Primary hemiarthroplasty for the elderly patient with cognitive dysfunction and a displaced femoral neck fracture: a prospective, observational cohort study

BACKGROUND

At least one-third of hip fracture patients have some degree of impaired cognitive status, which may complicate their postoperative rehabilitation.

AIM

We aimed to describe the outcome for elderly patients with cognitive dysfunction operated with hemiarthroplasty (HA) for a femoral neck fracture and to study the impact postoperative geriatric rehabilitation has on functional outcome up to 1 year after surgery.

METHODS

98 patients with a displaced femoral neck fracture with a mean age of 86 years were included and followed up to 1 year. The outcomes were hip-related complications and reoperations, the capacity to return to previous walking ability, health-related quality of life, hip function and mortality.

RESULTS

The prevalence of hip complications leading to a major reoperation was 6% and the 1-year mortality rate was 31%. The lack of geriatric rehabilitation was correlated with poorer outcomes overall and those who receive geriatric rehabilitation were less likely to be confined to a wheelchair or bedridden at the 1-year follow-up.

CONCLUSIONS

Hemiarthroplasty is an acceptable option for elderly patients with a displaced femoral neck fracture and cognitive dysfunction. A lack of structured rehabilitation is associated with a significant deterioration in walking ability despite a well-functioning hip. However, the causality of this could be due to selection bias of healthier patients being sent to geriatric rehabilitation.

Grief and loss in old age: Exploration of the association between grief and depression

BACKGROUND

The proportion of older adults is increasing due to demographic changes. Depression belongs to the most common mental disorders in late life. The loss of an emotionally significant person is a risk factor for the development of depression. The aim of this study is to analyze the association between depression and grief burden resulting from loss. Based on prior evidence, we examined loneliness as a possible mediator and social support as possible moderator of this association.

METHODS

The cross-sectional analyses are based on a sample (N = 863) of study participants aged 75+ (M = 81.4 years, SD = 4.4, 62.2% female) with loss experience deriving from the multicenter prospective German cohort study AgeMooDe. Regression analyses (moderated mediation) were performed.

RESULTS

With increasing age (β = 0.10, p = .005) and grief burden (β = 0.33, p <. 001) depression severity increased. There was an indirect mediating effect of loneliness on the correlation of grief burden and depression (b = 0.04, CI [0.03, 0.05]), but no moderating effect of social support on the correlation of grief burden and loneliness. People living alone had a significantly higher risk of depression, increased loneliness and lack of social support.

LIMITATIONS

Assessments were based on self-reporting and recorded dimensionally. The cross-sectional design limits conclusions about directions and causality of associations. Sampling bias cannot be completely excluded.

CONCLUSION

The study provides empirical evidence and a better understanding of the association between grief and depression among the very old and the mediating role of loneliness.

Postnatally acquired CMV meningitis diagnosed via BioFire FilmArray: A case report

Postnatally acquired cytomegalovirus (CMV) is commonly acquired via breast milk, with premature infants more frequently developing symptoms of CMV infection in comparison to term infants. Meningitis is a rare clinical manifestation of CMV infection. The diagnosis of meningitis is difficult to make in infants, particularly those who are preterm. Consequentially, broad-spectrum empiric antimicrobial coverage is often administered for several days while waiting for current gold standard CSF testing to result. The BioFire FilmArray (BFA) simultaneously tests for 14 different pathogens, including CMV, allowing for quicker diagnosis and shorter time to definitive treatment. Here, we report a very low birth weight infant with postnatally acquired CMV meningitis, the first to our knowledge to be diagnosed using the BioFire FilmArray.

The influence of depression on patient-reported outcomes for hip-fracture patients 1 year after surgery: a prospective cohort study

BACKGROUND

Depression is common in elderly hip-fracture patients and together with cognitive impairment is associated with increased risk of mortality.

AIM

We aimed to examine the influence depression has on patient-reported outcome up to 1 year after acute hip fracture.

METHODS

162 hip-fracture patients participated in the prospective observational cohort study and were followed up at baseline, and 3 and 12 months using patient-reported outcome scores. Patients with cognitive impairment were excluded. Depression was defined as a score ≥ 8 on the depression subscale of the Hospital Anxiety Depression Scale (HADS D), having a diagnosis of depression or being treated with anti-depressant medication. Hip function was assessed using Harris Hip Score (HHS), EQ-5D was used to assess health status and Quality of life, and the Pain Numerical Rating Scale (PRNS) was used to assess pain levels. A linear regression model adjusted for group, age, sex, and ASA class was used to identify risk factors for functional outcome 12 months after fracture.

RESULTS

35 patients were included in the depression group versus 127 in the control group. No statistical differences were found in the demographic data (age, sex, ASA class, fracture type, operation method, living situation, activities of daily living ADL and clinical pathway) between the groups. In the regression model, we found no correlation between depression and the patient-reported outcome.

CONCLUSION

In young elderly hip fracture patients without cognitive dysfunction, depression may not be of major importance for the rehabilitation of hip function in the short term.

HOPE-Trial: Hemiarthroplasty Compared with Total Hip Arthroplasty for Displaced Femoral Neck Fractures in Octogenarians: A Randomized Controlled Trial

Background

The choice of primary hemiarthroplasty or total hip arthroplasty in patients ≥80 years of age with a displaced femoral neck fracture has not been adequately studied. As the number of healthy, elderly patients ≥80 years of age is continually increasing, optimizing treatments for improving outcomes and reducing the need for secondary surgery is an important consideration. The aim of the present study was to compare the results of hemiarthroplasty with those of total hip arthroplasty in patients ≥80 years of age.

Methods

This prospective, randomized, single-blinded trial included 120 patients with a mean age of 86 years (range, 80 to 94 years) who had sustained an acute displaced femoral neck fracture <36 hours previously. The patients were randomized to treatment with hemiarthroplasty (n = 60) or total hip arthroplasty (n = 60). The primary end points were hip function and health-related quality of life at 2 years. Secondary end points included hip-related complications and reoperations, mortality, pain in the involved hip, activities of daily living, surgical time, blood loss, and general complications. The patients were reviewed at 3 months and 1 and 2 years.

Results

We found no differences between the groups in terms of hip function, health-related quality of life, hip-related complications and reoperations, activities of daily living, or pain in the involved hip. Hip function, activities of daily living, and pain in the involved hip deteriorated in both groups compared with pre-fracture values. The ability to regain previous walking function was similar in both groups.

Conclusions

We found no difference in outcomes after treatment with either hemiarthroplasty or total hip arthroplasty in active octogenarians and nonagenarians with a displaced femoral neck fracture up to 2 years after surgery. Hemiarthroplasty is a suitable procedure in the short term for this group of patients.

Level of Evidence

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Influences on students' empathy in medical education: an exploratory interview study with medical students in their third and last year

BACKGROUND

Empathy is beneficial for patients and physicians. It facilitates treatment and improves physical and psychosocial outcomes. The therapeutic relevance of empathy emphasizes the need to help medical students develop their empathic abilities. Our study aimed to identify factors which promote or hinder the development and expression of empathy in medical students during the course of their studies.

METHODS

We interviewed 24 medical students (six male and six female students in their 6th semester as well as six male and six female students in their final clinical year) using semi-structured interviews. The interviews were recorded, transcribed verbatim and analyzed using Braun & Clarke's thematic analysis.

RESULTS

We identified four main themes influencing the development and expression of empathy. 1) Course of studies: hands-on-experience, role models, science and theory, and emphasis on the importance of empathy; 2) students: insecurities and lack of routine, increasing professionalism, previous work experiences, professional distance, mood, maturity, and personal level of empathy; 3) patients: "easy" and "difficult" patients including their state of health; and 4) surrounding conditions: time pressure/stress, work environment, and job dissatisfaction.

