Modulating the Thermoresponsive Characteristics of PLGA-PEG-PLGA Hydrogels via Manipulation of PLGA Monomer Sequences.

Hydrogels are promising materials for biomedical applications, particularly in drug delivery and tissue engineering. This study highlights thermoresponsive hydrogels, specifically poly(lactic-co-glycolic acid) (PLGA)-poly(ethylene glycol) (PEG)-PLGA triblock copolymers, and introduces a feed rate-controlled polymerization (FRCP) method. By utilizing an organic catalyst and regulating the monomer feed rate, the sequence distribution of PLGA within the triblock copolymer is controlled. Various analyses, including 13C NMR and rheological measurements, were conducted to investigate the impact of sequence distribution. Results show that altering sequence distribution significantly influences the sol-gel transition, hydrophobicity-hydrophilicity balance, and drug release profile. Increased sequence uniformity lowers the glass transition temperature, raises the sol-gel transition temperature due to enhanced hydrophilicity, and promotes a more uniform drug (curcumin) distribution within the PLGA domain, resulting in a slower release rate. This study emphasizes the importance of PLGA sequence distribution in biomedical applications and the potential of FRCP to tailor thermoresponsive hydrogels for biomedical advancements.

Comparative In Vitro Dissolution Assessment of Calcined and Uncalcined Hydroxyapatite Using Differences in Bioresorbability and Biomineralization.

This study reports the effect of the not-calcining process on the bioresorption and biomineralization of hydroxyapatite through in vitro dissolution assessment. The prepared calcined hydroxyapatite (c-HAp) and uncalcined hydroxyapatite (unc-HAp) have a particle size of 2 µm and 13 µm, surface areas of 4.47 m2/g and 108.08 m2/g, and a Ca/P ratio of 1.66 and 1.52, respectively. In vitro dissolution assessments of c-HAp and unc-HAp were performed for 20 days at 37 °C in a citric acid buffer according to ISO 10993-14. During the dissolution, the c-HAp and unc-HAp confirmed an increase in weight, and the calcium and phosphorous ions were rapidly released. The calcium ions released from c-HAp formed rod-shaped particles with a longer and thinner morphology, while in unc-HAp, they appeared thicker and shorter. In the ICP-OES results, the concentrations of calcium elements were initially increased and then decreased by this formation. The rod-shaped particles identified as calcium citrate (Ca-citrate) through the XRD pattern. The calcium content of Ca-citrate particles from unc-HAp was higher than that from c-HAp. The unc-HAp demonstrated non-toxic properties in a cytotoxicity evaluation. Therefore, due to its higher bioresorption and biomineralization, unc-HAp exhibits enhanced biocompatibility compared to c-HAp.

Explainable Model Using Shapley Additive Explanations Approach on Wound Infection after Wide Soft Tissue Sarcoma Resection: "Big Data" Analysis Based on Health Insurance Review and Assessment Service Hub.

Background and Objectives: Soft tissue sarcomas represent a heterogeneous group of malignant mesenchymal tissues. Despite their low prevalence, soft tissue sarcomas present clinical challenges for orthopedic surgeons owing to their aggressive nature, and perioperative wound infections. However, the low prevalence of soft tissue sarcomas has hindered the availability of large-scale studies. This study aimed to analyze wound infections after wide resection in patients with soft tissue sarcomas by employing big data analytics from the Hub of the Health Insurance Review and Assessment Service (HIRA). Materials and Methods: Patients who underwent wide excision of soft tissue sarcomas between 2010 and 2021 were included. Data were collected from the HIRA database of approximately 50 million individuals' information in the Republic of Korea. The data collected included demographic information, diagnoses, prescribed medications, and surgical procedures. Random forest has been used to analyze the major associated determinants. A total of 10,906 observations with complete data were divided into training and validation sets in an 80:20 ratio (8773 vs. 2193 cases). Random forest permutation importance was employed to identify the major predictors of infection and Shapley Additive Explanations (SHAP) values were derived to analyze the directions of associations with predictors. Results: A total of 10,969 patients who underwent wide excision of soft tissue sarcomas were included. Among the study population, 886 (8.08%) patients had post-operative infections requiring surgery. The overall transfusion rate for wide excision was 20.67% (2267 patients). Risk factors among the comorbidities of each patient with wound infection were analyzed and dependence plots of individual features were visualized. The transfusion dependence plot reveals a distinctive pattern, with SHAP values displaying a negative trend for individuals without blood transfusions and a positive trend for those who received blood transfusions, emphasizing the substantial impact of blood transfusions on the likelihood of wound infection. Conclusions: Using the machine learning random forest model and the SHAP values, the perioperative transfusion, male sex, old age, and low SES were important features of wound infection in soft-tissue sarcoma patients.

