Electric-Field-Driven Nanosecond Ferroelastic-Domain Switching Dynamics in Epitaxial Pb(Zr,Ti)O_{3} Film.

Epitaxial oxide ferroelectric films exhibit emerging phenomena arising from complex domain configurations even at pseudoequilibrium, including the creation of domain states unfavored in nature and abrupt piezoelectric coefficients around morphotropic phase boundaries. The nanometer-sized domain configurations and their domain switching dynamics under external stimuli are directly linked to the ultrafast manipulation of ferroelectric thin films; however, complex domain switching dynamics under homogeneous electric fields has not been fully explored, especially at the nanosecond timescale. This Letter reports the nanosecond dynamics of ferroelastic-domain switching from the 90° to 180° direction using time-resolved x-ray microdiffraction under homogeneous electric fields onto an epitaxial Pb(Zr_{0.35},Ti_{0.65})O_{3} film capacitor. It is found that the application of electric fields induces spatially heterogeneous domain switching processes via intermediate domain structures with rotated polarization vectors. In addition, the domain switching time is shown to be inversely proportional to the magnitude of the applied electric field, and electric fields higher than 480 kV/cm are found to complete the ferroelastic switching within nanoseconds.

Technique for Preventing Troughing in Scarf Osteotomy.

Scarf osteotomy is a common operative procedure for mild-to-moderate hallux valgus. We describe a simple supportive technique that prevents troughing intraoperatively without additional bony procedures.

Anterior dislocation after a posterior stabilized total knee arthroplasty.

Dislocation of a total knee arthroplasty is a rare but serious complication. In previous literature, when dislocation does occur, it is usually in the posterior direction in cases with a posterior stabilized total knee arthroplasty due to cam jump. We report an unusual case of anterior dislocation of an 11-year-old posterior stabilized total knee arthroplasty in a 55-year-old woman with rheumatoid arthritis occurred after a slip.

Effects of zoledronic acid on bone mineral density during aromatase inhibitor treatment of Korean postmenopausal breast cancer patients.

The age distribution of breast cancer patients in Korea, where most are less than 60 years of age and have recently entered menopause, differs from that in the West. The aim of this study was to evaluate bone mineral density (BMD) changes in Korean breast cancer patients treated with an aromatase inhibitor (AI) either alone or in combination with zoledronic acid (ZA). Changes in BMD of the lumbar spine and hip were evaluated in 107 patients receiving AI treatment, of which 59 were treated in combination with ZA. The mean age of the patients was 54.9 years, and the median follow-up period was 38.2 months. With AI treatment alone, BMD loss was significant (all P < 0.0001) in the lumbar spine and hip 12 months (4.18 and 3.95%, respectively), 24 months (6.28 and 5.44%), and 36 months (8.17 and 6.82%) after treatment. In contrast, the combination treatment resulted in increased BMD in the lumbar spine and hip 12 months (2.45 and 0.89%, respectively), 24 months (3.51 and 1.03%), and 36 months (3.85 and 1.80%) after treatment. BMD loss in the lumbar spine was significantly greater in AI alone-treated women who had entered menopause within the past year compared with those who had entered menopause more than 1 year ago, when measured 12 and 24 months after treatment (P = 0.017 and 0.021, respectively). Importantly, ZA effectively inhibited AI-associated bone loss, independent of the postmenopausal interval. Because the proportion of patients in this study who had recently entered menopause was high, bone loss in Korean breast cancer patients treated with AI alone was higher than data reported from the Arimidex, Tamoxifen Alone or in Combination (ATAC) trial. In conclusion, we have shown that ZA is very effective in preventing AI-induced bone loss in Korean postmenopausal breast cancer patients.

High frequency of meniscal hypertrophy in persons with advanced varus knee osteoarthritis.

