Joint-preserving effect and patient-reported outcomes of transtrochanteric curved varus osteotomy for osteonecrosis of the femoral head

BACKGROUND

This study assessed the hip survival rate and patient-reported outcome measures (PROMs) of transtrochanteric curved varus osteotomy (CVO) for osteonecrosis of the femoral head (ONFH) compared with those of conservative management.

METHODS

The CVO group comprised 32 consecutive patients (39 hips) who underwent CVO for ONFH between 2000 and 2011. The conservative group consisted of 36 consecutive patients (37 hips) who were managed conservatively for at least 1 year after collapse and who had ONFH classified by the Japanese Investigation Committee of Health and Welfare as type B or C1, for which CVO is indicated. Kaplan-Meier analysis of hip survival used any ONFH-related therapeutic surgery as the endpoint. PROMs were evaluated for all patients with surviving hips and radiographs available at the latest follow-up.

RESULT

The 10-year hip survival rate in the CVO group was 86.7%, which was significantly higher than the 51.0% 5-year survival rate in the conservative group (p < 0.0001). The Oxford Hip Score and UCLA Activity Score were significantly better in the CVO group without joint space narrowing than in the conservative group, with no significant differences between the CVO group with joint space narrowing and the conservative group.

CONCLUSION

CVO could preserve hip joints more effectively than conservative follow-up after collapse, although the presence of joint space narrowing could reduce satisfaction levels even in patients with long-term hip survival.

Study of the electron-doping mechanism in single-walled carbon nanotubes using dimethylbenzimidazole

Single-walled carbon nanotubes (SWCNTs) exhibit p-type properties in air, necessitating electron doping using n-dopants (e.g., reducing agents) for the development of SWCNT-based electronic devices. Dimethylbenzimidazole (DMBI-H) derivatives serve as effective electron dopants, not only for SWCNTs, but also for various organic semiconducting materials. However, the doping reaction is still a subject of debate. In this study, the electron-doping reactions of ortho-methoxy-substituted DMBI-H for SWCNTs were analyzed in protic and aprotic solvents in the presence and absence of dioxygen (O2). The presence of O2 was found to cause the reduction of O2 on the SWCNT surface in the protic solvent, resulting in the production of DMBI cations and water through proton-coupled electron transfer (PCET) from the n-doped SWCNT and ethanol. This work elucidates the mechanism behind the air-stability of n-type SWCNTs.

Effects of the location of both anterior and lateral boundaries of the necrotic lesion on collapse progression in osteonecrosis of the femoral head

BACKGROUND

The location of the lateral boundary of the necrotic lesion to the weight-bearing portion of the acetabulum (Type classification) is an important factor for collapse in osteonecrosis of the femoral head (ONFH). Recent studies also reported the significance of the location of the anterior boundary of the necrotic lesion on the occurrence of collapse. We aimed to assess the effects of the location of both anterior and lateral boundaries of the necrotic lesion on collapse progression in ONFH.

METHODS

We recruited 55 hips with post-collapse ONFH from 48 consecutive patients, who were conservatively followed for more than one year. Using a plain lateral radiograph (Sugioka's lateral view), the location of the anterior boundary of the necrotic lesion to the weight-bearing portion of the acetabulum was classified as follows: Anterior-area I (two hips) occupying the medial one-third or less; Anterior-area II (17 hips) occupying the medial two-thirds or less; and Anterior-area III (36 hips) occupying greater than the medial two-thirds. The amount of femoral head collapse was measured by biplane radiographs at the onset of hip pain and each follow-up period, and Kaplan-Meier survival curves with collapse progression (≥1 mm) as the endpoint were produced. The probability of collapse progression was also assessed by the combination of Anterior-area and Type classifications.

RESULTS

Collapse progression was observed in 38 of the 55 hips (69.0%). The survival rate of hips with Anterior-area III/Type C2 was significantly lower. Among hips with Type B/C1, collapse progression occurred more frequently in hips with Anterior-area III (21 of 24 hips) than in hips with Anterior-area I/II (3 of 17 hips, P < 0.0001).

CONCLUSIONS

Adding the location of the anterior boundary of the necrotic lesion to Type classification was useful to predict collapse progression especially in hips with Type B/C1.

Radiological factors associated with posterior dislocation after total hip arthroplasty for osteonecrosis of the femoral head - A retrospective study

Purpose

The dislocation rate after total hip arthroplasty for osteonecrosis of the femoral head is higher than that after total hip arthroplasty for osteoarthritis. However, few reports have investigated the factors contributing to dislocation after total hip arthroplasty for osteonecrosis of the femoral head. The aim of this study was to assess radiological factors associated with posterior dislocation after total hip arthroplasty for osteonecrosis of the femoral head.

Methods

We retrospectively reviewed 179 cementless total hip arthroplasties for osteonecrosis of the femoral head using a posterolateral approach between 2002 and 2020 with a minimum follow-up period of 24 months. The following radiological factors were examined for a possible association with posterior dislocation after total hip arthroplasty: cup anteversion angle, cup inclination angle, femoral offset, and stem anteversion angle.

Results

Posterior dislocation occurred in seven hips (3.9 %). Compared to hips without posterior dislocation, those with posterior dislocation exhibited a significantly smaller cup anteversion angle (p = 0.045) and a nonsignificantly greater decrease in femoral offset (p = 0.089). Based on receiver operating characteristic curve analyses, the cutoff values for predicting posterior dislocation were 9.9° for the cup anteversion angle and 8.1 mm for the decrease in femoral offset. Logistic regression analysis showed a significantly higher risk of posterior dislocation among hips with a cup anteversion angle less than 9.9° (odds ratio = 7.1, p = 0.022) or with a decrease in femoral offset over 8.1 mm (odds ratio = 5.0, p = 0.040).

Conclusions

A small cup anteversion angle and a decreased femoral offset are suggested to be associated with posterior dislocation after total hip arthroplasty in patients with osteonecrosis of the femoral head.

Family History of Developmental Dysplasia of the Hip is a Risk Factor for the Progression of Hip Osteoarthritis

BACKGROUND

Developmental dysplasia of the hip (DDH) is considered to have genetic predisposition and presents many intrafamilial occurrences. However, there is no report that evaluates the effect of DDH family history on the progression after the onset of hip osteoarthritis (OA).

METHODS

Medical interviews about detailed clinical information including family history were conducted on 298 consecutive patients who had undergone surgery for OA due to DDH. Clinical or radiographic items that are associated with the severity of DDH (total hip arthroplasty [THA], involvement of bilateral DDH, onset age of hip pain, and three radiological indices of DDH: center-edge angle, sharp angle, and acetabular roof obliquity) were collected and evaluated in multivariate analyses for their associations with DDH family history in a qualitative or quantitative manner. Survival time analyses for THA as the endpoint was also performed to evaluate the effects of DDH family history on the progression of OA.

RESULTS

The DDH family history showed significant associations with bilateral involvement of DDH (odds ratio = 2.09 [95% confidence interval {CI} 1.05 to 4.16]; P = .037), early onset of hip pain (P = .0065), and radiological severity of DDH (P = .016). The DDH family history showed a significant association with undergoing THA (odds ratio = 2.25 [95% CI 1.09 to 4.66]; P = .029), further supported by the Cox regression analyses (hazards ratio = 1.56 [95% CI 1.15 to 2.11]; P = .0044).

CONCLUSION

A DDH family history is a risk factor for the progression of hip OA. Stronger genetic predisposition to DDH leads to faster onset and progression of hip OA.

Effects of bone mineral density at the lateral sclerotic boundary on the femoral head collapse onset in osteonecrosis of the femoral head: A preliminary study

BACKGROUND

In the natural course of osteonecrosis of the femoral head, sclerotic changes at the boundary of necrotic lesion gradually occur until femoral head collapse. This study aims to examine the effects of bone mineral density at the lateral boundary of necrotic lesion on a subsequent femoral head collapse.

METHODS

We developed patient-specific finite element models of 9 hips with subsequent collapse and 10 hips without subsequent collapse. Cubic regions of interest were selected at both subchondral areas of the lateral boundary and the adjacent necrotic lesion. Bone mineral density values of the regions of interest were quantitatively measured, and a ratio of bone mineral density values (lateral boundary/necrotic lesion) was calculated. Stress values at the lateral boundary were also evaluated.

FINDINGS

The ratio of bone mineral density values was significantly higher in hips with subsequent collapse than that without subsequent collapse (p = 0.0016). The median equivalent stress and shear stress were significantly higher in hips with subsequent collapse than that without subsequent collapse (p = 0.0071, and p = 0.0143, respectively). The ratio of bone mineral density values showed a promising value in predicting the occurrence of subsequent femoral head collapse (AUC = 0.97).

INTERPRETATION

Our results indicated that bone mineral density value at the lateral boundary of necrotic lesion may be associated with the occurrence of subsequent femoral head collapse in pre-collapse stage osteonecrosis of the femoral head.

Interleukin-6 receptor blockade improves bone healing following ischemic osteonecrosis in adolescent mice

Objective

Juvenile ischemic osteonecrosis (JIO) of the femoral head is one of the most serious hip disorders causing a permanent deformity of the femoral head in childhood. We recently reported that interleukin 6 (IL-6) is significantly increased in the hip synovial fluid of patients with JIO and that articular chondrocytes are primary source of IL-6. Adolescent JIO is particularly challenging to treat and has poor outcome. This study determined if IL-6 receptor blockade prevents bone loss and improves the bone healing in adolescent JIO.

Method

Adolescent mice (12-week-old) surgically induced with JIO were treated with either saline or MR16-1, an IL-6 receptor blocker.

Results

Micro-CT assessment showed significantly increased bone volume (p ​< ​0.001, Cohen's d ​= ​2.0) and trabecular bone thickness (p ​< ​0.001, d ​= ​2.3) after the MR16-1 treatment. Histomorphometric assessment showed significantly increased osteoblast number (p ​< ​0.01, d ​= ​2.3), bone formation rate (p ​< ​0.01, d ​= ​4.3), and mineral apposition rate (p ​< ​0.01, d ​= ​4.1) after the MR16-1 treatment. The number of osteoclasts was unchanged. Histologic assessment showed significantly increased revascularization (p ​< ​0.01) and restoration of the necrotic marrow with new hematopoietic bone marrow (p ​< ​0.01). Vascular endothelial growth factor (VEGF) expression was increased in the revascularized area and the articular cartilage, and in the cultured chondrocytes treated with IL-6 receptor inhibitor.

Conclusion

IL-6 blockade in adolescent mice with JIO enhanced bone formation and revascularization. The findings suggest IL-6 receptor blocker as a potential medical therapy for adolescent JIO.

Cellular uptake of liposome consisting mainly of glucocerebroside from the starfish Asterias amurensis into Caco-2 cells

Glucocerebroside (GlcCer) is a group of compounds consisting of β-linked glucose and ceramide with various chain lengths, some of which possess anti-tumor activity and improve skin barrier function for atopic patients when administered orally. The amphiphilic GlcCer molecules are generally easy to aggregate in aqueous solution and result in low absorption in the gut, which can be improved by forming a liposome. With a recognition that a relatively large amount of GlcCer is contained in the starfish and is being discarded, we prepared a liposome consisting mainly of GlcCer (over 95%) with 100 nm in diameter. The adsorption efficiency of the liposome into cultured Caco-2 cells was investigated by live-cell imaging using fluorescently labeled liposomes. We found an immediate internalization of GlcCer-liposome on exposure without significant accumulation on the plasma membrane. The membrane fluidity was transiently affected as evidenced by fluorescence recovery after photobleaching (FRAP) experiments without no significant cellular damage, which indicates a liposome with high content of GlcCer might be useful as the carrier of dietary and/or drug molecules.