Does the Clinical Presentation of Secondary Osteosarcoma in Patients Who Survive Retinoblastoma Differ From That of Conventional Osteosarcoma and How Do We Detect Them?

BACKGROUND: Osteosarcoma is the most common secondary malignancy among survivors of retinoblastoma. Most previous reports on secondary malignancy of retinoblastoma included all types of secondary malignancies without a focus on osteosarcoma, owing to its rarity. In addition, there are few studies suggesting tools for regular surveillance for early detection. QUESTIONS/PURPOSES: (1) What are the radiologic and clinical characteristics of secondary osteosarcoma after retinoblastoma? (2) What is the clinical survivorship? (3) Is a radionuclide bone scan a reasonable imaging modality for early detection in patients with retinoblastoma? METHODS: Between February 2000 and December 2019, we treated 540 patients for retinoblastoma. Twelve patients (six male, six female) subsequently developed an osteosarcoma in the extremities; two of these patients had two sites of osteosarcoma (10 femurs, four tibiae) . A Technetium-99m bone scan image was examined annually in all patients for regular surveillance after the treatment of retinoblastoma as per our hospital's policy. All patients were treated with the same strategy as that used for primary conventional osteosarcoma, namely neoadjuvant chemotherapy, wide excision, and adjuvant chemotherapy. The median follow-up period was 12 years (range 8 to 21 years). The median age at the time of diagnosis of osteosarcoma was 9 years (range 5 to 15 years), and the median interval from retinoblastoma diagnosis to osteosarcoma diagnosis was 8 years (range 5 to 15 years). Radiologic characteristics were assessed with plain radiographs and MRI, while clinical characteristics were assessed through a retrospective review of medical records. For clinical survivorship, we evaluated overall survival, local recurrence-free survival, and metastasis-free survival. We reviewed the results of bone scans and clinical symptoms at the time of diagnosis for osteosarcoma after retinoblastoma. RESULTS: In nine of 14 patients, the tumor had a diaphyseal center, and five of the tumors were located at the metaphysis. The femur was the most common site (n = 10), followed by the tibia (n = 4). The median tumor size was 9 cm (range 5 to 13 cm). There was no local recurrence after surgical resection of the osteosarcoma, and the 5-year overall survival rate after the diagnosis of osteosarcoma was 86% (95% CI 68% to 100%). In all 14 tumors, the Technetium bone scan showed increased uptake in the lesions. Ten of 14 tumors were examined in clinic because of patient complaints of pain in the affected limb. Four patients showed no clinical symptoms detected by abnormal uptake on bone scan. CONCLUSION: For unclear reasons, secondary osteosarcomas in patients who were alive after the treatment of retinoblastoma had a slight predilection for the diaphysis of the long bone compared with patients with spontaneous osteosarcoma in other reports. The clinical survivorship of osteosarcoma as a secondary malignancy after retinoblastoma may not be inferior to that of conventional osteosarcoma. Close follow-up with at least yearly clinical assessment and bone scans or other imaging modalities appears to be helpful in detecting secondary osteosarcoma after the treatment of patients with retinoblastoma. Larger multi-institutional studies will be needed to substantiate these observations.Level of Evidenc e Level IV, therapeutic study.

Thermally Stable and Reusable Silica and Nano-Fructosome Encapsulated CalB Enzyme Particles for Rapid Enzymatic Hydrolysis and Acylation.

