Third nationwide surveillance of bacterial pathogens in patients with acute uncomplicated cystitis conducted by the Japanese surveillance committee during 2020 and 2021: Antimicrobial susceptibility of Escherichia coli, Klebsiella pneumoniae, and Staphylococcus saprophyticus.

The Japanese surveillance committee conducted a third nationwide surveillance of antimicrobial susceptibility of acute uncomplicated cystitis at 55 facilities throughout Japan between April 2020 and September 2021. In this surveillance, we investigated the susceptibility of Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), and Staphylococcus saprophyticus (S. saprophyticus) for various antimicrobial agents by isolating and culturing bacteria from urine samples. In total, 823 strains were isolated from 848 patients and 569 strains of target bacteria, including E. coli (n = 529, 92.9 %), K. pneumoniae (n = 28, 4.9 %), and S. saprophyticus (n = 12, 2.2 %) were isolated. The minimum inhibitory concentrations of 18 antibacterial agents were determined according to the Clinical and Laboratory Standards Institute manual. In premenopausal patients, there were 31 (10.5 %) and 20 (6.8 %) fluoroquinolone (FQ)-resistant E. coli and extended-spectrum ß-lactamase (ESBL)-producing E. coli, respectively. On the other hand, in postmenopausal patients, there were 75 (32.1 %) and 36 (15.4 %) FQ-resistant E. coli and ESBL-producing E. coli, respectively. The rate of FQ-resistant E. coli and ESBL-producing E. coli in post-menopausal women was higher than that for our previous nationwide surveillance (20.7 % and 32.1 %: p = 0.0004, 10.0 % and 15.4 %; p = 0.0259). For pre-menopausal women, there was no significant difference in the rate of FQ-resistant E. coli and ESBL-producing E. coli between this and previous reports, but the frequency of FQ-resistant E. coli and ESBL-producing E. coli exhibited a gradual increase. For appropriate antimicrobial agent selection and usage, it is essential for clinicians to be aware of the high rate of these antimicrobial-resistant bacteria in acute uncomplicated cystitis in Japan.

Arterial Stiffness, Assessed Using the Cardio-Ankle Vascular Index, before and 2 Years after Total Knee Arthroplasty in Patients with Knee Osteoarthritis.

Purpose: Cardiovascular disease (CVD) is a major risk factor for mortality in patients with osteoarthritis, and such comorbidities increase the risk of postoperative complications following total knee arthroplasty (TKA). Arteriosclerosis plays a major role in hemodynamic dysfunction and CVD; however, the postoperative changes in arteriosclerosis following TKA have not been evaluated. Therefore, we assessed the postoperative changes in arteriosclerosis using the cardio-ankle vascular index (CAVI) in patients undergoing TKA, and its relationships with preoperative patient characteristics. Methods: Arteriosclerosis was prospectively evaluated in 119 consecutive patients (140 knees) (15 males (17), 104 females (123); median age 73 years) with knee osteoarthritis who underwent TKA. CAVI was measured before and 2 years after TKA, and the relationships between CAVI and preoperative age, sex, BMI, physical activity status, comorbidities, clinical score, triglyceride concentration, cholesterol concentration, and smoking history were analyzed. Results: CAVI remained stable or improved in 54 joints (39%) and worsened in 86 joints (61%) 2 years post-operation. The median difference between pre- and postoperative CAVI was 0.2 (-0.3, 0.8), and the only preoperative factor associated with this change was preoperative CAVI (r = -0.469, p < 0.001). No other preoperative factor had a significant effect on postoperative arteriosclerosis. Conclusions: The results suggest that patients who undergo TKA subsequently show less severe arteriosclerosis, and the protective effect of TKA on arterial stiffness is greater in those with a higher preoperative CAVI. TKA may be an effective means of reducing the deterioration of arteriosclerosis associated with knee osteoarthritis, at least in the relatively short term.

Patient factors impacting localization of popliteal artery before total knee arthroplasty.