The sourcil roundness index is a useful measure for quantifying acetabular concavity asphericity

This study aimed to clarify the clinical utility of the sourcil roundness index (SRI), a novel index for quantifying the asphericity of the acetabular concavity, by determining (1) the difference in the SRI between dysplastic and normal hips and (2) the correlation between the SRI and radiographic parameters of hip dysplasia. We reviewed standing anteroposterior pelvic radiographs of 109 dysplastic and 40 normal hips. The SRI was determined as the ratio of the distance from the medial edge of the sourcil to the most concave point of the acetabular sourcil (A) to the distance from the medial to the lateral edge of the sourcil (B). The formula for SRI is (A/B) × 100-50 (%), with an SRI of 0% indicating a perfectly spherical acetabulum, and higher SRI values indicating a more aspherical shape. The median SRI was greater in patients with hip dysplasia than in normal hips (5.9% vs. - 1.4%; p < 0.001). Furthermore, the median SRI was greater in the severe dysplasia subgroup (18.9%) than in the moderate (3.5%) and borderline-to-mild (- 1.3%) dysplasia subgroups (p < 0.05). Quantification of acetabular concavity asphericity by the SRI showed that dysplastic hips had a more lateral acetabular concave point than normal hips, and that the severity of hip dysplasia had an effect on the acetabular concavity asphericity.

Contralateral Hip Abductor Muscle Strength Associated with Comfort of Getting into and out of the Car after Total Hip Arthroplasty

There are no studies that have investigated the characteristics of car use across THA patients, including those who do not drive. This study aimed to evaluate, in THA patients, (1) postoperative car usage, (2) comfort while entering and exiting a car, and (3) whether lower limb muscle strength affects action comfort. One hundred seventy-two post-THA patients completed the questionnaire in 2020, along with assessments of hip abductor and knee extensor muscle strength before surgery and at discharge. Patients whose overall comfort level was judged as comfortable were defined as the comfort group; others were placed in the discomfort group. Of the 172 patients, 161 reported car usage at a mean of 5.6 years after THA. Of these, 114 and 47 patients were placed in the comfort and discomfort groups, respectively. Patients in the discomfort group were three times more likely to experience discomfort using the contralateral side door than the surgical side door, and about twice as many patients experienced discomfort when entering as when exiting. Lower preoperative contralateral hip abductor muscle strength was the only independent predictor for discomfort. The take-home messages were that prevention of contralateral-side weakness may improve comfort during the action after THA.

Arthroscopic Treatment of Septic Arthritis of the Ankle Caused by Group B Streptococcus: A Case Report

BACKGROUND The incidence of septic arthritis of a native joint caused by group B streptococcus (GBS, Streptococcus agalactiae) has been on the rise in non-pregnant women. GBS commonly colonizes the female genital tract. However, only a few reports have discussed serious cases of GBS infection, endocarditis, and joint infection associated with the Papanicolaou (Pap) smear test, which is routinely conducted to detect cervical cancer. Specifically, to the best of our knowledge, there have been few reports about arthroscopic treatment for septic arthritis of the ankle caused by GBS. CASE REPORT A 60-year-old woman, who had previously completed the treatment of total laparoscopic hysterectomy with bilateral adnexectomy and postoperative chemotherapy for ovarian cancer, underwent a routine Pap smear test. Four weeks later, she suddenly presented with high fever and abdominal pain. The pain and swelling in her left ankle gradually worsened. Finally, septic arthritis of the ankle was diagnosed, and thus the patient underwent emergent arthroscopic irrigation and debridement. GBS was isolated from both the ankle fluid and blood culture. After surgical intervention and intravenous antibiotic administration, the patient's symptoms gradually improved. Four months later, the patient had no ankle pain or restriction of ankle motion. CONCLUSIONS Although cervical cytology tests are essential in screening for cervical cancer, transient bacteremia can be induced by the tests. Thus, physicians must watch out for the development of septic arthritis caused by GBS when patients present with fever or swollen joints after a recent Pap smear test. Emergent diagnosis and appropriate surgical intervention is also important.

Reverse dynamics analysis of contact force and muscle activities during the golf swing after total hip arthroplasty

There are no reports on hip kinetics including contact forces and muscle activities during the golf swing after total hip arthroplasty (THA). The aim of this study was to identify the characteristics of three-dimensional dynamics during the golf swing. Ten unilateral primary THA patients participated in motion capture test of their driver golf swing. The driver swing produced approximately 20-30° of rotation in both lead and trail replaced hips. The mean hip contact forces (HCFs) of lead and trail replaced hips were 5.1 and 6.6 × body weight, respectively. Left and right THAs showed similar HCFs of lead and trail hips. More than 60% of the Percent maximum voluntary isometric contraction was found in bilateral iliopsoas muscles in all unilateral THA. Three factors [female sex, lower modified Harris Hip Score, and higher HCF of surgical side] were associated with the golf-related replacement hip pain. Golf is an admissible sport after THA because driver swings do not contribute excessive rotation or contact forces to hip prostheses. HCF could be reduced through swing adjustments, which may allow patients with golf-related replacement hip pain to develop a comfortable golf game free from pain.

Evaluation of the anterior acetabular coverage with a false profile radiograph considering appropriate range of positioning

This study aimed to (1) set a reference value for anterior center edge angle (ACEA) for preoperative planning of periacetabular osteotomy (PAO), (2) investigate the effects of pelvic rotation and inclination from false profile (FP) radiographs on the measured ACEA, and (3) determine the "appropriate range of positioning" for FP radiograph. This single-centered, retrospective study analyzed 61 patients (61 hips) who underwent PAO from April 2018 and May 2021. ACEA was measured in each digitally reconstructed radiography (DRR) image of the FP radiograph reconstructed in different degrees of pelvic rotation. Detailed simulations were performed to determine the "appropriate range of positioning" (0.67 < ratio of the distance between the femoral heads to the diameter of the femoral head < 1.0). The vertical-center-anterior (VCA) angle was measured on the CT sagittal plane considering the patient-specific standing positions, and its correlation with the ACEA was investigated. The reference value of ACEA was determined by receiver operating characteristic (ROC) curve analysis. The ACEA measurement increased by 0.35° for every 1° pelvic rotation approaching the true lateral view. The pelvic rotation with the "appropriate range of positioning" was found at 5.0° (63.3-68.3°). The ACEA on the FP radiographs showed a good correlation with the VCA angle. The ROC curve revealed that an ACEA < 13.6° was associated with inadequate anterior coverage (VCA < 32°). Our findings suggest that during preoperative PAO planning, an ACEA < 13.6° on FP radiographs indicates insufficient anterior acetabular coverage. Images with the "appropriate positioning" can also have a measurement error of 1.7° due to the pelvic rotation.

Does Flexion Varus Osteotomy Improve Radiographic Findings Compared With Patients Treated in a Brace for Late-onset Legg-Calvé-Perthes Disease?

BACKGROUND

Legg-Calvé-Perthes disease (LCPD) is a childhood hip disease characterized by osteonecrosis of the femoral head. Because severe deformity of the femoral head can cause secondary osteoarthritis in adulthood, progressive collapse should be prevented in children with a necrotic epiphysis. The prognosis of patients with LCPD generally worsens as the age at disease onset increases, and the appropriate treatment for late-onset LCPD remains unclear. Based on the limited effect of nonoperative treatment using a nonweightbearing brace, flexion varus osteotomy (FVO) was introduced in 2010 as an initial treatment for late-onset LCPD in place of brace treatment, which we used in our institution before that time.

QUESTIONS/PURPOSES

We asked, (1) Which treatment, FVO or a nonweightbearing brace, is associated with a lower likelihood of progressive femoral head collapse in children whose diagnosis of LCPD was made at the age of ≥ 8 years and who were followed for a minimum of 3 years after their intervention? (2) What proportion of patients in the brace group had surgery despite the treatment, and what percentage of children in the FVO group had a second operation to remove hardware and/or additional operations?

METHODS

The initial treatment was applied in 181 patients with LCPD between 1995 and 2018 in our institution. Patients whose disease onset was at ≥ 8 years old (late-onset LCPD) with complete clinical and radiologic data were considered potentially eligible. In 2010, treatment for these patients changed from brace treatment to FVO for all patients. A total of 35% (42 of 121) of patients who were treated with a nonweightbearing brace between 1995 and 2009 and 40% (24 of 60) of patients who were treated with FVO between 2010 and 2018 were eligible. Among patients treated with a brace, 21% (nine of 42 patients) were excluded because of hospital transfer (three patients), short-term follow-up (three), the period from onset to the first visit was ≥ 7 months (two), and inability to use the brace because of mental incapacity (one patient). In patients treated with FVO, 12% (three of 24 patients) were excluded (two patients with a period from onset to the first visit ≥ 7 months and one with a comorbidity and multiple-epiphyseal dysplasia). Among the remaining patients, 79% (33 of 42 patients) were classified into the brace group and 88% (21 of 24 patients) were classified into the FVO group for analyses. There were no overlapping patients at the timepoint when the treatment strategy for late-onset LCPD changed. In the FVO group, subtrochanteric osteotomy with 35° to 40° of flexion and 15° to 20° of varus was performed using a locking compression plate for pediatric use. Patient demographics, radiographic parameters, and the assessment of femoral head deformity using the Stulberg classification were compared between the two groups. There was a greater proportion of boys than girls in both groups (brace: 88% and FVO: 86%), and there were no differences in the distribution of genders between the groups (p = 0.82). The right side was more frequently treated in the brace group, but there was no difference in laterality between the groups (brace: 58% right and FVO: 62% left; p = 0.16). There was no difference between groups in the median age at disease onset (9.0 years [range 8.0 to 12.5 years] in the brace group and 9.6 years [range 8.0 to 12.4 years] in the FVO group; p = 0.26). There was no difference between the groups in the period of treatment from onset (1.7 ± 1.9 months in the brace group and 1.5 ± 1.5 months in the FVO group; p = 0.73) or the follow-up period (6.7 ± 2.1 years in the brace group and 6.2 ± 2.1 years in the FVO group; p = 0.41). The LCPD stage at the first visit was assessed using the modified Waldenström classification. The intraobserver and interobserver values of the modified Waldenström classification, evaluated using kappa statistics, were excellent (kappa value 0.89 [95% CI 0.75 to 0.97]; p < 0.01) and good (kappa value 0.65 [95% CI 0.43 to 0.87]; p < 0.01). The radiographic degree of collapse at the maximum fragmentation stage was assessed using the lateral pillar classification. The intraobserver and interobserver reliabilities of the lateral pillar classification were excellent (kappa value 0.84 [95% CI 0.73 to 0.94]; p < 0.01) and excellent (kappa value 0.83 [95% CI 0.71 to 0.94]; p < 0.01). The degree of femoral head deformity at the most recent follow-up examination was compared between the groups in terms of the Stulberg classification, in which Classes I and II were classified as good and Classes III through V were classified as poor. The intraobserver and interobserver reliabilities of the Stulberg classification were good (kappa value 0.74 [95% CI 0.55 to 0.92]; p < 0.01) and good (kappa value 0.69 [95% CI 0.50 to 0.89]; p < 0.01). The evaluators were involved in the patients' clinical care as part of the treating team.

