Decoupling and Cloaking of Rectangular and Circular Patch Antennas and Interleaved Antenna Arrays with Planar Coated Metasurfaces at C-Band Frequencies-Design and Simulation Study.

An electromagnetic cloaking approach is employed with the intention to curb the destructive effects of mutual interference for rectangular and circularly shaped patch antennas situated in a tight spacing. Primarily, we show that by coating the top surface of each patch with an appropriately designed metasurface, the mutual coupling is considerably reduced between the antennas. Furthermore, the cloak construct is extended to a tightly spaced, interleaved linear patch antenna array configuration and it is shown that the coated metasurfaces successfully enhance the performance of each array in terms of their matching characteristics, total efficiencies and far-field realized gain patterns for a broad range of beam-scan angles.

Cloaking of Equilateral Triangle Patch Antennas and Antenna Arrays with Planar Coated Metasurfaces.

We have proposed an effective metasurface design to accomplish the cloaking of equilateral patch antennas and their array configuration. As such, we have exploited the concept of , employing the mantle cloaking technique with the intention to eliminate the destructive interference ensuing between two distinct triangular patches situated in a very congested arrangement (sub-wavelength separation is maintained between the patch elements). Based on the numerous simulation results, we demonstrate that the implementation of the planar coated metasurface cloaks onto the patch antenna surfaces compels them to become to each other, at the intended frequencies.

A preliminary safety assessment of vertebral augmentation withP brachytherapy bone cement.

Comprehensive treatment for vertebral metastatic lesions commonly involves vertebral augmentation (vertebroplasty or kyphoplasty) to relieve pain and stabilize the spine followed by multiple sessions of radiotherapy. We propose to combine vertebral augmentation and radiotherapy into a single treatment by addingP, a-emitting radionuclide, to bone cement, thereby enabling spinal brachytherapy to be performed without irradiating the spinal cord. The goal of this study was to address key dosimetry and safety questions prior to performing extensive animal studies.

Concurrent notalgia paresthetica and brachioradial pruritus associated with cervical degenerative disc disease.

Notalgia paresthetica (NP) is a common, often refractory sensory neuropathic syndrome with the hallmark symptoms of localized pruritus and dysesthesia of the unilateral infrascapular region. Brachioradial pruritus (BRP) is similarly classified as a localized pruritus syndrome but of the upper extremities, typically one or both forearms. Notalgia paresthetica and BRP are both generally chronic, nonlethal, incurable conditions with intermittent remissions and exacerbation.

Notalgia paresthetica associated with cervical spinal stenosis and cervicothoracic disk disease at C4 through C7.

Notalgia paresthetica (NP) is a common refractory, sensory, neuropathic syndrome with the hallmark symptom of localized pruritus of the unilateral infrascapular back. It generally is a chronic noncurable condition with periodic remissions and exacerbations. While the dermatologic syndrome may be multifactorial in etiology, a possible association with underlying cervical spine disease should be evaluated for proper treatment.

Lytic lesions in the femoral neck: Importance of location and evaluation of a novel minimally invasive repair technique.

Proximal femoral metastases can lead to pathologic fracture. The goals of this study were to improve guidelines for assessing pathologic hip fracture risk by quantifying the effect of location of femoral neck metastases on hip strength under single-limb stance loading and to evaluate the effectiveness of a proposed minimally invasive surgical repair technique for restoring hip strength. Twelve matched pairs of human cadaveric proximal femora were used to create a total of 564 finite element models before and after introduction and repair of simulated lytic defects, modeled as spherical voids, at various locations within the femoral neck.

The effect of simulated metastatic lytic lesions on proximal femoral strength.

Metastatic lesions in the proximal femur can reduce hip strength and lead to pathologic fracture. However, current methods for identifying patients at risk of pathologic fracture are inadequate. We hypothesized the percentage of intact proximal femoral strength remaining after formation of a simulated lytic defect within the femoral neck or at the level of the lesser trochanter depends on defect location within the respective region.

