Biomedical subjects

Warren R Dunn

Publications and source records attributed to Warren R Dunn.

4 recordsLinked to original sources

PubMed2004

An augmented fixation method for distal fibular fractures in elderly patients: a biomechanical evaluation.

This biomechanical investigation compared two fixation techniques for distal fibular fractures. Elderly cadaver lower extremities with simulated fibula fractures underwent fixation either with a plate and intramedullary Kirschner wires (K-wires) with or without the addition of three screws inserted through the four cortices of the fibula and the tibia. The specimens were axially loaded to body weight on a materials testing machine, and the supinated foot was externally rotated to failure. Displacement at the fracture site was monitored with an extensometer. Comparing the augmented technique with the technique without additional screws, mean stiffness was 460 +/- 100 and 320 +/- 200 N-mm/deg, strength at failure was 31 +/- 10 and 19 +/- 7 N-m, strength at 30 degrees external rotation was 15 +/- 5 and 10 +/- 6 N-m, and axial deformation was 0.04 +/- 0.06 mm and 0.10 +/- 0.04 mm, respectively. All differences were statistically significant.

Aged↗

PubMed2003

Research methodology.

Research aims to reach valid conclusions through scientific enquiry. Valid conclusions can only be reached if bias is minimized or eliminated. Bias can potentially take place in the design, implementation, or analysis of a study. Various study designs reduce bias, and this article reviews some of the more common study designs in orthopaedic sports medicine. We also discuss bias and confounding factors as they relate to these studies.

Bias↗

PubMed2003

Occupational disability after hospitalization for the treatment of an injury of the anterior cruciate ligament.

BACKGROUND: To date, no large population-based studies have focused on permanent occupational disability after injury of the anterior cruciate ligament as far as we know. The purpose of our study was to determine the risk factors for occupational disability after an injury of the anterior cruciate ligament. METHODS: We identified a cohort of 2192 active-duty personnel in the Army who had been hospitalized between 1989 and 1997 because of an injury of the anterior cruciate ligament and had completed a health risk-assessment survey. With use of the Total Army Injury and Health Outcomes Database, we retrospectively followed these individuals for up to nine years and collected clinical, demographic, occupational, and psychosocial data. These data were then evaluated with bivariate and proportional-hazards regression analyses to identify risk factors for receiving a disability discharge related to an injury of the anterior cruciate ligament. RESULTS: Overall, 209 (9.5%) of 2192 initial anterior cruciate ligament injuries resulted in a permanent disability discharge. In bivariate analyses, the following factors were related to a disability discharge: lower job satisfaction (p < 0.0001), lower education level (p < 0.0001), shorter length of service (p < 0.0001), lower pay grade or rank (p < 0.0001), occupational classification (p < 0.0001), older age (p < 0.01), cigarette-smoking (p = 0.01), and greater mental stress at work (p = 0.02). Associated cartilage injury (p = 0.07) and occupational physical demands (p = 0.08) approached significance; however, with the numbers available, other variables that were hypothesized to contribute to the development of disability, such as gender (p = 0.85), reconstruction of the anterior cruciate ligament (p = 0.52), and other secondary comorbidities of the knee, demonstrated no significant association. Proportional-hazards regression analysis confirmed that pay grade or rank, occupational classification, job satisfaction, age, and length of service were independent predictors of disability discharge. CONCLUSIONS: In keeping with risk profiles of several other musculoskeletal disorders, such as low-back pain and carpal tunnel syndrome, the results revealed a multifactorial risk profile in which psychosocial factors were strongly associated with disability discharge from active military duty after injury of the anterior cruciate ligament.

Adolescent↗

PubMed2002

A biomechanical study of two postoperative prostheses for transtibial amputees: a custom-molded and a prefabricated adjustable pneumatic prosthesis.

We evaluated an adjustable pneumatic prefabricated prosthesis and a rigid custom-molded prosthesis for immediate postoperative use. Twelve transtibial amputations were performed on cadaver limbs. Differential variable reluctance transducers were placed subcutaneously across the wound edge medially and laterally. The limbs were then placed in either the pneumatic prosthesis (five limbs) or the rigid prosthesis (seven limbs). The specimens underwent static and cyclic loading to simulate weight bearing. The strain readings for static and cyclic loading were greater in the rigid prosthetic group. Only the mean medial strain measurement after cyclic loading was statistically significant. The results demonstrate that the pneumatic prosthesis places less strain across the wound than a rigid prosthesis.

Air↗