Auditory training remodels hippocampus-related memory in adult rats.

Consequences of perceptual training, such as improvements in discriminative ability, are highly stimulus and task specific. Therefore, most studies on auditory training-induced plasticity in adult brain have focused on the sensory aspects, particularly on functional and structural effects in the auditory cortex. Auditory training often involves, other than auditory demands, significant cognitive components. Yet, how auditory training affects cognition-related brain regions, such as the hippocampus, remains unclear. Here, we found in female rats that auditory cue-based go/no-go training significantly improved the memory-guided behaviors associated with hippocampus. The long-term potentiations of the trained rats recorded in vivo in the hippocampus were also enhanced compared with the naïve rats. In parallel, the phosphorylation level of calcium/calmodulin-dependent protein kinase II and the expression of parvalbumin-positive interneurons in the hippocampus were both upregulated. These findings demonstrate that auditory training substantially remodels the processing and function of brain regions beyond the auditory system, which are associated with task demands.

Selective corticofugal modulation on sound processing in auditory thalamus of awake marmosets.

Cortical feedback has long been considered crucial for the modulation of sensory perception and recognition. However, previous studies have shown varying modulatory effects of the primary auditory cortex (A1) on the auditory response of subcortical neurons, which complicate interpretations regarding the function of A1 in sound perception and recognition. This has been further complicated by studies conducted under different brain states. In the current study, we used cryo-inactivation in A1 to examine the role of corticothalamic feedback on medial geniculate body (MGB) neurons in awake marmosets. The primary effects of A1 inactivation were a frequency-specific decrease in the auditory response of most MGB neurons coupled with an increased spontaneous firing rate, which together resulted in a decrease in the signal-to-noise ratio. In addition, we report for the first time that A1 robustly modulated the long-lasting sustained response of MGB neurons, which changed the frequency tuning after A1 inactivation, e.g. some neurons are sharper with corticofugal feedback and some get broader. Taken together, our results demonstrate that corticothalamic modulation in awake marmosets serves to enhance sensory processing in a manner similar to center-surround models proposed in visual and somatosensory systems, a finding which supports common principles of corticothalamic processing across sensory systems.

Prevalence, associated factors, and gene polymorphisms of obesity in Tibetan adults in Qinghai, China.

OBJECTIVES: To explore the prevalence and associated factors of obesity in Tibetan adults in Qinghai, China, and to determine the association between the FTO (rs1121980 and rs17817449) and MC4R gene (rs17782313 and rs12970134) polymorphisms with obesity. METHODS: A cross-sectional survey was conducted in 2015 in Qinghai to selected Tibetan adults aged 20 to 80 years. Prevalence of obesity (BMI ≥ 28 kg/m2) and overweight (BMI 24 ~ 27.9 kg/m2) were evaluated. Multivariable logistic models were used to determine the associated factors. Pair-matched subjects of obesity cases and normal-weight controls were selected for the gene polymorphism analyses. Conditional logistic models were used to assess the association between gene polymorphisms with obesity. Additive and multiplicative gene-environment interactions were tested. RESULTS: A total of 1741 Tibetan adults were enrolled. The age- and sex- standardized prevalence of obesity and overweight was 18.09% and 31.71%, respectively. Male sex, older age, heavy level of leisure-time exercise, current smoke, and heavy level of occupational physical activity were associated with both obesity and overweight. MC4R gene polymorphisms were associated with obesity in Tibetan adults. No significant gene-environment interaction was detected. CONCLUSION: The prevalence of obesity and overweight in Tibetan adults was high. Both environmental and genetic factors contributed to the obesity prevalent.

Corticofugal modulation of temporal and rate representations in the inferior colliculus of the awake marmoset.