RESULTS

Good radiographic results (Stulberg Class I or II) were obtained more frequently in the FVO group (76% [16 of 21 patients]) than in the brace group (36% [12 of 33 patients]), with an odds ratio of 5.6 (95% CI 1.7 to 18.5; p < 0.01). In the brace group, a subsequent femoral varus osteotomy was performed in 18% (six of 33) of patients with progressive collapse and hinge abduction, and implant removal surgery was performed approximately 1 year after the first procedure. This traditional varus osteotomy was occasionally performed in patients who were considered for conversion from nonoperative treatment before 2009 because FVO had not yet been introduced. In the FVO group, all patients (n = 21) had a second procedure to remove the implant at a mean of 10.5 ± 1.2 months postoperatively. Additional procedures were performed in 24% (five of 21) of patients, including a second FVO for progressive collapse (one patient), guided growth for a limb length discrepancy (one patient), and flexion valgus osteotomy for coxa vara in patients with a limb length discrepancy (three patients).

CONCLUSION

Our historical control study found that FVO may increase the possibility of obtaining good radiographic results (Stulberg Class I or II) compared with brace treatment for patients with late-onset LCPD, although surgical interventions after the first and second implant removal procedures may be indicated. Surgeons can consider FVO if they encounter patients with late-onset LCPD, which is a challenging condition. A larger study with long-term follow-up is needed to confirm the efficacy of FVO.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Relationship between the degree of subchondral collapse and articular surface irregularities in osteonecrosis of the femoral head

Articular surface irregularities are often observed in collapsed femoral heads with osteonecrosis, while the effects of the degree of collapse on the articular surface are poorly understood. We first macroscopically assessed the articular surface irregularities on 2-mm coronal slices obtained using high-resolution microcomputed tomography of 76 surgically resected femoral heads with osteonecrosis. These irregularities were observed in 68/76 femoral heads, mainly at the lateral boundary of the necrotic region. The mean degree of collapse was significantly larger for femoral heads with articular surface irregularities than for those without (p < 0.0001). Receiver operating characteristic analysis showed that the cutoff value for the degree of collapse in femoral heads with articular surface irregularities at the lateral boundary was 1.1 mm. Next, for femoral heads with <3-mm collapse (n = 28), articular surface irregularities were quantitatively assessed based on the number of automatically counted negative curvature points. Quantitative evaluation showed that the degree of collapse was positively correlated with the presence of articular surface irregularities (r = 0.95, p < 0.0001). Histological examination of articular cartilage above the necrotic region (n = 8) revealed cell necrosis in the calcified layer and abnormal cellular arrangement in the deep and middle layers. In conclusion, articular surface irregularities of the necrotic femoral head depended on the degree of collapse, and articular cartilage was already altered even in the absence of macroscopically determined gross irregularities.

Abductor recovery after muscle-sparing periacetabular osteotomy using a lateral approach

To decrease hip abductor dysfunction after periacetabular osteotomy using a lateral/trochanteric approach, we aimed to modify transposition osteotomy of the acetabulum (TOA) to not cut the greater trochanter and abductor-iliac crest detachment. We subsequently compared abductor muscle strength recovery between TOAs with [conventional TOA (C-TOA)] and without [modified TOA (M-TOA)] trochanteric osteotomy. C-TOA and M-TOA were performed in 27 and 34 hips, respectively. Hip abduction, flexion and knee extension muscle strength were measured preoperatively and at 3, 5, 10, 24 and 52 weeks postoperatively. The muscle strength ratio of the affected and contralateral lower limbs was compared between the C-TOA and M-TOA groups. Neither the mean Merle d'Aubigné-Postel score at the final follow-up nor the postoperative center-edge angle showed significant differences between the M-TOA and C-TOA groups (15.7 versus 16.4 points; P = 0.25 and 38.5° versus P = 0.62 and 39.8°, respectively). The mean muscle strength ratios of hip abduction at 5, 12 and 24 weeks postoperatively were significantly higher in the M-TOA group than in the C-TOA group (0.62 versus 0.39, 0.76 versus 0.59 and 0.94 versus 0.70; P = 0.03, 0.04 and 0.01, respectively). There were no significant differences between groups at Postoperative Week 52 (P = 0.36). Discomfort at the greater trochanter was observed in 18 hips (66.7%) in the C-TOA group but only in 4 hips (11.2%) in the M-TOA group. In conclusion, M-TOA is less invasive than C-TOA and allows an earlier recovery of abductor muscle strength without significant correction loss.

Posterior Pelvic Tilt in the Standing Position Might Be Associated with Collapse Progression in Post-Collapse Stage Osteonecrosis of the Femoral Head

OBJECTIVE

Excessive pelvic tilt has been reported to impair the biomechanical loading of the hip joint. However, the influence of pelvic tilt in osteonecrosis of the femoral head (ONFH) remains unclear. This study aims to assess whether sagittal pelvic posture in the standing position correlates with progression of femoral head collapse in post-collapse stage ONFH.

METHODS

This is a single-center retrospective study. We investigated 107 patients (107 hips; 73 males and 34 females; mean age, 48 years) diagnosed with Association of Research Circulation Osseous (ARCO) stage III ONFH at the first visit and who subsequently underwent surgical treatment in our institution from July 2016 to December 2020. The sagittal pelvic posture in the standing position before surgery was quantified as the angle formed by the anterior pelvic plane and the vertical z-axis in the sagittal view (APP angle). An APP angle <0° indicated posterior pelvic tilt. Progression of femoral head collapse was calculated as collapse speed. The following factors potentially associated with collapse speed were evaluated by exploratory data analysis followed with multiple linear regression analysis: sex, age, BMI, etiology, pelvic incidence, contralateral hip condition, time interval between the first visit and surgery, size of necrotic lesion, location of necrotic lesion, and APP angle.

RESULTS

As ONFH progressed from ARCO stage IIIA to stage IV, APP angle decreased significantly and continuously (stage IIIA, -0.2° ± 5.5°; stage IIIB, -3.7° ± 5.8°; stage IV, -7.1° ± 6.4°). The factors significantly associated with collapse speed were size of necrotic lesion (p = 0.0079), location of necrotic lesion (p = 0.0190), and APP angle (p < 0.0001). APP angle showed a negative correlation with collapse speed (r = -0.40, p < 0.0001). After stratifying by size of necrotic lesion (<50% and ≥50% involvement) and location of necrotic lesion (JIC type C1 and C2), a significant negative correlation was observed between APP angle and collapse speed in each group (JIC type C1 with <50% involvement, r = -0.69, p < 0.0001; JIC type C1 with ≥50% involvement, r = -0.58, p = 0.0475; JIC type C2 with <50% involvement, r = -0.51, p = 0.0124; JIC type C2 with ≥50% involvement, r = -0.39, p = 0.0286).

CONCLUSIONS

Our results suggest that posterior pelvic tilt in the standing position occurred as ONFH progressed from ARCO stage IIIA to stage IV, which might be associated with progression of femoral head collapse in ONFH.

AB0332 EVALUATION OF THE RABBIT RISK SCORE IN JAPANESE PATIENTS WITH RHEUMATOID ARTHRITIS NEWLY TREATED WITH BIOLOGIC DMARDS: DATA FROM THE IORRA COHORT

Background

Serious infection is one of the most critical adverse events in patients with rheumatoid arthritis (RA) using biologic disease-modifying antirheumatic drugs (bDMARDs). During the first year, infections occur more frequently. Therefore, estimating the risk of developing a serious infection is important for the safe use of bDMARDs. The Rheumatoid Arthritis Observation of Biologic Therapy (RABBIT) risk score predicted the incidence rate of serious infection during 1 year in patients with RA taking DMARDs. Moreover, it has been validated using data from various observational cohort studies and nationwide registries with favorable results, with a reported area under the receiver operating characteristic curve (AUROC) of 0.68–0.871–5. However, the RABBIT risk score has not been validated in RA patients starting a first bDMARD.

Objectives

To investigate the discriminatory ability of the RABBIT risk score for predicting the development of serious infection during 1 year after starting first bDMARDs in Japanese patients with RA using data from the Institute of Rheumatology, Rheumatoid Arthritis (IORRA) cohort.

Methods

The IORRA cohort is a large observational cohort at the Institute of Rheumatology, Tokyo Women’s Medical University. Japanese patients with RA visiting our institute were registered and clinical parameters were assessed biannually. This study enrolled patients with RA who were registered in the IORRA cohort and treated with a first bDMARD. Patients who were missing data needed to calculate the RABBIT risk score were excluded. The RABBIT risk score was calculated using the patient’s age, comorbidities, Japanese-Health Assessment Questionnaire score, history of previous infections, and types of DMARDs used. Serious infections were defined as those requiring hospitalization or treatment with intravenous antibiotics. The occurrence of serious infection during 1 year after starting the first bDMARDs was identified using data from the biannual IORRA cohort and confirmed using medical records. The discriminatory ability of the RABBIT risk score was analyzed by the AUROC.

Results

A total of 1,081 patients with RA and a median age of 55.3 years, in which females were the majority (88.2%), were included. Serious infection occurred in eight patients during 1 year before starting their first bDMARDs. The number of patients starting a TNF inhibitor, IL-6 inhibitor, and abatacept were 830 (76.8%), 170 (15.7%), and 81 (7.5%), respectively. A total of 23 patients (1.7%) had serious infections during 1 year after starting the first bDMARD; the most frequent infection was pneumonia (n=16, 69.6%). The median RABBIT score was 2.3 (IQR 1.6–5.4) in patients with serious infections during the follow-up period, and 1.6 (IQR 1.2–2.5) in patients without serious infections. The discriminatory ability of the RABBIT risk score was slightly poor, with an AUROC of 0.67 (95% CI, 0.52– 0.79).

Conclusion

The RABBIT risk score is highly practical; however, our present study suggested that some adjustments may be required to predict the risk of serious infection in Japanese patients with RA starting a first bDMARD.

Figure 1.

ROC curve of serious infection and RABBIT score with an AUROC of 0.67 (95% CI, 0.52– 0.79).

Disclosure of Interests

Tomoaki Higuchi: None declared, Eiichi Tanaka Speakers bureau: Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Paid instructor for: Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Eisuke Inoue Speakers bureau: Bristol-Meyers and Pfizer, Consultant of: Nippontect systems, Mai Abe: None declared, Kumiko Saka: None declared, Eri Sugano: None declared, Naohiro Sugitani: None declared, Yoko Shimizu: None declared, Moeko Ochiai: None declared, Rei Yamaguchi: None declared, Katsunori Ikari Speakers bureau: Asahi Kasei Pharma Corp., Astellas Pharma Inc., AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., Janssen Pharmaceutical K.K., Kaken Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corp. Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., Teijin Pharma Ltd and UCB Japan Co. Ltd., Yamanaka Hisashi: None declared, Masayoshi Harigai Speakers bureau: AbbVie Japan, Ayumi, Boehringer Ingelheim Japan, Bristol-Myers Squibb, Chugai, Eisai, Eli Lilly Japan, GlaxoSmithKline, Kissei, Pfizer Japan Inc, Takeda, Teijin, Consultant of: AbbVie Japan, Boehringer Ingelheim Japan, Bristol-Myers Squibb, Kissei, Teijin, Grant/research support from: AbbVie Japan, Asahi Kasei, Astellas, Ayumi, Bristol-Myers Squibb, Chugai, Daiichi-Sankyo, Eisai, Kissei, Mitsubishi Tanabe, Nippon Kayaku, Sekiui Medical, Shionogi, Taisho, Takeda, Teijin.