CONCLUSIONS

The development and use of empathy could be promoted by increasing: hands-on-experiences, possibilities to experience the patient's point of view and offering patient contact early in the curriculum. Students need support in reflecting on their actions, behavior and experiences with patients. Instructors need time and opportunities to reflect on their own communication with and treatment of patients, on their teaching behavior, and on their function as role models for treating patients empathically and preventing stress. Practical experiences should be made less stressful for students. The current changes implemented in some medical school curriculums (e.g., in Germany) seem to go in the right direction by integrating patient contact early on in the curriculum and focusing more on teaching adequate communication and interaction behaviors.

Abstract P2-09-09: Polyligand profiling differentiates cancer patients according to their benefit of treatment

Introduction: Deconvolution of multi-nodal perturbations in cancer network architecture demands highly multiplexed profiling assays. We demonstrate the value of polyligand profiling of tumor systems states using libraries of single stranded oligodeoxynucleotides (ssODN) to distinguish between tumor tissue from breast cancer patients who did or did not derive benefit from treatment regimens containing trastuzumab.

Methods: This study included cases from women with invasive breast cancer who received chemotherapy+ trastuzumab (C+T) or trastuzumab monotherapy with available retrospective data on the time to next treatment (TTNT). A library of 2x1012 unique ssODN was exposed to FFPE tissues from patients who benefited (B) or not (NB) from trastuzumab-based regimens in several rounds of positive and negative selection. Two enriched libraries were screened on independent set of 42 B and 19 NB cases using a modified IHC protocol for detection of bound ssODNs. Poly-Ligand Profiles (PLP) were scored by a blinded pathologist. Two libraries, EL-NB and EL-B, showed significant p-values between groups of responders and non-responders. A Cox-PH model was fitted using either tumors' HER2 status or PLP test results as the independent variable. Median survival time was calculated from the Kaplan-Meier estimate. A separate group of 63 cases with TTNT data from chemotherapy without trastuzumab was used as a control to distinguish prognostic from predictive performance.

Results: The PLP scores of EL-NB and EL-B were assessed by receiver operating characteristic (ROC) curves and resulted in a combined AUC value of 0.81. EL-NB and EL-B were able to effectively classify B and NB patients with either HER2-negative/equivocal (AUC = 0.73) or HER2-positive cancers (AUC = 0.84). In contrast, HER2 status alone yielded an AUC value of 0.47. The combined PLP scores for the independent set of 63 patients treated with C excluding trastuzumab resulted in an AUC value of 0.53, indicating that the assay was predictive and not simply prognostic. Kaplan-Meier curves analysis shows that PLP+ cases have 429 days median TTNT, while PLP- cases have 129 days (HR = 0.38, log-rank p = 0.001). Analysis based on HER2 status showed no significant difference in TTNT between patients that were HER2+ (280 days) or HER2-negative/equivocal (336 days, HR = 1.27, log-rank p =0.45).

Summary: Performance of the PLP assay in differentiating patients who did or did not benefit from trastuzumab therapy outperforms the standard IHC assay for HER2 status. These results represent a promising step towards the development of a CDx to identify the 50-70% of HER2+ patients who will not benefit from trastuzumab. In addition, PLP also has the potential to identify the HER2-negative/equivocal patients who may benefit from trastuzumab-containing regimens.

Citation Format: Domenyuk V, Gatalica Z, Santhanam R, Wei X, Stark A, Kennedy P, Toussaint B, Levenberg S, Wang R, Xiao N, Greil R, Rinnerthaler G, Gampenrieder S, Heimberger AB, Berry DJ, Barker A, Demetri GD, Quackenbush J, Marshall JL, Poste G, Vacirca JL, Vidal GA, Schwartzberg LS, Halbert DD, Voss A, Miglarese MR, Famulok M, Mayer G, Spetzler D. Polyligand profiling differentiates cancer patients according to their benefit of treatment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-09.

Artificial intelligence for analyzing orthopedic trauma radiographs

Background and purpose - Recent advances in artificial intelligence (deep learning) have shown remarkable performance in classifying non-medical images, and the technology is believed to be the next technological revolution. So far it has never been applied in an orthopedic setting, and in this study we sought to determine the feasibility of using deep learning for skeletal radiographs. Methods - We extracted 256,000 wrist, hand, and ankle radiographs from Danderyd's Hospital and identified 4 classes: fracture, laterality, body part, and exam view. We then selected 5 openly available deep learning networks that were adapted for these images. The most accurate network was benchmarked against a gold standard for fractures. We furthermore compared the network's performance with 2 senior orthopedic surgeons who reviewed images at the same resolution as the network. Results - All networks exhibited an accuracy of at least 90% when identifying laterality, body part, and exam view. The final accuracy for fractures was estimated at 83% for the best performing network. The network performed similarly to senior orthopedic surgeons when presented with images at the same resolution as the network. The 2 reviewer Cohen's kappa under these conditions was 0.76. Interpretation - This study supports the use for orthopedic radiographs of artificial intelligence, which can perform at a human level. While current implementation lacks important features that surgeons require, e.g. risk of dislocation, classifications, measurements, and combining multiple exam views, these problems have technical solutions that are waiting to be implemented for orthopedics.

Comparison of metal ion concentrations and implant survival after total hip arthroplasty with metal-on-metal versus metal-on-polyethylene articulations

Background and purpose - Large metal-on-metal (MoM) articulations are associated with metal wear and corrosion, leading to increased metal ion concentrations and unacceptable revision rates. There are few comparative studies of 28-mm MoM articulations with conventional metal-on-polyethylene (MoP) couplings. We present a long-term follow-up of a randomized controlled trial comparing MoM versus MoP 28-mm articulations, focused on metal ions and implant survival. Patients and methods - 85 patients with a mean age of 65 years at surgery were randomized to a MoM (Metasul) or a MoP (Protasul) bearing. After 16 years, 38 patients had died and 4 had undergone revision surgery. 13 patients were unavailable for clinical follow-up, leaving 30 patients (n = 14 MoM and n = 16 MoP) for analysis of metal ion concentrations and clinical outcome. Results - 15-year implant survival was similar in both groups (MoM 96% [95% CI 88-100] versus MoP 97% [95% CI 91-100]). The mean serum cobalt concentration was 4-fold higher in the MoM (1.5 μg/L) compared with the MoP cohort (0.4 μg/L, p < 0.001) and the mean chromium concentration was double in the MoM (2.2 μg/L) compared with the MoP cohort (1.0 μg/L, p = 0.05). Mean creatinine levels were similar in both groups (MoM 93 μmol/L versus MoP 92 μmol/L). Harris hip scores differed only marginally between the MoM and MoP cohorts. Interpretation - This is the longest follow-up of a randomized trial on 28-mm MoM articulations, and although implant survival in the 2 groups was similar, metal ion concentrations remained elevated in the MoM cohort even in the long term.

More complications with uncemented than cemented femoral stems in total hip replacement for displaced femoral neck fractures in the elderly

Background and purpose - Total hip replacement (THR) is the preferred method for the active and lucid elderly patient with a displaced femoral neck fracture (FNF). Controversy still exists regarding the use of cemented or uncemented stems in these patients. We compared the effectiveness and safety between a modern cemented, and a modern uncemented hydroxyapatite-coated femoral stem in patients 65-79 years of age who were treated with THR for displaced FNF. Patients and methods - In a single-center, single-blinded randomized controlled trial, we included 69 patients, mean age 75 (65-79) and with a displaced FNF (Garden III-IV). 35 patients were randomized to a cemented THR and 34 to a reverse-hybrid THR with an uncemented stem. Primary endpoints were: prevalence of all hip-related complications and health-related quality of life, evaluated with EuroQol-5D (EQ-5D) index up to 2 years after surgery. Secondary outcomes included: overall mortality, general medical complications, and hip function. The patients were followed up at 3, 12, and 24 months. Results - According to the calculation of sample size, 140 patients would be required for the primary endpoints, but the study was stopped when only half of the sample size was included (n = 69). An interim analysis at that time showed that the total number of early hip-related complications was substantially higher in the uncemented group, 9 (among them, 3 dislocations and 4 periprosthetic fractures) as compared to 1 in the cemented group. The mortality and functional outcome scores were similar in the 2 groups. Interpretation - We do not recommend uncemented femoral stems for the treatment of elderly patients with displaced FNFs.