Feasibility of a percutaneous technique for repairing proximal femora with simulated metastatic lesions.

Fracture of the proximal femur due to metastatic disease is a significant cause of morbidity and mortality among breast cancer patients. Prophylactic surgical fixation is advised for patients at risk of fracture and typically involves placement of an orthopaedic implant. We propose that some proximal femora with metastases can be repaired by removing the lesion and filling the resulting defect with bone cement (polymethylmethacrylate), a procedure that could be performed percutaneously without the use of hardware.

The effect of the "mini" incision in total hip arthroplasty on component position.

This study compares cemented and uncemented total hip arthroplasties performed through either a standard or mini incision. The parameters evaluated were dislocation rates, Gruen and DeLee zones, Barrack cement grading, component positioning, and heterotopic bone levels. There were no statistically significant differences found between the mini and standard incision groups except in 2 parameters.

Predicting the strength of femoral shafts with and without metastatic lesions.

To evaluate a potential tool for assessing the risk of a pathologic fracture of the femoral shaft, we examined whether fracture loads computed by our computed tomography scan-based finite element models are predictive of measured fracture loads. We also evaluated whether the precision of the computed fracture loads for shafts with metastases is altered if models are generated using mechanical property-density relationships for bone without metastases. We investigated whether femoral shafts with a hemispheric defect and shafts with metastases have qualitatively similar structural behavior.

Predicting proximal femoral strength using structural engineering models.

Hip fracture related to osteoporosis and metastatic disease is a major cause of morbidity and mortality. An accurate and precise method of predicting proximal femoral strength and fracture location would be useful for research and clinical studies of hip fracture. The goals of this study were to develop a structural modeling technique that accurately predicts proximal femoral strength; to evaluate the accuracy and precision of this predicted strength on an independent data set; and to evaluate the ability of this technique to predict fracture location.

Concerns about ceramics in THA.

Currently available ceramic materials are superior to those used originally in total hip arthroplasty, which should translate into a much lower complication rate than what has been reported previously. In spite of this, a number of concerns remain. The ceramic-on-ceramic articulation is not immune to wear and surface damage.

Multimodal acute pain management.

Unrelieved postoperative pain following arthroplasty has been shown to delay patients' recovery and discharge from the hospital. Undertreatment of acute pain may also result in greater use of healthcare resources and ultimately lead to poor outcomes. This article reviews a multimodal approach to reduce pain at each step of the pain nocioception process by combining various analgesics that each operate through a different site or mechanism of action, allowing the physician to tailor the regimen to the patient.

Results of a multimodal analgesic trial involving patients with total hip or total knee arthroplasty.

The mainstays for pain relief after total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been the opioids, but these medications, though excellent analgesics, have problems limiting their effectiveness. Alternative analgesics have been considered too mild for the pain caused by THA and TKA. These medications have been used in combination, but only in pairs and not in a "stacked modality.

Clinical implications of thromboprophylaxis in the management of total hip and knee arthroplasty.

Thrombosis is the most common cause of mortality in the United States, resulting in more than 2 million deaths per year. Almost an equal number of individuals are affected each year by nonfatal thrombosis, including deep vein thrombosis and nonfatal pulmonary embolism. A large proportion of thrombotic episodes can be prevented by the appropriate selection of prophylactic therapy--a clinical decision that figures greatly in numerous clinical conditions associated with an increased risk of thrombosis, including major orthopedic surgery.

Advances in Adult Reconstructive Orthopaedics Total joint arthroplasty.

The greying of America has produced a strong demand for improving total joint arthroplasty. The primary application of joint replacement technology is at the hip and knee, but arthroplasty of the shoulder and elbow has also made significant advances. Increasing numbers of people are reaching retirement age and require a level of function that will enable their enjoyment of leisure activities such as golf and bicycling.