This study reports the preparation of silica-coated and nano-fructosome encapsulated Candida antarctica lipase B particles (CalB@NF@SiO2) and a demonstration of their enzymatic hydrolysis and acylation. CalB@NF@SiO2 particles were prepared as a function of TEOS concentration (3-100 mM). Their mean particle size was 185 nm by TEM. Enzymatic hydrolysis was performed to compare catalytic efficiencies of CalB@NF and CalB@NF@SiO2. The catalytic constants (Km, Vmax, and Kcat) of CalB@NF and CalB@NF@SiO2 were calculated using the Michaelis-Menten equation and Lineweaver-Burk plot. Optimal stability of CalB@NF@SiO2 was found at pH 8 and a temperature of 35 °C. Moreover, CalB@NF@SiO2 particles were reused for seven cycles to evaluate their reusability. In addition, enzymatic synthesis of benzyl benzoate was demonstrated via an acylation reaction with benzoic anhydride. The efficiency of CalB@NF@SiO2 for converting benzoic anhydride to benzyl benzoate by the acylation reaction was 97%, indicating that benzoic anhydride was almost completely converted to benzyl benzoate. Consequently, CalB@NF@SiO2 particles are better than CalB@NF particles for enzymatic synthesis. In addition, they are reusable with high stability at optimal pH and temperature.

Manipulating Nanoparticle Aggregates Regulates Receptor-Ligand Binding in Macrophages.

The receptor-ligand interactions in cells are dynamically regulated by modulation of the ligand accessibility. In this study, we utilize size-tunable magnetic nanoparticle aggregates ordered at both nanometer and atomic scales. We flexibly anchor magnetic nanoparticle aggregates of tunable sizes over the cell-adhesive RGD ligand (Arg-Gly-Asp)-active material surface while maintaining the density of dispersed ligands accessible to macrophages at constant. Lowering the accessible ligand dispersity by increasing the aggregate size at constant accessible ligand density facilitates the binding of integrin receptors to the accessible ligands, which promotes the adhesion of macrophages. In high ligand dispersity, distant magnetic manipulation to lift the aggregates (which increases ligand accessibility) stimulates the binding of integrin receptors to the accessible ligands available under the aggregates to augment macrophage adhesion-mediated pro-healing polarization both in vitro and in vivo. In low ligand dispersity, distant control to drop the aggregates (which decreases ligand accessibility) repels integrin receptors away from the aggregates, thereby suppressing integrin receptor-ligand binding and macrophage adhesion, which promotes inflammatory polarization. Here, we present "accessible ligand dispersity" as a novel fundamental parameter that regulates receptor-ligand binding, which can be reversibly manipulated by increasing and decreasing the ligand accessibility. Limitless tuning of nanoparticle aggregate dimensions and morphology can offer further insight into the regulation of receptor-ligand binding in host cells.

Assessment of rapidly advancing bone age during puberty on elbow radiographs using a deep neural network model.

OBJECTIVES: Bone age is considered an indicator for the diagnosis of precocious or delayed puberty and a predictor of adult height. We aimed to evaluate the performance of a deep neural network model in assessing rapidly advancing bone age during puberty using elbow radiographs. METHODS: In all, 4437 anteroposterior and lateral pairs of elbow radiographs were obtained from pubertal individuals from two institutions to implement and validate a deep neural network model. The reference standard bone age was established by five trained researchers using the Sauvegrain method, a scoring system based on the shapes of the lateral condyle, trochlea, olecranon apophysis, and proximal radial epiphysis. A test set (n = 141) was obtained from an external institution. The differences between the assessment of the model and that of reviewers were compared. RESULTS: The mean absolute difference (MAD) in bone age estimation between the model and reviewers was 0.15 years on internal validation. In the test set, the MAD between the model and the five experts ranged from 0.19 to 0.30 years. Compared with the reference standard, the MAD was 0.22 years. Interobserver agreement was excellent among reviewers (ICC: 0.99) and between the model and the reviewers (ICC: 0.98). In the subpart analysis, the olecranon apophysis exhibited the highest accuracy (74.5%), followed by the trochlea (73.7%), lateral condyle (73.7%), and radial epiphysis (63.1%). CONCLUSIONS: Assessment of rapidly advancing bone age during puberty on elbow radiographs using our deep neural network model was similar to that of experts. KEY POINTS: • Bone age during puberty is particularly important for patients with scoliosis or limb-length discrepancy to determine the phase of the disease, which influences the timing and method of surgery. • The commonly used hand radiographs-based methods have limitations in assessing bone age during puberty due to the less prominent morphological changes of the hand and wrist bones in this period. • A deep neural network model trained with elbow radiographs exhibited similar performance to human experts on estimating rapidly advancing bone age during puberty.