To examine the morphological changes of the medial meniscus in advanced knee osteoarthritis (OA) we examined 167 knee joints of 106 patients who subsequently underwent total knee joint arthroplasty from January to May, 2007. All 106 patients were females and their ages ranged from 57 to 83 years (mean 68.7 +/- 5.6 years). For patients with complete loss of medial joint space by weight-bearing radiography, the meniscal position was assessed by measuring meniscal subluxation and meniscal height. Meniscal morphology was assessed using a modified WORMS MRI-based method. Description of the prevalence of different meniscal morphologies and their respective positions are presented. The predominant type (32.2, 64.1 and 83.8% in anterior horn, mid-body and posterior horn, respectively) of meniscal morphology abnormality was a hypertrophied displaced tear. Medial meniscus height was found to be higher than lateral meniscus height. In persons with an hypertrophied meniscus the height of the medial meniscus was 8.06 +/- 1.15, 10.03 +/- 1.79, and 8.61 +/- 1.57 mm at anterior horn, mid-body and posterior horn, respectively, compared to those in other categories whose height was 6.04 +/- 0.92, 5.08 +/- 1.68 and 6.43 +/- 1.26 mm. A large proportion of persons with end stage varus knee OA have a paradoxically hypertrophied medial meniscus. This new finding of hypertrophied menisci highlights that not all menisci in persons with end stage OA are macerated or destroyed.

Radiographic healing with hemispherical allogeneic femoral head bone grafting for opening-wedge high tibial osteotomy.

PURPOSE: The aim of this study was to investigate the remodeling process after hemispherical femoral head allograft grafting in opening-wedge high tibial osteotomy with a plate and screw. METHODS: The study group included 105 knees in 92 women and 7 knees in 7 men from January 2007 through December 2007. The radiographic bone remodeling process was determined by use of a modification of the radiologic rating system described previously by van Hemert et al. in 4 groups: group A, 7-mm plate correction; group B, 9-mm plate correction; group C, 11-mm plate correction; and group D, 13-mm plate correction. RESULTS: The postoperative femorotibial angle and tibial slope were not significantly changed at latest follow-up in comparison to immediate postoperative status. The mean follow-up period was 25.4 months (range, 18 to 30 months). In all groups radiologic bone healing higher than phase 3 was successfully achieved between 3 and 6 months. The healing process slowed with increasing correction angle. CONCLUSIONS: A hemispherical femoral head allograft is a good alternative osseous graft material when patients are selected appropriately with the following criteria: body mass index lower than 40, no symptomatic osteoarthritis of the patellofemoral joint and lateral compartment, no systemic inflammatory arthritis, no history of fracture or previous open surgery to the lower limb, and no flexion contracture. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Rear-edge, low-diversity, and haplotypic uniformity in cold-adapted Bupleurum euphorbioides interglacial refugia populations.

The high genetic diversity of rear-edge refugia populations is predicted to have resulted from species repeatedly migrating to low latitudes during glacial periods over the course of Quaternary climate change. However, several recent empirical studies of cold-tolerant plants revealed the opposite pattern. We investigated whether current habitats of the cold-adapted and range-restricted Bupleurum euphorbioides in the Baekdudaegan, South Korea, and North Korea could be interglacial refugia, and documented how their rear-edge populations differ genetically from those of typical temperate species. Phylogeographic analysis and ecological niche modeling (ENM) were used. The genetic structure was analyzed using microsatellite markers and chloroplast DNA sequences. The congener B. longiradiatum was included as a typical temperate plant species. Despite having almost identical life history traits, these congeneric species exhibited contrasting patterns of genetic diversity. ENM revealed an apparent maximum range contraction during the last interglacial. In contrast, its range expanded northward to the Russian Far East (Primorsky) during the Last Glacial Maximum. Thus, we hypothesize that B. euphorbioides retreated to its current refugia during interglacial periods. Unlike populations in the central region, the rear-edge populations were genetically impoverished and uniform, both within populations and in pooled regional populations. The rear-edge B. euphorbioides survived at least one past interglacial, contributing to the species' genetic diversity. We believe that such genetic variation in the cold-adapted B. euphorbioides gives the species the necessary adaptations to survive an upcoming favorable environment (the next glacial), unless there is artificial environmental change.

Fractured polyethylene tibial post in a posterior-stabilized knee prosthesis presenting as a floating palpable mass.

