3D-printed guides versus computer navigation for pedicle screw placement in the surgical treatment of congenital scoliosis deformities.

BACKGROUND: To compare the safety and clinical outcomes of 3D-printed guides versus computer navigation for pedicle screw placement in the correction of congenital scoliosis deformities. METHODS: The study was a single-centre retrospective controlled study and was approved by the hospital ethics committee for the analysis all patients under the age of 18 years with at least 2 years of follow-up. Sixty-three patients who underwent surgical correction for congenital scoliosis deformities in our hospital from January 2015 to December 2020 were divided into two groups based on the decision following preoperative doctor‒patient communication. Among them, 43 patients had pedicle screws placed with 3D-printed guider plates, while the remaining 20 patients had screws inserted with the assistance of computer navigation. The perioperative period, follow-up results and imaging data were compared between the groups. RESULTS: The operation was completed successfully for patients in both groups. The 3D-printed guide-assisted screw placement technique proved to be significantly superior to the computer navigation technique in terms of operation time, screw placement time, and intraoperative blood loss (p < .05), although the former had more frequent intraoperative fluoroscopies than the latter (p < .05). The mean follow-up time was 41.4 months, and the SRS-22 scores significantly improved in both groups over time postoperatively (p < .05). The 3D-printing group had better SRS-22 scores than the navigation group 6 months after surgery and at the last follow-up (p < .05). Compared with preoperative values, the coronal Cobb angle, local kyphotic Cobb angle, C7-S1 coronal deviation (C7PL-CSVL), and sagittal deviation (SVA) were significantly improved in both groups after surgery (p < .05). CONCLUSION: Both techniques achieve the purpose of precise screw placement and proper correction of the deformities. In contrast, the 3D-printed guide-assisted screw placement technique showed advantages in terms of operation time, screw placement time, intraoperative blood loss and patient satisfaction with outcomes.

Risk factors for misdiagnosis in children with developmental dysplasia of the hip: a retrospective single centre study.

OBJECTIVE: To investigate risk factors of misdiagnosis at the first visit of children with developmental dysplasia of the hip (DDH) who did not participate in hip ultrasound screening. METHODS: A retrospective review was conducted on children with DDH admitted to a tertiary hospital in northwestern China between January 2010 and June 2021. We divided the patients into the diagnosis and misdiagnosis groups according to whether they were diagnosed at the first visit. The basic information, treatment process and medical information of the children were investigated. We made a line chart of the annual misdiagnosis rate to observe the trend in the annual misdiagnosis rate. Univariate and multivariate logistic regression analyses were used to identify significant risk factors for missed diagnosis. RESULTS: A total of 351 patients met the inclusion criteria, including 256 (72.9%) patients in the diagnosis group and 95 (27.1%) patients in the misdiagnosis group. The line chart of the annual rate of misdiagnoses among children with DDH from 2010 to 2020 showed no significant change trend. Multiple logistic regression analysis showed that the paediatrics department (v the paediatric orthopaedics department: OR 0.21, p<0.001), the general orthopaedics department (v the paediatric orthopaedics department: OR 0.39, p=0.006) and the senior physician (v the junior physician: OR 2.47, p=0.006) on the misdiagnosis at the first visit of children were statistically significant. CONCLUSION: Children with DDH without hip ultrasound screening are prone to be misdiagnosed at their first visit. The annual misdiagnosis rate has not been significantly reduced in recent years. The department and title of the physician are independent risk factors for misdiagnosis.

Quantification of femoral position on radiographic acetabular coverage in children.