Development of a murine model of ischemic osteonecrosis to study the effects of aging on bone repair

Age at onset is one of the most important predictors of outcome following ischemic osteonecrosis (ON). Currently, there is no well-established animal model to study the effects of age on the repair process following ischemic ON. The purpose of this study was to further advance a murine model of ischemic ON using four age groups of mice to determine the effects of aging on revascularization and bone repair following ischemic ON. Ischemia was surgically induced in the distal femoral epiphysis of four age groups of skeletally immature and mature mice; juvenile (5 weeks), adolescent (12 weeks), adult (22 weeks), and middle age (52 weeks). Mice were euthanized at 2 days or 4 weeks post-ischemia surgery to evaluate the extent of ON, revascularization, and bone repair. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining showed extensive cell death in the epiphysis of all four age groups at 2 days post-ischemia surgery. At 4 weeks, the juvenile mice followed by the adolescent mice had significantly greater revascularization and repair of the necrotic marrow space, increased osteoblast and osteoclast numbers, and increased bone formation rates compared to the adult and middle-age mice. Faster revascularization and bone healing were observed in the skeletally immature mice compared to the skeletally mature mice following ischemic ON. The findings resemble the clinical observation of aging on bone repair following ischemic ON. The mouse model may serve as a useful tool to investigate the mechanisms underlying the age-related impairment of bone repair in adolescent and adult ON and to develop novel therapeutic strategies.

Clinical usefulness of a novel fluorescence technique for the intraoperative diagnosis of surgical margins in patients with breast cancer

In both 5- and 15-min data, FI was significantly higher in malignant tissues than in benign tissues. The diagnostic accuracy was similar at 5 and 15 min. Therefore, the 5-min FI was enough applying in the further analyses.

Analysis of sex difference in the tubular reabsorption of lithium in rats

Lithium is used in the treatment of bipolar disorder. We previously demonstrated that two types of transporters mediate the tubular reabsorption of lithium in rats, and suggested that sodium-dependent phosphate transporters play a role in lithium reabsorption with high affinity. In the present study, we examined sex differences in lithium reabsorption in rats. When lithium chloride was infused at 60 µg/min, creatinine clearance and the renal clearance of lithium were lower, and the plasma concentration of lithium was higher in female rats. These values reflected the higher fractional reabsorption of lithium in female rats. In rats infused with lithium chloride at 6 µg/min, the pharmacokinetic parameters of lithium examined were all similar in both sexes. The fractional reabsorption of lithium was decreased by foscarnet, a representative inhibitor of sodium-dependent phosphate transporters, in male and female rats when lithium chloride was infused at the low rate. Among the candidate transporters mediating lithium reabsorption examined herein, the mRNA expression of only PiT2, a sodium-dependent phosphate transporter, exhibited sexual dimorphism. The present results demonstrated sex differences in the tubular reabsorption of lithium with low affinity in rats.

Inappropriate use of ozone generators and their sales status: questionnaire survey of healthcare providers and investigation of online sales

Ozone generators have attracted attention as a result of the spread of severe acute respiratory syndrome coronavirus-2. In a questionnaire survey targeting healthcare facilities, 20 (91%) used ozone generators in patient areas, and five (23%) used them in indoor spaces occupied by people. A search for ozone generators on the Amazon Japan website revealed that 76% of products lacked information on ozone emission rate, coverage area and/or use time. These results suggest that ozone generators may be used inappropriately in hospitals and clinics, and have been sold to the general public without adequate information for assessing their safety and efficacy.

A longitudinal study for the prediction of the mature acetabular morphology using childhood magnetic resonance imaging

BACKGROUND

Although acetabular dysplasia is a common etiology of osteoarthritis of the hip regardless of the history of developmental dysplasia of the hip (DDH), whether or not corrective surgeries are beneficial for the childhood asymptomatic acetabular dysplasia remains controversial due to a lack of evidence. We conducted a longitudinal study to compare the cartilaginous morphology on childhood magnetic resonance imaging (MRI) and the mature hip morphology of the same patient and to assess the predictive indicators for future acetabular dysplasia.

METHODS

A total of 92 unaffected hips (47 unilateral DDH and 45 unilateral Legg-Calvé-Perthes disease) were reviewed for X-ray and MRI findings on childhood (mean age: 6.0 years) and X-ray findings from a skeletally mature age with a mean follow-up period of 15.1 years. The following parameters were measured and compared: the immature-acetabular index (AI) and center edge angle (CE) on immature X-ray; the cartilage- and bone- AI, CE, Sharp and acetabular head index (AHI) on childhood MRI; and the mature-acetabular roof obliquity (ARO), CE, Sharp and AHI on skeletally mature X-ray. The prognostic factors on childhood MRI for acetabular dysplasia, defined by a CE of <20° on skeletally mature X-ray were also assessed.

RESULTS

Positive correlations were shown between the cartilage-AI and mature-ARO (7.6°/6.3°; r = 0.44), the cartilage-CE and mature-CE (27.8°/28.0°; r = 0.62), the cartilage-Sharp and mature-Sharp (44.4°/41.8°; r = 0.52) and the cartilage-AHI and mature-AHI (78.7%/80.3%; r = 0.46). A multivariate analysis indicated cartilage-CE to be an independent predictor for acetabular dysplasia with a cut-off value of 22°. Children with a cartilage-CE <22° developed more frequently acetabular dysplasia compared to the others (52.4% vs. 1.4%).

CONCLUSIONS

Childhood MRI findings are useful for the prediction of acetabular dysplasia without a DDH history. Children with a cartilage-CE ≥23° are likely to achieve a non-dysplastic hip without the need for surgical intervention.

Tumor microenvironment in triple-negative breast cancer: the correlation of tumor-associated macrophages and tumor-infiltrating lymphocytes

Purpose

Immune cells such as cytotoxic T cells, helper T cells, B cells or tumor-associated macrophages (TAMs) contribute to the anti-tumor response or pro-tumorigenic effect in triple negative breast cancer (TNBC). The interrelation of TAMs, T and B tumor-infiltrating lymphocytes (TILs) in TNBC has not been fully elucidated.

Methods

We evaluated the association of tumor-associated macrophages, T and B TILs in TNBC.

Results

TNBCs with a high CD68+, CD163+ TAMs and low CD4+, CD8+, CD20+ TILs had a significantly shorter relapse-free survival (RFS) and overall survival (OS) than those with low CD68+, CD163+ TAMs and high CD4+, CD8+, CD20+ TILs. TNBCs with high CD68+ TAMs/low CD8+ TILs showed a significantly shorter RFS and OS and a significantly poorer prognosis than those with high CD68+ TAMs/high CD8+ TILs, low CD68+ TAMs/high CD8+ TILs, and low CD68+/low CD8+. TNBCs with high CD163+ TAMs/low CD8+, low CD20 + TILs showed a significantly shorter RFS and OS and a significantly poorer prognosis than those with high CD163+ TAMs/high CD8+ TILs and high CD163+ TAMs /high CD20+ TILs.

Conclusions

Our study suggests that TAMs further create an optimal tumor microenvironment (TME) for growth and invasion of cancer cells when evasion of immunoreactions due to T and B TILs occurs. In TNBCs, all these events combine to affect prognosis. The process of TME is highly complex in TNBCs and for an improved understanding, larger validation studies are necessary to confirm these findings.

Subchondral fracture of the femoral head in children: Differential diagnosis of pediatric hip pain

This report describes clinical and radiographic characteristics of two pediatric patients with a presumptive diagnosis of subchondral fracture of the femoral head made based on their clinical course and imaging findings. An 8-year-old boy and an 8-year-old girl had subchondral fracture in the femoral head without osteonecrosis, which was verified by contrast-enhanced magnetic resonance imaging. Although complete disappearance of the fracture line was confirmed in the boy, the girl had a residual femoral head deformity after conservative treatment. Subchondral fracture of the femoral head should be included in the differential diagnosis of pediatric hip pain.

Proximal femoral morphology after transtrochanteric posterior rotational osteotomy for osteonecrosis of the femoral head: A three-dimensional simulation study

BACKGROUND

Transtrochanteric posterior rotational osteotomy (PRO) is one of the joint-preserving surgeries for osteonecrosis of the femoral head. In general, postoperative femoral neck-shaft varus realignment is planned to obtain a sufficient intact articular surface of the femoral head in the weight-bearing portion. Unlike anterior rotational osteotomy, PRO allows for more than 90° rotation of the femoral head, resulting in more complicated morphology. However, little is known about the potential risk of postoperative femoral retroversion after PRO. This simulation study aims: 1) to assess whether postoperative femoral neck-shaft varus realignment can coexist with preserved femoral anteversion after PRO, 2) and whether postoperative proximal femoral morphology could be predicted with approximation equations.

HYPOTHESIS

High degree (>90°) PRO is favourable for femoral neck-shaft varus realignment, but unfavourable for maintaining postoperative femoral anteversion.

MATERIALS AND METHODS

PRO was simulated by using CT data from 10 hips in 10 healthy volunteers. During simulation, the intertrochanteric osteotomy plane was determined three-dimensionally based on anteroposterior-view line (the osteotomy line on anteroposterior view) and lateral-view line (the osteotomy line on lateral view). By changing either the angle of anteroposterior-view line or lateral-view line, we simulated 90°, 110°, 130° and 150° PRO. To clarify the effects of various posterior rotation angles on postoperative proximal femoral morphology, we made simplified PRO models through changing only the posterior rotation angle.

RESULTS

In the 90°, 110°, 130° and 150° PRO models, the vertically inclined angle of anteroposterior-view line showed a significant positive correlation with femoral neck-shaft varus realignment (90° PRO, r=0.90; 110° PRO, r=0.95; 130° PRO, r=0.97; 150° PRO, r=0.99), while a significant negative correlation with postoperative femoral anteversion angle (90° PRO, r=-0.97; 110° PRO, r=-0.95; 130° PRO, r=-0.92; 150° PRO, r=-0.7). Likewise, the posteriorly tilted angle of lateral-view line showed a significant negative correlation with both femoral neck-shaft varus realignment (90° PRO, r=-0.81; 110° PRO, r=-0.81; 130° PRO, r=-0.79; 150° PRO, r=-0.72) and postoperative femoral anteversion angle (90° PRO, r=-0.90; 110° PRO, r=-0.89; 130° PRO, r=-0.92; 150° PRO, r=-0.88). In the simplified PRO models, the posterior rotation angle showed a significant positive correlation with femoral neck-shaft varus realignment (r=0.33), while a significant negative correlation with postoperative femoral anteversion angle (r=-0.76). The approximation equations for predicting the proximal femoral morphology after PRO were validated.

DISCUSSIONS

It was confirmed that high-degree PRO (>90°) is favourable for femoral neck-shaft varus realignment, but works against preserving femoral anteversion. With the approximation equations developed in the current study, surgeons could examine the feasibility of PRO based on postoperative femoral anteversion. In terms of hip joint function and subsequent total hip arthroplasty, excessive deformities including femoral retroversion and severe varus deformity could be avoided.

LEVEL OF EVIDENCE

IV; case series without control group.

