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Objectives Periprosthetic bone fragility due to stress shielding (SS) can be a risk factor of periprosthetic fracture after cementless total hip arthroplasty (THA). We aimed to obtain epidemiological information on periprosthetic fragility fracture of the femur (PPFF) after THA. Methods We retrospectively reviewed the medical records of 1062 hips that had undergone cementless THA. We evaluated the epidemiological data as well as the features of PPFFs. Results Of the 1062 hips, 8 (0.8%) were diagnosed with PPFFs. The survival rates, with the occurrence of PPFF as the end point, were 99.2% and 97.6% at 10 and 16 years postoperatively, respectively. When patients were classified as having either mild or severe SS on radiographs 5 years postoperatively, there was no significant difference in the survival rate, with PPFF as the end point. Conclusions In our cases, the incidence of PPFF after cementless THA was 0.8%.

The etiology of autism spectrum disorder (ASD) is complex, and its pathobiology is characterized by enhanced inflammatory activities; however, the precise pathobiology and underlying causes of ASD remain unclear. This study was performed to identify inflammatory indicators useful for diagnosing ASD. The mRNA expression of cytokines, including tumor necrosis factor-α (TNF-α), was measured in cultured M1 and M2 macrophages from patients with ASD (n = 29) and typically developed (TD) individuals (n = 30). Additionally, TNF-α expression in the monocytes of patients with ASD (n = 7), showing aberrations in TNF-α expression in M1/M2 macrophages and TD individuals (n = 6), was measured. TNF-α expression in M1 macrophages and the TNF-α expression ratio in M1/M2 macrophages were markedly higher in patients with ASD than in TD individuals; however, this increase was not observed in M2 macrophages (M1: sensitivity = 34.5%, specificity = 96.7%, area under the curve = 0.74, positive likelihood ratio = 10.34; ratio of M1/M2: sensitivity = 55.2%, specificity = 96.7%, area under the curve = 0.79, positive likelihood ratio = 16.55). Additionally, TNF-α expression in monocytes did not significantly differ between patients with ASD and TD individuals. In conclusion, further studies on TNF-α expression in cultured macrophages may improve the understanding of ASD pathobiology. LAY SUMMARY: TNF-α expression in differentiated M1 macrophages and TNF-α expression ratio in differentiated M1/M2 macrophages were markedly higher in patients with ASD than in TD individuals, while no difference in TNF-α expression was found in pre-differentiation cells such as monocytes. These measurements allow elucidation of the novel pathobiology of ASD and can contribute to biomarker implementation for the diagnosis of adult high-functioning ASD.

Short stems have recently become popular in total hip arthroplasty. Previous studies aimed at elucidating the efficacy of short stems did not eliminate the influence of other factors aside from stem length. This study aimed to evaluate the usefulness of short stems compared with that of standard-length stems that have the same proximal morphology, surface coating, and material. This was a prospective randomized study comparing 5-year midterm outcomes in 29 patients who underwent one-stage bilateral total hip arthroplasty with short and standard-length stems inserted in each of the two femurs. Clinical, radiographical, and dual-energy X-ray absorptiometry outcomes were compared. No significant differences were found in perioperative and radiographic characteristics (femoral neck anteversion, flare index, operation sequence, operation side, operation time, stem anteversion, and stem alignment). The number of joints with complications, appearance of radiopaque lines around the stems, or bone mineral density changed in stem regions 5 years postoperatively. However, greater micromotion of the stem was seen on the side of the short stem. Satisfactory improvement in hip function was seen on both sides. Based on the 5-year midterm outcomes, both stems obtained satisfactory clinical outcomes despite the greater micromotion with short stems. Both stems attained bone ingrowth fixation. Moreover, the stems were not significantly different in terms of stress shielding; however, further long-term studies (> 5 years) are required to validate our findings related to stress shielding.

Nerve palsy following total hip arthroplasty (THA) critically impacts patient clinical function. However, few studies have focused on femoral nerve palsy (FNP) following THA via the modified Watson-Jones approach. Previous reports have suggested that THA, regardless of the approach, is associated with several FNP risk factors, including female gender, hip dysplasia, revision surgery, and short stature. Magnetic resonance imaging (MRI) has suggested that a shorter distance between the femoral nerve and the anterior acetabular edge (dFN) is related to FNP after THA. The purposes of this study were: 1) to determine the presumed risk factors through a retrospective investigation of FNP clinical courses, and 2) to identify the relationships between FNP occurrence and the short dFN following primary THA via the modified Watson-Jones approach.Short stature is a risk factor for femoral nerve palsy following THA. i.e. a significant difference in dFN exists between patients with and without FNP.This retrospective case-control study was performed at a single university hospital. From January 2016 to December 2020, 676 THAs were performed via the modified Watson-Jones approach at our institution. These included 495 THAs performed in the supine position and 181 in the lateral position. In this study, FNP was defined as weakness of the quadriceps femoris (manual muscle testgrade 3) with or without sensory disturbance over the anteromedial aspect of the thigh. The incidence of FNP was calculated. Patient background factors (age, sex, preoperative diagnosis, surgical position, height, weight, body mass index, surgeon experience, type of components, the method of anesthesia, leg lengthening during the surgery, and operation time) were compared between the FNP group and a non-FNP control group. The dFN was measured in T1-weighted MRI axial images at the level of the hip center. The distance between the femoral nerve and the anterior acetabular edges, where retractors are commonly placed during surgery, was also measured and compared between the FNP group and the non-FNP control group. The FNP group and non-FNP control group were extracted by 1:4 matching of patient height and weight. All data were statistically evaluated using the Mann-Whitney U test, and p values less than 0.05 were considered statistically significant.FNP occurred in 6 out of 676 joints (0.88%) following primary THA via the modified Watson-Jones approach. In all 6 cases, the motor deficit recovered completely within a year. Patient height was significantly shorter in the FNP group than in the non-FNP control group (148.4±3.3cm vs. 155.4±8.1cm [p=0.01]). The dFN was significantly shorter in the FNP group (16.3±4.1mm vs. 21.5±4.0mm [p=0.034]).Short stature and short dFN are risk factors for FNP after THA using the modified Watson-Jones approach.III, case-control study.