An accurate assessment of the radiographic acetabular coverage is essential for clinical diagnosis or surgical decision-making in hip disorders. This study aimed to evaluate the effect of femoral position on acetabular coverage and to predict the actual acetabular coverage from nonstandard radiographs. A total of 21 children (34 hips) with normative acetabular coverage were screened in this retrospective study. The Mimics-based local-rotation fluoroscopy simulation method was used to tilt, incline, and rotate the femur in 4° increments within the range of femoral motion. The acetabular coverage, namely acetabular-head index (AHI) and center-edge angle (CEA), increased with femoral abduction but decreased with other motions. Compared to the femoral neutral position, no significant differences were identified in AHI with the rotation (range: 0°-16°) and in CEA with the tilt (range: -20°-4°), inclination (range: 0°-4°), or rotation (range: -8°-40°). The linear regression analysis showed that the CEA increased by about 0.20° for each 1° increase in femoral inclination and decreased by about 0.01°, 0.07°, 0.06°, or 0.07° for each 1° increase in internal rotation, external rotation, flexion, or extension, respectively. And a more significant change in AHI was observed. All femoral malpositions, especially the inclination, affected radiographic acetabular coverage in children. Therefore, each pelvic radiograph should assess potential femoral malpositioning before diagnosing hip disorders. This study will assist surgeons in predicting the acetabular coverage on nonstandard radiographs.

Closing-opening wedge osteotomy for the treatment of congenital kyphosis in children.

BACKGROUND: To evaluate the safety and effectiveness of posterior closed-open wedge osteotomy for treatment of congenital kyphosis in children. METHODS: Imaging and clinical data from January 2010 to December 2019 of posterior closed-open wedge osteotomy of congenital kyphosis with at least 2-year follow up was analyzed retrospectively. Perioperative indicators such as operation time, osteotomy site, osteotomy method and occurrence of complications, and imaging indicators were observed. The 3D printed models were used to measure the expanded distance of anterior edge vertebra and closed length of spinal canal line. The clinical effect was evaluated through SRS-22 questionnaires. RESULTS: There were 15 CK patients in this study. The osteotomy segments and details are as follows: 1 case each for T6-9 and L2, 2 cases at T11, 3 cases at T12, and 6 cases at L1. The average operation time was 314 min, the average blood loss was 970 mL, the average fusion range was 6.3 segments, and the average time of follow up was 70.5 months. The Cobb angle of local kyphosis was corrected from 65.6 ± 18.8° to 11.3 ± 7.1°(p < .001). The range of kyphosis correction was 40-90°, and average correction rate was 83.2% (67.7-95.7%). The correction was stable in follow-up, and the kyphotic angle was 11.0 ± 7.6 (p = .68). The preoperative SVA was 31.5 ± 21.8 mm, and the postoperative recovery was 18.0 ± 15.5, while the last follow-up was 9.1 ± 7.9. The p values were 0.02 and 0.07 respectively. By using 3D printed models, the expanded distance of anterior edge vertebra and closed length of spinal canal line were 14.5 ± 7.5 mm and 24.5 ± 8.0 mm respectively. Self-image and satisfaction in SRS-22 improved significantly. There was no recurrence of deformity and junctional kyphosis. CONCLUSIONS: The posterior closing-opening wedge osteotom for treatment of congenital kyphosis in children is satisfactory, if selected appropriately. During the longitudinal follow-up, the patients could achieve solid fusion and the correction could be well maintained.Evidence of Confidence: IVa.

Clinical evidence for association of neoadjuvant chemotherapy or chemoradiotherapy with efficacy and safety in patients with resectable esophageal carcinoma (NewEC study).