Differences in the microarchitectural features of the lateral collapsed lesion between osteonecrosis and subchondral insufficiency fracture of the femoral head

BACKGROUND

Like osteonecrosis of the femoral head (ONFH), subchondral insufficiency fracture of the femoral head (SIF) causes femoral head collapse. However, little is known about the differences between the two diseases regarding the morphological features of the collapsed lesion. We tested the hypothesis that the morphological features of the lateral collapsed lesion would differ between ONFH and SIF.

METHODS

Twenty femoral heads histopathologically diagnosed as ONFH (n = 10) or SIF (n = 10) were used in this study. In the lateral collapsed lesion of each femoral head, cubic regions of interest (ROIs) were selected within the collapsed subchondral area and the nearby non-collapsed subchondral area. Micro-CT-based microarchitectural parameters were compared between the ROIs in each disease. Additionally, correlations between histopathological and microarchitectural features were evaluated.

RESULTS

In ONFH, bone volume fraction, trabecular thickness, and bone mineral density in the collapsed area were all significantly lower than those in the nearby non-collapsed area where thickened bone trabeculae accompanied by appositional bone formation were invariably seen. On the other hand, in SIF there were no significant differences between the ROIs in any of these microarchitectural parameters. Histopathologically, varying degrees of callus formation overlying the fracture of the subchondral plate were seen around the lateral collapsed lesion.

CONCLUSION

The morphological features of the lateral collapsed lesion were inconsistent between ONFH and SIF, suggesting different pathomechanisms of femoral head collapse.

Is bone mineral density lower in the necrotic lesion in pre-collapse osteonecrosis of the femoral head?

The purpose of this study was to clarify whether bone mineral density (BMD) of the necrotic lesion in precollapse osteonecrosis of the femoral head (ONFH) is reduced according to Hounsfield unit (HU) values on computed tomography (CT). The superior one-third of the femoral head in the coronal section was set as the region of interest (ROI) for the measurement of HU values. First, HU values of 101 control participants were assessed to identify relevant confounding factors. Next, the relationship between HU values and BMD on dual-energy X-ray absorptiometry (DXA) was verified. Then the mean HU value of the ROI in patients with pre-collapse ONFH was compared with that in propensity score-matched control participants. Finally, the HU values of the lateral boundary in the patients with and without subsequent collapse were compared. Multivariable analysis showed that both age and BMI were significantly correlated with the HU value, which showed a strong correlation with the BMD of the femoral neck on DXA (r = 0.92). In 25 ONFH patients and 25 propensity-matched control participants, no significant difference was found in the HU value of the ROI (p = .54). The mean HU value of the lateral boundary in patients with subsequent collapse was found to be significantly higher than that in patients without subsequent collapse (p < .01). The assessment of HU values on CT was useful for the evaluation of BMD of the femoral head. The current assessment did not demonstrate reduced bone mineral density of the necrotic lesion in pre-collapse ONFH.

Is lateral acetabular rotation sufficient to correct anterolateral deficiency in periacetabular reorientation osteotomy? A CT-Based simulation study

BACKGROUND

Residual acetabular deficiency after periacetabular reorientation osteotomy can result in suboptimal outcome. The optimal algorithm of acetabular fragment correction to achieve normal anterolateral acetabular coverage is not well characterized. The aim of this study was to determine the prevalence of residual anterolateral deficiency after lateral acetabular rotation and to evaluate the ability of additional sagittal and axial rotation of the acetabulum to normalize the acetabular coverage in periacetabular osteotomy.

METHODS

We performed computed tomography-based simulated periacetabular osteotomy on 85 patients (85 hips) with hip dysplasia. The acetabular fragment was rotated laterally to achieve a lateral center-edge angle (CEA) of 30°. For hips with residual anterolateral deficiency, which were identified based on the reference interval of the anterior CEA, the acetabulum was further rotated in the sagittal or axial direction in 5-degree increments from 5° to 20°, and the ability of these two manoeuvres to restore a normal anterior CEA was assessed.

RESULTS

After lateral acetabular rotation, 16 hips (19%) had residual anterolateral deficiency, 67 hips (79%) had normal acetabular coverage, and 2 hips (2.4%) had acetabular overcoverage. A preoperative anterior CEA <37° predicted residual deficiency (sensitivity, 94%; specificity, 81%). Additional anterior sagittal rotation was more effective than posterior axial rotation in normalizing the anterior CEA, while minimizing the decrease in posterior CEA. The highest number of hips with normal anterior and posterior CEA was noted at 10° sagittal rotation (81%), which was followed by 15° sagittal rotation (63%).

CONCLUSIONS

Normal anterolateral coverage was achieved in 79% of patients after rotating the acetabulum laterally. However, lateral rotation of the acetabulum may be insufficient to correct the anterolateral deficiency in patients with an anterior CEA of <37°. In them, additional 10°-15° anterior sagittal rotation may be appropriate to achieve sufficient anterolateral coverage while retaining posterolateral coverage.

Subacute Combined Degeneration of the Spinal Cord Caused by Autoimmune Gastritis

A 68-year-old woman presented with a 2-year history of worsening unsteady gait. Her neurological examination revealed peripheral neuropathy with lower limb sensory dominance. T2-weighted imaging revealed a disorder of the posterior cervical cord. Blood test findings revealed vitamin B₁₂ deficiency, and gastroscopy revealed typical findings of autoimmune gastritis. She received vitamin B₁₂ supplementation, but some peripheral neuropathy symptoms persisted due to longstanding vitamin B₁₂ deficiency. Asymptomatic patients should undergo gastroscopy to detect autoimmune gastritis, as chronic vitamin B₁₂ deficiency causes irreversible peripheral neuropathy.

Chemical characterization and source apportionment of ambient nanoparticles: a case study in Hanoi, Vietnam

PM_0.1 has been believed to have adverse short- and long-term effects on human health. However, the information of PM_0.1 that is needed to fully evaluate its influence on human health and environment is still scarce in many developing countries. This is a comprehensive study on the levels, chemical compositions, and source apportionment of PM_0.1 conducted in Hanoi, Vietnam. Twenty-four-hour samples of PM_0.1 were collected during the dry season (November to December 2015) at a mixed site to get the information on mass concentrations and chemical compositions. Multiple linear regression analysis was utilized to investigate the simultaneous influence of meteorological factors on fluctuations in the daily levels of PM_0.1. Multiple linear regression models could explain about 50% of the variations of PM_0.1 concentrations, in which wind speed is the most important variable. The average concentrations of organic carbon (OC), elemental carbon (EC), water-soluble ions (Ca²⁺, K⁺, Mg²⁺, Na⁺, NH₄⁺, Cl^-, NO₃^-, SO₄^2-, C₂O₄^2-), and elements (Be, Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba, Tl, Pb, Na, Fe, Mg, K, and Ca) were 2.77 ± 0.90 μg m^-3, 0.63 ± 0.28 μg m^-3, 0.88 ± 0.39 μg m^-3, and 0.05 ± 0.02 μg m^-3, accounting for 51.23 ± 9.32%, 11.22 ± 2.10%, 16.28 ± 2.67%, and 1.11 ± 0.94%, respectively. A positive matrix factorization model revealed the contributions of five major sources to the PM_0.1 mass including traffic (gasoline and diesel emissions, 46.28%), secondary emissions (31.18%), resident/commerce (12.23%), industry (6.05%), and road/construction (2.92%).

Risk factors for radiological changes after bipolar hemiarthroplasty for osteonecrosis of the femoral head

OBJECTIVES

This study aimed to report the mid-term radiological outcomes of patients with bipolar hemiarthroplasty (BHA) for stage 3 osteonecrosis of the femoral head (ONFH), and to identify the risk factors for postoperative radiological changes.

METHODS

We retrospectively investigated 62 patients (38 men and 24 women; mean age, 50.1 years) aged <70 years who underwent primary BHA for Association Research Circulation Osseous stage 3 ONFH between 1998 and 2010. The mean follow-up period after BHA was 12.8 years. The following changes were assessed on follow-up radiographs: outer head migration, polyethylene wear, and femoral osteolysis. The association between demographic data and the development of postoperative radiological changes was evaluated.

RESULTS

Radiological changes were found in 20 hips (32.3%) at a mean of 8.1 years after BHA; of these, three hips (4.8%) underwent total hip arthroplasty conversion at a mean of 10.9 years after BHA. Both univariate and multivariate analysis revealed that younger age and female sex were independent risk factors for the development of postoperative radiological changes.

CONCLUSION

The current results suggest that the indication of BHA should be carefully determined in young or female patients with ONFH, even when the disease is in the early stage.

THU0144 DESCRIPTIVE ANALYSIS OF PREGNANCY, DELIVERY, AND LACTATION IN PATIENTS WITH RHEUMATOID ARTHRITIS FROM THE IORRA COHORT

Background:

Rheumatoid Arthritis (RA) is common in women with reproductive age. For this reason, RA treatment during pregnancy and lactation is very important. In recent years, the use of biologic disease-modifying antirheumatic drugs (bDMARDs) has become common in RA treatment (1), treatment during pregnancy and lactation has changed drastically (2,3).

Objectives:

To investigate the pregnancy, delivery and lactation status of RA patients and treatment during that period in daily practice.

Methods:

The IORRA cohort is a large, single institute-based, observational cohort of RA patients established at Institute of Rheumatology, Tokyo Women’s Medical University, in 2000. We identified female RA patients aged 20-49 years who answered ‘pregnant’ or ‘delivered’ in the IORRA survey in 2010-2016 and whose pregnancies were confirmed in the medical records. We examined the Disease Activity Score with 28 joint count (DAS28)-CRP, medication use situation, the outcome of pregnancy, and lactation in those patients.

Results:

A total of 101 patients and 143 pregnancies were confirmed, of which 136 outcomes of pregnancy could be confirmed in the medical records. Among 136 confirmed pregnancy cases, there were 106 births and 30 miscarriages. Among 106 births, 4 cases (3.8%) were birth defects that could be confirmed in the medical records. The average age at pregnancy was 34.2±3.7 years and 36.1±3.3 years in delivered and miscarried cases, respectively. Miscarried cases were significantly older pregnancies (p=0.01). Of the 106 births, 65 birth weeks were confirmed, with an average of 37.9±1.8 weeks. The number of preterm delivery was 11 cases (16.9%). The average birth weight of 59 babies whose birth weight could be confirmed was 2699±517 g. There were 21 cases (35.6%) of low birth weight infants. The proportion of patients in DAS28-CRP remission was 73.1% before pregnancy, 61.6% during pregnancy, and 68.0% 1 year after delivery. Drugs used before pregnancy were glucocorticoid (48.8%), non-steroidal anti-inflammatory drugs (14.2%), conventional synthetic DMARDs (24.8%), and bDMARDs (48.0%). Etanercept accounted for 90% of bDMARDs. Among taking bDMARDs patients, 73.8% were discontinued after the pregnancy, and 26.2% were continued during pregnancy. Among those patients who continued bDMARDs, lactating patients were 12/26 (46.2%) cases after delivery, 10/30 (33.3%) cases in six months after delivery, and 7/36 (19.4%) cases in 1 year after delivery, respectively.

Conclusion:

The actual situation of pregnancy, delivery, and lactation in RA patients was revealed. Especially, bDMARDs were used at relatively high rates in RA patients who wish to have a child.

References:

[1]Lancet. 2017;10;389:2338-2348.

[2]Semin Arthritis Rheum. 2019;49:S32-S35.

[3]Rheumatology. 2016;55:1693-7.