Abstract P4-12-08: Use of an aptamer library based next generation omics platform for the development of a novel trastuzumab predictive assay

Introduction: Previous attempts to use individual aptamers as diagnostic reagents have failed to consistently achieve performance comparable to antibodies. Here we report a novel systems biology approach using poly-ligand aptamer libraries to identify responders and non-responders to traztuzumab-based regimens in metastatic breast cancer.

Methods: To overcome the fundamental limitation of the individual aptamer binding affinities, large libraries (106 species) were created so that potentially thousands of aptamers could bind to each of a multitude of targets related to the whole cellular changes in response to trastuzumab therapy. A set of breast cancer patients, which received trastuzumab mono- or combined therapy for at least 7 months were classified as “Responders” (R); cases with particular regimen discontinued in the period not exceeding 5 months were classified as “Non-Responders”(NR). A library of 2x1012 unique 90-mer ssDNA oligodeoxynucleotides (ssODN) was trained on FFPE tissue of both R and NR patients. Partitioning of aptamer libraries was done by microdissection of the tumor tissue, after incubation of aptamer library with the entire tissue section, to drive selection pressure toward cancer cells. A total of 10 cases of R and NR, 6 Her2+ cases each, were used to train separate aptamer libraries, with 1 positive and 2 counter selection cases per enrichment. Enriched libraries were screened on 20 R and 20 NR cases (11 Her2+ cases each) by adopting modified immunohistochemistry protocol. Each library was used as an independent reagent (similar to an antibody in IHC) across all 40 cases to evaluate the efficacy of the aptamer library to distinguish differences between the R and NR groups. Staining (DAB chromogen) profiles were scored from 0 to 3+ (nuclear and cytoplasmic staining) by a pathologist without any knowledge of the clinical outcomes. Initial validation was done by t-test using raw histological scores. Four libraries showed significant p-values between groups of responders and non-responders, a classification algorithm was constructed and evaluated using area under the receiver-operator characteristic curve (AUC). The datasets of two best-performing libraries were combined into one model using logistic regression to further improved the classifier performance.

Results: Of seventeen trained libraries, eight were evaluated and four showed significant correlation to clinical benefit with a minimum accuracy of 75% for each library when evaluated independently. Furthermore, two libraries showed exceptional performance (ROC curve AUC of 0.86 and 0.77). Combination of the profiling data from these two libraries using logistic regression resulted in an AUC of 0.985. A prospective validation of aptamer histochemical theranostic testing has been initiated.

Summary: Enriched aptamer libraries appear to distinguish trastuzumab responsiveness in metastatic breast cancer. This technology could be used as an additional technique beyond FISH testing to determine sensitivity to anti-HER2 agents. The demonstrated platform is applicable to virtually any disease where the safe and effective use of corresponding drug is yet to be improved.

Citation Format: Spetzler D, Domenyuk V, Santhanam R, Wei X, Stark A, Wang J, Gatalica Z, Miglarese M, Vidal G, Schwartzberg LS. Use of an aptamer library based next generation omics platform for the development of a novel trastuzumab predictive assay [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-08.

Waiting time to surgery is correlated with an increased risk of serious adverse events during hospital stay in patients with hip-fracture: A cohort study

BACKGROUND

Hip fractures are common in the elderly and are associated with a high adverse event and mortality rate. Time to surgery is one of the major modifiable risk factors influencing adverse outcomes in hip-fracture patients. National guidelines and recommendations have been introduced which advocate specific time frames in which surgery should be performed i.e. within 24-48h. These time constraints have been arbitrarily set without being modelled on the linear assumption i.e. that risk increases continually over time and not within specific cut-off times.

OBJECTIVES

To investigate how waiting time to surgery influenced the risk of serious adverse events in hip-fracture patients during the hospital stay and to examine how the risk increased over time.

DESIGN

An observational single cohort study Participants 576 patients (72.4% females, mean [SD] age 82 [10]) years, with a hip fracture were included in the cohort study.

METHODS

The outcomes of the study were the occurrence of serious adverse events during hospital stay, length of stay and one-year mortality. A structured medical record review was carried out to identify outcomes and mortality data was obtained from the Swedish National Death Registry. Waiting time to surgery was used as the exposure variable and age, sex, type of fracture, comorbidities using the American Society of Anaesthesiologists classification score and the presence of cognitive dysfunction were identified as confounders. A logistic regression analysis was performed to identify risk factors influencing outcomes.

RESULTS

A total of 119 patients (20.6%) suffered 397 (range 1-5) serious adverse events during hospital stay. Every 10h of waiting time to surgery increased the risk of serious adverse events by 12% (odds ratio 1.12 [95% confidence interval 1.02-1.23]). We found no optimal cut-off times for waiting time to surgery. For every 24h of waiting time, the length of stay from surgery was increased by 0.6days (95% CI 0.1-1.1). We found no correlation between waiting time to surgery and one-year mortality.

CONCLUSIONS

A large proportion of patients suffered from at least one serious adverse event after hip-fracture surgery and there are no safe limits for waiting time to surgery for hip-fracture patients. As the risk increases with every hour of waiting time, patients with higher American Society of Anesthesiologists classification scores, males and those with subtrochanteric fractures should be prioritized for surgery.

A validation of the Swedish version of the WORC index in the assessment of patients treated by surgery for subacromial disease including rotator cuff syndrome

Background

The Western Ontario Rotator Cuff Index (WORC) is a widely used instrument to measure quality of life in patients with subacromial pain or rotator cuff syndrome.

The purpose of this study was to evaluate the psychometric properties of the Swedish version of the WORC for assessment of subacromial disease including rotator cuff syndrome treated by surgery.

Methods

A total of 65 patients were included in this study, mean age 60 years (range 36–82), 42 % women, all were candidates for surgery for subacromial pain conditions at two orthopedic units during 2004–2006 and 2011–2012. Calculations of the validity of Pearson’s correlation coefficient, floor and ceiling effects, reliability and responsiveness have formed the basis of assessment of the WORC index properties. WORC has been tested against Western Ontario Osteoarthritis of the Shoulder (WOOS), Oxford Shoulder Score and EQ-5D.

An additional 49 patients, mean age 64 years (range 36–74) 20 % of whom were women, were analyzed in a WORC test-retest with ICC and also correlated to Constant-Murley Score.

Results

The validity analysis of WORC showed high correlations with both the specific and the generic health measurement instrument. The reliability calculations of the WORC resulted in ICC = 0.97 and Cronbach’s alpha = 0.97. Responsiveness was also excellent for WORC with Effect size = 1.35 and Standardized Response mean = 1.01. We found that the WORC showed a strong correlation with the WOOS (0.97) and the Constant-Murley Score (0.85). A good correlation was found with the Oxford Shoulder Score (0.74) and the EQ-5D (0.71).

Conclusions

The Swedish version of WORC can be considered reliable, valid and responsive for use as an assessment of outcome and a health measurement instrument for patients treated by surgery for subacromial disease including rotator cuff syndrome.

Abstract P6-12-14: Comparative analysis of breast cancer phenotypes in African American, White American, and African patients- Correlation between African ancestry and triple negative breast cancer

Introduction: Population-based incidence rates of triple negative breast cancer (TNBC) are higher for African American (AA) compared to White American (WA) women, but it is unclear whether TNBC risk is genetically associated with African ancestry because AA women represent an ancestrally admixed population. Higher frequencies of TNBC have also been observed in sub-Saharan African breast cancer (BC) patients, but comparative analyses of biomarker expression among datasets that include AA, WA, and African women are sparse. We report findings from an international registry that features specimens from a diverse patient population in Detroit, Michigan as well as a hospital in Kumasi, Ghana.