PURPOSE: Intraoperative injury to the popliteal artery (PA) should be avoided during total knee arthroplasty (TKA). This study was performed to clarify the preoperative localization of the PA and the patient factors that impact its localization as a preventive measure. METHODS: Ninety-seven patients (110 knees; 18 men, 79 women) with osteoarthritis who underwent primary TKA were retrospectively reviewed. Preoperative sagittal magnetic resonance imaging was used to measure the distance between the PA and the closest point at three levels: the femoral epicondyle (DPF), the tibial articular surface (DPAS), and the posterior tibial cortex (DPT). All variables are expressed in millimeters as median (interquartile range). RESULTS: The median distance was 10.35 (7.90-12.34) mm for DPF, 6.32 (5.12-8.57) mm for DPAS, and 3.76 (2.28-5.26) mm for DPT. Body height and weight showed weak correlations with DPF (r = 0.324, p < 0.001 and r = 0.207, p = 0.03, respectively). DPF was smaller in women [9.82 (7.64-12.23) mm] than in men [11.27 (10.26-12.75) mm] (p = 0.004). A larger flexion angle and range of motion showed a weak negative correlation with DPT (r = - 0.282, p = 0.003 and r = - 0.236, p = 0.016, respectively). Multiple regression analysis revealed that DPF was related to body height (ß = 0.341, p < 0.001) and that DPT was related to the flexion angle (ß = - 0.264, p = 0.005). CONCLUSIONS: Special attention should be paid to women with a small physique on the femoral side and/or patients with a large flexion angle on the tibial side as a strategy to prevent PA-related complications.

Positive effect of total knee arthroplasty on progression of arteriosclerosis evaluated by cardio-ankle vascular index.

INTRODUCTION: Physical function is expected to improve with an increase in physical activity owing to improvement in knee joint pain after total knee arthroplasty (TKA). This study was performed to evaluate the impact of TKA on arteriosclerosis by measuring the cardio-ankle vascular index (CAVI) before and after surgery. MATERIALS AND METHODS: In total, 206 consecutive patients undergoing unilateral TKA were investigated. The CAVI, an index of the overall stiffness of the artery from the origin of the aorta to the ankle, was used to evaluate the degree of arteriosclerosis. The CAVI of the TKA side and non-TKA side was compared before and 1 year after TKA. RESULTS: There were no differences in the CAVI before and after TKA on the TKA side and non-TKA side, although these values should have worsened at 1 year compared with preoperative values. The CAVI, which did not differ between the two sides preoperatively, differed significantly between the two sides postoperatively (p = 0.013). A generalized linear model showed no interaction between each time point and the measured sides in terms of the CAVI. The relationship between the preoperative CAVI and the difference between the preoperative and postoperative CAVI were examined, showing that R = - 0.428 (p < 0.001) for the TKA side and R = - 0.416 (p < 0.001) for the non-TKA side (significant negative correlation). CONCLUSIONS: The lack of significant age-related deterioration over time on both sides suggests that TKA may slow the progression of arteriosclerosis, especially on the operated side. The effect of TKA was found to be greater with a higher CAVI (i.e., more advanced arteriosclerosis).

Comparison of Operative Times in Primary Bilateral Total Knee Arthroplasty Performed by a Single Surgeon.

Purpose: Prolonged operative time (OT) is associated with adverse complications after total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative factors, such as sex, age, body mass index, body weight (BW), body height, American Society of Anesthesiologists grade, tibiofemoral angle, hospital for special surgery scores, surgical side, surgical order, and calendar year of surgery, affect OT. Methods: One hundred and nineteen patients (238 knees) with osteoarthritis who underwent staged bilateral primary TKA performed by a single surgeon were evaluated. The medical records of 15 males and 104 females were retrospectively reviewed. All variables were expressed as median (interquartile range). Results: The OT for all TKAs was 57 min (51, 65). The OT on the left side (59 min (52−67)) was longer than that on the right side (55 min (50−62)) (p = 0.015). Multiple regression analysis revealed that longer OT was related to BW (ß = 0.488, p < 0.001), calendar year of surgery (ß = −0.218, p< 0.001), and operative side (ß = −0.151, p = 0.007). The Jonckheere−Terpstra test showed a trend toward decreasing OT with calendar year on the left side (p = 0.037) (surgeon's non-dominant side), but not on the right (p = 0.795). Body height, BW, and body mass index showed weak correlations (r = 0.212, p = 0.001; r = 0.352, p < 0.001; r = 0.290, p < 0.001, respectively) with OT. Conclusion: Patients with a large physique, and especially obesity, with an affected knee on the surgeon's non-dominant side may require a longer OT; OT decreased over time.