Purpose Antipsychotic drug treatment can potentially lead to adverse events such as extrapyramidal symptoms (EPSs). If these events persist, they lower patient quality of life. The purpose of this report is to present our experience with such a case, as an example to encourage further study. Patients and methods The patient was a 64-year-old male who had been diagnosed with schizophrenia that had been treated with oral antipsychotics for over 40 years. Due to lack of compliance, he was treated with the long-acting injectable antipsychotic, paliperidone palmitate, but developed persistent EPSs after 6 months. He was subsequently treated and monitored in our inpatient facility. Results Antipsychotic treatment was stopped. After 6 weeks, the patient's psychosis had worsened, but his EPSs remained unchanged. Levodopa treatment was then started (up to 400 mg/d), which improved his EPSs, so he was restarted on oral antipsychotic therapy (aripiprazole, 6-18 mg/d). His psychotic symptoms improved over 2 months. The improvements in both psychosis and EPSs remained stable. Dopamine transporter scans revealed moderate dopamine transporter loss in the striatum, and computed tomography revealed no sign of brain abnormalities, suggesting that the patient was susceptible to dopamine reductions. Conclusion Paliperidone palmitate can induce EPSs, even if injected only a few times. Although the characteristics of the drug are potential causes, the patient's predisposition to dopamine perturbations can also influence the outcome. Therefore, adequate awareness is required before injection.

Objectives: The objective of the present study was to compare the cross-sectional areas (CSAs) of the gluteus medius on the affected and unaffected sides to assess long-term changes after total hip arthroplasty (THA). Methods : The data for 23 women who were diagnosed with unilateral hip osteoarthritis and who underwent primary THA via the posterolateral approach were retrospectively reviewed. The demographic data of the patients and the Japanese Orthopaedic Association hip scores were obtained from medical records. The CSA of the gluteus medius was measured on computed tomography images obtained at three different time points: preoperatively, 3 years postoperatively, and 8 years postoperatively. Results: The CSA of the gluteus medius on the affected side was significantly greater than the preoperative value at 3 (P

Whether different body positions during surgery affect postoperative stem alignment in total hip arthroplasty (THA) remains unclear. The purpose of this study was to clarify differences in tapered wedge stem alignment between supine and lateral positions in THA under the modified Watson-Jones anterolateral approach. We reviewed 242 consecutive, primary cementless THAs performed with ceramic-on-cross-linked polyethylene via the modified Watson-Jones approach in either supine or lateral positions between 2009 and 2015 (supine group: 113 cases; lateral group: 129 cases). No specific reasons to select supine or lateral positions for the surgery were given during the study period. Computed tomography was performed pre- and postoperatively to measure preoperative femoral anteversion and postoperative stem anteversion, respectively. Stem alignment in coronal and sagittal planes was also evaluated. Mean difference in stem anteversion and femoral anteversion was 8.6 ± 9.4 in the supine position and 13.0 ± 11.4 in the lateral position (p = 0.0013). Although no significant difference was seen between groups for stem alignment in the coronal plane, flexed implantation was more likely in the supine group (46/113, 40.7%) than in the lateral group (20/129, 15.5%). A significant correlation was found between femoral anteversion and stem anteversion in both the supine and lateral groups (r = 0.68, p

Background As no previous study has directly compared the linear wear rate in two types of second-generation annealed highly cross-linked polyethylene, we performed a retrospective study with a minimum of 5-year follow-up to assess primary arthroplasties in the (1) wear rates and (2) incidence of osteolysis of the two types of HXLPE. Hypothesis There was no significant difference in the linear wear rate and the incidence of osteolysis between the two types of second-generation annealed highly cross-linked polyethylene. Patients and methods In this single-center study, we reviewed 257 cases of primary cementless total hip arthroplasties between 2011 and 2015, which were performed with 32 mm delta ceramic on second-generation annealed highly cross-linked polyethylene (X3 and E1 were used in 105 and 103 cases, respectively.). The mean wear rate was evaluated using a computer-assisted method, and the incidence of osteolysis was evaluated based on the appearance of a localized area with loss of trabecular bone or cortical erosion adjacent to the implants during the latest follow-up. Results In total, we evaluated 208 cases, followed postoperatively for over 5 years (mean, 6.1 years, range: 5.0-8.0). There were no significant differences between the two groups with respect to age (list in order of Group X, Group E, p value) (61.2 ± 12.3, 62.7 ± 12.1, p = 0.36), sex (ratio of male: 17.1%, 14.6%, p = 0.61), body mass index (22.9 ± 3.7, 22.8 ± 4.0, p = 0.91), pre- (49.9 ± 14.8, 48.5 ± 13.8, p = 0.49) and post-operative (91.3 ± 9.1, 92.7 ± 7.0, p = 0.23) Japanese Orthopaedic Association Hip Score, cup size (50.8 ± 3.0, 50.9 ± 2.2, p = 0.70), cup inclination (38.7 ± 4.8, 37.6 ± 4.8, p = 0.10), and cup anteversion (18.7 ± 6.9, 18.5 ± 7.6, p = 0.80). The mean linear wear rates of the X3 and E1 groups were 0.057 ± 0.039 (range: 0–0.16) and 0.054 ± 0.037 mm/year (range: 0–0.15), respectively (p = 0.61). No osteolysis was found on the final plain radiographs in both groups. Discussion This study revealed that both types of highly cross-linked polyethylene have excellent linear wear rates and were equally safe to use. However, the difference between the two materials in terms of the long-term wear rate should be further validated. Level of evidence III; retrospective case control study.

