Search

Background: While hip resurfacing arthroplasty has been shown to be an effective prosthetic solution for end-stage osteoarthritis, prior studies have also reported an increasing concern regarding blood metal ion levels following the use of metal-on-metal articulations. The purpose of this study was to compare early and midterm blood metal ion levels to functional outcomes and implant survivorship for patients treated with the Birmingham Hip Resurfacing (BHR) implant system and the ReCap Magnum. Methods: A retrospective review identified 104 patients who underwent 134 hip resurfacing arthroplasties using BHR (n = 67) and ReCap (n = 67) at a single institution between 2006 and 2018. ReCap and BHR patients were matched 1:1 by sex, femoral head and acetabular cup sizes, age, and year of surgery. The primary outcome of interest was cobalt (Co) and chromium (Cr) ion levels. Results: The ReCap cohort had lower median metal ion levels compared to the BHR cohort at 1-2 y (Co: 1.5 vs 1.9 parts per billion [ppb], P = .018; Cr: 1.3 vs 2.8 ppb, P = .008) and 3-5 y (Co: 1.1 vs 1.9 ppb, P = .001; Cr: 1.2 vs 2.2 ppb, P = .003) after surgery. Correlation analysis showed no significant associations between Co and Cr ion levels and pre- and postoperative patient-reported outcomes. Indications for revision differed between groups. Three BHR hips were revised due to adverse reactions to metal debris, whereas 2 ReCap hips required revisions: one for instability and another for periprosthetic fracture. Conclusions: BHR patients had higher metal ion levels than ReCap patients at 1-2 and 3-5 y after surgery, though these metal levels are still low and in line with prior studies. Indications for revision differed between patients treated with BHR and ReCap. Surgeons should be aware of these outcomes when counseling patients regarding these metal-on-metal articulations.

Objective The “weekend effect” occurs when patients cared for during weekends versus weekdays experience worse outcomes. But reasons for this effect are unclear, especially amongst patients undergoing elective cervical spinal fusion (ECSF). Our aim was to analyze whether index weekend admission affects 30- and 90-day readmission rates post-ECSF. Methods All ECSF patients > 18 years were retrospectively identified from the 2016–2018 Healthcare Cost and Utilization Project Nationwide Readmissions Database (NRD), using unique patient linkage codes and International Classification of Diseases, Tenth Revision codes. Patient demographics, comorbidities, and outcomes were analyzed. Univariate logistic regression analyzed primary outcomes of 30- and 90-day readmission rates in weekday or weekend groups. Multivariate regression determined the impact of complications on readmission rates. Results Compared to the weekday group (n = 125,590), the weekend group (n = 1,026) held a higher percentage of Medicare/Medicaid insurance, incurred higher costs, had longer length of stay, and fewer routine home discharge (all p < 0.001). There was no difference in comorbidity burden between weekend versus weekday admissions, as measured by the Elixhauser Comorbidity Index (p = 0.527). Weekend admissions had higher 30-day (4.30% vs. 7.60%, p < 0.001) and 90-day (7.80% vs. 16.10%, p < 0.001) readmission rates, even after adjusting for sex, age, insurance status, and comorbidities. All-cause complication rates were higher for weekend admissions (8.62% vs. 12.7%, p < 0.001), specifically deep vein thrombosis, infection, neurological conditions, and pulmonary embolism. Conclusion Index weekend admission increases 30- and 90-day readmission rates after ECSF. In patients undergoing ECSF on weekends, postoperative care for patients at risk for specific complications will allow for improved outcomes and health care utilization.

Aims: Traditionally, acetabular component insertion during total hip arthroplasty (THA) is visually assisted in the posterior approach and fluoroscopically assisted in the anterior approach. The present study examined the accuracy of a new surgeon during anterior (NSA) and posterior (NSP) THA using robotic arm-assisted technology compared to two experienced surgeons using traditional methods. Methods: Prospectively collected data was reviewed for 120 patients at two institutions. Data were collected on the first 30 anterior approach and the first 30 posterior approach surgeries performed by a newly graduated arthroplasty surgeon (all using robotic arm-assisted technology) and was compared to standard THA by an experienced anterior (SSA) and posterior surgeon (SSP). Acetabular component inclination, version, and leg length were calculated postoperatively and differences calculated based on postoperative film measurement. Results: Demographic data were similar between groups with the exception of BMI being lower in the NSA group (27.98 vs 25.2; p = 0.005). Operating time and total time in operating room (TTOR) was lower in the SSA (p < 0.001) and TTOR was higher in the NSP group (p = 0.014). Planned versus postoperative leg length discrepancy were similar among both anterior and posterior surgeries (p > 0.104). Planned versus postoperative abduction and anteversion were similar among the NSA and SSA (p > 0.425), whereas planned versus postoperative abduction and anteversion were lower in the NSP (p < 0.001). Outliers > 10 mm from planned leg length were present in one case of the SSP and NSP, with none in the anterior groups. There were no outliers > 10° in anterior or posterior for abduction in all surgeons. The SSP had six outliers > 10° in anteversion while the NSP had none (p = 0.004); the SSA had no outliers for anteversion while the NSA had one (p = 0.500). Conclusion: Robotic arm-assisted technology allowed a newly trained surgeon to produce similarly accurate results and outcomes as experienced surgeons in anterior and posterior hip arthroplasty.