Preoperative characteristics and intraoperative factors do not correlate with accomplishments of active straight-leg raising, standing up, and walking after primary total knee arthroplasty.

BACKGROUND: The correlations between patient characteristics and early postoperative functional performances after total knee arthroplasty have not been adequately studied. The purpose of this study was to clarify the effects of preoperative characteristics (sex, age, body mass index, American Society of Anesthesiologists grade, hospital for special surgery score) and intraoperative factors (duration of surgery and tourniquet use) on the time required to accomplish active straight-leg-raising, standing up, and walking as the objective performances for the initiation of early postoperative rehabilitation. METHODS: This cross-sectional retrospective study included 307 patients (384 primary total knee arthroplasties). Postoperative times required until each activity was accomplished were measured. Various preoperative characteristics and intraoperative factors that might affect three objective performances were evaluated. RESULTS: The postoperative times required before each activity was accomplished were 1.5 ± 0.5 days for active straight-leg-raising, 1.2 ± 0.5 days for standing up, and 1.4 ± 0.7 days for walking. There were no significant correlations between any factor (age, body mass index, hospital for special surgery score, duration of surgery, and tourniquet use) and the three objective performances using Spearman's correlation coefficient. There were no differences in sex or American Society of Anesthesiologists grade for three objective functional assessments by Wilcoxon rank sum test. CONCLUSIONS: Differences in patient preoperative characteristics and intraoperative factors are unlikely to affect three objective functional performances in the early postoperative period. Therefore, there is no need to consider differences between patients when initiating early postoperative rehabilitation.

Histopathological and immunohistochemical features of proliferative lesions in the pituitary pars distalis of rats.

Pituitary proliferative lesions derived from the endocrine cells of the pars distalis are frequently encountered and adenomas/carcinomas are a common cause of death in standard 2-year carcinogenicity studies using various rat strains, especially Sprague-Dawley. This report describes the immunohistochemical characteristics of pituitary tumors derived from the pars distalis in rats. Prolactin (PRL)-containing tumors are the most common, with PRL/growth hormone (GH) dual positive tumor masses (PRL/GH co-positive tumor masses) being more prevalent than only PRL-positive tumor masses (PRL single-positive tumor masses). GH-containing tumors are relatively numerous and many of these are also PRL/GH co-positive tumor masses. TSH-containing tumors are common in females. PRL-containing tumors have been shown to increase the incidence of hyperlactation in males and mammary adenomas/adenocarcinomas in females, suggesting that these masses are functional tumors.

Immunohistochemical Characteristics of Thymomas and Hyperplastic Lesions in Wistar Hannover Rats.

Previously, we investigated the higher incidence of hyperplastic lesions and thymomas and histopathological resemblance of cortex-medullary structures between thymomas and normal thymuses in Wistar Hannover (WH) rats. Thymomas had pale-staining cell foci (PA) similar to medulla but without lymphocytes. Here, we focused on the differences in cytokeratin (CK) expression in the thymic epithelia of the cortex and medulla and compared the structures of thymomas and normal thymuses. Thymomas, hyperplastic lesions, and normal thymuses obtained from background studies of WH rats were stained with antibodies against CK14, CK18, and CD20. In normal thymuses, the epithelial cells were positive for CK14 in the medulla and subcapsular area and for CK18 in the cortex, B-cells were positive for CD20 in the medulla. In thymomas, the epithelial cells were positive for CK14 in the medullary differentiation (MD) areas and for CK18 in the cortex-like lymphocyte rich and PA, and B-cells were positive for CD20 in the MD areas.

Predictive factors for longer operative times in patients with medial knee osteoarthritis undergoing total knee arthroplasty.