Background The etiology of autism spectrum disorder (ASD) is complex. Its pathobiology is characterized by enhanced inflammatory activities; however, the exact ASD pathobiology remains unclear. Some cases of ASD are difficult to diagnose using existing psychological assessments because the careful exclusion of other psychiatric disorders is challenging. To distinguish between the appropriate targets for interventions and research, the demand for identifying efficient diagnostic biomarkers is increasing. This study aimed to find an inflammatory indicator beneficial for the diagnosis of ASD.Methods Cytokine mRNA expression, including tumor necrosis factor-α (TNF-α), was measured in the differentiated M1 and M2 macrophages of ASD patients (n = 29) and typically developed (TD) individuals (n = 30). TNF-α expression was also measured in the monocytes of ASD patients (n = 7) and TD individuals (n = 6).Results TNF-α expression in M1 macrophages and TNF-α expression ratio of M1/M2 macrophages were markedly higher in ASD patients than in TD subjects; however, this difference was not observed in M2 macrophages (M1: p < 0.01; ratio of M1/M2: p < 0.0001; M2: p > 0.05), suggesting that this indicator could be a useful tool for diagnosing ASD (M1: sensitivity = 34.5%, specificity = 96.7%, area under the curve (AUC) = 0.74, positive likelihood ratio (PLR) = 10.34; ratio of M1/M2: sensitivity = 55.2%, specificity = 96.7%, AUC = 0.79, PLR = 16.55). However, there was no significant difference in the TNF-α expression in monocytes between ASD and TD individuals (p > 0.05).Conclusion These findings suggest that TNF-α expression in differentiated macrophages represents a novel adjunctive tool for the diagnosis of ASD.

Post-operative tensor fascia lata (TFL) muscle atrophy due to superior gluteal nerve (SGN) injury during total hip arthroplasty (THA) can affect patients’ post-operative hip function. This study aimed to determine the incidence of TFL muscle atrophy in THA performed via the modified Watson-Jones anterolateral approach and the risk factors for TFL atrophy. We reviewed pre- and post-operative magnetic resonance imaging (MRI) data of 164 patients who underwent cementless THA via the modified Watson-Jones approach at one institution. TFL atrophy was defined as worsening of ≥ 2 grades in the Goutallier classification or > 40% decrease in the cross-sectional area (CSA) of the TFL on post-operative MRI compared to that on preoperative MRI. Patients’ backgrounds were compared between those with or without TFL atrophy to determine the risk factors of TFL atrophy. Fatty atrophy grade and CSA of the gluteus minimus and medius were also evaluated. Thirteen (8.0%) cases of TFL atrophy were detected. The mean body mass index (BMI) in the cases with TFL atrophy was significantly higher than in those without TFL atrophy (p = 0.012). The fatty atrophy grade was worse post-operatively than preoperatively; moreover, the CSA of the gluteus minimus decreased. We found a low incidence of TFL atrophy due to SGN injury after THA using the modified Watson-Jones approach. High BMI can be a risk factor for nerve injury. The gluteus minimus can be injured directly during surgery. We suggest that overexposure of the surgical site should be avoided, especially in patients with high BMI.

Purpose The Clinical Practice Guidelines for Osteonecrosis of the Femoral Head (ONFH) 2019 Edition, written by the working group for ONFH guidelines of the Japanese Investigation Committee (JIC) for ONFH under the auspices of the Japanese Ministry of Health, Labour, and Welfare and endorsed by the Japanese Orthopaedic Association, were published in Japanese in October 2019. The objective of this guideline is to provide a support tool for decision-making between doctors and patients. Methods Procedures for developing this guideline were based on the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014, which proposed an appropriate method for preparing clinical guidelines in Japan. Results This clinical practice guideline consists of 7 chapters: epidemiology; pathology; diagnosis; conservative therapy; surgical treatment: bone transplantation/cell therapy; surgical treatment: osteotomy; and surgical treatment: hip replacement. Twelve background questions and 13 clinical questions were determined to define the basic features of the disease and to be addressed when deciding treatment in daily practice, respectively. Conclusions The clinical practice guidelines for the ONFH 2019 edition will be useful for physicians, investigators, and medical staff in clinical practice, as well as for patients, during the decision-making process when defining how to treat ONFH.