Complications associated with posterior-stabilized total knee arthroplasty (TKA) include patellar clunk syndrome, posterior subluxation of the tibial component, tibial post wear, and tibial post failure. Recently, an increasing number of reports have been issued on polyethylene tibial post failure in posterior-stabilized TKA. In most of these cases, tibial post failure in a well-functioning posterior-stabilized TKA was suspected based on clinical symptoms, such as a sudden onset of pain, effusion, patellar clunking, knee instability, and prosthesis dislocation. However, a floating, palpable, hard, mass-like symptom in the knee joint has not been previously reported. The authors report a case of a fractured polyethylene tibial post in a posterior-stabilized TKA that manifested as a palpable mass in the suprapatellar pouch.

ACL injury while jumping rope in a patient with an unintended increase in the tibial slope after an opening wedge high tibial osteotomy.

High tibial osteotomy (HTO) is an accepted surgical technique for the treatment of medial compartmental arthrosis of the knee in younger patients. Compared to total knee arthroplasty, HTO may be a good choice in patients who wish to continue with heavy labor and/or impact sports. Based on the rehabilitation protocol after HTO, impact sports, such as running, jumping rope, and full sports activities, are generally permitted 6 months postoperatively. Jumping rope is an excellent form of aerobic exercise, and when done properly, jumping rope can lead to a dramatic improvement in rehabilitation and full sports activities. However, an adequate evaluation should be performed prior to initiating impact sports. We present the case of a ruptured anterior cruciate ligament that occurred in a patient with an unintended increase in the tibial slope after an opening wedge HTO who was jumping rope.

Clinicopathologic Characteristics and Optimal Surgical Treatment of Duodenal Gastrointestinal Stromal Tumor.

BACKGROUND: The clinicopathologic characteristics of duodenal gastrointestinal stromal tumor (GIST) were unclear and the optimal surgical procedure for duodenal GIST remains poorly defined. We aimed to analyze clinicopathological characteristics, survival outcomes based on the surgical procedure, and recommend optimal surgical treatment for duodenal GIST. METHODS: From July 2000 to April 2017, 118 patients with localized duodenal GIST underwent curative surgical resection at a single institution. We retrospectively reviewed the clinicopathological characteristics and survival outcomes. RESULTS: The 5-year overall survival (OS) and disease-free survival (DFS) rates were 94.9 and 79.2%, respectively. On multivariate analysis, the mitotic count was a statistically significant prognostic factor for DFS. Limited resection (LR) was performed in 20 patients with GIST in the first or fourth portion of the duodenum. Both LR and pancreaticoduodenectomy (PD) were performed in 98 patients with GIST in second or third portion of the duodenum. The patients in the LR group had less late complications than in the PD group and no postoperative newly developed diabetes mellitus. The minimally invasive LR (MI-LR) group had a shorter duration of surgery and shorter length of postoperative hospital stay. CONCLUSION: LR is a feasible and effective surgical treatment for patients with small-sized and antimesenteric-sided duodenal GIST in terms of late complications and postoperative diabetic complications. MI-LR has better perioperative outcomes than open LR. Therefore, we should consider MI-LR as an optimal surgical treatment for selected patients with duodenal GIST.

The 180° spin of meniscal bearing in unicompartmental knee arthroplasty.

Mobile-bearing Oxford medial unicompartmental knee arthroplasty (UKA) has been widely used and has produced good results in the treatment of medial compartmental osteoarthritis. But it is associated with the potential risk of meniscal bearing dislocation. Symptoms caused by most meniscal bearing dislocations include acute pain, knee swelling, and locking. We report two unusual cases of meniscal bearing spinning of 180° without remarkable symptoms, which would have been easily missed if we had not watched carefully. Therefore, if there is sudden locking, pain, swelling, or a slight locking history, the possibility of meniscal bearing spin out as well as meniscal bearing dislocation should be considered and the direction of meniscal bearing markers should be confirmed, especially on lateral radiographs.

Patterns and Biologic Features of p53 Mutation Types in Korean Breast Cancer Patients.

