PRDM16 enhances nuclear receptor-dependent transcription of the brown fat-specific Ucp1 gene through interactions with Mediator subunit MED1.

PR domain-containing 16 (PRDM16) induces expression of brown fat-specific genes in brown and beige adipocytes, although the underlying transcription-related mechanisms remain largely unknown. Here, in vitro studies show that PRDM16, through its zinc finger domains, directly interacts with the MED1 subunit of the Mediator complex, is recruited to the enhancer of the brown fat-specific uncoupling protein 1 (Ucp1) gene through this interaction, and enhances thyroid hormone receptor (TR)-driven transcription in a biochemically defined system in a Mediator-dependent manner, thus providing a direct link to the general transcription machinery. Complementary cell-based studies show that upon forskolin treatment, PRDM16 induces Ucp1 expression in undifferentiated murine embryonic fibroblasts, that this induction depends on MED1 and TR, and, consistent with a direct effect, that PRDM16 is recruited to the Ucp1 enhancer. Related studies have defined MED1 and PRDM16 interaction domains important for Ucp1 versus Ppargc1a induction by PRDM16. These results reveal novel mechanisms for PRDM16 function through the Mediator complex.

Minimum 10-Year Follow-Up of Total Hip Arthroplasty With a Collarless Triple-Tapered Polished Cemented Stem With Line-to-Line Implantation Using a Direct Anterior Approach.

BACKGROUND: The Trilliance stem (B. Braun-Aesculap, Tuttlingen, Germany), a novel collarless triple-tapered polished stem, was introduced in 2009. The aim of this study is to evaluate the long-term clinical and radiological results of the Trilliance stem with line-to-line implantation in primary total hip arthroplasty using a direct anterior approach. METHODS: A consecutive retrospective series of 130 patients (151 hips) who underwent total hip arthroplasty between February 2009 and August 2011 were evaluated for a minimum of 10 years. Of these, 87.4% had a diagnosis of secondary osteoarthritis based on developmental hip dysplasia. Clinical and radiological results, complications were evaluated and survival analysis was performed. RESULTS: The mean follow-up was 10.7 years (range, 10.0-12.1). Thirteen hips (13 patients, 6.8%) were lost to follow-up. Adequate cementation (Barrack grade A) was achieved in 136 hips (93.8%) 1 week post-operatively. Nearly all (144 hips, 99.3%) had been inserted within the range of 3°. No significant differences were identified between high- (≥30 procedures/year) and low- (<30 procedures/year) volume surgeons. The Kaplan-Meier survival analysis with revision of the femoral component for aseptic loosening, revision of the femoral component for any reason and revision of either component for any reason as the end points, cumulative survivorship was 100.0%, 97.6% (95% confidence interval (CI) 95.4-100.0) and 96.5% (95% CI 93.8-99.3) at 10 years, respectively. CONCLUSION: The Trilliance stem with line-to-line implantation using a direct anterior approach has an excellent clinical and radiological outcome at a minimum of 10 years' follow-up. LEVEL OF EVIDENCE: Level IV, Retrospective cohort study.

Minimum ten-year outcome of a triple-tapered femoral stem implanted with line-to-line cementing technique.

BACKGROUND: A triple-tapered polished femoral stem was implanted with line-to-line cementing technique. The purpose of this study was to determine the survivorship, loosening rate, stem subsidence, radiologic changes and clinical outcomes in the minimum 10-year follow-up. METHODS: This was a retrospective study done in three institutes. Finally, 118 hips in 97 patients could be followed-up at the mean follow-up period of 126.3 months. The survivorship, radiological and clinical outcomes were investigated. RESULTS: Radiologically, 107 hips (90.7%) were categorized to Barrack cementing grade A, and 108 stems (91.5%) were inserted in neutral position. All hips were not loose and were not revised due to any reason. Survival with revision for any reason as the endpoint was 100% after 10 years. At the last follow-up, the mean subsidence was 0.43 mm, and the subsidence was less than 1 mm in 110 hips (93.2%). JOA hip score improved from 42.7 ± 8.9 points preoperatively to 92.8 ± 6.8 points at the last follow-up. No patient complained thigh pain. CONCLUSIONS: Line-to-line cementing technique with use of a triple-tapered polished stem was effective to achieve good cementation quality and centralization of the stem. The subsidence was small, and the minimum 10-year results were excellent without any failures related to the stem. TRIAL REGISTRATION: Retrospectively registered.