Temporal processing is crucial for auditory perception and cognition, especially for communication sounds. Previous studies have shown that the auditory cortex and the thalamus use temporal and rate representations to encode slowly and rapidly changing time-varying sounds. However, how the primate inferior colliculus (IC) encodes time-varying sounds at the millisecond scale remains unclear. In this study, we investigated the temporal processing by IC neurons in awake marmosets to Gaussian click trains with varying interclick intervals (2-100 ms). Strikingly, we found that 28% of IC neurons exhibited rate representation with nonsynchronized responses, which is in sharp contrast to the current view that the IC only uses a temporal representation to encode time-varying signals. Moreover, IC neurons with rate representation exhibited response properties distinct from those with temporal representation. We further demonstrated that reversible inactivation of the primary auditory cortex modulated 17% of the stimulus-synchronized responses and 21% of the nonsynchronized responses of IC neurons, revealing that cortico-colliculus projections play a role, but not a crucial one, in temporal processing in the IC. This study has significantly advanced our understanding of temporal processing in the IC of awake animals and provides new insights into temporal processing from the midbrain to the cortex.

Toll-like receptor 4-mediated necroptosis in the development of necrotizing enterocolitis.

BACKGROUND: Dramatic intestinal epithelial cell death leading to barrier dysfunction is one of the mechanism of neonatal necrotizing enterocolitis (NEC), in which Toll-like receptor 4 (TLR4) plays a pivotal role. This study explored the role of necroptosis, a drastic way of cell death in NEC. METHODS: The expression of necroptotic proteins was tested in NEC intestinal tissue and compared with controls. NEC was induced in neonatal wild-type mice and a necroptosis inhibitor was given to investigate whether NEC could be relieved. The general condition, macroscopic scoring, and histological evaluations were performed. The expression of tight junction proteins, inflammatory cytokines, and necroptosis-related proteins was measured, and barrier function was examined. Then, NEC was induced in TLR4-knockout pups to confirm the role of TLR4 in necroptosis. RESULTS: Necroptotic proteins were significantly upregulated in both NEC patient and animal models, together with the expression of TLR4. NEC could be relieved and inflammatory infiltration was decreased by necrostatin-1s. TLR4-knockout mice showed milder tissue degradation and less necroptosis after NEC induction. CONCLUSIONS: Necroptosis is an essential pathological process of NEC. TLR4 may be one stimulator of necroptosis in NEC. Inhibiting the intestinal cell necroptosis might be a useful strategy in the treatment of NEC. IMPACT: Necroptosis is a key pathological process in NEC, which appears to involve TLR4. Anti-necroptosis treatment is a promising strategy that could significantly relieve the symptoms of NEC.

Predictive factors for open reduction of flexion-type supracondylar fracture of humerus in children.

OBJECTIVE: The incidence of open reduction and internal fixation (ORIF) in flexion-type supracondylar humerus fractures (SCHF) in children is significantly higher than that of extension-type fractures. This study aimed to identify risk factors for ORIF in flexion-type SCHF. METHODS: One hundred seventy-one patients with Wilkins type III flexion-type SCHF from January 2012 to December 2021 were retrospectively enrolled in a tertiary paediatric hospital. Patients were divided into ORIF group versus closed reduction and internal fixation (CRIF) group. Then, patients data of age, sex, injury side, obesity, deviation of displacement, fracture level, rotation, nerve injury, and delay from injury to surgery were reviewed. Univariate analysis and multivariate logistic regression were used to identify independent risk factors and odds ratios (OR) of ORIF. RESULTS: Overall, 171 children with type III flexion-type SCHF were analyzed (average aged 7.9 ± 2.8 years). Displacement was lateral in 151 cases, medial in 20. 20 cases had combined ulnar nerve injury. The failed closed reduction rate was 20%. Univariate analysis indicated age, distal fracture fragment rotation, and ulnar nerve injury were significantly associated with ORIF. (P = 0.047, P = 0.009, and P = 0.001, respectively). Multivariate logistic regression analysis showed that distal fracture fragment rotation (OR, 3.3; 95%CI:1.1-9.5; P = 0.028) and ulnar nerve injury (OR, 6.4; 95%CI:2.3-18.3; P = 0.001) were independent risk factors; however, the age was not an independent one (OR, 1.5; 95%CI:0.6-3.5; P = 0.397) for ORIF in the Wilkins type III flexion-type SCHF. CONCLUSION: Distal fracture fragment malrotation on initial x-rays and ulnar nerve injury were significant risk factors for ORIF in Wilkins type III flexion-type SCHF. Surgeons should prepare tourniquets or other open reduction instruments when treating these types of fractures. LEVEL OF EVIDENCE: Level IV.

