Aspherical magnetically modulated optical nanoprobes (MagMOONs)

Aspherical magnetic particles orient in a magnetic field due to magnetic shape anisotropy. They also emit different fluxes of light from their different geometric faces due to self-absorption and total internal reflection within the particles. The particles rotate in response to rotating magnetic fields and appear to blink as they rotate. We have made pancake and chain shaped particles and magnetically modulated their fluorescent intensities. Demodulating the signal extracts the probe fluorescence from electronic and optical backgrounds dramatically increasing signal to noise ratios. The probes have applications in sensitive and rapid immunoassays, improved intracellular sensors, and inexpensive single molecule analysis. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70021/2/JAPIAU-93-10-6698-1.pd

Brownian modulated optical nanoprobes

Brownian modulated optical nanoprobes (Brownian MOONs) are fluorescent micro- and nanoparticles that resemble moons: one hemisphere emits a bright fluorescent signal, while an opaque metal darkens the other hemisphere. Brownian motion causes the particles to tumble and blink erratically as they rotate literally through the phases of the moon. The fluctuating probe signals are separated from optical and electronic backgrounds using principal components analysis or images analysis. Brownian MOONs enable microrheological measurements on size scales and timescales that are difficult to study with other methods. Local chemical concentrations can be measured simultaneously, using spectral characteristics of indicator dyes embedded within the MOONs. © 2004 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70496/2/APPLAB-84-1-154-1.pd

A smart polymer hydrogel as a chemical sensor on biomedical implant

Orthopedic implants are manufactured to support on healing fractured bones. In United States, over 2 million fracture fixation devices, including intra-medullary nails, external fixation pins, plates, and screws, and over 600 thousands joint prostheses, are implanted in patients annually. While fairly common, these fixation surgeries (5%) sometimes lead to unavoidable infection, which only amplifies health care costs accumulated from the initial procedures. In most cases, bacterial biofilms acutely causes infection which is a major reason of medical device failure. In order to obtain proper infections detection around biomedical implants a non-invasive chemical sensor is required. In vivo detection of low pH around implant is an indication of bacterial infection. Therefore, the sensor, which can detect low and/or high pH in the target, needs to be coupled with the implant. In addition, it should be biocompatible and stable material. To address this issue we are building a smart implant sensor out of soft, wet hydrogels which would be highly acceptable and useful

Symptomatic sacrococcygeal joint dislocation treated using closed manual reduction: A case report with 36-month follow-up and review of literature

Dislocation of the sacrococcygeal joint is a rare injury from trauma to the buttocks, most often from falling backwards. Standard of care for this injury has not been determined because it is rare. Left untreated this can cause coccydynia in the long-term. Here we present a case report to describe the treatment of an anterior sacrococcygeal dislocation with closed manual reduction. A 13-year-old female presented to the emergency department with buttock pain after slipping backwards down the stairs. On X-ray the coccyx was in bayonette apposition to the anterior distal sacrum and shortened by 6 mm. To manage the injury, closed manual reduction of the sacrococcygeal joint was performed. To our knowledge, this is the first successful case of sacrococcygeal dislocation treated with closed manual reduction, resulting in complete relief of symptoms at 36 months follow-up. Sacrococcygeal dislocations can be treated with closed manual reduction, resulting in lower morbidity and faster recovery compared to surgical treatment

Indications for Direct Laryngoscopic Examination of Vocal Cord Function Prior to Anterior Cervical Surgery

Recurrent laryngeal nerve palsy (RLNP) is among the most common complications in both thyroid surgeries and anterior approaches to the cervical spine, having both a diverse etiology and presentation. Most bilateral paresis, with subsequent devastating impact on patients, are due to failure to recognize unilateral recurrent laryngeal nerve paralysis and, although rare, are entirely preventable with appropriate history and screening. Recurrent laryngeal nerve palsy has been shown to present asymptomatically in as high as 32% of cases, which yields limitations on exclusively screening with physical examination. Based on the available literature, diagnosis of unilateral RLNP is the critical factor in preventing the occurrence of bilateral RLNP as the surgeon may elect to operate on the injured side to prevent bilateral paresis. Analysis of incidence rates shows postoperative development of unilateral RLNP is 13.1 (95% confidence interval [CI]: 6.1-28.1) and 13.90 (95% CI: 6.6-29.3) times more likely in anterior spine and thyroid surgery, respectively, in comparison with intubation. Currently, there is no consensus on when to order a preoperative laryngoscopic examination prior to anterior cervical spine surgery. The importance of patient history should be emphasized, as it is the basis for indications of preoperative laryngoscopy. Efforts to minimize postoperative complications must be made, especially when considering the rising rate of cervical fusion. This study presents a systematic review of the literature defining key causes of RLNP, with a probability-based protocol to indicate direct laryngoscopy prior to anterior cervical surgery as a screening tool in the prevention of bilateral RLNP