Minimum 5 year follow-up of clinical and radiographic results of cemented acetabular components with an interface bioactive bone cement technique in primary cemented total hip arthroplasty.

INTRODUCTION: A well-fixed cement-bone interface is a crucial factor for acetabular and femoral components in cemented total hip arthroplasty (THA). The aim of the present study was to evaluate the middle-term clinical and radiological results of fixing the acetabular component with an interface bioactive bone cement (IBBC) technique in primary cemented THA. MATERIALS AND METHODS: We undertook a retrospective review was undertaken of 193 primary cemented THAs in 174 patients using acetabular components cemented with an IBBC technique and followed for a minimum of 5 years (mean 8.3 years; range 5-17 years). Baseline data, clinical and radiological outcomes were evaluated. RESULTS: Japanese Orthopedic Association hip score and modified Harris hip scores demonstrated significant clinical improvement in all patients (p < 0.001). Radiolucent lines were detected in 15 hips (7.8%) at the first year and 24 hips (12.4%) at the final post-operative follow-up. The Kaplan-Meier survivorship with radiographic loosening as the end point was 97.8% [95% confidence interval (CI) 95.2-100]. With revision of the acetabular component for aseptic loosening as the end point, component survival was 99.0% (95% CI 97.5-100). With revision of the acetabular component for any reason as the end point, component survival was 97.0% (95% CI 93.9-100). CONCLUSIONS: Clinical and radiological results of the acetabular component with the IBBC technique in primary cemented THA were excellent.

[Case of Peritoneal Dissemination from Gastrointestinal Stromal Tumor of Jejunum Treated with Repeated Non-Curative Surgery].

A 71-year-old male presented with abdominal distension and fever to our hospital. Abdominal CT revealed a huge tumor in abdomen, and non-curative surgery was performed. Peritoneal dissemination was widespread and the tumor invaded the bladder and sigmoid-colon mesenterium. Two months after the initial surgery, CT showed liver metastasis, and oral administration of imatinib mesylate was started. The peritoneal dissemination and liver metastasis showed a decrease, and this was well controlled for 45 months without severe side effects. Abdominal CT revealed peritoneal dissemination in the ileocecum after 43 months since the administration of imatinib. Therefore, sunitinib treatment was initiated. After 3 months of sunitinib administration, the tumor perforated. Emergency operation was performed to resect the ileocecum, and sunitinib was continued for 1 year. In GIST with liver metastasis and peritoneal dissemination, repeated surgical resection combined with chemotherapy is important to improve the patient's survival.

Postoperative migration of the anatomical and functional anteversion angle following total hip arthroplasty with a well-fixed cemented femoral component with line-to-line implantation.

INTRODUCTION: Little is known about the association between well-fixed polished tapered cemented stems (PTCS) implanted by the line-to-line technique and changes of stem migration, or the change of functional anteversion of the femur after total hip arthroplasty (THA). MATERIALS AND METHODS: This retrospective study included 422 two-stage bilateral primary THAs performed using PTCS implanted by the line-to-line technique. CT scans were made on both the target side (first postoperative CT) and on the contralateral side (second postoperative CT) 1 week postoperatively. The mean follow-up was 7.8 months. CT data for each scan were transferred to 3D template software (Zed hip, Lexi, Japan). The postoperative changes of anatomical stem anteversion (ASA), functional femoral anteversion (FFA), and stem subsidence were evaluated. RESULTS: A total of 20 THAs with CT scans were available on 3D template software. The ASA and the FFA had migrated - 0.68° ± 0.62° and - 5.5° ± 9.7°, respectively, over the follow-up period. A significant positive correlation was observed between the change of subsidence and ASA (r2 = 0.34, p = 0.007), between the FFA on the second postoperative CT and ASA on the first postoperative CT (r2 = 0.26, p = 0.02) and between the FFA on the second postoperative CT and FFA on the first postoperative CT (r2 = 0.52, p = 0.0003). CONCLUSION: This study indicates that the change in axial rotation of a PTCS implanted by the line-to-line technique was less than that reported by other studies and the preoperative external rotation contracture was substantially improved after THA.

[A Case of Unresectable Pancreas Cancer with 32 Months Survival after Chemotherapy].