BACKGROUND: Prolonged operative time has frequently been implicated as a risk factor for various complications after total knee arthroplasty (TKA). We aimed to determine whether preoperative factors such as sex, age, body mass index (BMI), prosthetic design, tibiofemoral angle (TFA), range of motion, coronal laxity, Hospital for Special Surgery score and periarticular bone mineral density (BMD) affect operative time. METHODS: We evaluated 164 patients (187 knees) with medial osteoarthritis who underwent primary TKA performed by a single surgeon. The medical records of 27 males and 137 females (median age of 77 and 72 years, respectively) were retrospectively reviewed. TFA was measured on non-weightbearing, standard radiographs. We used dual-energy X-ray absorptiometry to measure BMD, and an arthrometer to evaluate total coronal laxity in each patient. RESULTS: According to univariate analyses, there was a weak positive correlation between BMI and operative time (r = 0.265, p < 0.001), between TFA and operative time (r = 0.235, p = 0.001) and between BMD of the femur and tibia and operative time (r = 0.280, p < 0.001, r = 0.286, p < 0.001, respectively). No significant correlations were found between the other factors and operative time. Based on multivariate analyses, only BMD of the tibia and TFA were significantly correlated with operative time (ß = 0.418, p < 0.001 and ß = 0.182, p = 0.007, respectively). CONCLUSIONS: TFA and BMD of the tibia were the variables more strongly correlated with operative time. Surgeons should recognize preoperatively that patients who have increased TFA, higher periarticular BMD, and higher BMI may have longer operative times. LEVEL OF EVIDENCE: Level IV retrospective study.

Clinical factors associated with bacterial translocation in Japanese patients with type 2 diabetes: A retrospective study.

OBJECTIVE: To explore clinical factors associated with bacterial translocation in Japanese patients with type 2 diabetes mellitus (T2DM). METHODS: The data of 118 patients with T2DM were obtained from two previous clinical studies, and were retrospectively analyzed regarding the clinical parameters associated with bacterial translocation defined as detection of bacteremia and levels of plasma lipopolysaccharide binding protein (LBP), the latter of which is thought to reflect inflammation caused by endotoxemia. RESULTS: LBP level was not significantly different between patients with and without bacteremia. No clinical factors were significantly correlated with the detection of bacteremia. On the other hand, plasma LBP level was significantly correlated with HbA1c (r = 0.312), fasting blood glucose (r = 0.279), fasting C-peptide (r = 0.265), body mass index (r = 0.371), high-density lipoprotein cholesterol (r = -0.241), and inflammatory markers (high-sensitivity C-reactive protein, r = 0.543; and interleukin-6, r = 0.456). Multiple regression analysis identified body mass index, HbA1c, high-sensitivity C-reactive protein, and interleukin-6 as independent determinants of plasma LBP level. CONCLUSION: The plasma LBP level was similar in patients with and without bacteremia. While both bacteremia and LBP are theoretically associated with bacterial translocation, the detection of bacteremia was not associated with LBP level in T2DM.

Spontaneous globule leukocyte tumor accompanied by inflammatory cells in a Wistar Hannover rat.

We encountered hematolymphoid neoplastic lesions in the form of many nodules in the spleen and liver in a 110-week-old male Wistar Hannover rat (Crl:WI (Han)). The lesions contained atypical proliferative cells, eosinophils, lymphocytes, and macrophages. The proliferative cells comprised various atypical cell types with or without cytoplasmic eosinophilic granules. The granules were positively stained using periodic acid-Schiff and elastase stains, were bluish purple using phosphotungstic acid and hematoxylin, and showed no metachromasia using toluidine blue. In immunohistochemical staining, the proliferative cells with or without granules were positive for granzyme B, rat mast cell protease II, and Ki67. Electron microscopic examination revealed that single to multiple high-density granules of variable size were covered by a membrane. These findings led to a diagnosis of globule leukocyte tumor. The accompaniment of this tumor by inflammatory cells is likely evoked by mast cell-like active mediators contained in the granules of the globule leukocytes.

Mobile-bearing total knee arthroplasty implants combined with surface cementation produced satisfactory clinical and radiographic outcomes at the 5-year follow-up.