Reversal of Age-Related Changes in Cortical Sound-Azimuth Selectivity with Training.

The compromised abilities to understand speech and localize sounds are two hallmark deficits in aged individuals. Earlier studies have shown that age-related deficits in cortical neural timing, which is clearly associated with speech perception, can be partially reversed with auditory training. However, whether training can reverse aged-related cortical changes in the domain of spatial processing has never been studied. In this study, we examined cortical spatial processing in ~21-month-old rats that were trained on a sound-azimuth discrimination task. We found that animals that experienced 1 month of training displayed sharper cortical sound-azimuth tuning when compared to the age-matched untrained controls. This training-induced remodeling in spatial tuning was paralleled by increases of cortical parvalbumin-labeled inhibitory interneurons. However, no measurable changes in cortical spatial processing were recorded in age-matched animals that were passively exposed to training sounds with no task demands. These results that demonstrate the effects of training on cortical spatial domain processing in the rodent model further support the notion that age-related changes in central neural process are, due to their plastic nature, reversible. Moreover, the results offer the encouraging possibility that behavioral training might be used to attenuate declines in auditory perception, which are commonly observed in older individuals.

Prevalence and risk factors of refractive error in Qinghai, China: a cross-sectional study in Han and Tibetan adults in Xining and surrounding areas.

BACKGROUND: Our study aimed to explore the prevalence and risk factors of refractive error (RE) in Han and Tibetan population aged 50-79 years in Xining and surrounding areas in Qinghai Province on Qinghai-Tibet Plateau. METHODS: As part of the China National Health Survey, our cross-sectional study compared the age-adjusted prevalence of RE in Han and Tibetan older adults aged 50-79 years in Xining and surrounding areas. A multivariate logistic regression model was used to identify risk factors for myopia and hyperopia. RESULTS: Among 769 Han participants and 476 Tibetan participants, the age-adjusted prevalence of myopia (spherical equivalent (SE) < - 0.5D), hyperopia (SE > + 0.5D), high myopia (SE < -6.0D) and astigmatism (cylindrical equivalent > = 0.5D) is 28.56, 22.82, 2.80, and 69.38%. Han participants have higher age-adjusted prevalence of myopia (32.93% vs 21.64%, p < 0.001), high myopia (3.93% vs 1.02%, p = 0.001) and astigmatism (72.14% vs 64.94%, p = 0.021) compared to Tibetan participants. Being Tibetan is the protective factor of myopia compared to being Han (OR 0.58, 95%CI 0.42-0.79, p < 0.001). Older age (p = 0.032), longer time length in rural area (p = 0.048), undergraduate/graduate education level (p = 0.031), lighter active level (p = 0.007) and lower BMI (p = 0.015) are risk factors for myopia. Older age (all p < 0.001) and pterygium status of the same eye (p = 0.013) also increase the hyperopia risk. CONCLUSIONS: Our study found an overall prevalence of myopia of 28.56% in Xining and surrounding areas in adults older than 50 years. Han population has higher myopia risk than Tibetan population. More medical and social resources should be allocated to improve the vision and life quality of older adults.

Auditory Training Reverses Lead (Pb)-Toxicity-Induced Changes in Sound-Azimuth Selectivity of Cortical Neurons.

