Biomedical subjects
J Michelson
Publications and source records attributed to J Michelson.
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Sensory thresholds of normal human feet.
HYPOTHESES/PURPOSE: Although several studies in the literature have evaluated the abnormal sensory thresholds of diabetic feet to Semmes-Weinstein monofilament testing, there is very limited data on the sensory thresholds of individuals without diabetes or peripheral neuropathy. The purpose of this study was to assess the dorsal and plantar sensation of the feet from 40 healthy, college-aged volunteers using Semmes-Weinstein monofilaments. CONCLUSIONS/SIGNIFICANCE: Semmes-Weinstein testing is a useful tool in predicting which diabetic patients may be at risk for ulceration of the feet. Several studies have determined 5.07 to be the threshold for protective sensation. Based on the normal values derived in this study, the inability to feel a Semmes-Weinstein monofilament of 5.07 (as in diabetic neuropathy) represents a sensory threshold that is more than 50 times greater than normal. This means that roughly 98% of the sensory ability has been lost. METHODS: 20 male and 20 female volunteers between the ages of 18 to 22 years old were selected. None had a history of any significant injury or previous surgery to the foot or ankle. There were no known medical conditions associated with decreased foot sensation, (e.g.- diabetes, syphilis, leprosy, myelomeningocele, syringomyelia, or hereditary neuropathy). Volunteers were also questioned regarding participation in athletic activities. The subjects were blindfolded with the leg resting comfortably on a chair as 14 plantar and 5 dorsal locations were tested on each foot. The right foot was always tested first. Each site on the foot had the Semmes-Weinstein monofilaments applied to it first, in an order of increasing stiffness, then repeated in decreasing order, using all twenty monofilaments in the set. A positive threshold response was recorded when the subject could feel the filament and could accurately locate where on the foot the stimulus had been applied. The left foot was then tested in an identical fashion. RESULTS: The mean sensitivity for all sites was 3.63 (0.0075 SEM). There were significant differences between sites, between using increasing or decreasing monofilament stiffness, between subjects, and in some instances, between right foot and left foot values. When testing was performed from the higher to lower monofilament stiffness, subjects were found to have significantly better sensitivity, which indicates the importance of a consistent testing protocol (either all up or all down). Sensation in the lesser toes and the arch were the most sensitive followed by the hallux and the plantar metatarsal heads. The least sensitive site was the heel, with 1/6th the sensitivity of the most sensitive toes.
Disseminating information using an anesthesiology consultant report: impact on patient perceptions of quality of care.
STUDY OBJECTIVE: To determine if providing an Anesthesiology Consultant Report (ACR) to patients would result in enhanced patients' perceptions of their knowledge about their care and improve their perception of the quality of their care. DESIGN: Randomized, unblinded study. SETTING: Outpatient center associated with tertiary care center. PATIENTS: 371 outpatients without adverse anesthetic events. INTERVENTIONS: Patients were randomized to receive either routine discharge instructions or routine instructions and an anesthesia discharge summary (ACR). MEASUREMENTS AND MAIN RESULTS: Short questionnaire with discharge packet regarding knowledge of anesthetic and questions regarding satisfaction and perceptions of quality of care was distributed. The patients in the group that received an ACR were more satisfied with the management of their pain and other symptoms (p < 0.05, by Wilcoxon rank sums) and were more satisfied overall with the quality of the anesthesia care (p < 0.01, by Wilcoxon rank sums). Taken another way, significantly more patients deemed the quality of their anesthetic care as excellent in the ACR group compared to control (83% vs. 67%, p < 0.01). CONCLUSIONS: Providing patients, with uneventful anesthetic courses, with information regarding their anesthetic care, in the form of the ACR, results in improved perceptions of the quality of care.
Ankle fractures. The Lauge-Hansen classification revisited.
Rational treatment of ankle fractures requires knowledge of the extent of bone and soft tissue injury. Although the Lauge-Hansen classification attempts to do this by relating specific fracture patterns to injury mechanism, the experimental underpinning for this classification has not been reexamined rigorously using modern experimental methods. This study examines the hypothesis that the clinically occurring supination and external rotation injury pattern does not result from the mechanism described by Lauge-Hansen. Thirty-two anatomic specimen ankles were mounted on an MTS machine for combined axial loading with external rotation to failure testing. A foot plate supinated the foot 25 degrees. Testing was performed with the ankle at neutral, 25 degrees plantar flexed, 10 degrees to 15 degrees dorsiflexed, and in 6 degrees to 8 degrees leg valgus. Pure supination and external rotation with the ankle in neutral did not result in the Lauge-Hansen supination and external rotation type fractures. This outcome was not altered if the ankle specimens initially were placed in plantar flexion or dorsiflexion. The addition of a valgus load, which pushes the talus laterally against the fibula, resulted in the classic Lauge-Hansen supination and external rotation type fracture. All specimens had an isolated lateral injury or a lateral injury that preceded medial injury.
Zero modes for the D=11 membrane and five-brane.
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Posterior tibial tendon dysfunction in rheumatoid arthritis.