We report a case of unresectable pancreas cancer. A 70-year-old woman presented with worsening diabetes and serum CA19-9 elevation. A tumor with portal vein and supra-mesenteric vein invasion was observed by computed tomography. She was diagnosed with unresectable pancreas head cancer that was locally advanced. Chemotherapy was administered with gemcitabine and nab-paclitaxel for 19 courses, followed by gemcitabine alone for 4 courses. After the addition of 6 courses of chemotherapy, a 60%dose of chemotherapy was administered for 13 courses due to severe neutropenia. The patient died 32 months after the first visit. The 60% dose of gemcitabine and nab-paclitaxel also inhibited tumor growth. These findings suggest the effective and safe long-term use of gemcitabine and nab-paclitaxel.

Does the surgical approach influence the implant alignment in total hip arthroplasty? Comparative study between the direct anterior and the anterolateral approaches in the supine position.

PURPOSE: The purpose of this study was to clarify the difference in implant alignment between the direct anterior approach (DAA) and the anterolateral approach in the supine position (ALS). METHODS: A retrospective comparative study consisted of 215 consecutive primary total hip arthroplasties using tapered polished and straight cemented-stems via two different minimally invasive approaches (DAA group in 106 hips and ALS group in 109 hips). RESULTS: The cup radiographic anteversion angle was significantly lower in the ALS group than in the DAA group (12.9° versus 16.9°, p = 0.001). The frequency of the safe zone tended to be more favourable in the ALS group than in the DAA group (95% versus 87%, p = 0.052). Stem alignment in the sagittal plane was significantly better in the ALS group than in the DAA group (84% versus 71%, p = 0.022). CONCLUSIONS: Both cup and stem alignments were better in the ALS group than the DAA group.

Intraoperative blood pressure changes during cemented versus uncemented bipolar hemiarthroplasty for displaced femoral neck fracture: a multi-center cohort study : The effect of bone cement for bipolar hemiarthroplasty in elderly patients.

INTRODUCTION: The purpose of this study was to compare the cemented bipolar hemiarthroplasty with uncemented about the change of intraoperative blood pressure and the incidence of major complications in elderly patients with femoral neck fracture. MATERIALS AND METHODS: This multiple center prospective cohort study included only patients with acute displaced femoral neck fracture (Garden stage III or IV). All patients were treated with cemented or uncemented bipolar hemiarthroplasty using modified Hardinge or Watson-Jones approach in the lateral decubitus position. Baseline data, medical history, type of anesthesia, FiO2 value, the number of vasopressor using during operation, femoral component, intraoperative blood pressure, SaO2, and major complications were evaluated. RESULTS: Of 164 patients (45 males and 119 females), 86 underwent cemented and 78 underwent uncemented bipolar hemiarthroplasty. Baseline medical histories were similar in both groups. In both the cemented and uncemented groups, intraoperative systolic blood pressure significantly decreased during cementing or rasping (106.3 and 103.6 mmHg) and after femoral component insertion (103.3 and 99.1 mmHg) compared to before rasping (120.7 and 116.4 mmHg) (p < 0.0001, respectively). Donaldson's grade seemed more favorable in uncemented group than in cemented group during cementing or rasping, during stem insertion; however, no patients experienced the lethal complication in both groups. CONCLUSIONS: Intraoperative blood pressure did not change during cemented and uncemented bipolar hemiarthrplasty for displaced femoral neck fracture. If the standard modern cement technique was performed during operation, bone cement is a safe and acceptable for elderly patients who have a lot of medical histories.

Human mediator MED17 subunit plays essential roles in gene regulation by associating with the transcription and DNA repair machineries.

In eukaryotes, holo-Mediator consists of four modules: head, middle, tail, and CDK/Cyclin. The head module performs an essential function involved in regulation of RNA polymerase II (Pol II). We studied the human head module subunit MED17 (hMED17). Recent structural studies showed that yeast MED17 may function as a hinge connecting the neck and movable jaw regions of the head module to the fixed jaw region. Luciferase assays in hMED17-knockdown cells showed that hMED17 supports transcriptional activation, and pulldown assays showed that hMED17 interacted with Pol II and the general transcription factors TFIIB, TBP, TFIIE, and TFIIH. In addition, hMED17 bound to a DNA helicase subunit of TFIIH, XPB, which is essential for both transcription and nucleotide excision repair (NER). Because hMED17 associates with p53 upon UV-C irradiation, we treated human MCF-7 cells with either UV-C or the MDM2 inhibitor Nutlin-3. Both treatments resulted in accumulation of p53 in the nucleus, but hMED17 remained concentrated in the nucleus in response to UV-C. hMED17 colocalized with the NER factors XPB and XPG following UV-C irradiation, and XPG and XPB bound to hMED17 in vitro. These findings suggest that hMED17 may play essential roles in switching between transcription and NER.