Lead (Pb) causes significant adverse effects on the developing brain, resulting in cognitive and learning disabilities in children. The process by which lead produces these negative changes is largely unknown. The fact that children with these syndromes also show deficits in central auditory processing, however, indicates a speculative but disturbing relationship between lead-exposure, impaired auditory processing, and behavioral dysfunction. Here we studied in rats the changes in cortical spatial tuning impacted by early lead-exposure and their potential restoration to normal by auditory training. We found animals that were exposed to lead early in life displayed significant behavioral impairments compared with naïve controls while conducting the sound-azimuth discrimination task. Lead-exposure also degraded the sound-azimuth selectivity of neurons in the primary auditory cortex. Subsequent sound-azimuth discrimination training, however, restored to nearly normal the lead-degraded cortical azimuth selectivity. This reversal of cortical spatial fidelity was paralleled by changes in cortical expression of certain excitatory and inhibitory neurotransmitter receptor subunits. These results in a rodent model demonstrate the persisting neurotoxic effects of early lead-exposure on behavioral and cortical neuronal processing of spatial information of sound. They also indicate that attention-demanding auditory training may remediate lead-induced cortical neurological deficits even after these deficits have occurred.

Positive impacts of early auditory training on cortical processing at an older age.

Progressive negative behavioral changes in normal aging are paralleled by a complex series of physical and functional declines expressed in the cerebral cortex. In studies conducted in the auditory domain, these degrading physical and functional cortical changes have been shown to be broadly reversed by intensive progressive training that improves the spectral and temporal resolution of acoustic inputs and suppresses behavioral distractors. Here we found older rats that were intensively trained on an attentionally demanding modulation-rate recognition task in young adulthood substantially retained training-driven improvements in temporal rate discrimination abilities over a subsequent 18-mo epoch-that is, forward into their older age. In parallel, this young-adult auditory training enduringly enhanced temporal and spectral information processing in their primary auditory cortices (A1). Substantially greater numbers of parvalbumin- and somatostatin-labeled inhibitory neurons (closer to the numbers recorded in young vigorous adults) were recorded in the A1 and hippocampus in old trained versus untrained age-matched rats. These results show that a simple form of training in young adulthood in this rat model enduringly delays the otherwise expected deterioration of the physical status and functional operations of the auditory nervous system, with evident training impacts generalized to the hippocampus.

[Research progress in the treatment of distal humeral metaphyseal-diaphyseal junction fracture in children].

Objective: To summarize the research progress in the treatment of distal humeral metaphyseal-diaphyseal junction (DHMDJ) fractures in children and to provide reference for clinical practice. Methods: The characteristics and treatment methods of transverse and comminuted DHMDJ fractures in children were summarized and analyzed by referring to relevant literature at home and abroad. Results: DHMDJ fractures in children are not uncommon clinically, with high fracture line position, multi-directional instability, difficult closed reduction in treatment, and easy to cause complications such as coronal and sagittal deformity of the elbow. The Kirschner wire technique was effective for DHMDJ fractures with the fracture line at the middle and low levels, but was prone to iatrogenic ulnar nerve injury. Elastic stable intramedullary nail is suitable for higher-position transverse DHMDJ fractures. However, this technique requires a second operation to remove the internal fixator, and may cause iatrogenic epiphysis plate injury in children. External fixator is a new way to treat DHMDJ fractures, and it can show satisfactory results for transverse and comminuted DHMDJ fractures. However, at present, there are few relevant studies, and most of them focus on biomechanical studies, and the efficacy lacks high-quality clinical research support. Conclusion: The ultimate goal of DHMDJ fracture treatment in children is to restore the anatomical alignment of the fracture and prevent the loss of reduction. The choice of internal fixator depends on the location of the fracture line and the shape of the fracture to provide personalized treatment.

[Application of external fixator combined with Kirschner wire fixation for oblique and comminuted distal humeral metaphyseal-diaphyseal junction fractures in children].