Depletion of Mitochondrial Components from Extracellular Vesicles Secreted from Astrocytes in a Mouse Model of Fragile X Syndrome.

Mitochondrial dysfunction contributes to neurodegenerative diseases and developmental disorders such as Fragile X syndrome (FXS). The cross-talk between mitochondria and extracellular vesicles (EVs) suggests that EVs may transfer mitochondrial components as intermediators for intracellular communication under physiological and pathological conditions. In the present study, the ability of EVs to transfer mitochondrial components and their role in mitochondrial dysfunction in astrocytes were examined in the brains of Fmr1 knockout (KO) mice, a model of FXS. The amounts of mitochondrial transcription factor NRF-1, ATP synthases ATP5A and ATPB, and the mitochondrial membrane protein VDAC1 in EVs were reduced in cerebral cortex samples and astrocytes from Fmr1 KO mice. These reductions correspond to decreased mitochondrial biogenesis and transcriptional activities in Fmr1 KO brain, along with decreased mitochondrial membrane potential (MMP) with abnormal localization of vimentin intermediate filament (VIF) in Fmr1 KO astrocytes. Our results suggest that mitochondrial dysfunction in astrocytes is associated with the pathogenesis of FXS and can be monitored by depletion of components in EVs. These findings may improve the ability to diagnose developmental diseases associated with mitochondrial dysfunction, such as FXS and autism spectrum disorders (ASD).

Association of Ankle Dorsiflexion With Plantar Fasciitis.

This study aimed to compare the mean ankle dorsiflexion range between individuals with and without plantar fasciitis using passive ankle dorsiflexion with consistent pressure, and to identify the prevalence of an isolated gastrocnemius and gastrocnemius soleus complex contracture in 2 groups. 91 participants were prospectively classified into the plantar fasciitis group (45 subjects) and the control group (46 subjects). Ankle dorsiflexion was measured with the knee extended and with the knee flexed 90° using a standard orthopedic goniometer while a consistent force of 2 kg was applied under the plantar surface of the forefoot using a custom-made scale. Intraclass correlation coefficients (ICC) were calculated to determine the interobserver and intraobserver reliability of the current ankle dorsiflexion measurement. The current ankle dorsiflexion measurement revealed excellent interobserver and intraobserver reliability. The mean ankle dorsiflexion in the knee extended was -9.6° ± 8.1° and -11.2° ± 8.2° in the study and control groups, respectively (p = .353). The mean ankle dorsiflexion in the knee flexed was 7.8° ± 6.5° and 5.1° ± 7.4° in the study and control groups, respectively (p = .068). In the study and control groups, 68.9% and 65.2%, respectively, had an isolated gastrocnemius contracture and 24.4% and 30.4%, respectively, had a gastrocnemius-soleus complex contracture (p = .768). The present study demonstrated that there were no significant differences in passive ankle dorsiflexion and in the prevalence of an isolated gastrocnemius or gastrocnemius soleus complex contracture between individuals with and without plantar fasciitis.

Excision of Intramedullary Osteoid Osteomas in the Posterior Tibial Area via Medulloscopy: A Case Report.

Osteoid osteomas are benign bone-forming lesions that usually present in adolescence. In patients with severe pain and those not responding to medication, surgical treatment should be considered. Medulloscopy is a standard arthroscopic technique for visualizing the intramedullary canal of the tibia. Herein, we report two patients with intramedullary osteoid osteomas in the posterior area of the tibia, which were successfully treated using medulloscopy. Hence, medulloscopy is an effective minimally invasive method in patients with intramedullary osteoid osteomas in the posterior tibial area.

