Biomedical subjects

Andrea Hayes

Publications and source records attributed to Andrea Hayes.

3 recordsLinked to original sources

PubMed2006

Ankle morphometry on 3D-CT images.

Understanding three-dimensional (3D) morphology of the ankle is essential for a better total ankle replacement. Current designs neither mimic the articular geometry at the bearing surface interfaces nor match the native bony bed with the implant's external dimensions. This is likely due to insufficient anthropometric data on sizing and geometry. We performed this study to determine the range of possible sizes of ankle joints based on high-resolution 3D-CT images. Clinical 3D-CT images from twenty-one normal ankles (11 males, 10 females) were subjected to morphometric evaluation. A local coordinate system for measurement was established based on talar anatomic landmarks. Measurements included the width of the superior talar dome surface (measured at the anterior, middle, and posterior portions) and the arc radius of the talar dome. The results yielded an average anterior width of 29.9 +/- 2.6 mm, a middle width of 27.9 +/- 3.0 mm, and a posterior width of 25.2 +/- 3.7 mm. The talar dome radius was 20.7 +/- 2.6 mm. The width linearly decreased from anterior to posterior (p < 0.001). A significant gender difference was found in both the width and the radius (p-values < 0.05), except at the middle width (p = 0.07). The data describe talar topography in a Caucasian U.S. adult cohort, suggesting the capability of the 3D-CT approach for ankle morphometric evaluation and sizing for the fabrication of total ankle replacements.

Adult↗

PubMed2005

Epidemiology of ankle arthritis: report of a consecutive series of 639 patients from a tertiary orthopaedic center.

The purpose of our study was to identify the cause of symptomatic ankle arthritis in a consecutive series of patients presenting in a tertiary care setting. Between 1991 and 2004, 639 patients with Kellgren grade 3 or 4 ankle arthritis presented to the University of Iowa Orthopaedic Foot and Ankle Surgery service. The cause of the arthritis was determined based on medical history, physical examination, and imaging studies. To get a sense of the relative prevalence of the etiologies of lower extremity arthritis in our setting, we evaluated the cause of arthritis of all new patients presenting to the University of Iowa Orthopaedic Department from 1999-2004 with arthritis of the ankle, to those with arthritis of the hip or knee during one year. Of the 639 arthritic ankles, 445 (70%) were post-traumatic, 76 (12%) were rheumatoid disease and 46 (7%) were idiopathic (primary osteoarthritis). The post-traumatic ankle arthritis patients were most commonly associated with past rotational ankle fractures. The majority of ankle arthritis is associated with previous trauma, whereas the primary cause of knee or hip arthritis is idiopathic. Unique strategies to prevent or treat post-traumatic ankle arthritis are needed.

Ankle Injuries↗

PubMed2004

4.5-gram monofilament sensation beneath both first metatarsal heads indicates protective foot sensation in diabetic patients.

BACKGROUND: Loss of protective plantar foot sensation is the major cause of diabetic foot ulcerations and ultimate limb loss. Identification of patients without protective sensation can reduce the risk of unrecognized foot injury. The current recommended screening protocol requires 10-g monofilament testing of ten foot sites with use of a forced-choice paradigm. The objective of the present study was to determine whether testing of fewer than ten sites could provide accuracy comparable with that obtained by testing all ten sites. METHODS: A cross-sectional comparative study of plantar sensory levels in diabetic subjects with and without plantar ulceration was conducted in a tertiary-care teaching hospital setting. We examined forty-seven diabetic subjects with a history of foot ulceration and forty-five diabetic subjects with no history of foot ulceration. Plantar sensory threshold values at five sites on the sole of each foot were measured with a quasi-continuous range of applied forces, and receiver operating characteristic analysis techniques were applied. RESULTS: Screening on the basis of only the maximum force threshold for the left and right first metatarsal head sites provided comparable or better performance at high levels of sensitivity than did either the mean or the maximum force threshold across all ten sites. A sensory threshold of 4.5 g for both the left and right first metatarsal head sites predicted the risk of ulceration with a sensitivity of 100% and a specificity of 67%. CONCLUSIONS: Testing of diabetic patients for protective sensation may be simplified to testing under both first metatarsal heads with a 4.5-g monofilament. If a patient cannot sense the application of a 4.5-g monofilament under either first metatarsal head, he or she probably has lost protective sensation and should be considered to be at risk for undetected injury.

Adolescent↗