Objective: 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. Methods: 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. Results: 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. Conclusion: 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.

Comparison of ultrasound-guided closed reduction and percutaneous pinning fixation for unstable humeral lateral condylar fractures.

Objective: Ultrasound-guided techniques have become popular in severe humeral lateral condylar fractures (HLCFs). This study compared the results of ultrasound-guided closed reduction and percutaneous pinning (UG-CRPP) for Song types 4 and 5 and dislocation type of HLCFs. Methods: This retrospective study was conducted in patients with HLCFs treated between January 2021 and October 2022 at three hospitals. The patients were divided into three groups according to Song's classification and elbow dislocation. The surgical time, reduction failure rate, and outcomes of the three groups were compared. Results: The mean surgical time of the 94 patients across the three groups (Song 4 group, 42 cases; Song 5 group, 38 cases; and dislocation group, 14 cases) was the longest for Song 4 (66.14 ± 23.05 min), followed by the dislocation group (59.71 ± 21.07 min) and Song 5 (52.16 ± 14.94 min) (for all, P = 0.009). The failure rate decreased in the following order: dislocation group (5/14), Song 4 group (7/42), and Song 5 group (2/38). The failure rate of closed reduction in Song 4 was 3.2-fold higher than that in Song 5, and for the dislocation group, it was 7.6-fold higher than that in Song 5. Significant differences were observed between the Song 4, Song 5, and dislocation groups in terms of shaft-condylar angle and supination (P = 0.015, P = 0.043). No significant differences (P > 0.05) were observed in the carry angle, flexion, extension, or pronation of the three groups. Two cases of delayed healing, four cases of superficial infection, one case of trochlear necrosis, and 39 cases of lateral spur in the Song 4 group were observed. In the Song 5 group, five had a superficial infection, one had re-displacement, and 26 had a lateral spur. In the dislocation group, there were two cases of superficial infection and 10 of lateral spurs. Conclusions: Song 4 HLCFs require longer surgical time and present more postoperative complications than Song 5 and dislocation-type HLCFs and can easily lead to lateral spurs. The failure rates of closed reduction in Song 4 and the dislocation type were higher than those in Song 5. Thus, UG-CRPP can be used to treat patients with unstable HLCFs.

Criteria of ultrasound-guided closed reduction with percutaneous pinning in unstable humeral lateral condylar fractures: a three-center retrospective cohort study.

Background: Interventions using ultrasound-guided closed reduction and percutaneous pinning (UG-CRPP) of humeral lateral condylar fractures (HLCFs) have been increasingly applied; however, their effectiveness for unstable HLCFs and the criteria for ultrasound outcomes remain unclear. This study assessed the outcomes of UG-CRPP for HLCFs and evaluated the success criteria in children. Methods: Data were retrospectively collected from 106 patients with unstable HLCFs admitted to three hospitals between January 2021 and August 2022. Fifty-five cases were left-sided and 51 cases were right-sided: 74 male patients and 32 female patients were included. Perioperative data, elbow function, complications, and criteria for UG-CRPP were analyzed. Results: The mean rate of UG-CRPP was 88%. The mean surgical time was 54.56 ± 21.07 min, and the mean fluoroscopy frequency was 9.25 ± 2.93 times. At the last follow-up, there were significant differences in elbow flexion between the affected side (135.82° ± 6.92°) and the unaffected side (140.58° ± 5.85°) (p = 0.01). The Mayo score of the affected side was 90.28° ± 4.97°, the Baumann angle was 71.4° ± 5.4°, condylar shaft angle was 39.9° ± 6.4°, and the carrying angle was 8.4° ± 3.6°. Seventy patients presented mild lateral spurs and 16 patients exhibited moderate spurs. Fourteen patients presented with pin infection, and one patient exhibited postoperative re-displacement. There was no premature physeal closure, varus, or valgus elbow deformity, delayed union, or non-union. Successful ultrasound-based outcome criteria for UG-CRPP were defined as follows: (i) absent or less than a cartilage thickness step on the cartilage hinge on coronal plane parallel articular surface scanning, (ii) no lateral displacement and intact distal end of the condylar and capitellum on coronal plane vertical articular surface scanning, (iii) no anteroposterior displacement and absent or less than a cartilage thickness step on sagittal plane vertical articular surface scanning, and (iv) intact posterior fracture line or less than a cortex step on posterolateral sagittal plane vertical articular surface scanning. Conclusion: UG-CRPP is a procedure with minimal blood loss, less invasive, cosmetic, and no radiation exposure. It yielded good outcomes in unstable HLCFs. The successful criteria make it suitable for clinical application.