BACKGROUND: The efficacy and safety of neoadjuvant treatment over surgery alone and that of neoadjuvant chemoradiotherapy (NCRT) over neoadjuvant chemotherapy (NCT) in resectable esophageal carcinoma remains inconclusive. This study (NewEC) used global data to comprehensively evaluate these comparisons and to provide a preferable strategy for patient subsets. METHODS: This study included a meta-analysis of randomized controlled trials (RCTs) identified from inception to May 2019 from PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and congresses and a registry-based cohort study with patients from Massachusetts General Hospital (Massachusetts, USA) and Guangdong Provincial People's Hospital (Guangzhou, China) recruited from November 2000 and June 2017, to cross-validate the comparisons among NCRT versus NCT versus surgery. The GRADE approach was used to assessed quality of evidence in meta-analysis. Neural network machine learning propensity score-matched analysis was used to account for confounding by patient-level characteristics in the cohort study. The primary endpoint was overall survival (OS). The study was registered with PROSPERO CRD42017072242 and ClinicalTrials.gov NCT04027543. FINDINGS: Of 22,070 studies assessed, there were 38 (n = 6,993 patients) eligible RCTs. Additionally, 423 out of 467 screened patients were included in the cohort study. The results from trials showed that NCT had a better OS than surgery alone (hazard ratio [HR] 0·88, 95% confidence interval [CI] 0·79-0·98; high quality) and was only favorable for adenocarcinoma (HR 0·83, 95% CI 0·72-0·96; moderate quality). High-quality evidence showed a significantly better OS for NCRT than surgery alone (HR 0·74, 95% CI 0·66-0·82) for both adenocarcinoma (HR 0·73, 95% CI 0·62-0·86) and squamous cell carcinoma (SCC) (HR 0·73, 95% CI 0·65-0·83). The OS benefit of NCRT over NCT was seen in the pairwise (HR 0·78, 95% CI 0·62-0·99; high quality) and network (HR 0·82, 95% CI 0·72-0·93; high quality) meta-analyses, with similar results before (HR 0·60, 95% CI 0·40-0·91) and after (HR 0·44, 95% CI 0·25-0·77) matching in the cohort study, leading to a significantly increased 5-year OS rate in both adenocarcinoma and SCC before and after matching. The increased benefits from NCT or NCRT were not associated with the risk of 30-day or in-hospital mortality. INTERPRETATION: NewEC Study provided high-quality evidence supporting the survival benefits of NCRT or NCT over surgery alone, with NCRT presenting the greatest benefit for resectable esophageal carcinoma. FUNDING: National Science and Technology Major Project, the National Natural Science Foundation of China, the Natural Science Foundation of Guangdong Province, the Guangzhou Science and Technology Major Program, the Medical artificial intelligence project of Sun Yat-Sen Memorial Hospital, the Guangdong Science and Technology Department, the Guangdong Province Medical Scientific Research Foundation, and Guangdong Provincial People's Hospital Intermural Program.

Plantar Pressure Distribution of Right and Left Foot in Bilateral Clubfoot Treated by Ponseti Method: A Correlation Analysis.

BACKGROUND Congenital clubfoot is a common pediatric orthopedic deformity that can be corrected by Ponseti method, and pedobarographic analysis has been used to assess the outcomes. However, the relationship between the plantar pressure distribution of the right and left foot in children with bilateral clubfoot has not been studied. In this study, the pedobarographic data of patients with bilateral clubfoot who were treated by the Ponseti method were reviewed, and a correlation analysis was conducted to clarify the relationship between the right and left foot. MATERIAL AND METHODS A retrospective cross-sectional study of children with bilateral clubfoot who were treated by the Ponseti method in infancy was performed, in which all the patients were available for clinical evaluation, and pedobarographic analysis was conducted on each patient after treatment. The Pearson's correlation coefficient (r) were calculated for all the measurements of the left and right foot. RESULTS A total of 20 children (mean age 6.9±1.07 years, range 4-8 years) with bilateral clubfoot who were treated by the Ponseti method were included. The Dimeglio and Pirani scores before and after treatment between the right and left foot were significantly correlated. All the pedobarographic measurements between the left and right foot were correlated, indicating different degrees of positive correlation. CONCLUSIONS The plantar pressure measurements between the 2 feet in patients with bilateral clubfoot were highly correlated before treatment, and a correlation was also observed after those patients were treated by the Ponseti method. We should take these correlations into consideration during study design and analysis of clubfoot cases.

One-stage Surgical Treatment of Simultaneous Osteotomy and Asymmetric Lengthening on Short Femur with Severe Deformity of Genu Valgus.