PURPOSE: The p53 gene is one of the most frequently mutated genes in breast cancer. We investigated the patterns and biologic features of p53 gene mutation and evaluated their clinical significance in Korean breast cancer patients. METHODS: Patients who underwent p53 gene sequencing were included. Mutational analysis of exon 5 to exon 9 of the p53 gene was carried out using polymerase chain reaction-denaturing high performance liquid chromatography and direct sequencing. RESULTS: A total of 497 patients were eligible for the present study and p53 gene mutations were detected in 71 cases (14.3%). Mutation of p53 was significantly associated with histologic grading (p<0.001), estrogen receptor and progesterone receptor status (p<0.001), HER2 status (p<0.001), Ki-67 (p=0.028), and tumor size (p=0.004). The most frequent location of p53 mutations was exon 7 and missense mutation was the most common type of mutation. Compared with patients without mutation, there was a statistically significant difference in relapse-free survival of patients with p53 gene mutation and missense mutation (p=0.020, p=0.006, respectively). Only p53 missense mutation was an independent prognostic factor for relapse-free survival in multivariate analysis, with an adjusted hazard ratio of 2.29 (95% confidence interval, 1.08-4.89, p=0.031). CONCLUSION: Mutation of the p53 gene was associated with more aggressive clinicopathologic characteristics and p53 missense mutation was an independent negative prognostic factor in Korean breast cancer patients.

Prognostic factors for patients with bone-only metastasis in breast cancer.

PURPOSE: Bone is the most frequent site of metastasis among breast cancer patients. We investigated prognostic factors affecting survival following bone-only metastasis in breast cancer patients. MATERIALS AND METHODS: The medical records of breast cancer patients who were treated and followed at Gangnam Severance Hospital retrospectively reviewed to identify patients with bone-only metastasis. RESULTS: The median time from the diagnosis of bone-only metastasis to the last follow-up or death was 55.2 [95% confidence interval (CI), 38.6-71.9] months. The Kaplan-Meier overall survival estimate at 10 years for all patients was 34.9%. In the multivariate Cox regression model, bisphosphonate treatment [hazard ratio=0.18; 95% CI, 0.07-0.43], estrogen receptor positivity (hazard ratio=0.51; 95% CI, 0.28-0.94), and solitary bone metastasis (hazard ratio=0.32; 95% CI, 0.14-0.72) were significantly associated with longer overall survival in the bone-only recurrence group. Among the treatment modalities, only bisphosphonate treatment was identified as a significant prognostic factor. CONCLUSION: Identifying the factors influencing breast cancer mortality after bone-only metastasis will help clarify the clinical course and improve the treatment outcome for patients with breast cancer and bone-only metastasis. Bisphosphonates, as a significant prognostic factor, warrant further investigation.

The difference in prognostic factors between early recurrence and late recurrence in estrogen receptor-positive breast cancer: nodal stage differently impacts early and late recurrence.

BACKGROUND: Probability of recurrence in patients with estrogen receptor (ER)-positive breast cancer remains constant for long periods. We compared tumor burden impact on late versus early recurrence in our cohort with long-term follow-up. METHODS: Five hundred and ninety five patients diagnosed with ER-positive breast cancer between 1989 and 2001 were classified into three groups: early recurrence within 5 years, late recurrence after 5 years, and no recurrence. We identified prognostic factors among the groups using logistic regression analysis. RESULTS: At median follow-up of 11.7 years, among 595 ER-positive women, 98 (16.4%) had early recurrence and 58 (9.7%) had late recurrence. On multivariate analysis, higher nodal stage (N0 vs. N2, odds ratio [OR] 3.189; N0 vs. N3, OR 9.948), higher histologic grade (grade 1 vs. grade 2, OR 3.896; grade 1 vs. grade 3, OR 5.945), age >35 years (OR 0.295), and receiving endocrine therapy (OR 0.293) affected early recurrence. Compared to no recurrence, receiving endocrine therapy (OR 0.285) was solely related to decreased risk of late recurrence. Increased risk of early recurrence was noted with the higher nodal stage when early and no recurrences were compared. This phenomenon was not found in late recurrence. In the last comparison between the early and late recurrence, higher nodal stage (N0 vs. N3, OR 16.779) and higher histologic grade (grade 1 vs. grade 3, OR 18.111) repeatedly weighted for early recurrence. CONCLUSIONS: Nodal burden had an attenuated influence on late recurrence, which suggests that, unlike early recurrence, tumor biology might have a more important role than tumor load for late recurrence in ER-positive disease.