Short stems have recently become popular in total hip arthroplasty. Previous studies aimed at elucidating the efficacy of short stems did not eliminate the influence of other factors aside from stem length. This study aimed to evaluate the usefulness of short stems compared with that of standard-length stems that have the same proximal morphology, surface coating, and material.This was a prospective randomized study comparing 5-year midterm outcomes in 29 patients who underwent one-stage bilateral total hip arthroplasty with short and standard-length stems inserted in each of the two femurs. Clinical, radiographical, and dual-energy X-ray absorptiometry outcomes were compared.No significant differences were found in perioperative and radiographic characteristics (femoral neck anteversion, flare index, operation sequence, operation side, operation time, stem anteversion, and stem alignment). The number of joints with complications, appearance of radiopaque lines around the stems, or bone mineral density changed in stem regions 5 years postoperatively. However, greater micromotion of the stem was seen on the side of the short stem. Satisfactory improvement in hip function was seen on both sides.Based on the 5-year midterm outcomes, both stems obtained satisfactory clinical outcomes despite the greater micromotion with short stems. Both stems attained bone ingrowth fixation. Moreover, the stems were not significantly different in terms of stress shielding; however, further long-term studies (5 years) are required to validate our findings related to stress shielding.

This prospective study aimed to clarify whether this novel device can evaluate the cup orientation during total hip arthroplasty (THA) more closely to that measured in postoperative computed tomography (CT) compared to the surgeon’s estimate using a manual goniometer. We prospectively performed 30 cementless THAs via the anterolateral approach in supine position between October 2018 and July 2019, wherein cup orientation was evaluated by both a portable imageless navigation system (HipAlign) and a manual goniometer during surgeries. Primary outcome was the absolute estimate error [the absolute value of the difference between cup angles measured by postoperative CT and those measured by HipAlign (group H) or surgeon’s estimate using the manual goniometer (group S) during surgery]. The number of outliers of the absolute estimate error (> 10°) in each group was also estimated. The absolute estimate error of cup inclination in groups H and S was 3.3° ± 2.7° and 3.0° ± 2.5°, respectively (p = 0.51), whereas that of cup anteversion was 3.8° ± 3.4° and 6.0° ± 3.7°, respectively (p = 0.0008). The number of outliers of the estimate error in groups H and S was one case (3.3%) and six cases (20.0%), respectively (p = 0.04). In all six outlier cases, surgeons underestimated cup anteversion during surgeries. This portable imageless navigation system was a useful method, especially for avoiding incorrect cup anteversion. Underestimation of cup anteversion during THA in the supine position with the conventional alignment assisting device should be given attention.

Background The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast, this issue is not fully understood using highly crosslinked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case–control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively. Hypothesis The screw usage and screw holes adversely affect the implant fixation and incidence of wear-related osteolysis in THA with HXLPE. Patients and methods We reviewed 209 primary cementless THAs performed with 26-mm cobalt-chromium heads on HXLPE liners. To compare the effects of the use of screws and the presence of screw holes, the following groups were established: (1) with-screw (n = 140); (2) without-screw (n = 69); (3) no-hole (n = 27) and (4) group in which a cup with screw holes, but no screw was used (n = 42). Two adjunct groups (no-hole cups excluded) were established to compare the differences in the two types of HXLPE: (5) remelted group (n = 100) and (6) annealed group (n = 82). Implant stability and osteolysis were evaluated by plain radiography and computed tomography. The wear rate from 1 year to the final evaluation was measured using plain X-rays and PolyWare Digital software. Results All cups and stems achieved bony fixation. On CT-scan, no acetabular osteolysis was found, but there were 3 cases with a small area of femoral osteolysis. The mean steady-state wear rate of each group was (1) 0.031 ± 0.022, (2) 0.033 ± 0.035, (3) 0.031 ± 0.024, (4) 0.029 ± 0.018, (5) 0.030 ± 0.018 and (6) 0.034 ± 0.023 mm/year, respectively. A comparison of the effects of screw usage or screw holes found no significant between-group differences in the implant stability, prevalence of osteolysis [no acetabular osteolysis and 3/209 at femoral side (1.4%)] and steady-state wear rate. Discussion This study suggests that there are no adverse effects on the results of THA with HXLPE from the use of cups with screw holes and the use of screws for cup fixation. Level of evidence Level III retrospective case–control study.

Background Neurovascular injury is a critical complication in total hip arthroplasty (THA). However, neurovascular geographic variations around the hip joint in different body positions have not been examined. This study investigated the differences in hip neurovascular geography in the supine and lateral positions using magnetic resonance imaging (MRI). Hypothesis The neurovascular geography of the hip is influenced by differences in surgical body position. Patients and methods This was a single-center prospective study of 15 healthy volunteers enrolled between January 2018 and March 2019. Each subject's bilateral hips were scanned with a 3-T MRI scanner in both the supine and lateral positions. In T1-weighted axial images at the level of the hip center, the anterior and posterior acetabular edges were defined as reference points at which retractors are commonly placed during surgery. We measured the distance between the anterior acetabular edge and the femoral nerve (dFN), femoral artery (dFA), and femoral vein (dFV), as well as that between the posterior acetabular edge and the sciatic nerve (dSN). The primary outcome measures were the distances in both the supine and lateral positions. Results dFN, dFA, and dFV in the supine and lateral positions (mm, mean ± standard deviation) were 25.8 ± 5.6 and 32.4 ± 6.4 (p Discussion THA in the supine position may be accompanied by a higher risk of femoral neurovascular injury than that in the lateral position. The application of our findings could reduce the risk of femoral neurovascular injury during THA. Level of Evidence : III; Prospective Diagnostic case control study.