This study aimed to discuss the effects of one stage surgical treatment by simultaneous osteotomy and asymmetric lengthening by Ilizarov external fixator on short femur with severe deformity of genu valgus. A total of 12 cases with unilateral deformities treated by simultaneous osteotomy and Ilizarov asymmetric lengthening on short femur with severe deformity of genu valgus were retrospectively analyzed from January 2006 to April 2015. The affected limbs were 2.5-11 cm (5.2 cm on average) short, the femorotibial angle was 135°-158° (146.3° on average), and the ankle interval was 15-43 cm (24.7 cm on average). The Paley method was used to determine the osteotomy plane (distal femur) of genu valgus. According to this standard, the bone union results were as follows: 11 had excellent and 1 had good, where 7 patients had excellent and 5 had good functional outcomes. One stage surgical treatment by simultaneous osteotomy and asymmetric lengthening on short femur with severe deformity of genu valgus was considered to be an effective and reliable method with better osteotomy union, less trauma and fewer complications.

Pedobarographic Analysis following Ponseti Treatment for Unilateral Neglected Congenital Clubfoot.

Recent trends have led to an interest in Ponseti treatment for correcting neglected congenital clubfoot. Although good clinical and functional outcomes have been reported, the plantar pressure distribution after the treatment of neglected clubfoot has not been explored yet. The present study aimed to investigate whether plantar pressures normalized following Ponseti treatment in patients with neglected congenital clubfoot. Pedobarographic, clinical, and functional examinations were performed in 22 children (aged, 91.0 ± 40.3 months) with unilateral neglected congenital clubfeet, treated using Ponseti method at 27.8 ± 12.1 months of age. Plantar pressure parameters were recorded using a Footscan pressure plate. The contact time, contact area, peak pressure, and pressure-time integral were determined. The data of the affected feet were compared with those of the unaffected feet and healthy controls. Although clinical and functional examinations showed satisfactory results according to the Dimeglio and Pirani scores, considerable differences in plantar pressure parameters were identified among the affected feet, unaffected feet, and healthy controls. Internal foot progression angle and a load transfer from the medial forefoot and hindfoot to the lateral forefoot and midfoot were observed in the affected feet. Future studies should attempt to investigate the factors accounting for plantar pressure deviations and the possible effect of these deviations on the lower limb musculoskeletal development of children.

Reliability of the Footscan® Platform System in Healthy Subjects: A Comparison of without Top-Layer and with Top-Layer Protocols.

The Footscan platform is a useful tool for plantar pressure measurement. However, there is still controversy over whether or not the platform should be covered by top-layer during the test. This study was designed to compare the reliability of the Footscan platform and identify the differences of the foot loading parameters between without top-layer (WOT) and with top-layer (WT) protocols. Measurements were taken from thirty-two healthy subjects. Participants were tested with a Footscan platform using the WOT and WT protocols. Three trials were performed during two separate testing sessions with a 7-day interval. Peak pressure, contact time, contact area, and pressure-time integral at ten foot zones were recorded and calculated for intra- and intersession reliability using intraclass correlation coefficients (ICCs) and coefficients of variation (CVs). The reliability and values of the analyzed parameters for the two protocols were compared. Both protocols produced a moderate to good level of intra- and intersession reliability. Compared with the WT protocol, the WOT protocol showed higher ICCs, lower CVs, and higher values in most of the parameters analyzed. The results suggest that the WOT protocol showed better reliability than the WT protocol. We recommend not using the top-layer when performing the plantar pressure test.

Normal foot loading parameters and repeatability of the Footscan® platform system.