Methods: The study dataset included formalin-fixed, paraffin-embedded invasive BC tumors diagnosed between 1998 and 2014 at the Komfo Anokye Teaching Hospital in Ghana and the prospectively-maintained/annotated Henry Ford Health System cohort in Michigan. All Ghanaian tumors underwent pathology confirmation and immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR) and HER2/neu expression at the University of Michigan. Women were classified into five BC phenotypes and dichotomized into two age groups, &lt;50 and ≥50 years. Polychotomous multivariate GLM models were developed to estimate the risk for each BC phenotype. Statistical analyses were performed in SAS v. 9.0 (Carey, NC). This research was approved by the Institutional Review Boards of the participating institutions.

Results: A total of 234 Ghanaian cases with mean age 49 years (range 24-92); 271 AA with mean age 60 (range 27-87); and 321 WA with mean age 62 (range 31-91) (P=0.001) contributed to this study. Prevalence of histologic grade 3 was lowest in WA (n=107, 33.7%) which was statistically significant from the observed prevalence in AA (n=135, 50.4%) and Ghanaians (n=84, 53.8%) (P&lt;0.0001). ER-negative and TNBC were more common among Ghanaian and AA compared to WA cases (frequency ER-negativity 67.5%, 37.1%, and 19.8%, respectively, p&lt;0.0001; frequency TNBC 53.2%, 29.8%, and 15.5%, respectively, p&lt;0.0001). In the age group &lt;50 years, 82 women (42.5%) were diagnosed with ER+/PR+/HER2-, 65 (33.7%) with TNBC, 27 (14.0%) with ER+/PR+/HER2+, 14 (7.2%) with ER-/PR-/HER2+ and 5(2.6%) with ER-/PR+/HER2- phenotypes. In this young age group, prevalence of TNBC remained highest among Ghanaian women (50.8%), followed by AA (34.3%) and WA (15.9%); (P=.0006). In contrast, highest prevalence of ER+/PR+/HER2+ and ER+/PR+/HER2- phenotypes was observed in WA, followed by AA and Ghanaians. On multivariate analysis histologic grade 3 and racial heritage remained statistically significantly associated with the TNBC phenotype (OR for AA vs. WA with TNBC 1.87, 95% CI 1.15-3.04; OR for Ghanaian vs. WA with TNBC 10.63, 95% CI 5.32-21.25; OR for Grade 3 vs Grade 1 histology with TNBC 33.3, 95% CI 13.45-82.4).

Conclusions: This study confirms an association between the TNBC phenotype and African ancestry; furthermore, extent of African ancestry appears to be associated with an increased likelihood of having a TNBC tumor, since frequency of TNBC among AA patients was intermediate between WA and Ghanaian patients.

Citation Format: Newman LA, Jiagge E, Bensenhaver JM, Chitale D, Kleer C, Merajver S, Kyei I, Aitpillah F, Oppong J, Amankwaa-Frempong E, Adjei E, Wicha M, Awuah B, Stark A. Comparative analysis of breast cancer phenotypes in African American, White American, and African patients- Correlation between African ancestry and triple negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-14.

Abstract P2-01-08: Adaptive dynamic artificial poly-ligand targeting: Aptamer-based profiling of liquid biopsies to improve the accuracy of breast cancer diagnoses in women with dense breast tissue

Introduction:

Breast cancer screening relies upon mammography, but for women with dense breast tissue this method is often uninformative. Routine screening identifies suspicious breast lesions in some women, but the pain and risk associated with follow-up biopsies along with the poor accuracy of traditional histopathology urgently call for improved approaches to breast cancer screening. This is especially important for those high-risk patients for whom mammography is of limited value. We describe a non-invasive liquid biopsy method of profiling plasma exosome preps designed to improve the accuracy and safety of breast cancer screening for women with dense breast tissue.

Results:

We incubated plasma samples (300 microliters per sample) from breast cancer patients (n=60) and a control cohort (n=60) with a high-complexity DNA aptamer library using a modified SELEX scheme, termed “adaptive dynamic artificial poly-ligand targeting (ADAPTTM)”. Differentially bound (cancer vs. non-cancer) aptamers were recovered from precipitated exosomes and were identified by deep sequencing. Two thousand aptamer sequences were resynthesized and used to probe a larger set of 500 plasma samples from a patient cohort (n=206) and a control cohort comprised of self-reported healthy volunteers (n=117) and patients whose biopsies led to a diagnosis of non-cancer (n=177). We employed several statistical models to build a cancer/non-cancer predictor, including a Random Generalized Linear Model (RGLM) and a Random Forest Model (RFM). Both models yielded an equivalent classification performance with areas under the receiver-operator characteristic curve (ROC AUC) of 0.7. Testing the prediction performance by 100 Out-of-Bag permutations or by pre-filtered (read cutoff and estimated sample size) cross-validation (CV) resulted in ROC AUC values of 0.66 and 0.62, respectively. When samples were randomly assigned to groups, the aptamers were no longer able to distinguish the groups (ROC AUC = 0.54), indicating that the underlying information driving the model is truly specific to cancer. Importantly, incorporation of BIRAD results as a clinical covariate did not influence model performance, signifying that predictions by ADAPTTM were independent of breast tissue density.

Conclusions:

We have identified a set of 2000 DNA aptamers that distinguish women with breast cancer from women without breast cancer. Our liquid biopsy approach requires only 300 microliters of plasma and is amenable to high-throughput processing. By employing a number of statistical approaches including rigorous cross-validation, we consistently achieve cross validation ROC AUC values approaching 0.7. The performance of the predictor was not affected by BIRAD scores, supporting its potential utility in difficult cases where imaging is insufficient, such as in women with dense breast tissue. Further optimization of the aptamer library and testing on additional samples should improve performance. Upon complete validation, an ADAPTTM – derived breast cancer test may serve as a vital diagnostic adjunct that can be easily incorporated into standard clinical practice.

Citation Format: Domenyuk V, Zhong Z, Wang J, Stark A, Chen W, Xiao N, Miglarese MR, Famulok M, Mayer G, Spetzler DB. Adaptive dynamic artificial poly-ligand targeting: Aptamer-based profiling of liquid biopsies to improve the accuracy of breast cancer diagnoses in women with dense breast tissue. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-01-08.

Increased Long-Term Cardiovascular Risk After Total Hip Arthroplasty: A Nationwide Cohort Study

Total hip arthroplasty is a common and important treatment for osteoarthritis patients. Long-term cardiovascular effects elicited by osteoarthritis or the implant itself remain unknown. The purpose of the present study was to determine if there is an increased risk of late cardiovascular mortality and morbidity after total hip arthroplasty surgery.A nationwide matched cohort study with data on 91,527 osteoarthritis patients operated on, obtained from the Swedish Hip Arthroplasty Register. A control cohort (n = 270,688) from the general Swedish population was matched 1:3 to each case by sex, age, and residence. Mean follow-up time was 10 years (range, 7-21).The exposure was presence of a hip replacement for more than 5 years. The primary outcome was cardiovascular mortality after 5 years. Secondary outcomes were total mortality and re-admissions due to cardiovascular events.During the first 5 to 9 years, the arthroplasty cohort had a lower cardiovascular mortality risk compared with the control cohort. However, the risk in the arthroplasty cohort increased over time and was higher than in controls after 8.8 years (95% confidence interval [CI] 7.0-10.5). Between 9 and 13 years postoperatively, the hazard ratio was 1.11 (95% CI 1.05-1.17). Arthroplasty patients were also more frequently admitted to hospital for cardiovascular reasons compared with controls, with a rate ratio of 1.08 (95% CI 1.06-1.11).Patients with surgically treated osteoarthritis of the hip have an increased risk of cardiovascular morbidity and mortality many years after the operation when compared with controls.