A prospective study of the muscle strength and reaction time of the quadriceps, hamstring, and gastrocnemius muscles in patients with plantar fasciitis.

BACKGROUND: Muscle weakness is an important etiological factor in plantar fasciitis (PF), but available data on the role of the quadriceps, hamstring, and gastrocnemius (GCM) muscles are limited. The aim of this study was to compare the strength and reaction time of the quadriceps, hamstring, and GCM muscles and foot pressure between patients with PF and normal controls. METHODS: A total of 21 PF patients and 21 normal controls were enrolled. Muscle strength was measured by the peak torque per body weight (Nmkg- 1 × 100). Muscle reaction time was evaluated by the acceleration time (AT, milliseconds). Foot pressure and posture were assessed by pedobarography [valgus/varus index (VV index), %]. RESULTS: The strength of the quadriceps was significantly lower in the affected ankles of the PF group than in the control group (p = 0.005). The AT of the quadriceps and hamstring muscles was significantly increased in the affected ankles of the PF group than in the control group (quadriceps: p = 0.012, hamstring: p = 0.001), while the AT of the GCM muscle was significantly decreased (p = 0.009) and significantly correlated negatively with quadriceps muscle strength (r = -.598, p = 0.004) and AT (r = -.472, p = 0.031). Forefoot (p = 0.001) and hindfoot (p = 0.000) pressure were significantly greater, with the VV index showing hindfoot valgus, in the affected ankles in the PF group compared to the control group (p = 0.039). CONCLUSIONS: This study demonstrated weakness and delayed reaction time of the quadriceps and hamstring muscles, with a rapid reaction time of the GCM muscle, in patients with PF. CLINICAL RELEVANCE: Clinicians and therapists should assess the function of the quadriceps and hamstring muscles when planning the management of PF patients without muscle tightness.

Modified Broström procedure in patients with chronic ankle instability is superior to conservative treatment in terms of muscle endurance and postural stability.

PURPOSE: To compare muscle strength, muscle endurance, and postural stability in both the affected and unaffected ankles between patients with chronic ankle instability (CAI) who underwent conservative treatment and those who underwent the modified Broström procedure (MBP). METHODS: A total of 67 patients (37, conservative treatment; 30, MBP) participated. Muscle strength and muscle endurance were measured using an isokinetic device, and postural stability was tested using a postural stabilometry system. We used the independent t test for continuous variables with a normal distribution and Fisher's exact test for categorical variables. RESULTS: There was no difference in the muscle strengths of the affected and unaffected ankles between the groups. The muscle endurance of plantarflexion and inversion muscles was significantly lower in the affected ankles of the conservative treatment group than in those of the MBP group (plantarflexion: 209 ± 103.1 vs. 318 ± 162.2, p = 0.001; inversion: 93 ± 58.7 vs. 154 ± 65.9, p < 0.001). Static postural stability testing showed no significant differences between the affected and unaffected ankles of the two groups. In the dynamic postural stability test, the overall, anterior-posterior, and medial-lateral stability indices were all significantly higher in the affected ankles of the conservative treatment group than in those of the MBP group (p < 0.001, p = 0.004, p = 0.004, respectively), with no differences observed in the unaffected ankles. CONCLUSION: The MBP may significantly improve muscle endurance and dynamic postural stability in CAI patients in whom conservative treatment has failed. Therefore, clinicians should consider using MBP instead of conservative treatment when patients show severe muscle weakness or dynamic postural instability. LEVEL OF EVIDENCE: Case-control study, Level III.

Individuals with recurrent ankle sprain demonstrate postural instability and neuromuscular control deficits in unaffected side.