BACKGROUND: The Footscan® platform system is one of the most commonly used clinical tools for the measurement of the foot pressure. The present study was designed to assess the repeatability of the system and identify the range of loading parameters observed in the normal foot. METHODS: Measurements were collected from 32 healthy participants, 15 females and 17 males, twice at an interval of 1 week. Peak pressure (PP), contact time (CT), contact area (CA), pressure-time integral (PTI), and maximum force (MaF) were recorded; these parameters were investigated in 10 areas of the foot: medial heel, lateral heel, midfoot, first to fifth metatarsals, hallux, and toes 2-5. The intra-session repeatability was evaluated by calculating the intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) across the three repeated trials within the same session. The inter-session repeatability was assessed using the average of the three trials in each session to determine the ICCs and CVs. RESULTS: The ICCs showed moderate to good repeatability for every variable of interest, and the CVs were all <28%. The highest zones of PP were found under the second and third metatarsals, followed by the medial heel. The CT was 68.5-82.8% of the total stance time under the metatarsal heads. CA was highest under the midfoot, PTI was highest under the second metatarsal, and MaF was highest under the medial heel. CONCLUSIONS: Footscan® platform system was found to be repeatable. Thus, it can be used as a valuable tool in the assessment of plantar pressure distribution, and the normal values of the foot loading parameters identified in this study can be employed to provide a reference range for the gait analysis performed by the Footscan® system.

Effects of arthroscopic-assisted surgery on irreducible developmental dislocation of hip by mid-term follow-up: An observational study.

The purpose of this study was to investigate the indications, surgical technique, and the clinical effects of arthroscopic-assisted treatment of irreducible developmental dislocation of the hip by mid-term follow-up. Arthroscopic-assisted surgeries were performed on 40 children (52 hips) between January 2005 and December 2009. Anterior and antero-superior greater trochanter portals were used in these treatments. Spica cast and abduction splint were applied for 3 months postoperatively. The follow-up was conducted on every 3 months postoperatively. During 12-month follow-up, a secondary treatment such as acetabuloplasty and/or femoral osteotomy (shortening, varus, and derotation) was applied if the acetabular angle was greater than 25°. The pelvic acetabular angle, Mckay and Severin score were evaluated every 6 months in all children. With 36 to 96 months (average 71 months) follow-up, 35 children (44 hips) were successfully followed up with complete case data while 5 children unsuccessfully. According to Tönnis classification, there were 5 grade 1 hips, 14 grade 2 hips, 14 grade 3 hips, 11 grade 4 hips, in which 3 children (4 hips) were failed in arthroscopic reduction and femoral head avascular necrosis occurred in 2 children (4 hips). According to Mckay standard, the good rate is 100%. According to Severin standard, the good rate is 84.1%. Arthroscopic assisted treatment is an effective way of reduction of the irreducible hip. Compared with the open reduction, arthroscopic treatment combined with acetabuloplasty and/or femoral osteotomy has advantages of less trauma and better function preservation.

Flour Quality and Related Molecular Characterization of High Molecular Weight Glutenin Subunit Genes from Wild Emmer Wheat Accession TD-256.

To clarify the effect of high molecular weight glutenin subunit (HMW-GS) from wild emmer wheat on flour quality, which has the same mobility as that from common wheat, the composition and molecular characterization of HMW-GS from wild emmer wheat accession TD-256, as well as its flour quality, were intensively analyzed. It is found that the mobilities of Glu-A1 and Glu-B1 subunits from TD-256 are consistent with those of bread wheat cv. 'XiaoYan 6'. Nevertheless, dough rheological properties of TD-256 reveal its poor flour quality. In the aspect of molecular structure from HMW-GS, only two conserved cysteine residues can be observed in the deduced protein sequence of 1Bx14* from TD-256, while most Glu-1Bx contain four conserved cysteine residues. In addition, as can be predicted from secondary structure, the quantity both of α-helixes and their amino acid residues of the subunits from TD-256 is fewer than those of common wheat. Though low molecular weight glutenin subunit (LMW-GS) and gliadin can also greatly influence flour quality, the protein structure of the HMW-GS revealed in this work can partly explain the poor flour quality of wild emmer accession TD-256.

Pedobarographic Analysis Following Pemberton's Pericapsular Osteotomy for Unilateral Developmental Dysplasia of the Hip: An Observational Study.