[Malignant Pleural Mesothelioma with Excessive Inflammation and High Level of Interleukin 6 - A Case Report].

Malignant mesothelioma is a rare aggressive solid tumor that is invariably incurable. A 23-year-old female patient with ascites, anemia, and high levels of ferritin and CRP was diagnosed with pleural mesothelioma by exploratory laparotomy. She remained asymptomatic, but 7 years later, she developed intractable diarrhea and fever. Systematic chemotherapy with both cisplatin and pemetrexed was administered. However, the treatment was discontinued due to side effects, after which time the diarrhea, ascites, and fever became progressively more severe. Hepatomegaly and hepatic siderosis also developed. At the same time, the patient's serum interleukin 6(IL-6)levels were abnormally high. Although there was a temporary symptomatic improvement after intraperitoneal injection of cisplatin, the intractable mesothelioma-associated symptoms returned a few days later. The patient died of liver failure 1 week later. The poor prognosis in this case was due to symptoms associated with the high IL-6 level. There are limited medically proven treatments, and it is important to develop new treatments. Therefore, "anti-IL-6 therapy" may have to be tested as a potential treatment for symptoms associated with high IL-6 levels.

Transcription cofactor PC4 plays essential roles in collaboration with the small subunit of general transcription factor TFIIE.

In eukaryotes, positive cofactor 4 (PC4) stimulates activator-dependent transcription by facilitating transcription initiation and the transition from initiation to elongation. It also forms homodimers and binds to single-stranded DNA and various transcriptional activators, including the general transcription factor TFIIH. In this study, we further investigated PC4 from Homo sapiens and the nematode Caenorhabditis elegans (hPC4 and cePC4, respectively). hPC4 strongly stimulated transcription on a linearized template, whereas it alleviated transcription on a supercoiled template. Transcriptional stimulation by PC4 was also alleviated by increasing the amount of TFIID. GST pull-down studies with general transcription factors indicated that both hPC4 and cePC4 bind strongly to TFIIB, TFIIEß, TFIIFα, TFIIFß and TFIIH XPB subunits and weakly to TBP and TFIIH p62. However, only hPC4 bound to CDK7. The effect of each PC4 on transcription was studied in combination with TFIIEß. hPC4 stimulated both basal and activated transcription, whereas cePC4 primarily stimulated activated transcription, especially in the presence of TFIIEß from C. elegans. Finally, hPC4 bound to the C-terminal region of hTFIIEß adjacent to the basic region. These results indicate that PC4 plays essential roles in the transition step from transcription initiation to elongation by binding to melted DNA in collaboration with TFIIEß.

Hip dysfunction-related urinary incontinence: a prospective analysis of 189 female patients undergoing total hip arthroplasty.

Patients reporting that their symptoms of urinary incontinence have decreased after total hip arthroplasty can be encountered in orthopedic practice. In this questionnaire-based study, we prospectively evaluated the symptoms of urinary incontinence before and after total hip arthroplasty. The International Consultation on Incontinence Questionnaire-Short Form was used to prospectively evaluate these symptoms in 189 consecutive female patients undergoing total hip arthroplasty. The patients were asked to fill in a questionnaire before and 3 months after surgery. A decrease in the International Consultation on Incontinence Questionnaire-Short Form score of ≥1 point was defined as an improvement, whereas an increase of ≥1 point was defined as worsening. A total of 81 (43%) patients reported urinary incontinence before total hip arthroplasty. At 3 months after surgery, symptoms of urinary incontinence were improved in 64% of these patients, remained unchanged in 32% and worsened in 4%. Mean International Consultation on Incontinence Questionnaire-Short Form score in patients with urinary incontinence before surgery significantly improved from 6.0 to 3.5 (P = 0.0002). These findings suggest a relationship between hip joint function and pelvic floor function, and consequently a hip dysfunction-related urinary incontinence.

An anatomic study of the impressions on the greater trochanter: bony geometry indicates the alignment of the short external rotator muscles.

In this study, 44 hip regions from 25 embalmed cadavers were dissected to identify the bony landmarks on the greater trochanter, which indicate the individual short external rotator muscle insertions. Micro-computed tomography (micro-CT) images were obtained to identify the bony impressions on the greater trochanter. Then, the soft tissues were removed and their insertions were identified to assess correlation with micro-CT images. Bony landmarks indicating the insertions and the running course of the piriformis muscle, the obturator internus muscle, and the obturator externus muscle were identified on the greater trochanter in all specimens. These findings could be helpful for preserving muscles during capsular release in the anterior approach because the alignment of the short external rotator muscles can be estimated preoperatively using CT images.