Disclosure of Interests:

Moeko Ochiai: None declared, Eiichi Tanaka Consultant of: ET has received lecture fees or consulting fees from Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Speakers bureau: ET has received lecture fees or consulting fees from Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Eisuke Inoue Speakers bureau: EI has received speaker fee from Bristol-Meyers, Pfizer, Merck serono., Mai Abe: None declared, Eri Sugano: None declared, Naohiro Sugitani: None declared, Kumiko Saka: None declared, higuchi yoko: None declared, Rei Yamaguchi: None declared, Naoki Sugimoto: None declared, Ikari Katsunori Speakers bureau: KI has received speaker’s fee from Asahi Kasei Pharma Corp., Astellas Pharma Inc., AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eis, ai Co., Ltd., Eli Lilly Japan K.K., Janssen Pharmaceutical K.K., Kaken Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corp.Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., Teijin Pharma Ltd and UCB Japan Co. Ltd., Ayako Nakajima Grant/research support from: AN has received research grants from Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Consultant of: AN has consultant fee from Nippon Kayaku Co. Ltd., Speakers bureau: AN has received speaker’s fee from AbbVie Japan GK, Actelion Pharmaceuticals Japan LTD., Asahi Kasei Pharma Co., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Hisamitsu Pharmaceutical Co. Inc., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., and Teijin Pharma Ltd., Atsuo Taniguchi: None declared, Hisashi Yamanaka Grant/research support from: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., Speakers bureau: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., masayoshi harigai Grant/research support from: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., and Teijin Pharma Ltd. MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Oxford Immuotec, Pfizer Japan Inc., and Teijin Pharma Ltd. MH is a consultant for AbbVie, Boehringer-ingelheim, Kissei Pharmaceutical Co., Ltd. and Teijin Pharma.

AB0257 ASSESSMENT OF PHYSICAL DYSFUNCTION IN PATIENTS WITH RHEUMATOID ARTHRITIS WHO PLANNED PREGNANCY FROM THE IORRA COHORT

Background:

It has been reported that female rheumatoid arthritis (RA) patients have a longer time to pregnancy than healthy women (1), and that high Disease Activity Score with 28 joint count (DAS28) -CRP in preconception increases the frequency of infertility (2). Before the era of biologics, RA treatment tended to be inadequate from pregnancy planning to the end of lactation. And it was not uncommon for female RA patients to be unable to get pregnant or develop physical dysfunction as a result of insufficient control of the disease. There are some reports of disease activity during pregnancy and postpartum in RA patients, and the effects of RA disease activity on pregnancy and childbirth outcomes (3-5), but there are few reports focusing on the physical function during pregnancy planning of RA patients.

Objectives:

To investigate disease activity and physical function in female patients with RA who planned and didn’t plan pregnancy.

Methods:

The IORRA cohort is a large, single institute-based, observational cohort of RA patients established at the Institute of Rheumatology, Tokyo Women’s Medical University, in 2000. We identified female RA patients aged 20-49 years who answered ‘pregnant’ or ‘delivered’ in the IORRA survey in 2010-2015 and whose pregnancy and the pregnancy planning time was confirmed in the medical records, and defined them as the pregnancy planning (PP) group. Matched control was extracted at 1:3 ratio from patients without pregnancy plan based on entry time, age, RA disease duration, DAS28-CRP, Japanese version of Health Assessment Questionnaire (J-HAQ) score, and comorbidities. The primary endpoint was J-HAQ at 3years from the baseline, which was defined as the most recent IORRA survey before planning pregnancy. The mixed-effect model for repeated measures was used to analyze group difference.

Results:

There were 40 patients in the PP group (average 32.2 years, disease duration 5.7 years, DAS28-CRP 1.7, J-HAQ 0.26), and 120 patients in the control group (average 32.4 years, disease duration 5.9 years, DAS28-CRP 1.7, J-HAQ 0.21). The proportion of user and dosage of MTX and glucocorticoid (GC) and bDMARDs user at baseline were comparable between the groups (MTX: PP 87.5% [9.8 mg/week], control 85.0% [8.8 mg/week]; GC: PP 32.5% [3.6 mg/day], control 27.5% [4.4 mg/day]; bDMARDs: PP 40.0%, control 27.5%). DAS28-CRP at year 3 of the PP group elevated and was higher than the control group (PP 2.3, control 1.7, p<0.01), while J-HAQ was stable over the observation period and did not differ significantly at year 3 (PP 0.21, control 0.22, p=0.92). At year 3, the proportion of patients taking MTX was lower and taking GC was higher in the PP group than those in the control group (MTX: PP 36.7%, control 76.7%, p<0.01; GC: PP 70.0%, control 25.6%, p<0.01). The proportion of patients taking bDMARDs was not different in both groups (PP 36.7%, control 32.6%, p=0.68).

Conclusion:

Physical function in pregnancy planning patients with RA did not deteriorate as well as the control patients in clinical settings.

References:

[1]Arthritis Rheum. 2011;63:1517-1521.

[2]Ann Rheum Dis. 2015;10:1836-1841.

[3]J Rheumatol. 2015;42:1376-1382.

[4]J Rheumatol. 2019;46:245-250.

[5]Arthritis Care Res. 2017;69:1297-1303.

Disclosure of Interests:

Moeko Ochiai: None declared, Eiichi Tanaka Consultant of: ET has received lecture fees or consulting fees from Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Speakers bureau: ET has received lecture fees or consulting fees from Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Eisuke Inoue Speakers bureau: EI has received speaker fee from Bristol-Meyers, Pfizer, Merck serono., Mai Abe: None declared, Eri Sugano: None declared, Naohiro Sugitani: None declared, Kumiko Saka: None declared, higuchi yoko: None declared, Rei Yamaguchi: None declared, Naoki Sugimoto: None declared, Ikari Katsunori Speakers bureau: KI has received speaker’s fee from Asahi Kasei Pharma Corp., Astellas Pharma Inc., AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eis, ai Co., Ltd., Eli Lilly Japan K.K., Janssen Pharmaceutical K.K., Kaken Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corp.Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., Teijin Pharma Ltd and UCB Japan Co. Ltd., Ayako Nakajima Grant/research support from: AN has received research grants from Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Consultant of: AN has consultant fee from Nippon Kayaku Co. Ltd., Speakers bureau: AN has received speaker’s fee from AbbVie Japan GK, Actelion Pharmaceuticals Japan LTD., Asahi Kasei Pharma Co., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Hisamitsu Pharmaceutical Co. Inc., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., and Teijin Pharma Ltd., Atsuo Taniguchi: None declared, Hisashi Yamanaka Grant/research support from: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., Speakers bureau: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., masayoshi harigai Grant/research support from: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., and Teijin Pharma Ltd. MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Oxford Immuotec, Pfizer Japan Inc., and Teijin Pharma Ltd. MH is a consultant for AbbVie, Boehringer-ingelheim, Kissei Pharmaceutical Co., Ltd. and Teijin Pharma.

OP0221 HAVE 5-YEAR SURVIVAL RATE AND MORTALITY CHANGED IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS IN THE PAST TWENTY YEARS?-RESULTS FROM THE IORRA COHORT

Background:

The mortality of patients with rheumatoid arthritis (RA) had been reported as being worse than that of the general population [1, 2], but is expected to have improved over time because the progress in treatment of RA during the past twenty years has been actively adopted to RA management [3, 4]. However, the change in the mortality still remains controversial in patients with early RA [5, 6].

Objectives:

To investigate whether the vital prognosis of patients with early RA has changed in the past twenty years.

Methods:

The IORRA cohort is a large observational cohort established in 2000 at the Institute of Rheumatology, Tokyo Women’s Medical University. Essentially, all Japanese patients diagnosed with RA at our institute were registered and clinical parameters were assessed biannually. As there is no National Death Registry in Japan, we obtained death report from residual families who responded to our mail query to patients who failed to conduct the subsequent IORRA survey, from physicians of affiliated hospitals and from police in case they found dead patient outside of a hospital. In this study, the patients with early RA (less than 2 years of disease duration) who participated in the survey for the first time from 2001 to 2012 were included and observed for five years from the date of the initial survey. We classified patients into group A (enrolled in 2001-2006) and B (enrolled in 2007-2012). Five-year survival rate and standardized mortality ratio (SMR) were calculated for each group. SMR was calculated using the life tables in Japanese general population reported by the Ministry of Health, Labour and Welfare, Japan. The effects of loss to follow-up cases were evaluated by multiple imputation method as a sensitivity analysis of SMR.

Results:

A total of 3,217 patients with early RA were analyzed. The number of patients was 1,609 (79.4% female) in the group A and 1,608 (81.8% female) in B. The median age at baseline was 55 in both groups. Among a total of 3,217 patients, 486 (15.1%) patients were lost during 5-year follow-up; 213 (13.2%) in the group A and 273 (17.0%) in B, respectively. During the observational period, deaths were confirmed in 47 cases (2.9%) in the group A and 45 (2.8%) in B. Major causes of death included malignancies (28% in the group A, 38% in B), respiratory involvement (23% in the group A, 40% in B), cerebrovascular disorders (11% in the group A, 2% in B), and cardiovascular disorders (11% in the group A, 0% in B). The five-year survival rate was 88.8% for the group A and 87.8% for B, and the SMR was 0.81 (95%CI: 0.59-1.08) for the group A and 0.78 (0.57-1.04) for B when assuming all the lost to follow-up patients were alive for 5 years. In the sensitivity analysis assuming that the mortality rate of patients who were lost to follow-up was twice as that of the general population, the SMR was 0.90 (0.68-1.19) for the group A and 0.92 (0.68-1.23) for B.

Conclusion:

The mortality of patients with early RA in the past twenty years has been comparable to that of the Japanese general population. In addition, the SMR and the five-year survival rate did not change overtime.

References:

[1]Cobb, S., et al. N Engl J Med 1953; 249(14): 553-556.

[2]Nakajima, A., et al. Scand J Rheumatol 2010; 39(5): 360-367.

[3]Smolen, J. S., et al. Ann Rheum Dis 2014; 73(3): 492-509.

[4]Singh, J. A., et al. Arthritis Care Res 2016; 68(1): 1-25.

[5]Lacaille, D., et al. Ann Rheum Dis 2017; 76(6): 1057-1063.

[6]Humphreys, J. H., et al. Arthritis Care Res 2014; 66(9): 1296-1301.

Disclosure of Interests:

Naohiro Sugitani: None declared, Eiichi Tanaka Consultant of: Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Eisuke Inoue Speakers bureau: EI has received speaker fee from Bristol-Meyers, Pfizer, Merck serono., Mai Abe: None declared, Eri Sugano: None declared, Kumiko Saka: None declared, Moeko Ochiai: None declared, Yoko Shimizu: None declared, Rei Yamaguchi: None declared, Naoki Sugimoto: None declared, Katsunori Ikari Speakers bureau: Asahi Kasei Pharma Corp., Astellas Pharma Inc., AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eis, ai Co., Ltd., Eli Lilly Japan K.K., Janssen Pharmaceutical K.K., Kaken Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corp.Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., Teijin Pharma Ltd and UCB Japan Co. Ltd., Ayako Nakajima Grant/research support from: AN has received research grants from Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Consultant of: AN has consultant fee from Nippon Kayaku Co. Ltd., Speakers bureau: AN has received speaker’s fee from AbbVie Japan GK, Actelion Pharmaceuticals Japan LTD., Asahi Kasei Pharma Co., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Hisamitsu Pharmaceutical Co. Inc., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., and Teijin Pharma Ltd., Atsuo Taniguchi: None declared, Hisashi Yamanaka Grant/research support from: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., Speakers bureau: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., masayoshi harigai Grant/research support from: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., and Teijin Pharma Ltd. MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Oxford Immuotec, Pfizer Japan Inc., and Teijin Pharma Ltd. MH is a consultant for AbbVie, Boehringer-ingelheim, Kissei Pharmaceutical Co., Ltd. and Teijin Pharma.