Successful clinical and radiographic outcomes have been reported in patients with unilateral developmental dysplasia of the hip (DDH) following Pemberton pericapsular osteotomy (PPO). However, residual gait deviations are seen in both the affected and unaffected limbs. To date it is not known whether these deviations result in abnormal plantar pressure in such patients. This study investigated this possibility by performing pedobarographic, clinical, and radiographic examinations after PPO in 20 patients (age: 102.5 ±â€Š19.0 months) with unilateral DDH who underwent PPO at 34.2 ±â€Š9.8 months of age. Plantar pressure was evaluated using the Footscan pressure plate (RsScan International, Olen, Belgium). Each foot was subdivided into 10 zones and peak pressure, force-time integral as a percentage of total FTI, and contact time as a percentage of total stance time was estimated. The minimum duration of follow-up was 24 months (mean: 68.3 ±â€Š20.3 months). The data were compared with 20 age- and weight-matched healthy controls. Despite clinical and radiographic examinations showing satisfactory results according to modified McKay and Severin criteria, significant differences in plantar pressure parameters were identified between the affected limbs, the unaffected limbs, and normal controls. No significant differences were found between patients classified as "excellent or good" and those rated as "fair" according to the modified Severin criteria. Pedobarographic results showed the existence of the residual plantar pressure deviations during walking in patients treated with PPO for unilateral DDH. Longer follow-up will be needed to more fully evaluate the effect of these deviations on gait.

Gorham-Stout syndrome presenting in a 5-year-old girl with a successful bisphosphonate therapeutic effect.

Gorham-Stout syndrome (GSS), also known as Gorham-Stout disease, massive osteolysis, disappearing bone disease or phantom bone, is a rare disorder of the musculo-skeletal system. It most commonly involves the skull, shoulder and pelvic girdle. Histological examination reveals a progressive osteolysis always associated with an angiomatosis of blood vessels and sometimes of lymphatics, which seemingly is responsible for the destruction of the bone. It is extremely rare that Gorham-Stout syndrome involves the bones of the entire body. A 5-year-old girl complaining of intermittent and dull back pain for 3 months was admitted to a local hospital. X-ray revealed left pleural effusion, and the patient was diagnosed with tuberculous pleurisy. Thus, anti-tuberculosis therapy was performed. However, it was not effective. A soft mass with significant tenderness was found in the upper segment of the right leg 50 days afterwards. X-ray revealed multiple osteolysis of the bilateral clavicle, scapula, rib, vertebral body, ilium, sacrum, femur and tibia. The biopsy from the right tibia disclosed that the lesion was composed of hyperplastic blood vessels and fibrous tissues similar to hemangioma. Based on the above clinical, radiological and histopathological findings, the clinical physician confirmed a diagnosis of Gorham-Stout disease, and prescribed oral anti-osteoclastic medications consisting of bisphosphonates. At present, the girl is alive and healthy, and new lesions have not been noted.

Accuracy and safety assessment of pedicle screw placement using the rapid prototyping technique in severe congenital scoliosis.

STUDY DESIGN: The application of rapid prototyping (RP) technique for improving accuracy of pedicle screw placement in congenital scoliosis is described in this study. OBJECTIVE: To compare the accuracy and safety of pedicle screw placement in congenital scoliosis using the RP technique versus the conventional fluoroscopy. SUMMARY OF BACKGROUND DATA: Maldeveloped vertebral components in congenital scoliosis leads to prolonged operation time and higher rate of screw misplacement. RP technique can enhance preoperative and perioperative planning. No data are available on the accuracy of pedicle screw fixation using the RP technique. METHODS: Sixty-two consecutive patients with hemivertebra had undergone posterior-only hemivertebra resection. Pedicle screws were implanted either by the conventional intraoperative fluoroscopy technique (C-arm group; n=28) or the RP technique (RP group; n=34). Accuracy of pedicle screw placement was compared by postoperative computed tomographic scan. RESULTS: Seventy of 677 inserted screws were found to be misplaced, showing an overall accuracy of 89.7% (90.8% in the thoracic spine and 87.4% in the lumbar spine). In the C-arm group, 86.1% (167 of 194) and 82.0% (82 of 100) of screws were accurately placed in the thoracic and lumbar spine, respectively. While in the RP group, the respective screw placement accuracies were 94.4% (238 of 252) and 91.6% (120 of 131). In the C-arm and the RP groups, 94.8% (279 of 294) and 97.9% (375 of 383) of the screws were within the safety zone, respectively. Compared with the fluoroscopy method, the RP-assisted technique showed a shorter operation time and higher scoliosis correction rate. No neurovascular-related complication was observed with this technique during the study. CONCLUSION: The application of RP technique in congenital scoliosis can reduce the operation time, the risk of screw misplacement and its consequent complications. The use of RP technique in congenital scoliosis is safe and efficacious.