Clinical outcomes of ductal carcinoma in situ of the breast treated with partial mastectomy without adjuvant radiotherapy.

PURPOSE: Some recent trials suggest that postoperative adjuvant radiotherapy (RT) may be safely omitted after breast-conserving surgery (BCS) for some patients with ductal carcinoma in situ (DCIS). In this study, we reviewed clinical outcomes of patients with DCIS treated with partial mastectomy (PM) without adjuvant RT. MATERIALS AND METHODS: Medical records of 28 patients (29 breasts) with DCIS who were treated with PM, but without RT, between April 1991 and December 2010 were retrospectively analyzed. Based on established criteria (2.0 cm or less in size and no comedonecrosis), 18 patients were treated without RT after PM. Seven patients (8 breasts) who did not receive RT due to refusal were also included in this study. Three other patients were excluded because data concerning comedonecrosis were not available. RESULTS: For the 25 patients included in this study, the mean age of the 18 patients who met the criteria was 47.9±6.2 years, and 47.6±12.7 years for the 7 patients who did not. The mean sizes of the primary tumors were 0.6±0.4 cm and 0.9±0.3 cm, respectively, in these two groups. Among these 25 patients (26 breasts) treated without RT, we observed no ipsilateral breast tumor recurrence or mortality within a mean follow-up of 84 months. CONCLUSION: Based on this small number of cases, patients with DCIS, who were selected for tumor size less than 2 cm and absence of comedonecrosis, may be treated successfully with BCS; adjuvant RT may be omitted.

'Suture-induced tear' after human meniscal allograft transplantation.

Meniscal allograft transplantation (MAT) is generally associated with good outcomes. However, the likelihood of a successful outcome is reduced by various complications, and a meniscal tear is one of the most common of these after MAT. Meniscal tears usually occur at the periphery of the meniscal allografts at the capsular junction or the posterior horn, and biomechanical factors, such as high contact stress areas, are possible causing mechanism. We encountered three unusual cases with multiple radial or horizontal tears possibly induced by the suture materials used for meniscus allograft fixation.

The short-term follow-up results of open wedge high tibial osteotomy with using an Aescula open wedge plate and an allogenic bone graft: the minimum 1-year follow-up results.

BACKGROUND: This study examined the results of open wedge high tibial osteotomy with using an Aescula open wedge plate and an allogenic bone graft as a surgical technique for the patients who suffer from osteoarthritis of the knee with a genu varum deformity. METHODS: From March 2007 to August 2007, 33 patients (37 cases) with osteoarthritis of the knee and a genu varum deformity underwent a high tibial osteotomy with using an Aescula open wedge plate and an allogenic bone graft. The patients were followed up for more than 1 year. Before and after surgery, the correction angle of the genu varum was measured by the lower extremity scannogram and the posterior tibial slope, the joint space distance and the time to bone union were evaluated. The functional factors were evaluated using the Knee Society Score. RESULTS: The average knee score and function score improved from 52.19 +/- 11.82 to 92.49 +/- 5.10 and 52.84 +/- 6.23 to 89.05 +/- 5.53, respectively (p < 0.001). According to the lower extremity scannogram, the mean preoperative varus angle was -1.86 +/- 2.76 degrees , and the average correction angle at the last follow-up was 10.93 +/- 2.50 degrees (p < 0.001). The tibial posterior slope before surgery and at the last follow-up were 8.20 +/- 1.80 degrees and 8.04 +/- 1.30 degrees , respectively (p = 0.437). The joint space distance increased from 4.05 +/- 1.30 mm to 4.83 +/- 1.33 mm (p < 0.001). The average time to complete bone union was 12.69 +/- 1.5 weeks. CONCLUSIONS: An open wedge high tibial osteotomy using an Aescula open wedge plate and an allogeneic bone graft to treat osteoarthritis of the knee with a genu varum deformity showed good results for the precision of the correction angle, the time to bone union and the functional improvement.

Accuracy of implantation during computer-assisted minimally invasive Oxford unicompartmental knee arthroplasty: a comparison with a conventional instrumented technique.