Lower periprosthetic bone loss and good fixation of an ultra-short stem compared to a conventional stem in uncemented total hip arthroplasty

BACKGROUND AND PURPOSE

We hypothesized that an ultra-short stem would load the proximal femur in a more physiological way and could therefore reduce the adaptive periprosthetic bone loss known as stress shielding.

PATIENTS AND METHODS

51 patients with primary hip osteoarthritis were randomized to total hip arthroplasty (THA) with either an ultra-short stem or a conventional tapered stem. The primary endpoint was change in periprosthetic bone mineral density (BMD), measured with dual-energy x-ray absorptiometry (DXA), in Gruen zones 1 and 7, two years after surgery. Secondary endpoints were change in periprosthetic BMD in the entire periprosthetic region, i.e. Gruen zones 1 through 7, stem migration measured with radiostereometric analysis (RSA), and function measured with self-administered functional scores.

RESULTS

The periprosthetic decrease in BMD was statistically significantly lower with the ultra-short stem. In Gruen zone 1, the mean difference was 18% (95% CI: -27% to -10%). In zone 7, the difference was 5% (CI: -12% to -3%) and for Gruen zones 1-7 the difference was also 5% (CI: -9% to -2%). During the first 6 weeks postoperatively, the ultra-short stems migrated 0.77 mm more on average than the conventional stems. 3 months after surgery, no further migration was seen. The functional scores improved during the study and were similar in the 2 groups.

INTERPRETATION

Up to 2 years after total hip arthroplasty, compared to the conventional tapered stem the ultra-short uncemented anatomical stem induced lower periprosthetic bone loss and had equally excellent stem fixation and clinical outcome.

No effect of risedronate on femoral periprosthetic bone loss following total hip arthroplasty. A 4-year follow-up of 61 patients in a double-blind, randomized placebo-controlled trial

BACKGROUND AND PURPOSE

We have previously shown that during the first 2 years after total hip arthroplasty (THA), periprosthetic bone resorption can be prevented by 6 months of risedronate therapy. This follow-up study investigated this effect at 4 years.

PATIENTS AND METHODS

A single-center, double-blind, randomized placebo-controlled trial was carried out from 2006 to 2010 in 73 patients with osteoarthritis of the hip who were scheduled to undergo THA. The patients were randomly assigned to receive either 35 mg risedronate or placebo orally, once a week, for 6 months postoperatively. The primary outcome was the percentage change in bone mineral density (BMD) in Gruen zones 1 and 7 in the proximal part of the femur at follow-up. Secondary outcomes included migration of the femoral stem and clinical outcome scores.

RESULTS

61 of the 73 patients participated in this 4-year (3.9- to 4.1-year) follow-up study. BMD was similar in the risedronate group (n = 30) and the placebo group (n = 31). The mean difference was -1.8% in zone 1 and 0.5% in zone 7. Migration of the femoral stem, the clinical outcome, and the frequency of adverse events were similar in the 2 groups.

INTERPRETATION

Although risedronate prevents periprosthetic bone loss postoperatively, a decrease in periprosthetic BMD accelerates when therapy is discontinued, and no effect is seen at 4 years. We do not recommend the use of risedronate following THA for osteoarthritis of the hip.

Larger femoral periprosthetic bone mineral density decrease following total hip arthroplasty for femoral neck fracture than for osteoarthritis: a prospective, observational cohort study

Studies on patients with degenerative joint disease of the hip show that femoral periprosthetic bone mineral decreases following total hip arthroplasty. Scarcely any osteodensitometric data exist on femoral neck fracture (FNF) patients and periprosthetic bone remodelling. In two parallel cohorts we enrolled 87 patients (mean age, 72 ± 12 years; male:female ratio, 30:57) undergoing total hip arthroplasty for either primary osteoarthritis (OA) of the hip (n = 37) or for an acute FNF (n = 50) and followed them for a mean of 5.4 years. Outcomes were bone mineral density (BMD) changes in the periprosthetic Gruen zones 1-7, the incidence of periprosthetic fractures and clinical outcome. The bone mineral loss in the fracture group was more than twice that of the osteoarthritis group, -16.9% versus -6.8% (p = 0.004). The incidence of periprosthetic fractures was 12% (6/50) in the fracture cohort compared with none (0%) in the OA cohort (p = 0.03). Periprosthetic bone mineral loss following total hip arthroplasty is significantly greater in patients who are treated for acute FNF than in OA patients. This decrease of BMD follows a different pattern with the FNF patients losing larger proportions of bone in Gruen zones 1, 2, 6, and 7 while the OA patients tend to have larger losses only in zones 1 and 7.

High risk of early periprosthetic fractures after primary hip arthroplasty in elderly patients using a cemented, tapered, polished stem

BACKGROUND AND PURPOSE

Postoperative periprosthetic femoral fracture (PPF) after hip arthroplasty is associated with considerable morbidity and mortality. We assessed the incidence and characteristics of periprosthetic fractures in a consecutive cohort of elderly patients treated with a cemented, collarless, polished and tapered femoral stem (CPT).

PATIENTS AND METHODS

In this single-center prospective cohort study, we included 1,403 hips in 1,357 patients (mean age 82 (range 52-102) years, 72% women) with primary osteoarthritis (OA) or a femoral neck fracture (FNF) as indication for surgery (367 hips and 1,036 hips, respectively). 64% of patients were ASA class 3 or 4. Hip-related complications and need for repeat surgery were assessed at a mean follow-up time of 4 (1-7) years. A Cox regression analysis was used to evaluate risk factors associated with PPF.

RESULTS

47 hips (3.3%) sustained a periprosthetic fracture at median 7 (2-79) months postoperatively; 41 were comminute Vancouver B2 or complex C-type fractures. The fracture rate was 3.8% for FNF patients and 2.2% for OA patients (hazard ratio (HR) = 4; 95% CI: 1.3-12). Patients > 80 years of age also had a higher risk of fracture (HR = 2; 95% CI: 1.1-4.5).

INTERPRETATION

We found a high incidence of early PPF associated with the CPT stem in this old and frail patient group. A possible explanation may be that the polished tapered stem acts as a wedge, splitting the femur after a direct hip contusion. Our results should be confirmed in larger, registry-based studies, but we advise caution when using this stem for this particular patient group.

In situ synchrotron radiation measurements of orthorhombic phase formation in an advanced TiAl alloy with modulated microstructure

New low aluminium high niobium TiAl alloys exhibit a nano scale modulated microstructure consisting of lamellae with a tweed substructure. These tweed like appearing lamellae are a modulated arrangement of at least two phases. One constituent of the crystallographic modulation in the lamellae is an orthorhombic phase, which is closely related to both the hexagonal α2-Ti3Al phase and the cubic B2 ordered βo-TiAl phase.

In this study the nature and formation of this orthorhombic phase has been investigated by high-energy X-ray diffraction.

Measurements have shown that the newly formed orthorhombic phase is structurally comparable to the O phase (Ti2AlNb). It forms in the temperature range of 550 °C to 670 °C from the α2 phase by small atomic displacements and chemical reordering. The in situ experiments yielded information about the thermal stability of the orthorhombic phase. After dissolving at temperatures above 700 °C the phase can be re-precipitated by annealing within the temperature range of formation.

2- to 9-year outcome of stemmed total knee arthroplasty. Similar failure rates in patients when used primary or as a revision

BACKGROUND AND PURPOSE

There is an increase in demand for primary and revision total knee joint procedures. We studied implant survival and functional outcome of patients operated with a constrained condylar knee (CCK) or a rotating hinge implant (RH) as a primary or a revision total knee arthoplasty (TKA).

PATIENTS AND METHODS

We evaluated clinically and radiographically 65 surgical procedures with a mean follow-up time of 5 (2-9) years (40 CCK and 25 RH). There were 24 primary TKAs-due to instability-and 41 revision TKAs, mostly due to aseptic loosening. Mean age at the index operation was 68 (31-88) years.