PURPOSE: Very little is known about the use of combined surface cementation (only tibial tray) and mobile-bearing tibial components in total knee arthroplasty (TKA). This study was investigated whether the index combinations show satisfactory clinical outcomes after mobile-bearing TKA using posterior cruciate ligament (PCL)-retaining meniscal-bearing (MB) and PCL-substituting rotating-platform (RP) TKA designed using different anteroposterior constraints. METHODS: This study is a retrospective evaluation of a prospective database. Five-year postoperative clinical outcomes were assessed in 127 patients (127 knees) and 122 patients (122 knees) who underwent TKA with an MB and RP design, respectively. The Hospital for Special Surgery (HSS) score, range of motion, loosening/radiolucency, and subsidence around both components were evaluated in the two designs. RESULTS: The postoperative median HSS score was excellent in both the MB and RP groups (93 and 92, respectively). Postoperative flexion and extension did not differ between the two designs. Neither design showed > 2-mm radiolucencies raising concern for femoral or tibial implant stability. Five (2%) of 249 patients (5 knees) (MB, n = 4; RP, n = 1) showed detectable subsidence of the tibial component. However, no revision TKA had been performed by the 5-year follow-up because no patients had complaints severe enough to necessitate revision surgery. CONCLUSIONS: Clinically good outcomes comparable with previous studies were obtained 5 years after mobile-bearing TKA with surface cementation using both MB and RP implant designs. Thus, equivalent mid-term clinical outcomes of the index combination can be obtained with other implant designs and cementation techniques. LEVEL OF EVIDENCE: Level II.

Second nationwide surveillance of bacterial pathogens in patients with acute uncomplicated cystitis conducted by Japanese Surveillance Committee from 2015 to 2016: antimicrobial susceptibility of Escherichia coli, Klebsiella pneumoniae, and Staphylococcus saprophyticus.

The Japanese Surveillance Committee conducted a second nationwide surveillance of antimicrobial susceptibility patterns of uropathogens responsible for acute uncomplicated cystitis (AUC) in premenopausal patients aged 16-40 years old at 31 hospitals throughout Japan from March 2015 to February 2016. In this study, the susceptibility of causative bacteria (Escherichia coli, Klebsiella pneumoniae, Staphylococcus saprophyticus) for various antimicrobial agents was investigated by isolation and culturing of organisms obtained from urine samples. In total, 324 strains were isolated from 361 patients, including E. coli (n = 220, 67.9%), S. saprophyticus (n = 36, 11.1%), and K. pneumoniae (n = 7, 2.2%). The minimum inhibitory concentrations (MICs) of 20 antibacterial agents for these strains were determined according to the Clinical and Laboratory Standards Institute (CLSI) manual. At least 93% of the E. coli isolates showed susceptibility to fluoroquinolones and cephalosporins, whereas 100% of the S. saprophyticus isolates showed susceptibility to fluoroquinolones and aminoglycosides. The proportions of fluoroquinolone-resistant and extended-spectrum ß-lactamase (ESBL)-producing E. coli strains were 6.4% (13/220) and 4.1% (9/220), respectively. The antimicrobial susceptibility of K. pneumoniae was retained during the surveillance period, while no multidrug-resistant strains were identified. In summary, antimicrobial susceptibility results of our second nationwide surveillance did not differ significantly from those of the first surveillance. Especially the numbers of fluoroquinolone-resistant and ESBL-producing E. coli strains were not increased in premenopausal patients with AUC in Japan.

Mediolateral coronal laxity does not correlate with knee range of motion after total knee arthroplasty.

INTRODUCTION: It remains controversial whether coronal laxity after total knee arthroplasty (TKA) is a critical factor in determining clinical outcomes such as knee range of motion (ROM). The purpose of this study was to evaluate the correlation between postoperative ROM and coronal laxity, which was defined as the angular motion from the neutral, unloaded position to the loaded position, in patients with medial knee osteoarthritis undergoing TKA. MATERIALS AND METHODS: Preoperative and 1-year postoperative coronal laxity were assessed using radiographs by applying a force of 150 N with an arthrometer. A consecutive series of 204 knees was examined. A knee was defined as clinically "balanced" when the difference between medial and lateral laxity was 3° or less. Active ROM was measured using a goniometer. Values were expressed as median values. RESULTS: The ROM was 105° preoperatively and 110° postoperatively, with the correlation being weak (r = 0.372, p < 0.001) between the periods. The total laxity also revealed a weak correlation (r = 0.270, p < 0.001) between the periods. Preoperative laxity was significantly larger (4° vs. 3°) on the medial side (p < 0.001) and postoperative laxity was larger (4° vs. 3°) laterally (p = 0.001). There was no significant correlation between postoperative ROM and laxity pre- and postoperatively. Additionally, there were no differences in ROM between the balanced and unbalanced groups in the pre- and postoperative periods. CONCLUSIONS: This study indicated that mediolateral coronal laxity in patients with an osteoarthritic knee did not correlate with knee ROM after TKA when 3°-4° of laxity in the medial and lateral orientations was maintained.