THU0086 FACTORS ASSOCIATED WITH TREATMENT RESPONSE IN PATIENTS WITH ELDERLY-ONSET RHEUMATOID ARTHRITIS: 3-YEAR OBSERVATION USING THE IORRA COHORT

Background:

Patients with elderly-onset rheumatoid arthritis (EORA) are on the rise in the aging or super-aging society, especially in Japan. Patients with EORA have more comorbidities than those with younger-onset RA, a higher risk of adverse drug reactions due to reduced drug metabolism, and a higher risk of infections1). Therefore, patients with EORA tend to receive suboptimal treatment, resulting in insufficient control of disease activity2). Although several studies reported treatment responsiveness in patients with EORA, many of them have a limited observation period3-8), and long-term treatment responses and their associated factors need to be clarified.

Objectives:

We retrospectively evaluated treatment responses of patients with EORA for 3 years and their associated factors in a clinical setting.

Methods:

The Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort is a large, single institute-based, observational cohort of RA patients established at Institute of Rheumatology, Tokyo Women’s Medical University, in 2000. The subjects were RA patients who first enrolled in the IORRA cohort from 2010 to 2014, were over 60 years old with less than 1-year disease duration, and had a DAS28-ESR over 3.2 at entry. The primary endpoint was DAS28-ESR <3.2 after 3-year observation. A multivariate logistic regression analysis was conducted to identify factors at baseline associated with the primary endpoint. The missing values of DAS28-ESR were imputed by using the last observation carried forward method.

Results:

Among a total of 250 patients in this study, 152 patients (60.8%) achieved DAS28-ESR <3.2 after 3-year observation (remission/low disease activity (RL) group), and 98 patients did not (moderate/high disease activity (MH) group). Baseline characteristics of the patients were as follows (average ± SD or %): the RL group, age 69.9 ± 6.5, female 77%, DAS28-ESR 4.3 ± 0.8, J-HAQ 0.9 ± 0.7, PSL user 23.7%, MTX user 64.5%, and biologics user 4.0%; the MH group, age 69.4 ± 6.7, female 80.6%, DAS28-ESR 4.4 ± 0.8, J-HAQ 1.0 ± 0.7, PSL user 36.7%, MTX user 64.3%, and biologics user 6.1%. Proportions of the patients with cardiovascular disease and malignancy were 13.3% and 11.2% in the MH group and 5.9% and 1.3% in the RL group, respectively. DAS28-ESR and J-HAQ score after 3-year observation of the RL group were 2.3±0.5 and 0.4±0.5, respectively, and those of the MH group were 3.4±0.9 and 1.0±0.8, respectively. Corticosteroid use and having malignancy at baseline were associated with not achieving DAS28-ESR <3.2 after 3-year observation using multivariate analysis (Table 1). Similar results were obtained when MTX use and corticosteroid use were replaced by the average dose of each drug.

Conclusion:

The majority of the patients with EORA achieved DAS28-ESR <3.2 after 3-year observation, and no use of corticosteroid and absence of malignancy at baseline were associated with the good outcome.

References:

[1]Nat Rev Rheumatol 2013;9:604-613

[2]Ann Rheum Dis 2006;65:1226-1229

[3]Ann Rheum Dis 2009;68:1470–1473

[4]Joint Bone Spine 2015;82:25-30

[5]J Rheumatol 2016;43:1974-1983

[6]Rheumatology 2015;54:798-807

[7]Rheumatology 2014;53:1075-1086

[8]Japanese Journal of Geriatrics 2018;55:251-258

Acknowledgments:

We thank all patients who participated in the IORRA survey and all of the members of the Institute of Rheumatology, Tokyo Women’s Medical University, for the successful management of the IORRA cohort.

Disclosure of Interests:

Mai Abe: None declared, Eiichi Tanaka Consultant of: Abbvie, Asahi Kasei pharma co., Bristol Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Co., Eisai Pharmaceutical, Janssen Pharmaceutical K.K., Nippon Kayaku, Pfizer, Takeda Pharmaceutical, Taisho Toyama Pharmaceutical Co., and UCB Pharma., Eisuke Inoue Speakers bureau: EI has received speaker fee from Bristol-Meyers, Pfizer, Merck serono., Eri Sugano: None declared, Naohiro Sugitani: None declared, Kumiko Saka: None declared, Moeko Ochiai: None declared, Yoko Shimizu: None declared, Rei Yamaguchi: None declared, Naoki Sugimoto: None declared, Katsunori Ikari Speakers bureau: Asahi Kasei Pharma Corp., Astellas Pharma Inc., AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eis, ai Co., Ltd., Eli Lilly Japan K.K., Janssen Pharmaceutical K.K., Kaken Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corp.Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., Teijin Pharma Ltd and UCB Japan Co. Ltd., Ayako Nakajima Grant/research support from: AN has received research grants from Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Consultant of: AN has consultant fee from Nippon Kayaku Co. Ltd., Speakers bureau: AN has received speaker’s fee from AbbVie Japan GK, Actelion Pharmaceuticals Japan LTD., Asahi Kasei Pharma Co., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Hisamitsu Pharmaceutical Co. Inc., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., and Teijin Pharma Ltd., Atsuo Taniguchi: None declared, Hisashi Yamanaka Grant/research support from: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., Speakers bureau: HY has received research grant or speaker fee from AbbVie, Astellas, Ayumi, Behringer, Bristol-Meyers, Chugai, Daiichi-Sankyo, Eisai, Kaken, Nippon-Shinyaku, Novartis, Ono, Pfizer, Taisyo-Toyama, Takeda, Tanabe-Mitsubishi, Teijin Pharma, Torii, UCB, YLbio., masayoshi harigai Grant/research support from: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., and Teijin Pharma Ltd. MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Oxford Immuotec, Pfizer Japan Inc., and Teijin Pharma Ltd. MH is a consultant for AbbVie, Boehringer-ingelheim, Kissei Pharmaceutical Co., Ltd. and Teijin Pharma.

Disseminated Pneumocystosis in a Toy Poodle

A 1-year and 7-months-old neutered male toy poodle was presented with persistent respiratory distress, gradual weight loss and melaena. Thoracic radiography showed an unstructured interstitial lung pattern. Histopathological examination of tissues collected at necropsy examination revealed disseminated infection by Pneumocystis carinii. The organisms were detected in the lungs, lymph nodes, liver, heart, kidneys, spleen, gastrointestinal tract and pancreas. In the lungs, the organisms were present in the alveolar space and interstitial tissue, and calcified foci containing P. carinii were observed. The presence of the organism in non-thoracic lymph nodes provided evidence of lymphogenous spread. A definitive diagnosis of disseminated pneumocystosis was achieved through the use of Grocott methenamine silver staining, immunohistochemistry (IHC) and polymerase chain reaction for P. carinii. Depletion of cells expressing immunoglobulin (Ig)A and IgG was confirmed by IHC of lymphoid tissue, suggesting possible underlying immunodeficiency.

Synthetic Studies on FNC-RED and Its Analogues Containing an All syn-Cyclopentanetetrol Moiety

FNC-RED exhibits innate immune receptor Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD2) stimulatory activity. We have developed a divergent synthetic route to FNC-RED derivatives containing various alkyl side chains. Key features of the synthetic study include stepwise palladium catalyzed cross-coupling reactions and the construction of an all syn-cyclopentanetetrol moiety.

Bovine Endocarditis Associated with Mycoplasma bovis

Mycoplasma bovis is a microorganism associated with pneumonia, mastitis, arthritis and otitis media of cattle; however, there are no reports of this organism causing bovine endocarditis. Five adult cattle with endocarditis characterized by caseated lesions (diameter 5-12 cm) of the endocardial surface of the left atrium, but without lesions in heart valves or affecting the right side of the heart, were identified in slaughterhouses in Japan. M. bovis was successfully isolated from the lesions and M. bovis antigen was detected immunohistochemically within the lesions. The results suggest that the lesions may have been associated with M. bovis alone. To our knowledge, this is the first demonstration of bovine endocarditis associated with M. bovis.

Abstract P3-08-03: Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort

Although rare, Metaplastic Breast Carcinomas (MBC) account for significant global breast cancer mortality. This subgroup is extremely heterogeneous and by definition exhibits metaplastic change to squamous and/or mesenchymal elements, including but not limited to spindle, squamous, chondroid, osseous and rhabdomyoid elements. The WHO working group recognizes that the current classification is inadequate and in the interim, has suggested a purely descriptive classification. The mixed epithelial-mesenchymal morphology has led to speculation that MBC represent 'stem cell tumours'; in support of this, MBC have been shown to have a CD44+/CD24-/low phenotype. Clinically, patients present with tumours that are larger (higher stage), have increased likelihood of distant metastases at presentation and overall, have a reduced 5-year survival rate compared to Invasive Carcinoma-NST. Hence, this is a unique subtype with poor outcome but without a robust classification or understanding of the biology to aid clinical management. We present a detailed morphological, immunohistochemical and genomic analysis of a large series of MBC (n=347), as amassed through the Asia-Pacific MBC consortium. We consider our morphological dissection using the WHO subtyping guidelines and show that an increasing number of phenotypes in a mixed MBC (classified as WHO_1) significantly associates with a poor prognosis. Immunohistochemical analysis showed that a pure spindle (WHO_5) is significantly less likely to express vimentin, CK5/6, CK14, and CK19 than a mixed WHO_1 with spindle features. Similarly, a WHO_1 with chondroid features is less likely to express EGFR than WHO_1 with chondroid features and rhabdoid or osseous differentiation. Across the cohort, positivity for the AE1/3 antibody and a lack of EGFR expression both significantly associate with a better outcome. We report no significant association between patient age at diagnosis and breast cancer specific survival, nor between age and specific WHO MBC subtypes. We report a significant association between WHO_1 types and increasing tumour grade, and also between tumour size and grade, with tumour size being a highly significant prognostic indicator in this cohort. Our exome sequencing confirms a significant enrichment for TP53 and PTEN mutations in MBC, and intriguingly for concurrent mutations of TP53, PTEN and PIK3CA. A novel enrichment for NF1 mutations is also presented. In summary, we provide a thorough assessment of a large cohort of MBC, including morphology, survival, IHC and exome sequencing, and present our analysis contextualized by the WHO guidelines, extending the existing knowledge base of this rare tumour type.

Citation Format: McCart Reed AE, Kalaw E, Nones K, Bettington M, Lim M, Bennett J, Johnstone K, Kutasovic JR, Kazakoff S, Xu QC, Saunus JM, Reid LE, Black D, Niland C, Ferguson K, Gresshoff I, Raghavendra A, Liu JC, Kalinowski L, Reid AS, Davidson M, Pearson JV, Yamaguchi R, Harris G, Tse G, Papadimos D, Pathmanathan R, Pathmanathan N, Tan PH, Fox S, O'Toole S, Waddell N, Simpson PT, Lakhani SR. Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-03.