PURPOSE: To compare proprioception, postural stability, and neuromuscular control between patients with mechanical laxity and recurrent ankle sprain. METHODS: Among 86 patients with ankle instability, 45 patients had mechanical laxity (mean age 27.2 ± 7.0 years) and 41 had recurrent ankle sprain (mean age 25.1 ± 9.2 years). Both the affected and unaffected ankles of each patient were evaluated. Proprioception and neuromuscular control tests were conducted using an isokinetic machine, and postural stability was tested using a postural stabilometry system. RESULTS: Proprioception was not significantly different between the unaffected or affected ankles of the mechanical laxity group compared with those of the recurrent ankle sprain group (n.s). Static and dynamic postural stability and neuromuscular control were similar in the affected ankles between the two groups (n.s). However, postural stability (static, overall: p = 0.009, anterior-posterior: p = 0.028, medial-lateral: p = 0.022; dynamic, overall: p = 0.012, anterior-posterior: p = 0.004, medial-lateral: p = 0.001) and neuromuscular control (inversion: p = 0.031, eversion: p = 0.039, dorsiflexion: p = 0.029, plantarflexion: p = 0.035) were significantly decreased in the unaffected ankles of the recurrent ankle sprain group compared with those of the mechanical laxity group. CONCLUSION: The unaffected ankles of the recurrent ankle sprain group showed significant decreases in both postural stability and neuromuscular control compared with the mechanical laxity group. Clinicians and therapists should consider unaffected ankle rehabilitation in patients with recurrent ankle sprain to prevent future sprain events. LEVEL OF EVIDENCE: Case-control study, III.

Hepatic serum amyloid A1 upregulates interleukin-17 (IL-17) in γδ T cells through Toll-like receptor 2 and is associated with psoriatic symptoms in transgenic mice.

Serum amyloid A (SAA) is an acute phase protein with pro-inflammatory cytokine-like properties. Recent studies have revealed that SAA promoted interleukin-17 (IL-17) production by various cells, including γδ T cells. γδ T cells are innate immune cells and express Toll-like receptor 2 (TLR2) on their surface, which is one of the SAA receptors. In this study, we investigated the relationship between γδ T cells and SAA1 through TLR2, by using hepatic SAA1-overexpressing transgenic (TG) mice. By injecting CU-CPT22, which is a TLR2 inhibitor, into the mice, we confirmed that SAA1 induced IL-17 in γδ T cells through TLR2. In vitro studies have confirmed that SAA1 increased IL-17 secretion in γδ T cells in combination with IL-23. We also observed a thickened epidermis layer and granulocyte penetration into the skin similar to the pathology of psoriasis in TG mice. In addition, strongly expressed SAA1 and penetration of γδ T cells in the skin of TG mice were detected. The exacerbation of psoriasis is associated with an increase in IL-17 levels. Therefore, these symptoms were induced by IL-17-producing γδ T cells increased by SAA1. Our study confirmed that SAA1 was a prominent protein that increased IL-17 levels through TLR2 in γδ T cells, confirming the possibility that SAA1 may exacerbate inflammatory diseases through γδ T cells.

Serum amyloid A1 is involved in amyloid plaque aggregation and memory decline in amyloid beta abundant condition.

Alzheimer's disease (AD) is a neurodegenerative disorder, characterized by cognitive impairment, progressive neurodegeneration, and amyloid-ß (Aß) lesion. In the neuronal death and disease progression, inflammation is known to play an important role. Our previous study on acute-phase protein serum amyloid A1 (SAA1) overexpressed mice showed that the liver-derived SAA1 accumulated in the brain by crossing the brain blood barrier (BBB) and trigger the depressive-like behavior on mouse. Since SAA1 involved in immune responses in other diseases, we focused on the possibility that SAA1 may exacerbate the neuronal inflammation related to Alzheimer's disease. A APP/SAA overexpressed double transgenic mouse was generated using amyloid precursor protein overexpressed (APP)-c105 mice and SAA1 overexpressed mice to examine the function of SAA1 in Aß abundant condition. Comparisons between APP and APP/SAA1 transgenic mice showed that SAA1 exacerbated amyloid aggregation and glial activation; which lead to the memory decline. Behavior tests also supported this result. Overall, overexpression of SAA1 intensified the neuronal inflammation in amyloid abundant condition and causes the greater memory decline compared to APP mice, which only expresses Aß 1-42.

Intraoperative hypotension is a risk factor for postoperative acute kidney injury after femoral neck fracture surgery: a retrospective study.