[Effectiveness comparison of ultrasound-guided closed reduction and Kirschner wire fixation for different unstable humeral lateralcondylar fractures of children].

Objective: To compare the effectiveness of ultrasound-guided closed reduction and Kirschner wire fixation for different unstable humeral lateralcondylar fractures of children. Methods: The clinical data of 94 children with unstable humeral lateralcondylar fractures admitted to three medical centers between January 2021 and October 2022 were retrospectively analyzed. The children were divided into three groups according to the Song classification and whether the elbow joint was dislocated or not, including 42 cases of Song 4 type (group A), 38 cases of Song 5 type (group B), and 14 cases of elbow joint dislocation (group C). There was no significant difference in gender, age, side, cause of injury, and time from injury to operation among the three groups ( P>0.05). All children were treated with ultrasound-guided closed reduction and Kirschner wire fixation. The operation time and complications of the three groups were recorded and compared, and the failure of closed reduction was evaluated by ultrasound. X-ray examination was performed at last follow-up to measure the Baumann angle, condylar angle, carrying angle, and lateral osteophyte of the affected side; the extension, flexion, pronation, and supination range of motion of the affected elbow joint were measured; the function of the elbow joint was evaluated by Mayo score. Results: The operation time in group A was significantly longer than that in groups B and C ( P<0.05). There were 7, 2, and 5 cases of closed reduction failure in groups A, B, and C, respectively, and there was no significant difference in the incidence of the closed reduction failure ( P>0.05). All patients were followed up 6-28 months, with an average of 15.7 months. There was no significant difference in the follow-up time among the three groups ( P>0.05). Complications: in group A, there were 2 cases of delayed union, 4 cases of needle tract infection, 1 case of trochlear necrosis, and 39 cases of lateral osteophyte; in group B, there was 1 case of malunion, 5 cases of needle tract infection, 1 case of redisplacement, and 26 cases of lateral osteophyte; in group C, there were 2 cases of needle tract infection and 10 cases of lateral osteophyte. There was no significant difference in the incidence of complications among the three groups ( P>0.05). No cubitus varus or cubitus valgus deformity was found in all patients. At last follow-up, except that the condylar angle in group A was significantly greater than that in groups B and C ( P<0.05), there was no significant difference in other imaging indicators, elbow range of motion, or Mayo score between groups ( P>0.05). Conclusion: The Song type 4 of humeral lateralcondylar fracture treated with ultrasound-guided closed reduction and Kirschner wire fixation has a longer operation time, more postoperative complications, and is more prone to lateral osteophyte.

[Comparative study of external fixator combined with Kirschner wire fixation and Kirschner wires fixation in treatment of cubitus varus deformity in children].

Objective: 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. Methods: 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. Results: 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). Conclusion: 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.

Application of ultrasound in the management of TRASH (the radiographic appearance seemed harmless) fractures in preschool children: A review.

