), external fixation time (2.02 ± 0.31 month vs. 2.57 ± 0.38 month, P = 0.045), external fixation index (0.27 ± 0.08 month/cm vs. 0.44 ± 0.09 month/cm, P = 0.042), and bone union time (8.37 ± 2.30 month vs. 9.07 ± 3.12, P = 0.032) between Group A and Group B. The excellent and good rate of bone and functional results were higher in Group A compared to Group B (76.9% vs. 75% and 84.6% vs. 58.3%). Statistically significant differences were observed in functional results (excellent/good/fair/poor, 5/6/2/0 vs. 2/5/4/1, P = 0.013) and complication per patient (0.38 vs. 1.16, P = 0.012) between Group A and Group B.
CONCLUSIONS: Bone transport using a combined technique of external fixators over an intramedullary nail proved to be an effective method in treating tibial bone defects caused by infection. In comparison to circular external fixators, bone transport utilizing a unilateral external fixator over an intramedullary nail resulted in less external fixation time, fewer complications, and better functional outcomes.

UNASSIGNED: To analyze the effectiveness comparison of external fixator combined with Kirschner wire fixation and Kirschner wire fixation in the treatment of cubitus varus deformity in children.
UNASSIGNED: A retrospective case-control study was conducted to collect 36 children of postoperative supracondylar humerus fracture complicating cubitus varus deformity between January 2018 and July 2022. Among them, 17 cases were treated with distal humeral wedge osteotomy external fixation combined with Kirschner wire fixation (observation group), and 19 cases were treated with distal humeral wedge osteotomy and Kirschner wire fixation (control group). The baseline data including age, gender, deformity side, time from fracture to operation, carrying angle of the healthy side and preoperative carrying angle of the affected side, elbow flexion and extension range of motion, and lateral condylar prominence index (LCPI) showed no significant difference between the two groups ( P>0.05). The operation time, hospitalization cost, healing time of osteotomy, postoperative complications, and the carrying angle, LCPI, and elbow flexion and extention range of motion were recorded and compared between the two groups. The elbow function was assessed by Oppenheim score at 3 months after operation and at last follow-up.
UNASSIGNED: The children in both groups were followed up 13-48 months, with an average of 26.7 months. There was 1 case of needle tract infection in the observation group and 2 cases in the control group, and no nerve injury occurred, the difference in the incidence of complication (5.88% vs 10.53%) between the two groups was not significant ( χ 2=0.502, P=0.593). There was no significant difference in the operation time and fracture healing time between the two groups ( P>0.05); the hospitalization cost of the observation group was significantly higher than that of the control group ( P<0.05). The Oppenheim score of the observation group was significantly better than that of the control group at 3 months after operation ( P<0.05), but there was no significant difference in the Oppenheim score between the two groups at last follow-up ( P>0.05). At last follow-up, the carrying angle of affected side significantly improved in both groups when compared with preoperative ones ( P<0.05); the differences of the pre- and post-operative carrying angle of affected side and elbow flexion and extension range of motion showed no significant differences between the two groups ( P>0.05), but the difference in pre- and post-operative LCPI of the observation group was significantly better than that of the control group ( P<0.05).
UNASSIGNED: External fixator combined with Kirschner wire fixation and Kirschner wire fixation both can achieve satisfactory correction of cubitus varus deformity in children, and the former can achieve better short-term functional recovery of elbow joint and reduce the incidence of humeral lateral condyle protrusion.
UNASSIGNED: 比较外固定架结合克氏针固定与克氏针固定治疗儿童肘内翻畸形的疗效。.
UNASSIGNED: 回顾分析2018年1月—2022年7月收治且符合选择标准的36例肱骨髁上骨折术后并发肘内翻畸形患儿临床资料。其中17例采用肱骨远端楔形截骨外固定架结合克氏针固定（观察组），19例采用肱骨远端楔形截骨克氏针固定（对照组）。两组患儿年龄、性别、畸形侧别、骨折至此次手术时间、健侧提携角及术前患侧提携角、肘关节屈伸活动度、外侧髁突出指数（lateral condylar prominence index，LCPI）等基线资料比较，差异均无统计学意义（ P>0.05）。记录并比较两组患儿手术时间、住院费用、截骨愈合时间、术后并发症及末次随访时患侧提携角、LCPI和肘关节屈伸活动度；术后3个月、末次随访时采用Oppenheim评分评估肘关节功能。.
UNASSIGNED: 两组患儿均获随访，随访时间13～48个月，平均26.7个月。观察组和对照组分别发生1例和2例针道感染，均无神经损伤发生，两组并发症发生率（5.88% vs 10.53%）比较差异无统计学意义（ χ 2=0.502， P=0.593）。两组手术时间和截骨愈合时间比较差异无统计学意义（ P>0.05）；观察组住院费用高于对照组（ P<0.05）。观察组术后3个月Oppenheim评分优于对照组（ P<0.05），但末次随访时两组Oppenheim评分比较差异无统计学意义（ P>0.05）。末次随访时，两组患侧提携角均较术前显著改善（ P<0.05）；两组间患侧提携角和肘关节屈伸活动度手术前后差值比较差异均无统计学意义（ P>0.05），但观察组LCPI手术前后差值优于对照组，差异有统计学意义（ P<0.05）。.
UNASSIGNED: 采用外固定架结合克氏针固定及单纯克氏针固定治疗儿童肘内翻畸形均可获得满意畸形矫正，而前者术后早期肘关节功能恢复更好，并可降低术后肱骨外侧髁突出的发生。.