The short-term effect of an anchor in treatment of congenital vertical talus in infants.

OBJECTIVE: To investigate the short-term effect of a mini anchor in treatment of congenital vertical talus (CVT) in infants. METHODS: From February 2006 to March 2008, seven patients (nine feet) with CVT were treated in the authors' hospital by the Kumar method combined with transferring and fixing the tendon of the anterior tibial muscle to the head of the talus with a mini anchor. There were five girls and two boys, aged from 10 to 42 months (mean, 18 months). All the feet had a rocker-bottom when the infants were taken to the hospital by their parents and none of them could walk independently. All cases were followed up in the outpatient department, and the Hamanishi and Adelaar standards were used to evaluate the radiograph and clinical results, respectively. RESULTS: All cases were followed up for 20 to 29 months (mean, 24 months). The parents of these infants were all satisfied with this operation, and five infants can now walk independently. At the most recent follow-up, seven feet were fine and two good according to the Adelaar standard, and six feet were good and three fine according to the Hamanishi standard. CONCLUSION: The short-term effect of an anchor in treatment of CVT in infants was satisfactory with no recurrence nor talus necrosis.

Distribution of kappa-opioid receptor in the pulmonary artery and its changes during hypoxia.

The present study evaluated the distribution of kappa-opioid receptors (kappa-ORs) in pulmonary arteries (PAs) in rats and investigated whether kappa-ORs are altered in PAs during hypoxia. An animal model of hypobaric/hypoxic pulmonary hypertension and a pulmonary artery smooth muscle cell (PASMC) model of hypoxia were utilized. Distribution of kappa-ORs was determined by fluorescence immunohistochemistry and changes in kappa-ORs expression in PAs and PASMCs were determined by fluorescence immunohistochemistry or Western blot techniques. The kappa-ORs were primarily distributed in the smooth muscle layer of the PAs and in the nucleus of PASMCs. The expression of the kappa-ORs were increased in PAs of rats subjected to hypoxia for 1-4 week (P < 0.01). Accordingly, the expression of kappa-ORs in PASMCs were also increased when subjected to hypoxia for 12-36 hr (P < 0.05). The present study has provided evidence for the first time of the precise location of kappa-ORs in PAs and PASMCs of rats and that hypoxia upregulates expression of kappa-ORs.

Musculoskeletal training for orthopaedists and nonorthopaedists in China.

No diploma for orthopaedic surgery is available in the current medical education and licensing system in China. The orthopaedist generally receives on-the-job training in a clinical practice after getting a license to practice surgery. There are multiple training pathways to and opportunities in orthopaedic surgery, and these vary from hospital to hospital and from region to region. These include on-the-job training, academic visits, rotation through different departments based on local medical needs, fellowship training in large general or teaching hospitals (locally, regionally, nationally, or internationally), English language training, postgraduate diploma training, and Internet CME. Due to the current training system, orthopaedic techniques and skill levels vary greatly from hospital to hospital.

Cardioprotective and antiarrhythmic effect of U50,488H in ischemia/reperfusion rat heart.