Elbow fracture is one of the most common fractures in preschool children, and the secondary ossification center appears regularly with age increasing. Transphyseal separation of the distal humerus, medial humeral condyle fracture, lateral humeral condyle fracture, radial head osteochondral separation, and Monteggia fracture (minimal ulnar bow type) are difficult to diagnose based on X-ray films alone because of the unossified secondary ossification center or a suspicious non-alignment of the anatomical cartilage of the elbow joint in preschool children. These 5 fractures above are defined as The Radiographic Appearance Seemed Harmless fractures in preschool children (TRASH-PS). The TRASH-PS fractures must be taken into consideration when there is swelling at the injured site without fracture feature on X-ray. Additionally, relevant misdiagnosis or unsuitable management can lead to elbow dysfunction and deformity. Therefore, this work reviews the application of ultrasound in the management of TRASH-PS fractures.

[Reconstruction of medial and lateral column periosteal hinge using Kirschner wire to assist in closed reduction of multi-directional unstable humeral supracondylar fractures in children].

Objective: To investigate the effectiveness of medial and lateral column periosteal hinge reconstruction using Kirschner wire in the closed reduction of multi-directional unstable humeral supracondylar fractures in children. Methods: A clinical data of 43 children with multi-direction unstable humeral supracondylar fractures, who met the selection criteria and were admitted between August 2020 and August 2022, was retrospectively analyzed. Twenty-one cases of fractures were treated wuth closed reduction after medial and lateral column periosteal hinge reconstruction using Kirschner wire and percutaneous Kirschner wires fixation (study group), while 22 cases of fractures were treated by traditional closed reduction technique and percutaneous Kirschner wire fixation (control group). There was no significant difference in gender, age, cause of injury, fracture side, and interval from injury to operation between the two groups ( P>0.05). The operation time, intraoperative fluoroscopy times, the number of children who were changed to open reduction after closed reduction failure, fracture healing time, complications within 2 months after operation, and the Flynn score of elbow joint function at last follow-up were compared between the two groups. Results: All the fractures in the study group were successfully closed reduction, and 4 cases in the control group were changed to open reduction and completed the operation, the difference between the two groups was significant ( P=0.040). The operation time and intraoperative fluoroscopy times of the study group were significantly less than those of the control group ( P<0.05). All children in both groups were followed up 6-18 months with an average of 9.0 months in the study group and 9.8 months in the control group. Imaging review showed that the fractures of both groups healed, and the difference in the healing time between the two groups was not significant ( P=0.373). According to Flynn score at last follow-up, the excellent and good rate of elbow joint function was 95.2% (20/21) in the study group and 86.4% (19/22) in the control group, with no significant difference ( P=0.317). There was no complication such as infection or irritation at the end of Kirchner wire within 2 months after operation. Conclusion: For children with multi-directional unstable humeral supracondylar fractures, the use of Kirschner wires to reconstruct the medial and lateral column periosteal hinge to assist in closed reduction has the advantages of shortening operation time, reducing intraoperative fluoroscopy times, and effectively reducing the incidence of open reduction, and can achieve similar postoperative elbow joint function when compared with traditional closed reduction technique.

Assessment of Instant Loss of Elbow Flexion in Children with Untreated Gartland IIA Humeral Supracondylar Fractures-A Simulation Study with Lateral Elbow Radiographs.