Thymomas and Associated Hyperplastic Lesions in Wistar Hannover Rats.

Thymomas occur prevalently in aged Wistar Hannover (WH) rats, along with hyperplastic lesions that cannot be categorized as thymomas. We compared the histological features of hyperplastic lesions and thymomas in WH rats, the incidences of these lesions, and the relationship of these lesions to the degree of thymic involution and also compared these lesions with those of Sprague Dawley (SD) rats in 4-, 13-, 26-, and 104-week studies. There were no morphological differences between hyperplastic cells and benign tumor cells in thymomas. The histological difference between hyperplastic lesions and thymomas was the size of the proliferative areas and the number of medullary differentiation areas. The hyperplastic lesions of the thymus in WH rats might have a potential for progression to thymomas due to the observed multiple hyperplastic lesions or mixed lesions with thymomas. The incidence of these proliferative lesions in the thymus was higher in females than in males. Further, the incidence of these proliferative lesions was higher in WH rats than in SD rats. Thymic involution was more severe in males than in females and more severe in SD rats than in WH rats. The differences in involution progression may have been reflected in the incidence of thymic proliferative lesions in SD and WH rats.

Insall-Salvati ratio stabilizes one year after mobile-bearing total knee arthroplasty and does not correlate with mid-to-long-term clinical outcomes.

PURPOSE: It has not been established whether changes in the length of the patellar tendon (LPT) after total knee arthroplasty (TKA) affect clinical outcomes. Therefore, this prospective cohort study aimed to evaluate changes in the LPT over time postoperatively and clarify their impact on clinical outcomes after bilateral TKA, performed with differently designed mobile-bearing (meniscal-bearing and rotating-platform) implants on contralateral knees. METHODS: 51 patients who required staged bilateral mobile-bearing TKA were recruited. LPT was evaluated by measuring the Insall-Salvati ratio (ISR) preoperatively and at 1 week, 6 months, and 1, 2, and ≥ 5 years postoperatively. Hospital for Special Surgery score and range of motion were assessed at the final follow-up. RESULTS: Based on the ISR, there were no differences in the patterns of change between the two types of implant (n.s.). At the 6-month follow-up, the ISRs of both implants had significantly decreased (p = 0.002). Throughout the follow-up, the ISR was significantly lower (p < 0.001) for the meniscal-bearing knees than for the rotating-platform knees. After the 1-year follow-up, there were no further substantial changes in the ISR in either group. There was also no significant correlation between the ISR and clinical outcomes. CONCLUSIONS: LPT decreased after both mobile-bearing TKAs for up to 1 year postoperatively, although the decrease was more significant for the meniscal-bearing knees than the rotating-platform knees. After 1 year postoperatively, however, these conditions had stabilized, with no further changes. Thus, LPT plays a minimal role in mid-to-long-term clinical outcomes after TKA. LEVEL OF EVIDENCE: Therapeutic prospective study, Level II.

Impact of anesthesia modality and mechanical venous thromboembolism prophylaxis on the incidence of symptomatic deep venous thrombosis after TKA.

