Evaluation of component positioning in primary total hip arthroplasty using an imageless navigation device compared with traditional methods

Acetabular orientation affects the success of total hip arthroplasty. Computer-assisted navigation systems may reduce positional errors. Total hip arthroplasty results were analyzed using an imageless navigation system. We hypothesized that reliability and accuracy would improve. One hundred forty-nine total hip arthroplasties were performed using minimally invasive surgical techniques in 3 cohorts: manual (n = 53), initial navigation cases (n = 49), navigation second series (n = 47). Manual patients' cup orientation variation from desired range was -19 degrees to +18 degrees anteversion (SD, 9.1 degrees ), -11 degrees to +25 degrees abduction (SD, 6.7 degrees ). Navigation variation from desired was -18 degrees to +15 degrees (SD, 7.3 degrees ) in group 1 and -15 degrees to +9 degrees (SD, 5.9 degrees ) in group 2 in anteversion and -15 degrees to +13 degrees (SD, 6.1 degrees ) in group 1 and -15 degrees to +11 degrees (SD, 4.7 degrees ) in group 2 in abduction. Results were statistically significant. There were significant differences for operating room time and estimated blood loss, but not incision size or body mass index. Navigation provided controlled, reproducible acetabular alignment; but a learning curve existed in terms of accuracy, estimated blood loss, and operating room time.     

Which fractures are most attributable to osteoporosis?

Background

Determining anatomic sites and circumstances under which a fracture may be a consequence of osteoporosis is a topic of ongoing debate and controversy that is important to both clinicians and researchers.

Methods

We conducted a systematic literature review and generated an evidence report on fracture risk based on specific anatomic bone sites and fracture diagnosis codes. Using the Research and Development/University of California at Los Angeles appropriateness process, we convened a multidisciplinary panel of 11 experts who rated fractures according to their likelihood of being because of osteoporosis based on the evidence report. Fracture sites (as determined by International Classification of Diseases Clinical Modification codes) were stratified by four clinical risk factor categories based on age, sex, race/ethnicity (African American and Caucasian), and presence or absence of trauma.

Results

Consistent with current clinical experience, the fractures rated most likely because of osteoporosis were the femoral neck, pathologic fractures of the vertebrae, and lumbar and thoracic vertebral fractures. The fractures rated least likely because of osteoporosis were open proximal humerus fractures, skull, and facial bones. The expert panel rated open fractures of the arm (except proximal humerus) and fractures of the tibia/fibula, patella, ribs, and sacrum as being highly likely because of osteoporosis in older Caucasian women but a lower likelihood in younger African American men.

Conclusion

Osteoporosis attribution scores for all fracture sites were determined by a multidisciplinary expert panel to provide an evidence-based continuum of the likelihood of a fracture being associated with osteoporosis.     

An implanted upper-extremity neuroprosthesis using myoelectric control

PURPOSE: The purpose of this study was to evaluate the potential of a second-generation implantable neuroprosthesis that provides improved control of hand grasp and elbow extension for individuals with cervical level spinal cord injury. The key feature of this system is that users control their stimulated function through electromyographic (EMG) signals. METHODS: The second-generation neuroprosthesis consists of 12 stimulating electrodes, 2 EMG signal recording electrodes, an implanted stimulator-telemeter device, an external control unit, and a transmit/receive coil. The system was implanted in a single surgical procedure. Functional outcomes for each subject were evaluated in the domains of body functions and structures, activity performance, and societal participation. RESULTS: Three individuals with C5/C6 spinal cord injury received system implantation with subsequent prospective evaluation for a minimum of 2 years. All 3 subjects demonstrated that EMG signals can be recorded from voluntary muscles in the presence of electrical stimulation of nearby muscles. Significantly increased pinch force and grasp function was achieved for each subject. Functional evaluation demonstrated improvement in at least 5 activities of daily living using the Activities of Daily Living Abilities Test. Each subject was able to use the device at home. There were no system failures. Two of 6 EMG electrodes required surgical revision because of suboptimal location of the recording electrodes. CONCLUSIONS: These results indicate that a neuroprosthesis with implanted myoelectric control is an effective method for restoring hand function in midcervical level spinal cord injury.     

三个监测点医院2001-2004年婴幼儿轮状病毒腹泻监测

目的 了解3个监测点医院2001年8月至2004年7月住院的5岁以下婴幼儿轮状病毒腹泻流行状况。方法 以医院为基础的哨点监测,监测对象为5岁以下腹泻住院患儿。收集患儿的临床资料和粪便标本并进行轮状病毒检测和分型。结果 共检测3121份腹泻患儿的粪便标本,轮状病毒检出率为51%。94%的轮状病毒腹泻发生在2岁以下儿童。G3型为流行优势株,占69．9%,其次为G1型6．6%、G2型2．9%、G9型2．2%、G4型0．3%。P[8]型为最常见的P基因型。最常见的P-G组合型是P[8]G3,占64．0%,还有其他7种不常见的P-G组合的毒株类型。结论 轮状病毒是3个监测点医院住院腹泻患儿的主要病原,P[8]G3型为主要流行株。     

Intrapleural silicone granuloma mimicking pleural malignancy

We describe a 78-year-old initially presenting with left breast cancer, status post mastectomy and bilateral dual-lumen breast implant placement, subsequently developed lung cancer years later status post lobectomy, who later developed FDG-avid pleural nodularity and thickening. The differential diagnosis of pleural thickening and nodularity can be broad, including metastatic cancer, asbestos-related pleural disease, loculated fluid (including simple pleural effusion, hemothorax, or chylothorax), and pleural infection. However, in the setting of two different primary malignancies, our patient''s FGD-avid pleural thickening was concerning for metastatic disease. Further workup with a core-needle biopsy of the pleural nodule revealed “droplets of foreign material and foreign body giant cell reaction consistent with contents of ruptured medical device”, without evidence of malignancy. Prior imaging did not indicate breast implant compromise. A subsequent mammogram suggested findings of bilateral implant rupture, however, no further clinical workup was performed. A screening mammogram a decade later indicated possible extracapsular silicone within the right breast and left mastectomy site and an MRI was recommended for further workup. Subsequent MRI showed bilateral extracapsular silicone implant rupture with a thick layer of silicone signal within the left pleura in a similar distribution to her pleural thickening and nodularity. Her breast MRI findings, in conjunction with her pleural biopsy result, are concordant with pleural silicone granulomas from extracapsular breast implant rupture via radio-occult tract from prior left lobectomy procedure.