Interleukin-6 deletion stimulates revascularization and new bone formation following ischemic osteonecrosis in a murine model

Legg-Calvé-Perthes disease (LCPD) is a childhood form of ischemic osteonecrosis of the femoral head which can produce a permanent femoral head deformity and early osteoarthritis. The femoral head deformity results from increased bone resorption and decreased bone formation during repair and remodeling of the necrotic femoral head. A recent study showed that a pro-inflammatory cytokine, interleukin-6 (IL-6), is significantly elevated in the synovial fluid of patients with LCPD. We hypothesized that IL-6 elevation decreases bone formation during the repair process following ischemic osteonecrosis and that IL-6 depletion will increase new bone formation. To test this hypothesis, we surgically induced ischemic osteonecrosis in the wild-type (n = 29) and IL-6 knockout (KO) mice (n = 25). The animals were assessed at 48 h, 2 weeks and 4 weeks following the induction of ischemic osteonecrosis using histologic, histomorphometric and micro-CT methods. IL-6 immunohistochemistry showed high expression of IL-6 in the osteonecrotic side of the wild-type mice at 48 h and 4 weeks following ischemic osteonecrosis, but not in the IL-6 KO mice. We also confirmed an undetectable level of IL-6 expression in the primary osteoblasts of the IL-6 KO mice compared to the readily detectable level in the wild-type mice. Furthermore, we confirmed that IL-6 deletion did not affect the extent of bone necrosis in the IL-6 KO mice compared to the wild-type mice by performing histologic and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assessments at 2 weeks following the induction of ischemia. Both groups had the same extent of ischemic osteonecrosis and absence of repair at 2 weeks. At 4 weeks, the necrotic epiphyses showed a significant increase in the extent of revascularization in the IL-6 KO mice compared to the wild-type mice (p = 0.001). In addition, a significantly greater recovery of the hematopoietic bone marrow was observed in the osteonecrotic side of the IL-6 KO mice compared to the wild-type mice (p < 0.01). Vascular endothelial growth factor (VEGF) immunohistochemistry showed regionally increased staining in the areas of repair in the osteonecrosis side of IL-6 KO mice compared to the wild-type mice at 4 weeks following ischemic osteonecrosis. Micro-CT assessment of the wild-type mice at 4 weeks showed a significant decrease in the percent bone volume (p < 0.01) in the osteonecrotic side compared to the control side. In contrast, IL-6 KO mice showed significantly increased bone volume in the osteonecrotic side compared to the osteonecrotic side of WT mice (p < 0.001). No significant difference in the bone volume percentage was found between the control side of the wild-type and the IL-6 KO mice. Histomorphometric analysis at 4 weeks revealed increased osteoblast number/bone surface (p < 0.001), bone formation rate (BFR) (p = 0.0001), and mineral apposition rate (MAR) (p < 0.0001) in the osteonecrotic side of the IL-6 KO mice compared to the wild-type mice. The number of osteoclast/bone surface was also increased in the IL-6 KO mice compared to the wild-type mice (p < 0.0001). No significant difference was observed between the control side of the wild-type and IL-6 KO mice with regards to the number of osteoblast or osteoclast/bone surface, BFR, and MAR. We next obtained primary osteoblasts from IL-6 KO mice and showed they expressed a significantly higher level of RANKL/OPG than wild-type mice (p = 0.001) in hypoxia culture condition. Taken together, the findings indicate that IL-6 deletion stimulates revascularization and new bone formation following ischemic osteonecrosis. This study provides new evidence that therapeutic strategies to block IL-6 may be beneficial for bone healing following ischemic osteonecrosis.

Local extensive granulomatous inflammation of the neck region and lymphangitis caused by Lichtheimia corymbifera infection in a Japanese Black calf

A 7-month-old female Japanese Black calf developed elongated, nodular mass measuring 30 × 16 cm extended from the retropharyngeal region to mid lateral neck region. Histological examination revealed granulomatous lymphangitis with non-septate fungal hyphae recognized throughout the lesions. Fungal culture, DNA sequencing and molecular phylogenetic tree analysis confirmed the sequence of Lichtheimia corymbifera. The lymphogenous route was speculated to be the main route of fungal spread leading to the characteristic nodular appearance of this case.

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

Histological and immunohistochemical evaluation of granulosa cells during different stages of folliculogenesis in bovine ovaries

Bovine granulosa cells (GC) vary in their morphological aspect during different stages of folliculogenesis. In this study, 10 morphologically normal bovine ovaries were collected to study the structural aspects of different stages of GC using intermediate filament protein antibodies including cytokeratin AE1/AE3 (AE1/AE3), vimentin, nectin-4 and desmin. Hormonal immunolocalization was assessed using the immunomarkers anti-Müllerian hormone (AMH) and inhibin alpha. In addition, tumour markers and proliferation markers using c-erbB-2 oncoprotein and proliferating cell nuclear antigen, respectively, were investigated. The immunolabelling of AE1/AE3 in GC was strongest in the early follicle stage and gradually decreased when reaching the Graafian follicle stage. Its immunolabelling increased again as the stage progressed from stage I to stage III. The immunolabelling of inhibin alpha was inversely proportional to that of AE1/AE3 in the developing ovarian follicles as their immunolabelling is opposite to each other during folliculogenesis. AMH was immunopositive in almost all GC stages in different intensities and percentages, except for some negative staining in the atretic IV follicles. The atretic IV follicle is a unique type of atretic follicle that shows Call-Exner body formation, which was mainly found in older cows in this study. The distinct patterns of immunoreactivity for various types of immunomarkers in the different GC stages will play an important role in diagnostic assistance of various follicle conditions, including cystic ovaries and GC tumours.

Characterization of anti-Müllerian hormone in a case of bovine male pseudohermaphroditism

The current report aimed to characterize plasma anti-Müllerian hormone (AMH) in bovine male pseudohermaphroditism. The blood AMH concentration in a Japanese Black male pseudohermaphrodite calf was compared with pre- and post-pubertal male and female calves and castrated calves. The concentration in the case was higher than in post-pubertal males, castrated males, and pre- and post-pubertal female calves (p < .05), but similar to that in pre-pubertal male calves. After extraction of the testes, the concentration in the case dropped to a certain extent. The extracted testes expressed AMH, as detected by immunohistochemistry. This study is the first to show the characterization of AMH in a male pseudohermaphrodite calf. AMH levels in peripheral blood might be useful to diagnose male pseudohermaphroditism in cattle.

Clinical outcomes of conservative treatment with a non-weight-bearing abduction brace for Legg-Calvé-Perthes disease

BACKGROUND

Treatment with a brace is the first choice as conservative treatment via the containment method for Legg-Calvé-Perthes disease (LCPD). The purpose of this study is to evaluate clinical outcomes and influential factors of conservative treatment with the non-weight-bearing abduction brace for LCPD.

METHODS

One hundred thirty hips in 130 patients were examined in this study. The mean age at onset was 7.0 years (3.3-12.4 years) and the mean follow-up period was 8.4 years (4.1-17.6 years). The extent of necrosis and lateral collapse of the femoral head were evaluated using the Catterall classification and the lateral pillar classification, respectively. Radiological outcome was assessed as good (classes I and II), fair (III), and poor (IV), according to the modified Stulberg classification.

RESULTS

Radiographic outcome at final follow-up was good in 82 hips (63%), fair in 40 hips (31%), and poor in 8 hips (6%). Multinomial logistic regression analysis showed that major influential factors for good outcomes were as follows: age at onset, lateral pillar classification, and Catterall classification. From the receiver operating characteristic curve, the cut-off value for age at onset was 8.4 years old to obtain good outcomes. Hips with Catterall group I and II and lateral pillar group A and B had significantly better results.

CONCLUSION

Patients younger than 8.4 years old at onset with lateral pillar group A or B or Catterall group I or II showed good outcomes with a non-weight-bearing abduction brace for LCPD. These results show that alternative treatment, such as surgery, may be another option for patients who are not included in the above groups.

Targeted Disruption of NF1 in Osteocytes Increases FGF23 and Osteoid With Osteomalacia-like Bone Phenotype

Neurofibromatosis type 1 (NF1, OMIM 162200), caused by NF1 gene mutations, exhibits multi-system abnormalities, including skeletal deformities in humans. Osteocytes play critical roles in controlling bone modeling and remodeling. However, the role of neurofibromin, the protein product of the NF1 gene, in osteocytes is largely unknown. This study investigated the role of neurofibromin in osteocytes by disrupting Nf1 under the Dmp1-promoter. The conditional knockout (Nf1 cKO) mice displayed serum profile of a metabolic bone disorder with an osteomalacia-like bone phenotype. Serum FGF23 levels were 4 times increased in cKO mice compared with age-matched controls. In addition, calcium-phosphorus metabolism was significantly altered (calcium reduced; phosphorus reduced; parathyroid hormone [PTH] increased; 1,25(OH)₂ D decreased). Bone histomorphometry showed dramatically increased osteoid parameters, including osteoid volume, surface, and thickness. Dynamic bone histomorphometry revealed reduced bone formation rate and mineral apposition rate in the cKO mice. TRAP staining showed a reduced osteoclast number. Micro-CT demonstrated thinner and porous cortical bones in the cKO mice, in which osteocyte dendrites were disorganized as assessed by electron microscopy. Interestingly, the cKO mice exhibited spontaneous fractures in long bones, as found in NF1 patients. Mechanical testing of femora revealed significantly reduced maximum force and stiffness. Immunohistochemistry showed significantly increased FGF23 protein in the cKO bones. Moreover, primary osteocytes from cKO femora showed about eightfold increase in FGF23 mRNA levels compared with control cells. The upregulation of FGF23 was specifically and significantly inhibited by PI3K inhibitor Ly294002, indicating upregulation of FGF23 through PI3K in Nf1-deficient osteocytes. Taken together, these results indicate that Nf1 deficiency in osteocytes dramatically increases FGF23 production and causes a mineralization defect (ie, hyperosteoidosis) via the alteration of calcium-phosphorus metabolism. This study demonstrates critical roles of neurofibromin in osteocytes for osteoid mineralization. © 2017 American Society for Bone and Mineral Research.

Appearance of US-like porcine epidemic diarrhoea virus (PEDV) strains before US outbreaks and genetic heterogeneity of PEDVs collected in Northern Vietnam during 2012-2015

Porcine epidemic diarrhoea virus (PEDV) is the aetiologic agent of porcine epidemic diarrhoea (PED), a highly contagious enteric disease that is threatening the swine industry globally. Since PED was first reported in Southern Vietnam in 2009, the disease has spread throughout the country and caused substantial economic losses. To identify PEDVs responsible for the recent outbreaks, the full-length spike (S) gene of 25 field PEDV strains collected from seven northern provinces of Vietnam was sequenced and analysed. The sequence analysis revealed that the S genes of Vietnamese PEDVs were heterogeneous and classified into four genotypes, namely North America and Asian non-S INDEL, Asian non-S INDEL, new S INDEL and classical S INDEL. This study reported the pre-existence of US-like PEDV strains in Vietnam. Thirteen Vietnamese variants had a truncated S protein that was 261 amino acids shorter than the normal protein. We also detected one novel variant with an 8-amino acid insertion located in the receptor-binding region for porcine aminopeptidase N. Compared to the commercial vaccine strains, the emerging Vietnamese strains were genetically distant and had various amino acid differences in epitope regions and N-glycosylation sites in the S protein. The development of novel vaccines based on the emerging Vietnamese strains may be contributive to the control of the current PED outbreaks.