OBJECTIVE: The suitability of in situ cast fixation for treating Gartland IIA humeral supracondylar fractures has remained controversial due to concerns regarding loss of elbow flexion. This study aimed to assess the instant loss of elbow flexion after Gartland IIA humeral supracondylar fractures based on the relationship between the anterior marginal line of the humerus and capitellum in the lateral view. METHODS: This simulation study was conducted with normal radiographs using Adobe Photoshop 14.0, followed by verification using clinical cases. Standard lateral views of normal elbows of children were collected from January 2008 to February 2020. Adobe Photoshop was used to simulate Gartland IIA supracondylar fractures with different degrees of angulation in the sagittal plane. A formula was deduced to assess flexion loss, and this method was verified in three cases. The data were grouped by age, and the relationship between elbow flexion loss and age, as well as the angulation of the fracture, was analyzed using a one-way or multivariate ANOVA. RESULTS: There was a flexion loss of 19° (11-30°) when the anterior margin line of the humerus was tangential to the capitellum. This loss increased with age at injury (r = 0.731, P = 0.000). Moreover, the difference in angulation in the sagittal plane also influenced the extent of elbow flexion loss (r = -0.739, P = 0.000). The more horizontal the fracture line in the lateral view, the greater the loss of elbow flexion. CONCLUSION: Instant elbow flexion loss after Gartland IIA humeral supracondylar fractures increases with age at the time of injury and decreases with angulation in the sagittal plane. When the anterior margin of the humerus is tangential to the capitellum, there will be an average loss of 19° in elbow flexion. These findings provide a quantitative reference for clinical decision-making in the treatment of Gartland IIA supracondylar fractures.

[Short-term effectiveness of ultrasound-guided Kirschner wire provocation technique in treatment of Salter-Harris types â and â ¡ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents].

Objective: To investigate the short-term effectiveness of ultrasound-guided closed reduction by Kirschner wire provocation technique in the treatment of Salter-Harris types Ⅰ and Ⅱ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents. Methods: Between May 2019 and May 2022, 41 patients with Salter Harris types Ⅰ and Ⅱ distal tibial epiphyseal fractures were admitted, all of whom had periosteal entrapment on preoperative MRI, and 38 cases (92.7%) were confirmed to have periosteal entrapment by intraoperative ultrasound. There were 24 males and 14 females, the age ranged from 6.8 to 15.7 years, with an average of 10.7 years; and there were 20 cases of Salter Harris type Ⅰ and 18 cases of type Ⅱ. The time from injury to operation was 22-76 hours, with an average of 28.4 hours. The preoperative imaging examination showed excellent alignment in 4 cases, good in 20 cases, and poor in 14 cases. The ultrasound guided Kirschner wire provocation technique for closed reduction and percutaneous Kirschner wire internal fixation were performed. The operation time, intraoperative fluoroscopy frequency, fracture healing time, and complications were recorded. Anteroposterior and lateral X-ray films of the affected ankle joint were taken before operation, at 3 months after operation, and at last follow-up to observe the healing of the fracture, and anteroposterior X-ray films of the whole length of both lower limbs were taken to evaluate the alignment of the force lines of the affected limbs. The range of motion (ROM), visual analogue scale (VAS) score, and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used to evaluate ankle function. The mechanical lateral distal tibia angle (mLDTA) and the anatomic anterior distal tibia angle (aADTA) were measured. Results: The operation time ranged from 17 to 52 minutes, with an average of 22.6 minutes, and the intraoperative fluoroscopy frequency ranged from 3 to 11 times, with an average of 4.2 times. X-ray examination during operation and at 2 days after operation showed that anatomical reduction was achieved. All patients were followed up 10-24 months, with an average of 16.4 months. All fractures healed in 6.1-7.2 weeks, with an average of 6.3 weeks; no fracture displacement occurred, and the patients recovered to their pre-injury level of motion at 6 months after operation. Needle tail irritation occurred in 2 cases at 4 weeks after operation, and they recovered after symptomatic treatment. During the follow-up, there was no serious complication such as incision deep infection, bone nonunion, delayed union, and malunion. At last follow-up, the patients' alignment were all excellent, and the difference was significant when compared with preoperative one ( Z=-7.471, P<0.001). The VAS score, AOFAS ankle-hindfoot score, dorsiflexion-plantar flexion ROM, varus-valgus ROM, mLDTA, and aADTA significantly improved at 3 months after operation and last follow-up when compared with preoperative ones ( P<0.05). Conclusion: Ultrasound-guided closed reduction by Kirschner wire provocation technique for treating Salter-Harris types Ⅰ and Ⅱ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents is minimally invasive and safe.