Structural behavior of the halo orthosis pin-bone interface: biomechanical evaluation of standard and newly designed stainless steel halo fixation pins

The structural response of the halo orthosis pin-bone interface to transverse loading was evaluated on an Instron testing machine using fresh cadaver calvarium sections. Commercially available stainless steel (control) pins and newly designed stainless steel experimental pins were evaluated. Cyclic loading tests and load-to-failure tests were performed. Of the many designs tested, one pin demonstrated an improvement in structural properties at the pin-bone interface compared with the control pin. Furthermore, the new pin design was more resistant to insertional torque reduction when subjected to cyclic loading after insertions at 4 and 6 in-lb. Both the control and experimental pins exhibited improved structural behavior at 8 in-lb of insertional torque compared to the currently recommended 6 in-lb.     

Methods to estimate and analyze medical care resource use. An example from liver transplantation.

This paper describes a method to construct a standardized health care resource use database. Billing and clinical data were analyzed for 916 patients who received liver transplantations at three medical centers over a 4-year period. Data were checked for completeness by assessing whether each patient's bill included charges covering specified dates and for specific services, and for accuracy by comparing a sample of bills to medical records. Detailed services were matched to a standardized service list from one of the centers, and a single price list was applied. For certain services, clinical data were used to estimate service use or, if a match was not possible, adjusted charges for the services were used. Twenty-three patients were eliminated from the database because of incomplete resource use data. There was very good correspondence between bills and medical records, except for blood products. Direct matches to the standardized service list accounted for 69.3% of services overall; 9.4% of services could not be matched to the standardized service list and were thus adjusted for center and/or time period. Clinical data were used to estimate resource use for blood products, operating room time, and medications; these estimations accounted for 21.3% of services overall. A database can be constructed that allows comparison of standardized resource use and avoids biases due to accounting, geographic, or temporal factors. Clinical data are essential for the creation of such a database. The methods described are particularly useful in studies of the cost-effectiveness of medical technologies.     

Surgical management of the secondary glaucomas: Part I

Surgical approaches to the secondary glaucomas vary depending on the pathogenesis and stage of the disease. In this first part, neovascular glaucoma management is reviewed. Panretinal ablation by laser or cryopexy and goniophotocoagulation used to reverse neovascularization are helpful, but not permanently curative. Filtering surgery is not as successful for neovascular glaucoma as it is for the primary adult glaucomas. Therefore, modifications using 5-fluorouracil, carbon dioxide lasers, and alloplastic implants have been investigated. Although ciliary body ablation using cryotherapy or photocoagulation may reduce intraocular pressure, vision may still deteriorate.     

Personality trait correlates of attitudes toward older people

The objective of this study is to determine whether personality is related to attitudes toward older people. To address this question, a sample of 228 students and gerontology practitioners completed the Aging Opinion Survey, the Cattell 16 Personality Factors Test, and a demographic questionnaire. When the influence of age, sex, education, and social desirability are controlled, a constellation of personality traits remains significantly related to attitudes toward older people. Specific trait-attitude correlations are described, and traits related to positive attitudes toward older people are shown to fit within three personality groupings: low anxiety traits, sensitive-intuition traits, and intellectual ability. These traits combined with demographic variables account for up to 30 percent of the variance in attitudes toward older people. The results of this study indicate that personality traits are clearly related to attitudes toward older people.     

Evaluation of cervical spine inflammatory arthritis with somatosensory evoked potentials

Bilateral independent median nerve somatosensory evoked potentials (SEP) were obtained in 15 patients with inflammatory arthritis of the cervical spine. Limitation of neck motion, neck pain, abnormal neurologic findings, and atlantoaxial subluxation were evaluated. Ten of 15 patients had abnormal SEP associated with subluxation in 9. Neurological signs specifically localizable to the central nervous system (CNS) were present in only 2 of the 10 patients. SEP were normal in the remaining 5 patients despite the presence of nonspecific neurological signs including atrophy of the intrinsic muscles of the hands and atlantoaxial subluxation determined by radiographic evaluation in 3 of 5 patients. Our study demonstrates the value of SEP in the evaluation of CNS function when findings on examination and radiographs may not conclusively document spinal cord impairment.     

Investigation of a Cluster of Syphilis,Gonorrhea, and Chlamydia Cases Among Heterosexual Micronesians Living on Oahu

A recent case investigation of secondary syphilis in a 27-year-old heterosexual Micronesian male and his 19-year-old chlamydia and syphilis co-infected female partner, conducted by the Hawaii State Department of Health, June to August 2007, identified a cluster of 13 case-patients with undiagnosed syphilis, chlamydia, and gonorrhea. The social network of Micronesians uncovered was characterized by having transient accommodations but a central gathering place. The critical factor in gaining access to this network was the establishment of a trusting relationship with a key social network member. Field interviews and the application of field diagnostic techniques helped to identify case-patients who otherwise would not have presented to a traditional office or clinic setting. Micronesians in Hawaii represent an at-risk population for adverse health indices including sexually transmitted diseases, based on their socioeconomic status.