Previous works had successfully demonstrated the clinical effectiveness of unilateral external fixator in treating various types of fracture, ranging from the simple type, such as oblique and transverse fractures, to complex fractures. However, literature that investigated its biomechanical analyses to further justify its efficacy is limited. Therefore, this paper aimed to analyse the stability of unilateral external fixator for treating different types of fracture, including the simple oblique, AO32C3 comminuted, and 20 mm gap transverse fracture. These fractures were reconstructed at the distal diaphysis of the femoral bone and computationally analysed through the finite element method under the stance phase condition. Findings showed a decrease in the fixation stiffness in large gap fracture (645.2 Nmm-1 for oblique and comminuted, while 23.4 Nmm-1 for the gap fracture), which resulted in higher displacement, IFM and stress distribution at the pin bone interface. These unfavourable conditions could consequently increase the risk of delayed union, pin loosening and infection, as well as implant failure. Nevertheless, the stress observed on the fracture surfaces was relatively low and in controlled amount, indicating that bone unity is still allowable in all models. Briefly, the unilateral fixation may provide desirable results in smaller fracture gap, but its usage in larger gap fracture might be alarming. These findings could serve as a guide and insight for surgeons and researchers, especially on the biomechanical stability of fixation in different fracture types and how will it affect bone unity.

BACKGROUND: External fixators (EF) are widely employed for pediatric tibial shaft fractures, being a prevalent choice in clinical practice. However, they are associated with numerous complications, such as loss of reduction, delayed union, and nonunion. An alternative approach involves the use of Ilizarov external fixators (IEF), which have been documented in the treatment of tibial shaft fractures in various studies. This study endeavors to retrospectively compare the clinical outcomes of EF and IEF in the treatment of pediatric tibial shaft fractures.
METHODS: The study retrospectively examined patients aged 5-14 years who underwent treatment for tibial shaft fractures at our institute between January 2017 and January 2023. These individuals were subsequently classified into EF and IEF groups. Exclusions comprised patients presenting with pathological fracture, neuromuscular disorder, metabolic disease, prior tibial fracture or instrumentation, and polytrauma. Additionally, individuals with a follow-up duration of more than 12 months or incomplete medical records were excluded.
RESULTS: A total of 45 patients were divided into two groups: the EF group, comprising 24 patients (18 males, 6 females), and the IEF group, consisting of 21 patients (17 males, 4 females). The two groups exhibited no statistically significant differences in terms of sex, age, body weight, time from injury to surgery, AO classification, or concomitant injuries. There were two cases of nonunion in the EF group. Radiological union occurred more rapidly in the IEF group (7.8 ± 0.4 weeks) than in the EF group (9.3 ± 1.1 weeks) (P < 0.05). The mean hospitalization duration differed significantly between the EF group (6.7 ± 3.4 days) and the IEF group (7.5 ± 1.1 days) (P > 0.05). The mean duration of the operative procedure significantly differed between the IEF group (147.8 ± 24.5 min) and the EF group (77.2 ± 43.9 min) (P < 0.001). A significant difference (P < 0.001) in weight-bearing time was observed between the IEF group (2.6 ± 0.7 weeks) and the EF group (9.9 ± 1.4 weeks). According to the Johner-Wruhs criteria, no significant differences were found between the two groups. A significant difference (P < 0.001) in hospitalization costs was observed between the IEF group (7848.0 ± 262.4 $) and the EF group (5403.0 ± 233.3 $).
CONCLUSIONS: EF is cheaper, quicker and simpler and we need more randomized controlled studies and that this is a pilot study only. Both types of surgery are good choices for children. Nevertheless, the IEF group demonstrates advantages such as early weight-bearing capability and faster fracture healing.