BACKGROUND: Hip fracture in elderly patients is a serious health concern due to the associated morbidity and mortality. Although acute kidney injury after hip fracture is known to be a significantly poor prognostic factor for morbidity and mortality, the literature regarding the risk factors for acute kidney injury after hip fracture is insufficient. This study aimed to investigate the incidence and associated risk factors for acute kidney injury in patients with femoral neck fracture. METHODS: A total of 248 patients who underwent an operation for femoral neck fracture between January 2011 and January 2015 were retrospectively analyzed. Acute kidney injury was defined according to the Kidney Disease: Improving Global Outcomes guidelines. RESULTS: The incidence of acute kidney injury was 17.7% (n = 44). Risk factors for acute kidney injury included diabetes mellitus, pre-existing renal disease, preoperative blood urea nitrogen (BUN), preoperative estimated glomerular filtration rate (eGFR), preoperative haemoglobin (Hb) level, type of operation, postoperative creatinine level and intraoperative hypotension (P <  0.05). After controlling for confounding variables, intraoperative hypotension was only the independent risk factor for acute kidney injury (P = 0.012). CONCLUSIONS: Acute kidney injury was found to occur frequently after surgery for femur neck fracture. Surgeons should be aware of acute kidney injury when planning the management of patients with femoral neck fracture and consider that the duration of intraoperative hypotension is a risk factor for acute kidney injury.

Physeal and Subphyseal Distraction Osteogenesis in Atrophic-type Congenital Pseudarthrosis of the Tibia: Efficacy and Safety.

PURPOSE: To examine the efficacy, safety, and clinical outcomes of distraction osteogenesis through the physis (PDO) or through subphyseal osteotomy (SPDO) in patients with atrophic-type congenital pseudarthrosis of tibia with proximal tibial dysplasia. METHODS: To validate the efficacy and safety of PDO and SPDO, radiographic and clinical parameters were compared between 5 patients who underwent proximal tibial metaphyseal or metadiaphyseal lengthening as a control (group 1) and 7 patients who underwent PDO or SPDO (group 2). Postoperative complication was also compared between the groups. RESULTS: A significant difference in terms of healing index (group 1, 83.3±24.7 d/cm; group 2, 35.0±11.1 d/cm; P=0.001) and percentage increase (11.0%±3.7% vs. 23.1%±10.5%, P=0.034) was observed between the 2 groups. According to the Paley classification, group 1 included 1 "problems" case and 3 "obstacles" cases, whereas group 2 included 2 "problems" cases and 1 "obstacles" case. According to the Lascombes classification, group 1 included 2 grade IIIb cases and 3 grade IV cases, whereas group 2 included 6 grade I cases and 1 grade IIa case. Severe complications were significantly higher in group 1 compared with the group 2 (P=0.007). CONCLUSIONS: This study demonstrated that PDO or SPDO can be effectively and safely performed for tibial lengthening in atrophic-type congenital pseudarthrosis of tibia patients with proximal tibial dysplasia. LEVEL OF EVIDENCE: Level III.

Lateral column lengthening versus subtalar arthroereisis for paediatric flatfeet: a systematic review.

PURPOSE: This systematic review aimed to compare radiographic correction, clinical outcomes, complications, and re-operations between lateral column lengthening (LCL) and arthroereisis (AR) for treating symptomatic flatfoot in children. METHODS: We conducted a comprehensive search on MEDLINE, EMBASE, and Cochrane Library databases. Literature search, data extraction, and quality assessment were conducted by two independent reviewers. The outcomes analyzed included radiographic parameters, clinical scores, satisfaction, complications, and re-operations. RESULTS: Twenty-one and 13 studies were included in the LCL and AR groups, respectively. The change in anteroposterior talo-first metatarsal angle was greater in the LCL (9.5° to 21.7°) than in the AR group (10.6° to 12.8°). The change in calcaneal pitch was greater in the LCL (2.1° to 26.53°) than in the AR group (- 1.3° to 3.23°). Improvements in the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were greater in the LCL (27.7 to 39.1) than in the AR group (17 to 22). The percentage of satisfaction was similar between the LCL (68% to 89%) and AR (78.5% to 96.4%) groups. The complication rate was higher in the LCL (0% to 86.9%) than in the AR group (3.5% to 45%). The most common complications were calcaneocuboid subluxation and persistent pain in the LCL and AR groups, respectively. The re-operation rate was similar between the LCL (0% to 27.3%) and AR (0% to 36.4%) groups. CONCLUSIONS: The LCL group has achieved more radiographic corrections and more improvements in the AOFAS score than the AR group. Complications were more common in the LCL group than in the AR group, and the re-operation rates were similar between the two groups.