Neurovascular injury is a critical complication in total hip arthroplasty (THA). However, neurovascular geographic variations around the hip joint in different body positions have not been examined. This study investigated the differences in hip neurovascular geography in the supine and lateral positions using magnetic resonance imaging (MRI).The neurovascular geography of the hip is influenced by differences in surgical body position.This was a single-center prospective study of 15 healthy volunteers enrolled between January 2018 and March 2019. Each subject's bilateral hips were scanned with a 3-T MRI scanner in both the supine and lateral positions. In T1-weighted axial images at the level of the hip center, the anterior and posterior acetabular edges were defined as reference points at which retractors are commonly placed during surgery. We measured the distance between the anterior acetabular edge and the femoral nerve (dFN), femoral artery (dFA), and femoral vein (dFV), as well as that between the posterior acetabular edge and the sciatic nerve (dSN). The primary outcome measures were the distances in both the supine and lateral positions.dFN, dFA, and dFV in the supine and lateral positions (mm, mean±standard deviation) were 25.8±5.6 and 32.4±6.4 (p0.0001), 25.7±4.5 and 32.2±5.0 (p0.0001), and 26.5±4.8 and 32.3±5.1 (p0.0001), respectively. Most of these elements moved anteromedially in the lateral position compared to the supine position. There was no significant difference in dSN between the supine and lateral positions (23.7±4.9 and 24.5±6.5 (p=0.46).THA in the supine position may be accompanied by a higher risk of femoral neurovascular injury than that in the lateral position. The application of our findings could reduce the risk of femoral neurovascular injury during THA.III; prospective diagnostic case control study.

Schizophrenia is a major psychiatric disorder, but the molecular mechanisms leading to its initiation or progression remain unclear. To elucidate the pathophysiology of schizophrenia, we used an in vitro neuronal cell culture model involving human induced pluripotent stem cells (hiPSCs) derived from a monozygotic-twin discordant schizophrenia pair. The cultured neurons differentiated from hiPSCs were composed of a mixture of glutamatergic excitatory neurons and gamma aminobutyric acid (GABA)ergic inhibitory neurons. In the electrophysiological analysis, a different pattern of spontaneous neuronal activity was observed under the condition without any stimulants. The frequency of spontaneous excitatory post-synaptic currents (sEPSCs) was significantly higher in the hiPSC-derived neurons of the patient with schizophrenia than in the control sibling at day-in-vitro 30. However, the synaptic formation was not different between the patient with schizophrenia and the control sibling during the same culture period. To explain underlying mechanisms of higher excitability of presynaptic cells, we focused on the potassium-chloride co-transporter KCC2, which contributes to excitatory-to-inhibitory GABA polarity switch in developing neurons. We also revealed the altered expression pattern of KCC2 in hiPSC-derived neurons from the patient with schizophrenia, which could contribute to understanding the pathology of schizophrenia in the developing nervous system.

The gut hormone ghrelin has been implicated in a variety of functional roles in the central nervous system through the brain-gut axis, one of which is an anti-inflammatory effect. An aberrant brain-gut axis producing immune dysfunction has been implicated in the pathobiology of autism spectrum disorder (ASD), and elevated expression of inflammatory markers has been shown in blood and brain tissue from subjects with ASD. We hypothesized that ghrelin may mitigate this effect. Lymphoblastoid cell lines from typically developed children (TD-C) (N = 20) and children with ASD (ASD-C) (N = 20) were cultured with PBS or human ghrelin (0.01 μM) for 24 h, and mRNA expression levels of the inflammation-related molecules interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nuclear factor kappa B (NF-κB) were measured to examine the effects of ghrelin as an anti-inflammatory agent. Expression levels of TNF-α and NF-κB mRNA, but not IL-1β or IL-6, were significantly elevated in ASD-C compared to TD-C. Ghrelin showed a tendency to reduce the expression of TNF-α and NF-κB, but this was not statistically significant. Considering the heterogenous pathobiology of ASD, we examined the effects of ghrelin on TD-C and ASD-C with expression levels of TNF-α and NF-κB in the highest and lowest quartiles. We found that ghrelin markedly reduced mRNA expression of TNF-α and NF-κB s in ASD-C with highest-quartile expression, but there were no effects in ASD-C with lowest-quartile expression, TD-C with highest quartile expression, or TD-C with lowest quartile expression. Together, these findings suggest that ghrelin has potential as a novel therapeutic agent for ASD with inflammation and/or immune dysfunction.