UNASSIGNED: We aimed to explore the associations of the early PVR in four cortices with Healing Index (HI), Lengthening Index (LI), and External Fixator Index (EFI) in the bone union and non-union groups.
UNASSIGNED: A total of 52 patients, including 39 bone union and 13 bone non-union subjects, were recruited in this study. The general characteristics and PVR in four cortices in each group were explored. Afterward, the early PVR in four cortices, including medial, lateral, anterior, and posterior sides, were compared. Finally, the associations of the early PVR in four cortices with HI, LI, and EFI were also investigated.
UNASSIGNED: The general characteristics of these patients were consistent, except for HI (31.54 ± 12.24 vs. 45.08 ± 27.10, P = 0.018) and EFI (57.63 ± 18.15 vs. 71.29 ± 24.60, P = 0.046). The growth of regenerated callus was asymmetrical in the bone union group (the posterior PVR seems to grow faster), whereas no statistical difference was obtained in the bone non-union group. Furthermore, the posterior PVR in the bone union group was significantly higher than that in the bone non-union group (the first month: 0.96 ± 0.17 vs. 0.86 ± 0.06, p = 0.047; the second month: 0.98 ± 0.14 vs. 0.89 ± 0.09, p = 0.041; the third month: 1.00 ± 0.12 vs. 0.92 ± 0.09, p = 0.039). Most importantly, the posterior PVR was inversely associated with HI, LI, and EFI (the first month: r = -0.343, p = 0.041; r = -0.346, p = 0.042; r = -0.352, p = 0.041; the second month: r = -0.459, p = 0.004; r = -0.277, p = 0.101; r = -0.511, p = 0.002; the third month: r = -0.479, p = 0.003; r = -0.398, p = 0.018; r = -0.551, p = 0.001) in the bone union group, respectively. However, this finding was lost in the bone non-union group.
UNASSIGNED: The early posterior cortex PVR seems to grow faster than the medial, lateral, and anterior sides in the bone union group, which represents an asymmetrical development pattern. Moreover, the posterior cortex PVR was negatively associated with HI, LI, and EFI, respectively. The posterior cortex PVR may be a novel and reliable detection index in the process of DO.

BACKGROUND: Current research lacks a model of knee extension contracture in rats.
OBJECTIVE: To elucidate the formation process of knee extension contracture.
METHODS: We developed a rat model using an aluminum external fixator. Sixty male Sprague-Dawley rats with mature bones were divided into the control group (n = 6) and groups that had the left knee immobilized with an aluminum external fixator for 1, 2, and 3 d, and 1, 2, 3, 4, 6, and 8 wk (n = 6 in each group). The passive extension range of motion, histology, and expression of fibrosis-related proteins were compared between the control group and the immobilization groups.
RESULTS: Myogenic contracture progressed very quickly during the initial 2 wk of immobilization. After 2 wk, the contracture gradually changed from myogenic to arthrogenic. The arthrogenic contracture progressed slowly during the 1st week, rapidly progressed until the 3rd week, and then showed a steady progression until the 4rd week. Histological analyses confirmed that the anterior joint capsule of the extended fixed knee became increasingly thicker over time. Correspondingly, the level of transforming growth factor beta 1 (TGF-β1) and phosphorylated mothers against decapentaplegic homolog 2 (p-Smad2) in the anterior joint capsule also increased with the immobilization time. Over time, the cross-sectional area of muscle fibers gradually decreased, while the amount of intermuscular collagen and TGF-β1, p-Smad2, and p-Smad3 was increased. Unexpectedly, the amount of intermuscular collagen and TGF-β1, p-Smad2, and p-Smad3 was decreased during the late stage of immobilization (6-8 wk). The myogenic contracture was stabilized after 2 wk of immobilization, whereas the arthrogenic contracture was stabilized after 3 wk of immobilization and completely stable in 4 wk.
CONCLUSIONS: This rat model may be a useful tool to study the etiology of joint contracture and establish therapeutic approaches.