Correlation between Femoral Head Lateralization and Bone Morphology in Primary Hip Osteoarthritis.

Background: Osteoarthritis (OA) is the most common disease of the hip in adults, and its etiology is divided into two groups: primary and secondary. Although acetabular dysplasia is the most frequent reason for total hip arthroplasty (THA) in Japan, primary OA has increased recently. Although there are two types of femoral head migration in primary OA: superior and medial, there are some patients with prominent femoral head lateralization. This study aimed at evaluating the relationship between femoral head lateralization and bone morphology of the acetabulum and proximal femur using radiographic factors in primary OA of the hip. Methods: A retrospective study was conducted between 2008 and 2017 to assess 1308 hips with OA who underwent primary THAs at our institute. The diagnostic criteria for primary OA were Crowe type 1, Sharp's angle <45°, and center-edge (CE) angle >25°. We classified patients with primary OA into two groups based on femoral head lateralization: group L with lateralization or group N without. Radiographic factors included Sharp's angle, CE angle, acetabular inclination, acetabular depth ratio (ADR), acetabular head index (AHI), and femoral neck-shaft angle (FNA), all examined on an anteroposterior pelvic radiograph. Femoral neck anteversion was calculated using computerized axial tomography. Results: Primary OA was diagnosed in 210/1308 hips (16.1%) (group L: 112 hips (8.6%); group N: 98 (7.5%)). Patient demographics were not significantly different. Radiographic factors with observed significant differences between group L and group N were the average CE angle (33.0° vs. 35.1°, respectively, p = 0.009), ADR (251.6 vs. 273.4, p < 0.001), AHI (77.2 vs. 80.4, p < 0.001), and FNA (136.9° vs. 134.8°, p = 0.012). Conclusions: This investigation suggests that primary OA with femoral head lateralization demonstrated specific identifiable radiographic characteristics in the acetabulum and proximal femur that might contribute to hip joint instability such as the dysplastic hip.

The influence of calcar collar and surface finish in the cemented femoral component on the incidence of postoperative periprosthetic femoral fracture at a minimum of five years after primary total hip arthroplasty.

INTRODUCTION: Cemented femoral component design including its mechanical behavior in total hip arthroplasty (THA) has influenced the occurrence of postoperative periprosthetic femoral fracture (PPFF). The main aim of this study was to investigate the influence of the calcar collar and surface finish in the cemented femoral component on the risk of PPFF. MATERIALS AND METHODS: This retrospective review was undertaken of 1082 primary THAs in 912 patients using cemented femoral components followed for a minimum of five years (mean, 9.4 years; range, 5-24 years). The incidence of PPFF, patients' demographics and surgical details were evaluated. Kaplan-Meier survivorship analysis was performed for four different outcomes: any PPFF, revision of the femoral component for PPFF, aseptic loosening, and for any reason. RESULTS: The overall incidence of PPFFs was 1.0% (n = 11): 1.4% (n = 10) in the collarless polished (CLP) group, none in the collared polished (CP) group and 0.6% (n = 1) in the collared non-polished (CNP) group (p > 0.05). Kaplan-Meier survival analysis for the femoral component at 12 years with PPFF as the end point was 97.4% (95% confidence interval [CI], 94.9 to 99.8) in the collarless group and 99.7% (95% CI, 99.1 to 100) in the collared group (p = 0.048). With revision of the femoral component for aseptic loosening as the end point, survivorship was 100.0% in the CLP and CP groups, and 98.1% (95% CI, 95.9 to 100) in the CNP group (CLP vs CP, p > 0.999; CLP vs CNP, p = 0.001; CP vs CNP, p = 0.112). CONCLUSION: This study demonstrated that the calcar collar in the cemented femoral component could play an important role to reduce the incidence of PPFF. The surface finish in the cemented femoral components influenced the incidence of femoral component revision for aseptic loosening over 5-12 years. Surgeons should consider not only the geometry and the mechanical function of the femoral components based on different design philosophies, but also potential complications associated with different designs that may require revision arthroplasty.

Inter-observer and intra-observer reliabilities of the Japanese Ministry of Health, Labor and Welfare type classification system for osteonecrosis of the femoral head.