The orientation of the acetabular cup is a critical factor for prevention of various postoperative complications in total hip arthroplasty (THA). Although most patients are treated in either supine or lateral position during surgery, it is still unclear which position is superior to achieve more accurate cup positioning. Our study was conducted in order to answer the following questions: (1) does the supine position provide a higher accuracy of cup positioning than the lateral position in THA using modified Watson-Jones approach? (2) is there any difference in the distribution of cup position between the two positions? Hypothesis Our hypothesis was that the supine position would provide a higher accuracy of cup positioning than the lateral position in THA using modified Watson-Jones approach.A single-center prospective randomized study (registration number: UMIN000021627) was conducted between May 2016 and December 2017. We recruited a total of 60 participants undergoing unilateral primary cementless THA using modified Watson-Jones anterolateral approach based on the result of the sample size calculation. They were randomly assigned to either supine position (n=29) or lateral position (n=31). The cup alignment was targeted using a goniometer during surgery. The radiographic cup inclination was targeted to 40° and the radiographic cup anteversion was targeted considering the femoral stem anteversion during surgery. Postoperative cup alignment was measured by plain radiography and computed tomography. We defined the difference between postoperative and target cup angle as target error and our primary outcome was the absolute value of the target angle. As secondary outcome, the distribution of the target error was evaluated. The target errors of each inclination and anteversion were divided into 3 groups; neutral (-3°≤the target error≤3°), positive error (3°the target error), and negative error (the target error-3°).The assessment of primary outcome for all recruited patients showed that supine group was significantly more accurate than lateral group in terms of radiographic inclination (2.4° vs. 4.5°, respectively, mean difference 2.1°; 95% confidence interval, 0.7 to 3.5; p0.01). There was no significant difference in terms of radiographic cup anteversion (5.6° vs. 5.2°, mean difference 0.4°; 95% confidence interval, -1.8 to 2.6; p=0.69). The rate of positive error of anteversion in supine and lateral group was larger than that of negative value of anteversion (51.7% vs. 10.3% and 48.4% vs. 12.9%, respectively). Any acute complication (dislocation, fracture, and infection) was not found in both groups during postoperative 3 months.In this randomized-controlled trial, higher accuracy of acetabular cup inclination was provided by supine position than by lateral position in THA. On the other hand, there was no significant difference between both groups in terms of cup anteversion. In both groups, most cups were placed with larger anteversion than we targeted. Modified Watson-Jones approach in both positions should be performed considering these results.UMIN000021627. Level of evidence II, randomised controlled study (population-limited).

A retrospective observational study.We evaluated the prognostic value of drain tip culture performed for surgical site infection (SSI) after spinal surgery with a large number of subjects, and investigated whether the type of surgery or timing of drain removal correlated with positive drain culture and SSI rates.In many institutions, routine culture of suction drain tips that are placed in the surgical site of spinal surgeries has been performed to detect contamination after removal. However, few reports have evaluated whether drain tip culture is prognostic for SSI after spinal surgery.A total of 1240 suction drain tips that had been used in spinal surgeries were cultured after removal. Prophylactic antibiotics were administered during and after the surgery for 48 hours. We evaluated the correlation between the results of positive drain tip culture, SSI, and drain removal timing.Positive drain tip cultures were found in 55 cases (4.4%). True SSI was identified in 18 cases (1.5%). The most frequently isolated microorganism in the both cases was Staphylococcus. The sensitivity of drain tip culture for SSI after spinal surgery was calculated as 0% according to the concordance rate between bacteria isolated in drain tip culture and SSI cases. There was no correlation between the duration of suction drainage and the drain tip culture results or the onset of SSI within 72 hours. The results of suction drain tip culture could not reflect those of SSI regardless of the type of surgery (primary or revision), surgical region, surgical procedure, or implant use.Drain tip culture in spinal surgery was not prognostic for SSI or helpful in detecting pathogenic bacteria for SSI. Routine use of drain tip culture when prophylactic antibiotics are used is not supported by the results of this study.4.

The difference in clinical results between the direct anterior approach (DAA) and the anterolateral approach (ALA) for total hip arthroplasty (THA) is still unclear. The purpose of this study was to compare clinical results, including nerve injuries, between DAA and ALA in one-stage bilateral THA in a prospective, randomized controlled trial.Thirty patients were recruited for primary bilateral THAs from 2014 to 2016. The left and right hips of each patient were randomly assigned to DAA and the others to ALA. We prospectively compared the clinical results, incidence of lateral femoral cutaneous nerve (LFCN) injury, and tensor fascia lata (TFL) atrophy considered to be related to superior gluteal nerve injury between both approaches.No significant difference was found in the clinical results between both sides at postoperative 1 year. Temporary symptom of LFCN injury was observed only in DAA sides (7/30, 23.3%). The ratio of 3-month postoperative to preoperative cross-sectional area of TFL on computed tomography was significantly lower on the side subjected to DAA (DAA side, 78.8 ± 22.8%) than on the side subjected to ALA (ALA side, 90.7 ± 17.7%) (p 0.01). In magnetic resonance imaging at postoperative 1 year, the mean grade of fatty atrophy of TFL by Goutalier classification was significantly higher in DAA sides (2.00 ± 1.6) than in ALA sides (1.1 ± 1.3) (p = 0.03).Excellent clinical results for both DAA and ALA were achieved. LFCN injury was found only in DAA sides. Although TFL atrophy was found in both approaches, it was found significantly more in DAA sides. Our study suggested that ALA should be used rather than DAA in terms of the risk of nerve injuries.