The objective of this study was to investigate the protective effect of U50,488H, a selective kappa-opioid receptor agonist, in the ischemia/reperfusion (I/R) rat and to delineate the underlying mechanism. Rat heart I/R injury was induced by occluding the left anterior descending coronary artery for 45 min and restoring perfusion for 120 min. U50,488H or vehicle was intravenously injected before ischemia. Electrocardiogram, heart rate (HR), arterial blood pressure (ABP), left ventricular pressure (LVP), systolic function (+dp/dtmax), and diastolic function (-dp/dtmax) were monitored in the course of the experiment. Myocardial infarction size was evaluated. Plasma concentrations of cardiac troponin T (cTnT), creatine kinase (CK), and lactate dehydrogenase (LDH) were measured. Single rat ventricular myocyte was obtained by enzymatic dissociation method. The potassium currents (IK) of isolated ventricular myocytes were recorded with the whole-cell configuration of the patch-clamp technique. Compared with the sham control group, no significant change was found in HR, while ABP, LVP and +/-dp/dtmax were significantly reduced in the I/R group. Administration of U50,488H significantly lowered HR in both control and I/R groups. Compared with the vehicle-treated I/R group, administration of U50,488H had no significant effect on I/R-induced reduction in ABP, LVP, and +/-dp/dtmax. However, this treatment significantly reduced the myocardial infarction size, and markedly decreased the contents of plasma cTnT, CK and LDH. During ischemia and reperfusion, the incidence of ventricular arrhythmia in U50,488H-treated rats was significantly reduced. These effects were independent of the bradycardia induced by U50,488H, as the reducing infarct size and antiarrhythmic effect of U50,488H were still observed in animals in which heart rate was kept constant by electrical pacing. U50,488H and BRL-52537 still produced an antiarrhythmic effect when the rat heart was subjected to a shorter ischemic period of 10 min occlusion of coronary artery, which produced no infarction. IK of the myocytes were inhibited by U50,488H in a dose-dependent manner in normal and hypoxic rat ventricular myocytes. However, the effects of U50,488H on IK did not show any significant difference in normal and hypoxic myocytes. The above-described effects of U50,488H were totally blocked by nor-Binaltorphimine, a selective kappa-opioid receptor antagonist. The results suggest that kappa-opioid agonist U50,488H exerts its direct cardioprotective and antiarrhythmic effects against I/R via kappa-opioid receptor, which participates in the regulation of potassium channels in normal and hypoxic ventricular myocytes.

Mechanisms involved in the hypotensive effect of a kappa-opioid receptor agonist in hypertensive rats.

BACKGROUND: It remains unclear whether the activation of kappa-opioid receptors has strong hypotensive effects under hypertensive condition, and the underlying mechanisms have not yet been investigated. Therefore, the present study is designed to use spontaneously hypertensive rats (SHR) to investigate the effects of a kappa-opioid receptor agonist on the regulation of urinary formation in hypertensive conditions and to identify its underlying mechanism. METHODS: The hemodynamics, urine flow rate, vasodilatation of isolated renal artery, and plasma hormones were determined by physiological in vivo experimental technique, isolated artery perfusion technique and radioimmunoassay. RESULTS: Intravenous administration of U50, 448H significantly decreased mean arterial blood pressure in both Wistar-Kyoto (WKY) rats and SHR. However, the blood pressure vasodepressor effect of U50, 448H was much more profound in SHR than in WKY rats. Administration of U50, 448H in SHR not only caused significantly greater effects in increasing urine volume and decreasing plasma anti-diuretic hormone than in WKY rats, but also caused significant reduction in plasma angiotensin. Moreover, vasodilatory effect of U50, 488H was significantly exhibited in the renal artery segments isolated from SHR. All effects described above were abolished by nor-binaltorphimine. CONCLUSIONS: These data indicate that the depressor effect of U50, 488H in SHR is significantly stronger than that in WKY rats, and the effect is mediated or modulated by a kappa-opioid receptor sensitive mechanism. The sensitized hypotensive effect of U50, 488H in SHR may be attributed, in part, to its vasodilatory effect, enhanced beneficial effect on plasma humoral factors, and stronger diuretic effect in these hypertensive animals.