The aim of this study was to clarify the reproducibility of the Japanese Ministry of Health, Labor and Welfare (JMHLW) type classification for osteonecrosis of the femoral head. We performed inter-observer and intra-observer trials using 40 sets of magnetic resonance imagings, 20 of which were produced by a 0.5 Tesla (T) superconductive unit and the other 20 produced by a 1.5 T unit, in patients with non-collapsed and asymptomatic osteonecrosis of the femoral head (JMHLW stage 1 or 2). The JMHLW type classification (A, B, C1, or C2) was determined from T1-weighted coronal images at the center of the femoral head. Six orthopedic surgeons independently assessed all 40 images twice, with an interval of 4-5 weeks between sessions. Regarding inter-observer reliability, the percent agreement was 85% and weighted kappa was 0.709 for 0.5 T, versus a percent agreement of 82% and weighted kappa of 0.724 for 1.5 T. Regarding intra-observer reliability, the percent agreement was 82% and weighted kappa was 0.780 for 0.5 T versus a percent agreement of 80% and weighted kappa of 0.800 for 1.5 T. Inter-observer and intra-observer reliabilities did not differ significantly between the 0.5 and 1.5 T units. The JMHLW type classification provided high inter-observer and intra-observer reliabilities.

Candidate plasticity gene 16 and jun dimerization protein 2 are involved in the suppression of insulin gene expression in rat pancreatic INS-1 ß-cells.

Chronic hyperglycemia causes pancreatic ß-cell dysfunction, impaired insulin secretion and the suppression of insulin gene expression. This phenomenon is referred to as glucotoxicity, and is a critical component of the pathogenesis of type 2 diabetes. We previously reported that the expression of candidate plasticity gene 16 (CPG16) was higher in rat pancreatic INS-1 ß-cells under glucotoxic conditions and CPG16 suppressed insulin promoter activity. However, the molecular mechanisms of the CPG16-mediated suppression of insulin gene expression are unclear. In this study, we found that CPG16 directly bound and phosphorylated jun dimerization protein 2 (JDP2), an AP-1 family transcription factor. CPG16 co-localized with JDP2 in the nucleus of INS-1 cells. JDP2 bound to the G1 element of the insulin promoter and up-regulated promoter activity. Finally, CPG16 suppressed the up-regulation of insulin promoter activity by JDP2 in a kinase activity-dependent manner. These results suggest that CPG16 suppresses insulin promoter activity by phosphorylating JDP2.

Mechanism of Chronic Pain of Symptomatic Hip Osteoarthritis by Association of its Distribution, Nociceptive, Neuropathic, Nociplastic, or Mixed-pain Screening, and the Prevalence of Lumbar Spinal Stenosis: A Cross-sectional Study.

OBJECTIVES: The pain of hip osteoarthritis (OA) is generally recognized as nociceptive in origin because of the local pathology. However, some patients with OA experience a neuropathic pain component as an essential part of some nociplastic pain subtype. Here, we sought to examine the mechanism of chronic pain of symptomatic hip OA by the association of its distribution, complex pain mechanism screening, and the prevalence of lumbar spinal stenosis. MATERIALS AND METHODS: We conducted a prospective cross-sectional study of 100 hips in 100 patients with symptomatic hip OA in a chronic state. We examined all baseline clinical characteristics including clinical and functional score, location of pain and numbness, and pain score (PainDETECT questionnaire and the Leeds Assessment of Neuropathic Symptoms and Signs), and magnetic resonance imaging of the hip and lumbar spine. RESULTS: The PainDETECT questionnaire and Leeds Assessment of Neuropathic Symptoms and Signs revealed that 23% of the patients had a neuropathic pain component. There were 24 variations of the pain pattern. By contrast, the pain localized around the hip joint was only 15%. Pain distal to the thigh and any numbness was significantly more frequent in the group with neuropathic pain (P<0.001). Lumbar spinal stenosis grade was not significantly different between patients with nociceptive pain and those with neuropathic pain. Pain score was significantly correlated with the pain in clinical and functional scores. DISCUSSION: Among patients with symptomatic hip OA, the distribution of pain was various, and about 23% of patients had neuropathic, nociplastic, or mixed pain as a possibility for somatosensory system disturbances.

Risk factors for a radiolucent line around the acetabular component with an interface bioactive bone cement technique after primary cemented total hip arthroplasty.

AIMS: The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA. METHODS: A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis. RESULTS: RLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7). CONCLUSION: This study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL. Cite this article: Bone Joint Open 2021;2(5):278-292.