BACKGROUND: Venous thromboembolic events (VTE) are a common complication of total knee arthroplasty (TKA). Prior studies have discussed the utility of mechanical VTE prophylaxis as a monotherapy for low-risk TKA patients. We assess the incidence of clinically significant deep venous thrombosis (DVT) or pulmonary embolism (PE) in low-risk TKA patients who receive mechanical VTE prophylaxis and undergo spinal, epidural, or general anesthesia for their surgery. METHODS: A retrospective study was performed on consecutive low-risk patients who received a TKA between July 2002 and June 2015 with spinal anesthesia (n = 65), epidural and general anesthesia (n = 154), or general anesthesia alone (n = 152). Patients with spinal anesthesia had mechanical VTE prophylaxis until 15 h postoperatively, when remobilization was permitted. Patients who received epidural or general anesthesia had mechanical VTE prophylaxis for 2 h postoperatively. Notable outcomes included development of clinically symptomatic DVT or PE, patient demographics, and perioperative lab values. Statistical analysis was performed using SPSS 22, with chi-squared and Fisher's exact tests for categorical variables and the Kruskal-Wallis test with Scheffe's method for continuous variables. RESULTS: No clinically symptomatic DVT or PE was diagnosed. Patient demographics were equivocal. A statistically significant decrease in prothrombin and activated partial thromboplastin times were noted in the general anesthesia group, but all measurements were within the normal range. CONCLUSIONS: A short course of mechanical VTE prophylaxis may be appropriate for low-risk patients who can immediately mobilize.

Morphological and immunohistochemical diversity of endometrial stromal sarcoma in rats.

To clarify the histopathological characteristics of rat endometrial stromal sarcoma (ESS), we morphologically reviewed 12 malignant uterine tumors protruding into the lumen in previous rat carcinogenicity studies. The 12 cases were classified into the following 6 types based on their morphological features: spindle cell and collagen rich type, pleomorphic/spindle cell and compact type, decidual alteration type, histiocytic and multinucleated giant cell mixture type, Antoni A-type schwannoma type, and Antoni B-type schwannoma type. Immunohistochemically, tumor cells in all cases exhibited focal or diffuse positive reactions for vimentin, and 11 of the 12 cases were positive for S-100. Interestingly, 9 cases were positive for desmin or αSMA, indicating tumor cells expressing smooth muscle properties. Both Antoni A- and B-type schwannoma types showed low reactions for both muscle markers. Positive results for estrogen receptor α in the 11 cases suggested that they were derived from endometrial stromal cells. On the basis of their immunohistochemical profiles, they were considered to be derived from endometrial stromal cells while they showed morphological variation. The detection of a basement membrane surrounding tumor cells might not be a definitive indicator for differential diagnosis of ESS from malignant schwannoma. In conclusion, ESS could exhibit wide morphological and immunohistochemical variation including features of schwannoma or smooth muscle tumor.

Tibial component coverage and rotational alignment accuracy after mobile-bearing total knee arthroplasty.

BACKGROUND: Tibial component coverage (TCC) and tibial rotational angle (TRA) have been studied simultaneously in simulations, but not in clinical studies after total knee arthroplasty (TKA). The purposes of this study were (1) to evaluate TCC and rotational setting postoperatively in mobile-bearing TKA patients and (2) to compare the results with previously published simulation data. METHODS: We prospectively examined 100 patients who underwent primary TKA using the LCS® Total Knee System (LCS) posterior cruciate ligament-substituting prosthesis. Clinical outcomes, TCC (coverage area of the tibial component over the tibia), and TRA (relative to the femoral transepicondylar axis (TEA)) were assessed. Quantitative three-dimensional computed tomography was used to assess TCC and TRA. All values are expressed as median (25th percentile, 75th percentile) using minus (-) for internal and plus (+) for external rotation. RESULTS: Hospital for Special Surgery scores improved from 46 (36, 50) preoperatively to 92 (90, 92) postoperatively. TRA showed a median divergence of - 2.0° (- 4.75°, + 2.74°). All knees were located within 10° of the TEA (range - 10.0° to + 9.7°). The median TCC of the knees was 82.7% (80.6, 84.7%), and there were no knees that hung over the tibial component in any direction. CONCLUSIONS: The LCS prosthesis had good clinical outcomes, comparable TCC, and improved TRA as compared to previous reports, as all knees were located within 10° of the TEA. Simultaneous optimization of both TCC and TRA may contribute to the excellent long-term outcomes that have been observed with this system. LEVEL OF EVIDENCE: Level II, Prognostic study.