Mortality and Financial Burden of Periprosthetic Fractures of the Femur

Objective: This study examines patient factors to identify risks of 12-month mortality following periprosthetic femur fractures. Hospital charges were analyzed to quantify the financial burden for treatment modalities. Methods: Data were retrospectively analyzed from a prospective database at a university hospital setting. One-hundred and thirteen patients with a periprosthetic fracture of the proximal or distal femur were identified. Risk factors for 12-month mortality were analyzed, and financial data were compared between the various treatment modalities. Results: In all, 14% of patients died (16 of 113) within 3 months and the 1-year mortality was 17.7% (20 of 113). Patients who died within 1 year had higher hospital charges (US$33 880 ± 25 051 vs US$22 886 ± 16 841; P = .01) and were older (87.6 ± 8.5 vs 81.5 ± 8.6; P = .004). Logistic regression analysis revealed age was the only significant predictor of 1-year mortality ( P = .029, odds ratio 1.1). Analysis of financial data revealed 4 distinct groups ( P < .05 between groups). Distal femoral revision arthroplasty (RA-DF) generated the highest hospital charges of US$91 035 ± 25 579 (n = 3). The second most highly charged group included proximal femoral fractures treated with revision arthroplasty (US$34 078 ± 17 832; n = 20) and hemi/total hip arthroplasty (THA; US$41 556 ± 23 651; n = 8). The third most charged group underwent open reduction internal fixation of the proximal (US$18 706 ± 6829; n = 35) and distal (US$22 381 ± 10 835; n = 35) femur. Nonoperative treatment generated the lowest charges (US$6426 ± 2899; n = 11). On average, the hospital lost money treating patients with RA-DF (US$−19 080 ± 2022 per patient) and hemi/THA (US$−6594 ± 9305 per patient), while all other treatment groups were profitable. Conclusion: One-year mortality after periprosthetic femur fractures was 17.7%, is mostly influenced by age, and 80% of deaths occur within 3 months. Patients treated with primary/revision arthroplasty generate more hospital charges than internal fixation. The average patient treated with revision arthroplasty of the distal femur or hemi/THA for a periprosthetic femur fractures resulted in net financial losses for the hospital

Financial Implications of Hospital Readmission After Hip Fracture

Introduction: Hip fracture is the leading orthopedic discharge diagnosis associated with 30-day readmission in terms of numbers. Because readmission to the hospital following a hip fracture is so common, it adds considerably to the costs on an already overburdened health care system. Methods: Patients aged 65 and older admitted to a 261-bed university-affiliated level 3 trauma center between April 30, 2005, and September 30, 2010, with a unilateral, native, nonpathologic low-energy proximal femur fracture were identified from a fracture registry and included for analysis. Readmissions within 30 days of hospital discharge, costs, and outcomes were collected and studied. Results: Of 1081 patients, 129 (11.9%) were readmitted within 30 days. The average hospital length of stay for readmissions was 8.7 ± 18.8 days, which was significantly longer than the initial stay (4.6 ± 2.3 days) ( P = .03). Nineteen percent (24 patients ∼19%) died during readmission versus 2.8% during the index admission. These patients accumulated an average hospital charge of US$16 308 ± US$6400 during their initial hospitalization for compared with charges for their readmissions of US$14 191 ± US$25 035 ( P = .36). Discussion: Readmission was usually associated with serious medical or surgical complications of the original hospitalization. Conclusions: Readmission after hip fracture is costly and harmful. Charges were similar between the original fracture admission and the readmission. Patients were readmitted most frequently for medical diagnoses following their original hospital stay. Some of these readmissions may have been avoidable

Go to: Negative effects of smoking, workers&apos; compensation, and litigation on pain/disability scores for spine patients

Abstract Background