Background The orientation of the acetabular cup is a critical factor for prevention of various postoperative complications in total hip arthroplasty (THA). Although most patients are treated in either supine or lateral position during surgery, it is still unclear which position is superior to achieve more accurate cup positioning. Our study was conducted in order to answer the following questions: (1) does the supine position provide a higher accuracy of cup positioning than the lateral position in THA using modified Watson-Jones approach? (2) is there any difference in the distribution of cup position between the two positions? Hypothesis Our hypothesis was that the supine position would provide a higher accuracy of cup positioning than the lateral position in THA using modified Watson-Jones approach. Patients and Methods A single-center prospective randomized study (registration number: UMIN000021627) was conducted between May 2016 and December 2017. We recruited a total of 60 participants undergoing unilateral primary cementless THA using modified Watson-Jones anterolateral approach based on the result of the sample size calculation. They were randomly assigned to either supine position (n = 29) or lateral position (n = 31). The cup alignment was targeted using a goniometer during surgery. The radiographic cup inclination was targeted to 40° and the radiographic cup anteversion was targeted considering the femoral stem anteversion during surgery. Postoperative cup alignment was measured by plain radiography and computed tomography. We defined the difference between postoperative and target cup angle as “target error” and our primary outcome was the absolute value of the target angle. As secondary outcome, the distribution of the target error was evaluated. The target errors of each inclination and anteversion were divided into 3 groups; neutral (−3° ≤ the target error ≤ 3°), positive error (3° Results The assessment of primary outcome for all recruited patients showed that supine group was significantly more accurate than lateral group in terms of radiographic inclination (2.4° vs. 4.5°, respectively, mean difference 2.1°; 95% confidence interval, 0.7 to 3.5; p Discussion In this randomized-controlled trial, higher accuracy of acetabular cup inclination was provided by supine position than by lateral position in THA. On the other hand, there was no significant difference between both groups in terms of cup anteversion. In both groups, most cups were placed with larger anteversion than we targeted. Modified Watson-Jones approach in both positions should be performed considering these results. Study registration number UMIN000021627. Level of evidence II, randomised controlled study (population-limited).

There is no previous report that directly compared wear resistance of second-generation annealed highly cross-linked polyethylene with that of first-generation remelted highly cross-linked polyethylene. We therefore performed a retrospective study at a minimum of 5-year follow-up comparing second-generation annealed and first-generation remelted highly cross-linked polyethylene in order to: (1) assess wear rates and (2) compare the incidence of osteolysis between, (3) identify the frequency of complication related to the two types of highly cross-linked polyethylene.There is a difference in the linear wear rate and the incidence of osteolysis between the two types of highly cross-linked polyethylene in total hip arthroplasty.In a single centre study, we reviewed 123 primary cementless total hip arthroplasties between 2010 and 2011 that were performed with 32mm alumina ceramic on second-generation annealed (X3) or first-generation remelted (Longevity) highly cross-linked polyethylene liner. There was no specific reason for the choice of the type of highly cross-linked polyethylene. There were no significant differences between the two groups in respect of gender, diagnosis, body mass index, pre- and post-operative functional and activity score, cup size, and cup orientation except the younger age in the X3 group. The mean wear rate and the incidence of osteolysis were evaluated at the latest follow-up.One hundred nine cases followed over 5 years post-operatively (88.6% in all consecutive cases) were evaluated. X3 and Longevity were used in 54 and 55 cases, respectively. The mean follow-up was 5.3 years in both groups. The mean linear wear rate of X3 and Longevity group was 0.045±0.023mm/year and 0.076±0.031mm/year, respectively (P0.001). No osteolysis was found on plain X-rays in both groups and no specific complication was related to these highly cross-linked components.Excellent wear resistance of both types of highly cross-linked polyethylene liner was revealed in our study. The difference of wear rate between two materials should be monitored in a longer follow-up.Level III retrospective case control study.

Background Low polyethylene wear rate and low incidence of osteolysis after total hip arthroplasty using annealed and remelted highly cross-linked polyethylene have been reported. However, there is no previous report that directly compared both types of highly cross-linked polyethylene. We therefore performed a retrospective study on a series of highly cross-linked polyethylene, in order to: (1) compare wear rates and the incidence of osteolysis between annealed and remelted highly cross-linked polyethylene at 7–10 years; (2) identify the frequency of complication related to annealed and remelted highly cross-linked polyethylene. Hypothesis There is no difference in the linear wear rate and the incidence of osteolysis between the annealed and remelted highly cross-linked polyethylene in total hip arthroplasty. Patients and methods Two hundred and sixteen cases of cementless total hip arthroplasties with annealed or remelted highly cross-linked polyethylene, which were performed between January 2003 and December 2006 in one institution, were followed for 7–10 years and received computed tomography scan, in addition to radiography at the latest follow-up. Annealed and remelted highly cross-linked polyethylene was used in 91 cases and 125 cases, respectively. A 26-mm cobalt-chromium head was used in all cases. Penetration rates from 1 year to the last evaluation were used to estimate the yearly linear wear rate. Existence of osteolysis was evaluated by plain radiography and computed tomography. Results There were no significant differences in patients’ background between the two groups. The linear wear rate of annealed and remelted group was 0.031 ± 0.022 mm/year and 0.032 ± 0.020 mm/year, respectively ( P = 0.91). Two cases of small femoral osteolysis were found in the annealed group. Any complication related to highly cross-linked polyethylene was not found in both groups. Discussion There was no significant difference in the linear wear rate and the incidence of osteolysis between the annealed and remelted group at postoperative 7 to 10 years. Excellent results of both types of highly cross-linked polyethylene were revealed by this study. Level of evidence Level III retrospective case control study.