RESULTS

Overall, there were 12 failures, including 8 reoperations due to deep infection. The overall 5-year survival rate with reoperation as the endpoint was 82% (95% CI: 72-99). Radiolucent lines on either the femoral or the tibial side were seen in 36 cases. When comparing the cases that were operated as a primary TKA or as a revision TKA, function, health-related quality of life, and survival were similar. However, after primary TKA the patients generally had less pain and a higher proportion of patients were very satisfied or satisfied.

INTERPRETATION

Although a high rate of severe complications was observed, most patients improved in function after surgery regardless of whether it was a primary or a revision TKA. We found narrow radiolucent lines-mainly on the tibial side-in nearly half of the cases, but none of the implants were loose radiographically. Overall patient satisfaction and health-related quality of life were high, and a minority had problems with persistent pain.

Solid-ionic liquid interfaces: pore filling revisited

The properties of ionic liquids on ordered and non-ordered mesoporous silicas (silica gel, MCM-41, SBA-15) were studied by nitrogen sorption, mercury intrusion and thermogravimetric analyses, as well as (129)Xe-NMR spectroscopy. The ionic liquids investigated are based on the 1-hexyl-3-methylimidazolium cation, which was combined with anions of low (bis(trifluoromethanesulfonyl)imide; [NTf2](-)), medium (trifluoromethylsulfonate; [CF3SO3](-)) to high (acetate; [OAc](-)) basicity. The surface coverage depends on both the type of ionic liquid and support used. This results not only in layer or droplet formation, but also in different physico-chemical properties of the ionic liquid when compared to the bulk, depending mainly on the strength of interaction at the interface. Furthermore, the mercury intrusion analysis of mesopores is shown not to be suitable for supported ionic liquids.

Unstable hip arthroplasties. A prospective cohort study on seventy dislocating hips followed up for four years

PURPOSE

Dislocating hip prosthesis remains a substantial clinical problem. The aim of this study is to describe the risk of recurrent instability after a primary dislocation of primary hip arthroplasty performed for osteoarthritis (OA) or femoral neck fracture (FNF).

METHODS

Seventy patients (male/females: 25/45; mean age 77 [range 46-94]) with dislocating hip arthroplasties were included in a prospective cohort study and followed for four years. Radiographs and all surgical records were reviewed. We compared stable hips to those who either continued to dislocate or were revised due to recurrent instability (unstable group).

RESULTS

Forty-two hips (60 %) had episodes of recurrent instability leading to repeated closed reductions or major revision surgery and were classified as unstable. A diagnosis of FNF and cognitive dysfunction (OR 9.3 [95 % CI 1.4-64.1]) or postoperative radiological discrepancies such as leg-lengthening and offset reduction increased the risk of further instability (OR 13.5 [95 % CI 1.3-148.1]). The surgical approach at primary surgery and ASA class did not significantly influence the risk of continued instability.

CONCLUSIONS

Patients with a FNF and cognitive dysfunction or with sub-optimal postoperative radiographs after hip arthroplasty surgery are at high risk of recurrent instability after a primary dislocation. For hip fracture patients, all efforts should be made to avoid the first dislocation.

Porous titanium construct cup compared to porous coated titanium cup in total hip arthroplasty. A randomised controlled trial

PURPOSE

The purpose of this study was to determine if a new titanium cup with increased porosity resulted in different periacetabular bone loss and migration compared to a porous coated cup.

METHODS

Fifty-one patients with primary hip osteoarthritis were randomized to either a cup with porous titanium construct backside (porous titanium group, n = 25) or a conventional porous coated titanium cup (control group, n = 26). The primary outcome variable was change in periacetabular bone mineral density two years after surgery measured with dual energy X-ray absorptiometry (DXA). Secondary outcomes were implant fixation measured with radiostereometry (RSA) and clinical outcome scores.

RESULTS

The pattern of bone remodelling was similar in the two groups with almost complete restoration to baseline values. BMD diminished in the two proximal zones and increased in the two distal zones. After minimal migration up to six months all implants in both groups became stable. We found no difference between the two groups in clinical outcome scores.

CONCLUSIONS

In this prospective, randomized, controlled trial on a new porous titanium cup we found, compared to the control group, no clinically relevant differences regarding periacetabular bone preservation, implant fixation or clinical outcome up to two years postoperatively.

Good stability but high periprosthetic bone mineral loss and late-occurring periprosthetic fractures with use of uncemented tapered femoral stems in patients with a femoral neck fracture

BACKGROUND AND PURPOSE

We previously evaluated a new uncemented femoral stem designed for elderly patients with a femoral neck fracture and found stable implant fixation and good clinical results up to 2 years postoperatively, despite substantial periprosthetic bone mineral loss. We now present the medium-term follow-up results from this study.

PATIENTS AND METHODS

In this observational prospective cohort study, we included 50 patients (mean age 81 (70-92) years) with a femoral neck fracture. All patients underwent surgery with a cemented cup and an uncemented stem specifically designed for fracture treatment. Outcome variables were migration of the stem measured with radiostereometry (RSA) and periprosthetic change in bone mineral density (BMD), measured with dual-energy X-ray absorptiometry (DXA). Hip function and health-related quality of life were assessed using the Harris hip score (HHS) and the EuroQol-5D (EQ-5D). DXA and RSA data were collected at regular intervals up to 4 years, and data concerning reoperations and hip-related complications were collected during a mean follow-up time of 5 (0.2-7.5) years.

RESULTS

At 5 years, 19 patients had either passed away or were unavailable for further participation and 31 could be followed up. Of the original 50 patients, 6 patients had suffered a periprosthetic fracture, all of them sustained after the 2-year follow-up. In 19 patients, we obtained complete RSA and DXA data and no component had migrated after the 2-year follow-up. We also found a continuous total periprosthetic bone loss amounting to a median of -19% (-39 to 2). No changes in HHS or EQ-5D were observed during the follow-up period.

INTERPRETATION

In this medium-term follow-up, the stem remained firmly fixed in bone despite considerable periprosthetic bone mineral loss. However, this bone loss might explain the high number of late-occurring periprosthetic fractures. Based on these results, we would not recommend uncemented femoral stems for the treatment of femoral neck fractures in the elderly.

Neutron and synchrotron probes in the development of Co–Re-based alloys for next generation gas turbines with an emphasis on the influence of boron additives

Nickel-based superalloys are the materials of choice in the hot section of current gas turbines, but they are reaching temperature limits constrained by their melting temperature range. Co–Re alloy development was prompted by a search for new materials for future gas turbines, where the temperature of application will be considerably higher. Addition of the very high melting point refractory metal Re to Co can increase the melting range of Co alloys to much higher temperatures than the commercial Co alloys in use today. The alloy development strategy is first discussed very briefly. In this program, model ternary and quaternary compositions were studied in order to develop a basic understanding of the alloy system.In situneutron and synchrotron measurements (small and wide angle) at high temperatures were extensively used for this purpose and some selected results from thein situmeasurements are presented. In particular, the effect of boron doping in Co–Re–Cr alloys and the stability of the TaC precipitates at high temperatures were investigated. A fine dispersion of TaC precipitates strengthens some Co–Re alloys, and their stability at the application temperature is critical for the long-term creep properties.

Age- and health-related quality of life after total hip replacement: decreasing gains in patients above 70 years of age

BACKGROUND

While age is a common confounder, its impact on health-related quality of life (HRQoL) after total hip replacement is uncertain. This could be due to improper statistical modeling of age in previous studies, such as treating age as a linear variable or by using age categories. We hypothesized that there is a non-linear association between age and HRQoL.