Is the Transverse Acetabular Ligament Hypertrophied and Hindering Reduction in Developmental Dysplasia of Hip?

PURPOSE: To investigate the arthroscopic pathoanatomy of the transverse acetabular ligament (TAL) and determine whether a TAL incision is necessary for the concentric reduction of developmental dysplasia of the hip (DDH) in infants and young children. METHODS: We retrospectively reviewed patients who underwent arthroscopic-assisted reduction for DDH between July 2008 and April 2016. The indications for this intervention included patients in whom closed reduction failed and those who did not require bone operations. The arthroscopic findings and the effect of the TAL incision on DDH reduction were evaluated. TAL pathology was apparent when it was pulled superiorly or hypertrophied. RESULTS: We identified a consecutive series of 13 patients (13 hips). Two patients with teratologic dislocation were excluded. There were 9 girls, 8 first-born infants, and 3 breech-position infants. Six patients showed positive Ortolani test findings. In all cases the TAL was considered not hypertrophied when it appeared as a narrow, cord-like structure that was continuous and in smooth transition with the TAL-labral ring, without prominence or elongation. All postreduction magnetic resonance imaging scans showed reduced femoral heads; however, residual subluxation was observed in 8 of 11 hips owing to the interposed anteroinferior labrum. On arthrography at 6 weeks after reduction, the femoral head was located deeper in the acetabulum and the medial dye pool width was within 2 mm in all patients. CONCLUSIONS: The TAL was not observed to be hypertrophied or stretched in any of the DDH patients, and it did not act as an obstacle to reduction. After the TAL incision, the gap of the cut margin was not remarkably widened, although there were varying degrees of release. The incision of the TAL does not appear to result in the immediate alteration of the TAL-labral ring in favor of deeper acetabular seating or to enhance reduction. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Increased Serum Ion Levels After Ceramic-on-Metal Bearing Total Hip Arthroplasty: Influence of an Asian Lifestyle.

BACKGROUND: Recent clinical studies have suggested that systemic metal ion levels are significantly elevated at midterm follow-up in patients with ceramic-on-metal (COM) bearing. However, it is not clear whether there is a correlation between patient-related factors including the lifestyle and elevated levels of serum metal ions following COM total hip arthroplasty (THA). METHODS: Serum metal levels were measured in 201 patients (234 hips) including 121 COM patients (140 hips) and 80 non-COM patients (94 hips). The Harris Hip Score, University of California, Los Angeles activity scale score, and Western Ontario and McMaster Universities Osteoarthritis Index score were measured and radiographs were obtained for the analysis. RESULTS: Significantly higher levels of cobalt (Co) and chromium (Cr) were detected in the serum of the COM THA group (Co: 1.86 ± 4.0 µg/L; Cr: 1.81 ± 2.87 µg/L) than those of the non-COM THA group (Co: 0.27 ± 0.14 µg/L; Cr: 0.19 ± 0.25 µg/L; P < .001). The serum metal levels of patients who achieved the squatting position and the kneeling position were significantly higher than those of patients who could not squat (Co: P = .033; Cr: P = .074) and kneel (Co: P = .049; Cr: P = .031). The metal ion levels of the COM THA group correlated with the total range of motion (Co: P = .0293; Cr: P = .0399). CONCLUSION: Patients who underwent a 36-mm COM THA showed high serum metal levels although good clinical outcomes at the midterm follow-up. We found that COM THA patients who were capable of greater range of motion, squatting, and kneeling are at risk of metal ion-related problems.