Although hindfoot pathology in rheumatoid arthritis is a significant cause of disability for patients, the etiology of the planovalgus deformity is controversial. The present study surveys 99 patients with clinically proven rheumatoid arthritis for the presence and severity of hindfoot pathology. Specific attention was directed at the function of the posterior tibial tendon, as disruption of this structure has been implicated by some investigators as a cause of hindfoot deformity in rheumatoid arthritis. Assessment of posterior tibial function was by manual testing using two different grading scales, as well as by examination for several signs associated with posterior tibial tendon dysfunction. Between 13% and 64% of the study population could be considered to have posterior tibial tendon dysfunction, depending upon the specific diagnostic criteria used. Using the presence of all three of the most stringent criteria for diagnosis, 11% of patients were believed to have posterior tibial tendon dysfunction. These criteria were loss of the longitudinal arch, inability to perform a heel-rise, and lack of a palpable posterior tibial tendon. This study demonstrates that planovalgus deformity in rheumatoid arthritis can be due to clinically evident dysfunction of the posterior tibial muscle-tendon unit. There is a complex interplay between hindfoot joint disruption due to the inflammatory process and deformity due to tendinous dysfunction. If there is primary subtalar joint instability secondary to the inflammatory process, the posterior tibial tendon is rendered dysfunctional due to deranged hindfoot mechanics, as with primary posterior tibial tendon rupture. Since treatment of either condition (i.e., primary hindfoot instability or primary posterior tibial tendon rupture) is similar, the distinction is not important clinically.(ABSTRACT TRUNCATED AT 250 WORDS)
Foot and ankle problems in rheumatoid arthritis.
The purpose of this study was to examine the prevalence of foot and ankle problems in 99 patients with clinically proven rheumatoid arthritis. Patients were recruited from outpatient rheumatology clinics; no attempt was made to select patients on the basis of the severity of their disease, duration of disease, or symptom constellation. Each patient was examined by an investigator utilizing a predesigned protocol to assess their functional status, functional capacity, and overall joint involvement. Ninety-three of 99 patients had complaints referable to the foot or ankle at some time since diagnosis of rheumatoid arthritis. Ankle problems were paramount in 42%, forefoot difficulties in 28%, and equal ankle and forefoot problems in another 14%. Only four patients had had any treatment involving foot orthotic devices or special shoe wear. The prevalence of foot and ankle symptoms was related to the duration of systemic illness, but was present in > 50% of patients at any time after diagnosis of rheumatoid arthritis. Patients with longstanding rheumatoid arthritis have a high prevalence of foot and ankle symptoms. Unlike previous reports, the present study found a high prevalence of ankle and hindfoot symptoms, as opposed to forefoot complaints. Despite this finding, the patients had been treated infrequently by either conservative nonoperative management directed at accommodating footwear or surgical intervention to favorably alter their foot and ankle mechanics.
Clinical significance of magnetic resonance imaging in preoperative planning for reconstruction of posterior tibial tendon ruptures.
A retrospective study of attenuated/ruptured posterior tibial tendons was conducted of all patients who underwent tendon reconstruction over a 4-year period. The study comprised 20 feet in 19 patients having an average age of 53.3 years, with an average follow-up of 2 years. Preoperative magnetic resonance images were taken and graded for assignment to one of three magnetic resonance imaging (MRI)-based groups. The surgical grade was determined intraoperatively based on a previously described classification scheme. No medical or rheumatologic conditions predisposing to failure could be identified. Failure was defined as postoperative progression of pain and deformity which required subsequent triple arthrodesis. There were six failures at an average of 14.7 months. Surgical evaluation was not correlated to outcome following reconstruction. MRI grading, however, was predictive of outcome. The superior sensitivity of MRI for detecting intramural degeneration in the posterior tibial tendon that was not obvious at surgery may explain why MRI is better than intraoperative tendon inspection for predicting the outcome of reconstructive surgery. Therefore, it may be helpful to obtain preoperative MRI when this particular reconstruction of the posterior tibial tendon is contemplated, since this provides the best measure of tendon integrity and appears to be the best predictor of clinical success after such surgery.
Incidence and treatment of fractures in thalassemia.
Thalassemia major, a disorder of hemoglobin synthesis, contributes to skeletal deformities, marked osteopenia, and frequent fractures. Hypertransfusion therapy in the last 20 years has prolonged the life expectancy of thalassemics and decreased the orthopaedic manifestations of the disease. This study examines the incidence and treatment of fractures in hypertransfused thalassemics in whom the hemoglobin is kept above 8 g/dl. Over a 5-year period, there were eight fractures in 38 patients, which yields an incidence that is approximately 70% above the fracture rate in the general population. With the exception of one patient, all of the fractures healed in the expected time utilizing nonoperative treatment. The results of this study indicate that, although thalassemics are at moderately high risk for sustaining fractures, they respond well to standard casting methods. However, the iron overload found in thalassemia can deplete the body of vitamin C, which can subsequently retard fracture healing. Attention must, therefore, be paid to replenishing vitamin C very cautiously in order to avoid this complication.
Misconceptions in dental anesthesiology.
This is a short review of the history of anesthetic technique and opinions regarding the present day responsibilities of the dentist anesthesiologist and how it differs from the traditional laissez-faire approach.
Comparison of family-based behavior modification and nutrition education for childhood obesity.
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Investigation of periodicity in crisis intervention calls over an eight-year span.
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Controversies in ankle fractures.
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