METHODS

We selected a nationwide cohort from the Swedish Hip Arthroplasty Register of patients operated with total hip replacements due to primary osteoarthritis between 2008 and 2010. For estimating HRQoL, we used the generic health outcome questionnaire EQ-5D of the EuroQol group that consits or 2 parts: the EQ-5D index and the EQ VAS estimates. Using linear regression, we modeled the EQ-5D index and the EQ VAS against age 1 year after surgery. Instead of using a straight line for age, we applied a method called restricted cubic splines that allows the line to bend in a controlled manner. Confounding was controlled by adjusting for preoperative HRQoL, sex, previous contralateral hip surgery, pain, and Charnley classification.

RESULTS

Complete data on 27,245 patients were available for analysis. Both the EQ-5D index and EQ VAS showed a non-linear relationship with age. They were fairly unaffected by age until the patients were in their late sixties, after which age had a negative effect.

INTERPRETATION

There is a non-linear relationship between age and HRQoL, with improvement decreasing in the elderly.

Colostrogenesis during an induced lactation in dairy cattle

Colostrum immunoglobulin G (IgG) is of major importance for the newborn calf because epitheliochorial placentae do not provide transport in utero. The formation of colostrum occurs in the later stages of pregnancy. Our objectives were to induce lactation in non-pregnant dairy cows and (i) to determine the changes of IgG in serum and mammary secretions during the induction process and (ii) to establish α-lactalbumin (αLA) and prolactin (Prl) alterations to monitor the changing mammary epithelial tight junction status and development pattern. Estradiol-17β (E2) and progesterone (P4) injections in a 1-7 days series were combined with a 3-day injection series (day 21-23) of dexamethasone (DEX). Blood and both front quarter secretion samples were collected daily. Milking started 24 days after the start of the experiment. Results show that the mammary secretory IgG1 was increased at >7 days after the start of steroid injections and depicted a bimodal pattern reaching a high of 16 mg/ml at 21 day compared with 3.2 mg/ml in the serum. There was a small increase in secretory IgG2 that did not correlate with tight junction status, but never reached the serum concentration. The injections of DEX resulted in constriction of tight junctions. Secretory αLA was immediately increased with steroid injections, dropped precipitously after 7 days and then began a steady increase until the start of milking. Changes in serum αLA are related to mammary tight junctions while serum Prl gradually increased from 30 to >60 ng/ml after the steroid injections stopped. These results provide insights into the mechanisms and timing of colostrogenesis during an induced lactation protocol.

Measurement of the migration of a focal knee resurfacing implant with radiostereometry

BACKGROUND AND PURPOSE

Articular resurfacing metal implants have been developed to treat full-thickness localized articular cartilage defects. Evaluation of the fixation of these devices is mandatory. Standard radiostereometry (RSA) is a validated method for evaluation of prosthetic migration, but it requires that tantalum beads are inserted into the implant. For technical reasons, this is not possible for focal articular resurfacing components. In this study, we therefore modified the tip of an articular knee implant and used it as a marker for RSA, and then validated the method.

MATERIAL AND METHODS

We modified the tip of a resurfacing component into a hemisphere with a radius of 3 mm, marked it with a 1.0-mm tantalum marker, and implanted it into a sawbone marked with 6 tantalum beads. Point-motion RSA of the "hemisphere bead" using standard automated RSA as the gold standard was compared to manual measurement of the tip hemisphere. 20 repeated stereograms with gradual shifts of position of the specimen between each double exposure were used for the analysis. The tip motion was compared to the point motion of the hemisphere bead to determine the accuracy and precision.

RESULTS

The accuracy of the manual tip hemisphere method was 0.08-0.19 mm and the precision ranged from 0.12 mm to 0.33 mm.

INTERPRETATION

The accuracy and precision for translations is acceptable when using a small hemisphere at the tip of a focal articular knee resurfacing implant instead of tantalum marker beads. Rotations of the implant cannot be evaluated. The method is accurate and precise enough to allow detection of relevant migration, and it will be used for future clinical trials with the new implant.

Abstract P6-11-04: Profound prevention of experimental brain metastases of breast cancer by temozolomide in a MGMT-dependent manner

Purpose: Brain metastases of breast cancer cause neurocognitive damage and are incurable. We evaluated in experimental brain metastasis model a role of temozolomide, an oral brain permeable alkylating agent characterized by significant uptake in the central nervous system, in the prevention of brain metastases of breast cancer.

Material and methods: To assess preventive role of temozolomide, mice were inoculated with 175,000 triple-negative 231-BR-EGFP cells in 0.1 mL PBS in the left ventricle of the heart. Three days after tumor cell inoculation, mice were randomized to temozolomide at the dose of 50 mg/kg delivered by oral gavage in saline, 5 days a week for 4 weeks, or vehicle. Subsequent experiments used temozolomide doses of 25, 10, 5, 1 and 0.5 mg/kg. To evaluate the efficacy of temozolomide in treating established BM, mice received temozolomide (50 mg/kg) beginning on either day 18 or day 24 post-injection of 231-BR-EGFR cells, 5 days a week for two and one week, respectively. To investigate the impact of temozolomide on survival, mice injected with 231-BR-EGFP cells were randomized to vehicle, temozolomide on days 3-14, or temozolomide on days 17-28 post-injection, per the schedule described above. To determine the functional contribution of MGMT expression in the BM preventive model, similar experiments were performed using 231-BR-EGFP cells with induced MGMT expression, and MGMT-positive Jimt-1 cells. Metastases were counted in step sections of one hemisphere of each brain. Additionally, the percentage of MGMT-positive tumor cells in 62 patient-matched sets of breast cancer primary tumors and resected brain metastases was determined immunohistochemically.

Results: Temozolomide, when dosed at 50, 25, 10 or 5 mg/kg, 5 days/week, beginning 3 days after inoculation, completely prevented the formation of experimental brain metastases from MGMT-negative 231-BR-EGFP cell line. At a 1 mg/kg dose, temozolomide prevented 68% of large brain metastases, and was ineffective at a dose of 0.5 mg/kg. When the 50 mg/kg dose was administered beginning on days 18 or 24, temozolomide efficacy was reduced or absent. Both schedules of temozolomide (days 3-14 and days 17-28) significantly increased survival (P = .0003 by long-rank test). Earlier administration of temozolomide resulted in long term survival of 6 and 2 out of 10 mice, respectively; a significant difference compared to vehicle (P &lt; .0001 and .0003, respectively).Temozolomide was ineffective at preventing brain metastases in the MGMT-positive 231-BR-EGFP and Jimt-BR3 sublines. In 62 patient-matched sets of primary breast tumors and resected brain metastases 43.5% of the specimens had concordant low MGMT expression, while in another 14.5% sets high MGMT staining in the primary tumor corresponded with low staining in the brain metastasis.

Conclusions: Temozolomide profoundly prevents the outgrowth of experimental brain metastases of breast cancer in a MGMT-dependent manner. The majority of patients had low MGMT expressing brain metastases. These data provide a compelling rationale for investigating preventive efficacy of temozolomide in high-risk advanced breast cancer patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-04.

The influence of comorbidity scores on re-operations following primary total hip replacement: comparison and validation of three comorbidity measures

While an increasing amount of arthroplasty articles report comorbidity measures, none have been validated for outcomes. In this study, we compared commonly used International Classification of Diseases-based comorbidity measures with re-operation rates after total hip replacement (THR). Scores used included the Charlson, the Royal College of Surgeons Charlson, and the Elixhauser comorbidity score. We identified a nationwide cohort of 134 423 THRs from the Swedish Hip Arthroplasty Register. Re-operations were registered post-operatively for up to 12 years. The hazard ratio was estimated by Cox's proportional hazards regression, and we used C-statistics to assess each measure's ability to predict re-operation. Confounding variables were age, gender, type of implant fixation, hospital category, hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant relationship with increased risk of re-operation, with increased scores for both one to two and three or more comorbidities. However, the predictive C-statistic in this period for the Elixhauser score was poor (0.52). None of the measures proved to be of any value between two and 12 years. They might be of value in large cohort or registry studies, but not for the individual patient.