Background: This single-center retrospective cohort study aimed to evaluate and compare implant survival and patient-reported outcome measures in 2 distinct age groups separated by 20 years who underwent hip resurfacing arthroplasty (HRA). Methods: Between 2005 and 2014, 2042 HRAs were performed by a single-surgeon, and 75 and 377 hips from patients aged ≤35 years and ≥55 years, respectively, were included in this study. Implant survival was determined for all available hips. Clinical features and patient-reported outcome measures were collected. Results: Seven hips were revised, 4 for aseptic loosening of one or both components, one for infection, one for accelerated wear and metallosis, and one for femoral neck fracture. There was no difference in all-cause 10-year revision, with 97.1% (95% confidence interval 80.9 to 99.6) and 99.6% (95% confidence interval: 97 to 99.9) survivorship in younger and older patients, respectively (P = .246). Preoperatively, younger patients were less active than older patients on the Lower Extremity Activity Scale (LEAS) or University of California, Los Angeles, activity scale, but at follow-up, younger patients outpaced older ones. Conclusion: Original to our study was the isolation and comparison of 2 distinct age groups. With excellent results in disparate age groups, HRA can be applied to a broad patient demographic and is suitable for those patients who want to achieve a high activity level as defined by Lower Extremity Activity Scale or University of California, Los Angeles, scores.

Fibroblasts can be collected from deceased individuals, grown in culture, reprogrammed into induced pluripotent stem cells (iPSCs), and then differentiated into a multitude of cell types, including neurons. Past studies have generated iPSCs from somatic cell biopsies from either animal or human subjects. Previously, fibroblasts have only been successfully cultured from postmortem human skin in two studies. Here we present data on fibroblast cell cultures generated from 146 scalp and/or 53 dura mater samples from 146 postmortem human brain donors. In our overall sample, the odds of successful dural culture was almost two-fold compared with scalp (OR = 1.95, 95% CI: [1.01, 3.9], p = 0.047). Using a paired design within subjects for whom both tissues were available for culture (n = 53), the odds of success for culture in dura was 16-fold as compared to scalp (OR = 16.0, 95% CI: [2.1-120.6], p = 0.0007). Unattended death, tissue donation source, longer postmortem interval (PMI), and higher body mass index (BMI) were associated with unsuccessful culture in scalp (all p

Neuregulin1 (NRG1)-ErbB signaling has been implicated in the pathogenesis of cancer and schizophrenia. We have previously reported that NRG1-stimulated migration of B lymphoblasts is PI3K-AKT1dependent and impaired in patients with schizophrenia and significantly linked to the catechol-o-methyltransferase (COMT) Val108/158Met functional polymorphism.We have now examined AKT1 activation in NRG1-stimulated B lymphoblasts and other cell models and explored a functional relationship between COMT and AKT1. NRG1-induced AKT1 phosphorylation was significantly diminished in Val carriers compared to Met carriers in both normal subjects and in patients. Further, there was a significant epistatic interaction between a putatively functional coding SNP in AKT1 (rs1130233) and COMT Val108/158Met genotype on AKT1 phosphorylation. NRG1 induced translocation of AKT1 to the plasma membrane also was impaired in Val carriers, while PIP(3) levels were not decreased. Interestingly, the level of COMT enzyme activity was inversely correlated with the cells' ability to synthesize phosphatidylserine (PS), a factor that attracts the pleckstrin homology domain (PHD) of AKT1 to the cell membrane. Transfection of SH-SY5Y cells with a COMT Val construct increased COMT activity and significantly decreased PS levels as well as NRG1-induced AKT1 phosphorylation and migration. Administration of S-adenosylmethionine (SAM) rescued all of these deficits. These data suggest that AKT1 function is influenced by COMT enzyme activity through competition with PS synthesis for SAM, which in turn dictates AKT1-dependent cellular responses to NRG1-mediated signaling.Our findings implicate genetic and functional interactions between COMT and AKT1 and may provide novel insights into pathogenesis of schizophrenia and other ErbB-associated human diseases such as cancer.

  1. Brain-derived neurotrophic factor (BDNF) supports serotonergic neuronal development and our recent study found that heterozygous mice lacking one BDNF gene allele interbred with male serotonin transporter (SERT) knockout mice had greater reductions in brain tissue serotonin concentrations, greater increases in anxiety-like behaviors and greater ACTH responses to stress than found in the SERT knockout mice alone.