Biomedical subjects

James R Kasser

Publications and source records attributed to James R Kasser.

5 recordsLinked to original sources

PubMed2004

Delay in diagnosis of slipped capital femoral epiphysis.

OBJECTIVE: Delay in diagnosis of slipped capital femoral epiphysis (SCFE) has important implications in terms of slip severity and long-term hip outcome. The purpose of this study was to identify predictors of delay in the diagnosis of SCFE. METHODS: A review of 196 patients with SCFE was performed. The primary outcome measure was delay from onset of symptoms to diagnosis. Covariates included age, gender, side, weight, pain location, insurance status, family income, slip severity, and slip stability. Delay in diagnosis was not normal in distribution; therefore, nonparametric univariate and multivariate analyses were performed. RESULTS: The median delay in diagnosis was 8.0 weeks. There was a significant relationship between delay in diagnosis and slip severity (<30 degrees : 10.0 weeks; 30 degrees to 50 degrees : 14.4 weeks; >50 degrees : 20.6 weeks). There were no significant associations between delay in diagnosis and covariates of age, gender, side, and weight. There were significant associations between longer delay in diagnosis and covariates of knee/distal-thigh pain versus hip/proximal-thigh pain (6.0 vs 15.0 weeks), Medicaid coverage versus private insurance (12.0 vs 7.5 weeks), lower family income, and stable slips versus unstable slips (8.0 vs 6.5 weeks). Controlling for the other covariates, knee/distal-thigh pain, Medicaid insurance, and stable slips remained significant independent multivariate predictors of delay in diagnosis. CONCLUSIONS: Patients who present with primarily knee or distal-thigh pain, patients with Medicaid coverage, and patients with stable slips have longer delays in diagnosis of SCFE. Focused intervention programs to reduce the delay in diagnosis of SCFE should emphasize patients with knee/thigh pain and patients with Medicaid coverage.

Child↗

PubMed2003

Osteopetrosis.

Osteopetrosis is a rare skeletal condition characterized by skeletal sclerosis caused by aberrant osteoclast-mediated bone resorption. Three clinically distinct forms of osteopetrosis are recognized--the infantile malignant autosomal recessive form, the intermediate autosomal recessive form, and the adult benign autosomal dominant form. The disease represents a spectrum of clinical variants because of the heterogeneity of genetic defects resulting in osteoclast dysfunction. The pathogenic defects may be intrinsic to either the osteoclast-monocyte lineage or the mesenchymal cells that constitute the microenvironment that supports osteoclast ontogeny and activation. Implicated factors include specific proto-oncogenes, growth factors, and immune regulators. A subset of patients with the intermediate autosomal recessive form has been characterized with carbonic anhydrase II isoenzyme deficiency. Management of patients with osteopetrosis requires a comprehensive approach to characteristic clinical problems including hematologic and metabolic abnormalities, fractures, deformity, back pain, bone pain, osteomyelitis, and neurologic sequelae. Medical treatment of osteopetrosis is based on efforts to stimulate host osteoclasts or provide an alternative source of osteoclasts. Stimulation of host osteoclasts has been attempted with calcium restriction, calcitrol, steroids, parathyroid hormone, and interferon. Bone marrow transplant has been used with cure for infantile malignant osteopetrosis. As osteopetrosis likely represents a spectrum of underlying etiologies resulting in osteoclast dysfunction, effective therapies most likely need to be individualized.

Humans↗

PubMed2003

A clinical practice guideline for treatment of septic arthritis in children: efficacy in improving process of care and effect on outcome of septic arthritis of the hip.

BACKGROUND: The development of clinical practice guidelines is a central precept of the evidence-based-medicine movement. The purposes of this study were to develop a guideline for the treatment of septic arthritis in children and to evaluate its efficacy with regard to improving the process of care and its effect on the outcome of septic arthritis of the hip in children. METHODS: A clinical practice guideline was developed by an interdisciplinary expert committee using evidence-based techniques. Efficacy was evaluated by comparing a historical control group of thirty consecutive children with septic arthritis of the hip managed before the utilization of the guideline with a prospective cohort group of thirty consecutive children treated with use of the guideline. Benchmark parameters of process and outcome were compared between groups. RESULTS: The patients treated with use of the guideline, compared with those treated without use of the guideline, had a significantly higher rate of performance of initial and follow-up C-reactive protein tests (93% compared with 13% and 70% compared with 7%), lower rate of initial bone-scanning (13% compared with 40%), lower rate of presumptive drainage (13% compared with 47%), greater compliance with recommended antibiotic therapy (93% compared with 7%), faster change to oral antibiotics (3.9 compared with 6.9 days), and shorter hospital stay (4.8 compared with 8.3 days). There were no significant differences between the groups with regard to other process variables, and there were no significant differences with regard to outcome variables, including readmission to the hospital, recurrent infection, recurrent drainage, development of osteomyelitis, septic osteonecrosis, or limitation of motion. CONCLUSIONS: Patients treated according to the septic arthritis clinical practice guideline had less variation in the process of care and improved efficiency of care without a significant difference in outcome.

Anti-Bacterial Agents↗

PubMed2002

Prospective reevaluation of the association between thrombotic diathesis and legg-perthes disease.

BACKGROUND: Legg-Perthes disease is associated with ischemia of the capital femoral epiphysis in children. Thrombophilia has been implicated as a potential cause of the condition, and screening of patients with Legg-Perthes disease for thrombophilia has been recommended. We analyzed the value of screening for inherited thrombophilia in patients with Legg-Perthes disease by examining the association between Legg-Perthes disease and abnormalities in the thrombotic pathway. METHODS: A random series of consecutive patients with Legg-Perthes disease were prospectively enrolled in this study. Assays for the detection of factor-V Leiden mutation and the plasma concentrations of protein C, protein S, antithrombin III, and lipoprotein (a) were performed on plasma samples from children with Legg-Perthes disease, and the results were compared with those for pooled plasma from normal controls. Plasma concentrations below the 95% midrange of the control values were classified as protein deficiencies. The estimated population frequency of each coagulation abnormality was compared with the proportion of the study group with the corresponding abnormality. RESULTS: The proportion of abnormalities observed in the study group did not differ from the estimated population frequency for protein C, protein S, antithrombin III, or factor-V Leiden mutation. A lipoprotein (a) level of >30 mg/dL (>1.07 micro mol/L) was found in 16% of the study group. CONCLUSIONS: Our data do not suggest that thrombotic diatheses due to deficiency of protein C, protein S, or antithrombin III or due to factor-V Leiden mutation are major causes of Legg-Perthes disease. The elevated levels of lipoprotein (a) in children with Legg-Perthes disease suggest that they may be at risk for atherosclerosis as adults.

Anticoagulants↗

PubMedDate not supplied

Virtual reality simulation of arthroscopy of the knee.

The virtual reality arthroscopic knee simulator (VR-AKS) consists of a computer platform, a video display, and two force-feedback (haptic) interfaces known as "PHANToMs" that also monitor the position of the instruments in the user's hands. The forces that the user would normally apply to the lower limb during arthroscopy are directed through an instrumented surrogate leg. Proprietary software provides the mathematical representation of the physical world and replicates the visual, mechanical, and behavioral aspects of the knee. This includes moderating the haptic interface and simultaneously executing a collision-detection algorithm that prevents the instruments from moving through "solid" surfaces. Modeling software interacts with this algorithm to send the appropriate images to the video display, including knee pathology such as meniscal tears and chondral defects as well as normal anatomy. Task-oriented programs monitor specific performance such as executing a proper examination of the knee or shaving a torn meniscus.

Arthroscopy↗