Dynamic Recovery and Recrystallization during Hot-Working in an Advanced TiAl Alloy

Intermetallic TiAl alloys are light-weight high-temperature materials and intended to partly replace Ni based alloys in jet engines. Due to difficult forming operations, component prices are high and limit the possible field of application. During hot-working, recovery and recrystallization effects determine the microstructural evolution and thereby the mechanical properties of the finished part as well as its behavior during deformation. To study the occurring phenomena, in-situ diffraction experiments with high-energy X-rays were conducted. By means of this method, the dominating processes were identified. The results were validated through electron back scatter diffraction experiments.

Objective evaluation by reflectance spectrophotometry can be of clinical value for the verification of blanching/non blanching erythema in the sacral area

Early detection of non blanching erythema (pressure ulcer category I) is necessary to prevent any further skin damage. An objective method to discriminate between blanching/non blanching erythema is presently not available. The purpose of this investigation was to explore if a non invasive objective method could differentiate between blanching/non blanching erythema in the sacral area of patients undergoing hip fracture surgery. Seventy-eight patients were included. The sacral area of all patients was assessed using (i) conventional finger-press test and (ii) digital reading of the erythema index assessed with reflectance spectrophotometry. The patients were examined at admission and during 5 days postsurgery. Reflectance spectrophotometry measurements proved able to discriminate between blanching/non blanching erythema. The reliability, quantified by the intra-class correlation coefficient, was excellent between repeated measurements over the measurement period, varying between 0·82 and 0·96, and a significant change was recorded in the areas from day 1 to day 5 (P < 0·0001). The value from the reference point did not show any significant changes over the same period (P = 0·32). An objective method proven to identify early pressure damage to tissue can be a valuable tool in clinical practice.

Colostrogenesis: candidate genes for IgG1 transcytosis mechanisms in primary bovine mammary epithelial cells

Bovine colostrogenesis is distinguished by the specific transfer of IgG1 from the blood to mammary secretions. The process has been shown to be initiated by hormones and occurs during the last weeks of pregnancy when steroid concentrations of estradiol (E2 ) and progesterone (P4 ) are highly elevated. Rodent intestinal uptake of immunoglobulin G is mediated by a receptor termed Fc fragment of IgG, Receptor, Transporter, alpha (FcGRT) and supported by light chain Beta-2-Microglobulin (β2M). We hypothesized that steroid hormone treatments (E2 and P4 ) of bovine mammary epithelial cells in vitro would induce up-regulation of IgG1 transcytosis candidate gene mRNA expression suggesting involvement in IgG1 transcytosis. Two different primary bovine mammary epithelial cell cultures were cultured on plastic and rat tail collagen and treated with hormonal combinations (steroids/lactogenic hormones). Evaluated mRNA components were bLactoferrin (bLf: a control), bFcGRT, β2M, and various small GTPases; the latter components are reported to direct endosomal movements in eukaryotic cells. All tested transcytosis components showed strong expression of mRNA in the cells. Expression of bFcGRT, bRab25 and bRhoB were significantly up-regulated (p < 0.05) by steroid hormones. bRab25 and bRhoB showed increased expression by steroid treatments, but also with lactogenic hormones. Analysis for the oestrogen receptor (ER) mRNA was mostly negative, but 25% of the cultures tested exhibited weak expression, while the progesterone receptor (PR) mRNA was always detected. bRab25 and bRhoB and likely bFcGRT are potential candidate genes for IgG1 transcytosis in bovine mammary cells.

Abstract P4-13-12: Identifying women at increased risk for breast cancer using the electronic health record in an integrated health system

Women at increased risk for breast cancer (BC) are eligible to take selective estrogen receptor modulators (SERMs) to reduce their risk; Food and Drug Administration (FDA) approval of tamoxifen or raloxifene for BC risk reduction and American Society of Clinical Oncology (ASCO) guidelines for the use of SERMs recommend the two drugs for any woman over the age of 35 years with a 5-year risk of 1.67% or greater, but identifying those women can be both challenging and costly. We used an electronic database (Centricity RIS-IC) from the Geisinger Health System (GHS) Department of Radiology with 77,000 women ages 35–90 years to calculate 5-year and lifetime risks of developing invasive BC using National Cancer Institute's (NCI) Breast Cancer Risk Assessment Macro (BrCa RAM). BrCa RAM calculates risk based on patient age, number of biopsies, did a biopsy ever display atypical hyperplasia (Yes/No), age at menarche, age at first live birth, number of first degree relatives with breast cancer, and patient race. Demographic information (age, race, sex) was obtained from the electronic health record (EpicCare), pathology information (number of biopsies, atypical hyperplasia) was obtained from the pathology application (CoPath), and personal history (number of first degree relatives with breast cancer) were obtained from RIS. Age at menarche and age at first live birth could not be obtained, but makes a small relative contribution to the risk of BC. Sensitivity analysis explored implications of missing data; imputing ages for age at first live birth and age at menarche showed that the absence of this data did not overestimate the five-year and lifetime risks. There were 5,897 patients with calculated 5-year breast cancer risk 2; mean age was 65.8 years, mean 5-yr risk of BC = 3.05% (max 18.2%). The number of patients by 5-year risk score category were: risk 2–2.5% (n = 1728); 2.5%–3% (n = 3188); 3%+ (n = 981). There were 4,196 patients with a GHS primary care physician (PCP); 5,086 patients had seen any Geisinger physician within the past year; 4,113 women had seen their PCP in the past year. Only 239 patients ever received a prescription for tamoxifen or raloxifene, and some received raloxifene for prevention or treatment of osteoporosis and not for BC risk reduction. Only 40 were currently taking tamoxifen or raloxifene. These data from an integrated health system with an electronic health record validate the under-utilization of SERMs for primary BC risk reduction. Strategies are being designed to increase their use in GHS by using the risk score to identify the population and attempt to intervene using a risk modification clinical program.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-13-12.

Dual-mobility cups for revision due to instability are associated with a low rate of re-revisions due to dislocation: 228 patients from the Swedish Hip Arthroplasty Register

BACKGROUND AND PURPOSE

Revision total hip arthroplasty (THA) due to recurrent dislocations is associated with a high risk of persistent instability. We hypothesized that the use of dual-mobility cups would reduce the risk of re-revision due to dislocation after revision THA.

PATIENTS AND METHODS

228 THA cup revisions (in 228 patients) performed due to recurrent dislocations and employing a specific dual-mobility cup (Avantage) were identified in the Swedish Hip Arthroplasty Register. Kaplan-Meier survival analysis was performed with re-revision due to dislocation as the primary endpoint and re-revision for any reason as the secondary endpoint. Cox regression models were fitted in order to calculate the influence of various covariates on the risk of re-revision.

RESULTS

58 patients (25%) had been revised at least once prior to the index cup revision. The surgical approach at the index cup revision was lateral in 99 cases (44%) and posterior in 124 cases (56%). Median follow-up was 2 (0-6) years after the index cup revision, and by then 18 patients (8%) had been re-revised for any reason. Of these, 4 patients (2%) had been re-revised due to dislocation. Survival after 2 years with the endpoint revision of any component due to dislocation was 99% (95% CI: 97-100), and it was 93% (CI: 90-97) with the endpoint revision of any component for any reason. Risk factors for subsequent re-revision for any reason were age between 50-59 years at the time of the index cup revision (risk ratio (RR) = 5 when compared with age > 75, CI: 1-23) and previous revision surgery to the relevant joint (RR = 1.7 per previous revision, CI: 1-3).

INTERPRETATION

The risk of re-revision due to dislocation after insertion of dual-mobility cups during revision THA performed for recurrent dislocations appears to be low in the short term. Since most dislocations occur early after revision THA, we believe that this device adequately addresses the problem of recurrent instability. Younger age and prior hip revision surgery are risk factors for further revision surgery. However, problems such as potentially increased liner wear and subsequent aseptic loosening may be associated with the use of such devices in the long term.