The prognosis of unicompartmental knee arthroplasty (UKA) is strongly associated with the accuracy of the component alignment. To determine the accuracy of navigated UKA during primary minimally invasive Oxford UKA, twenty-nine knees of 29 consecutive patients (Group A) implanted using conventional instrumented UKA were followed by 23 knees of 17 consecutive patients (Group B) implanted by navigation assisted UKA and radiological results regarding alignments of the femorotibial mechanical axis, femur, and tibial component were compared in the two groups. Assessments of mechanical limb alignment revealed statistically significant increases in mechanical limb alignment post-operatively in both groups (p=0.0 for both). In terms of component alignment, Group B had more prostheses implanted in the satisfactory range (> ± 3° from the targeted values) for the femoral and tibial components than Group A. There were no significant differences in the rate of prosthesis implanted within the range of radiographic alignment variations for the coronal implantation of either femoral or tibial components in both groups. (Radiographic alignment variation; coronal orientation of femoral components 90 ± 10°, sagittal orientation of femoral components 90 ± 5°, coronal orientation of tibial components from 10° varus to 5° valgus, sagittal orientation of tibial components from 7° of posterior tibial flexion to 5° of anterior tibial flexion). However, significant increases in the accuracies of sagittal implantation of femoral and tibial components were observed in Group B versus Group A. Our data suggest that navigated implantation improves the accuracy of the radiological implantation of the Oxford UKA prosthesis without increasing complications versus conventional UKA.

Analysis of synovial fluid in culture-negative samples of suspicious periprosthetic infections.

Synovial fluid analysis can help to rule out a periprosthetic infection. The goal of this study was to evaluate the prognostic significance of synovial fluid suspicious for a periprosthetic infection given the synovial leukocyte count and percent of neutrophils. From August 2006 to November 2008, patients who had synovial fluid aspirated for painful knees and elevated C-reactive protein levels after total knee arthroplasty but revealed no growth of any microorganism were retrospectively evaluated by medical record review. Mean follow-up period was 827.7±250.6 days from the date of joint aspiration results. The optimal cut-off values for synovial leukocyte counts and percent neutrophils were determined using receiver operating characteristic curves. From a total of 56 patients, 14 were classified as having poor results. The remaining 42 patients had an uneventful clinical course with a stable prosthesis on radiographs without specific therapy during the follow-up period. The receiver operating characteristic curve showed that a synovial leukocyte count of 3600/uL had an 86% sensitivity and 79% specificity; with 89% synovial neutrophils, the sensitivity was 72% and specificity 62%. The synovial fluid leukocyte count and percent neutrophils were significant predictors of outcome in patients with cultures that were negative but suspicious for periprosthetic infections.

Acetabular screw head-induced ceramic acetabular liner fracture in cementless ceramic-on-ceramic total hip arthroplasty.

Ceramic liner fractures are rare after ceramic-on-ceramic THA. This article describes a case of an early ceramic liner fracture caused by impingement with a tilted acetabular screw head 2 months after cementless ceramic-on-ceramic THA. A 59-year-old man underwent primary THA for avascular necrosis of his right femoral head. The implant used was an Osteonics Secur-Fit HA ceramic-on-ceramic bearing system. The metal shell was fixed with 1 cancellous bone screw. During the index procedure, the acetabular screw seemed tilted in the metal shell hole, but the liner was fully seated in the metal shell without difficulty. However, 2 months later he re-presented due to pain and crepitation in the right hip. Radiographs showed that the ceramic acetabular insert had fractured. At revision, ceramic insert had fractured into large and numerous comminuted fragments, and the acetabular screw head was slightly tilted and protruded over the inner surface of the metal shell, which had worn eccentrically. The ceramic inner head and metal shell were visibly intact. Because the metal shell-bone fixation was firm, a new identical design ceramic liner and head were fitted, and no adverse event has occurred since. This case suggests that a complete check of the inside of the shell should be made when using an acetabular screw and ceramic liner. In particular, the screw head must not be tilted or left proud of the inside surface of the shell. Correct acetabular screw direction and seating are essential to avoid detrimental clinical consequences.