The purpose of this retrospective study is to report the incidence of osteolysis and evaluate the significance of screening computed tomography (CT) compared to plain radiography in detecting osteolysis after total hip arthroplasty with metal-on-highly cross-linked polyethylene bearings.We retrospectively reviewed 264 primary cementless total hip arthroplasties of 211 patients, 24 males, 187 females, who received postoperative screening CT scan in addition to radiography at postoperative 7-10 years (average 8.2 years). First-generation highly cross-linked polyethylene was used in all cases.On the plain radiographs, no acetabular osteolysis (0%) and two cases of femoral osteolysis (0.8%) were found in the follow-up period. No osteolysis was newly found by screening CT scan.Very low incidence of osteolysis after total hip arthroplasty with highly cross-linked polyethylene at postoperative 7-10 years was confirmed, and routine screening CT scan for detecting osteolysis in this setting was not supported from this study.

Background The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast this issue is not fully understood using highly cross-linked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case-control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis, and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively. Hypothesis The screw usage and screw holes adversely affect the implant fixation and incidence of wear-related osteolysis in THA with HXLPE. Patients and methods We reviewed 209 primary cementless THAs performed with 26-mm cobalt-chromium heads on HXLPE liners. To compare the effects of the use of screws and the presence of screw holes, the following groups were established: (1) with-screw (n = 140); (2) without-screw (n = 69); (3) no-hole (n = 27); and (4) group in which a cup with screw holes, but no screw was used (n = 42). Two adjunct groups (no-hole cups excluded) were established to compare the differences in the two types of HXLPE: (5) remelted group (n = 100) and (6) annealed group (n = 82). Implant stability and osteolysis were evaluated by plain radiography and computed tomography. The wear rate from 1 year to the final evaluation was measured using plain X-rays and PolyWare Digital software. Results All cups and stems achieved bony fixation. On CT-scan no acetabular osteolysis was found, but there were 3 cases with a small area of femoral osteolysis. The mean steady-state wear rate of each group was (1) 0.031 ± 0.022, (2) 0.033 ± 0.035, (3) 0.031 ± 0.024, (4) 0.029 ± 0.018, (5) 0.030 ± 0.018, and (6) 0.034 ± 0.023 mm/year, respectively. A comparison of the effects of screw usage or screw holes found no significant between-group differences in the implant stability, prevalence of osteolysis (no acetabular osteolysis and 3/209 at femoral side (1.4 %) and steady-state wear rate. Discussion This study suggests that there are no adverse effects on the results of THA with HXLPE from the use of cups with screw holes and the use of screws for cup fixation. Level of evidence: Level III retrospective case-control study.

Background There is no previous report that directly compared wear resistance of second-generation annealed highly cross-linked polyethylene with that of first-generation remelted highly cross-linked polyethylene. We therefore performed a retrospective study at a minimum of 5-year follow-up comparing second-generation annealed and first-generation remelted highly cross-linked polyethylene in order to: (1) assess wear rates and (2) compare the incidence of osteolysis between, (3) identify the frequency of complication related to the two types of highly cross-linked polyethylene. Hypothesis There is a difference in the linear wear rate and the incidence of osteolysis between the two types of highly cross-linked polyethylene in total hip arthroplasty. Materials and methods In a single center study, we reviewed 123 primary cementless total hip arthroplasties between 2010 and 2011 that were performed with 32 mm alumina ceramic on second-generation annealed (X3) or first-generation remelted (longevity) highly cross-linked polyethylene liner. There was no specific reason for the choice of the type of highly cross-linked polyethylene. There were no significant differences between the two groups in respect of gender, diagnosis, body mass index, pre- and postoperative functional and activity score, cup size, and cup orientation except the younger age in the X3 group. The mean wear rate and the incidence of osteolysis were evaluated at the latest follow-up. Results One hundred and nine cases followed over 5 years postoperatively (88.6% in all consecutive cases) were evaluated. X3 and longevity were used in 54 and 55 cases, respectively. The mean follow-up was 5.3 years in both groups. The mean linear wear rate of X3 and longevity group was 0.045 ± 0.023 mm/year and 0.076 ± 0.031 mm/year, respectively (P Discussion Excellent wear resistance of both types of highly cross-linked polyethylene liner was revealed in our study. The difference of wear rate between two materials should be monitored in a longer follow-up. Level of evidence Level III retrospective case control study.

Since the aging of infrastructure and production facilities of Japanese society is in progress, the importance of the development and utilization of infrastructure inspection and maintenance robot is increasing. It can prevent and/or reduce damage in the event of natural disasters, and it can deal with the expansion of everyday maintenance requirement. In addition, conversion to disaster responder is practically possible since its technologies and capabilities of robot are quite similar. As technological challenges, combined type mobile robot technique, development of aerial robot control software for inspection task and the mobile technology on the wall are essential. There is an urgent need to develop techniques and the standards for explosion proof mobile robot. As advanced practical research theme for inspection robot, we propose to establish the Disaster Management Centre, where the robot functional verification, performance evaluation, and technical information exchange will be conducted in peacetime, in disaster and in all aspects of recovery process.