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Precision of periprosthetic BMD after total knee arthroplasty
216
Abstracts
fracture risk is of interest. This study evaluated the reliability and reproducibility of height measurements among technologists in a clinical DXA laboratory setting. Fifty subjects referred for BMD testing were recruited to have their height measured a total of six times, twice each by three technologists. Participants were measured in stockinged- or bare-feet with a ruler affixed to an exam room wall to the nearest 1/16th inch. A triangle was used to square the measurements to the wall, and participants were repositioned between measurements. The average patient height was 63.9 inches (range 58.1e69.7). Mean height measurements between the three technologists were not significantly different by ANOVA (p 5 0.15). CV of between-technologist precision was 0.42%, with a least significant change (LSC) of 0.75 inches. Within-subject precision was good for all 3 technologists, with one tech (C) slightly more precise than the other two (p 5 0.0087).
has not been reported following TKA using the GE dedicated knee application software. Subjects underwent TKA with an uncemented tantalum (HedrocelÒ) tibial base plate and a cemented CoCr cruciate-retaining femoral component. Scans were performed six weeks post-surgery with a GE Healthcare Lunar Prodigy densitometer (software version 11.1). Fourteen subjects were measured 3 times in the supine position, repositioning between scans. Three user-designed regions-of-interest (ROI) in the proximal tibial metaphysics were selected. ROIs 1 and 2 were adjacent rectangles measuring 4.7 1.6 cm centered below the base plate and each included one of two base plate pegs. ROI 3 (6.0 1.5 cm) was centered directly below ROIs 1 and 2 and extended beyond the tibial outer margins. Average (SD) age, height and weight of 12 males and 2 females was 56.2 (7.4) years, 179.3 (7.3) cm, 102.9 (17.9) kg, respectively. BMD precision error measured using the root-mean-square method ranged from 3.0% to 3.6% for each of the three regions, with slightly better precision (2.8% error) for the three sites combined. Precision errors indicate that anticipated BMD changes greater than 8 10%, depending on ROI, would be detected as a significant change from baseline in an individual patient. Periprosthetic tibial BMD is a valid methodology as a research tool to study tibial bone density following TKA.
Poster Number 163 Poster Number 161
Patient Education
IS A PATIENT-FOCUSED POSTER ABOUT DUAL-ENERGY X-RAY ABSORPTIOMETRY (DXA) USEFUL FOR PATIENT EDUCATION? SL Morgan, MD, RD, CCD, Professor of Nutrition Sciences and Medicine, University of Alabama at Birmingham N Nunnally, RT (R), CDT, DXA Technologist, The Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL; L Burroughs, RT (R), CDT, DXA Technologist, The UAB Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL; MB Hager, Clinic Nurse-Team Leader, The Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL; N Norris, RN, BSN, CNOR, Director TKC Clinical Services, The Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL We developed a patient-focused poster which was placed on the wall of both dualenergy x-ray absorptiometry (DXA) rooms so that it was easily visualized by a patient lying on the DXA table. The poster defined osteoporosis and discussed DXA scans, vertebral fracture analysis (VFA) and T-scores with many visual examples. Exemption from IRB approval was obtained to do a survey of our DXA population about the poster s usefulness. After completion of a DXA scan, patients were randomly asked if they would complete a survey by the DXA technologists from September 1eOctober 31, 2006. 242 surveys were completed. The mean age of the respondents was 58.6 years, 84.4% were female; 31% indicated that they have a diagnosis of osteopenia or osteoporosis, 33% were currently taking a medication for osteoporosis/osteopenia and 7.9% had fractures after the age of 45 not related to trauma. 67.8% of individuals stated that they did notice the poster. 40.9% of the patients indicated that the poster information was easy to understand and 16.94% said that the poster was somewhat easy to understand. 31.8% stated that the poster improved their understanding about the diagnosis of osteoporosis and 19.83% stated that the poster somewhat improved their understanding of osteoporosis. 34.7% stated that they will be more likely to talk to their physician about their bones and 10.7% said they were somewhat more likely to talk to their physician. We conclude that patient education posters on the wall of DXA rooms are useful for teaching DXA patients.
Peripheral DXA
EFFECT OF PTH THERAPY ON RADIOGRAPHIC TEXTURE ANALYSIS (RTA) OF THE DENSITOMETRIC HEEL IMAGES Tamara Vokes, MD, Associate Professor of Endocrinology, University of Chicago Kristen Kasza, Department of Health Studies, University of Chicago; Joel Wilkie, Department of Radiology, University of Chicago; Ann Pham, Department of Medicine, University of Chicago; Maryellen Giger Purpose: RTA is a new method for non-invasive assessment of bone structure from computerized analysis of the pattern of bone radiographs. We have reported that RTA performed on high resolution (0.2 mm) calcaneal images from the peripheral densitometer differentiates patients with and without fractures. In this study we investigated whether RTA can detect changes in bone structure during anabolic therapy for osteoporosis. Methods: We measured the BMD of the lumbar spine, proximal femur and heel, and performed RTA on densitometric heel images at 0, 6, 12 and 18 months during treatment of osteoporotic postmenopausal women with 1,84 PTH or placebo (10 per group). All subjects received calcium and vitamin D supplementation. For statistical analysis we used repeated measures ANOVA with time as within-subject and treatment as between-subject factor. Results: The BMD did not change in placebo treated patients but increased at some sites in PTH group resulting in significant difference between groups (treatment-time interaction) for spine (p 5 0.03), and total hip (p 5 0.05), but not for femoral neck and heel. RTA features also showed significant difference between groups for Minkowski fractal (a measure of roughness-smoothness of the texture pattern, p 5 0.01), and for RMS (root mean square variation, the difference in the contrast between light and dark areas, p 5 0.03). Conclusion: These preliminary findings suggest that RTA performed on high resolution densitometric images may be a sensitive way of examining changes in bone structure during treatment of osteoporosis, at least with anabolic agents.
Poster Number 165
Prevention and Treatment of Osteoporosis
FRACTURE CLINIC MANAGEMENT OF OSTEOPOROTIC FRAGILITY FRACTURES
Poster Number 162
Peripheral DXA
PRECISION OF PERIPROSTHETIC BMD AFTER TOTAL KNEE ARTHROPLASTY C Simonelli, MD, CCD, Director, HealthEast Osteoporosis Care and Assoc. MC Schoeller, HealthEast Osteoporosis Care; AK Harrison, Dept. of Surgery, University of Minnesota; TJ Gioe, Adjunct Professor of Surgery, University of Minnesota We report the precision of DXA in measuring peri-prosthetic bone of the tibia following total knee arthroplasty (TKA). DXA is a useful technique for quantifying periprosthetic BMD changes around proximal femoral implants, but precision data
Journal of Clinical Densitometry
Rafid Al-Mahfoudh, MBChB, Surgical SHO Mersey Deanery, UK Purpose: To determine the demographics of patients with fragility fractures attending # clinic. To ascertain if the NICE guidelines for managing fragility # are being followed. To determine how to improve the practice, policies and care pathways for patients with osteoporotic fragility fractures. Methods: Prospective study. 2 weeks of # clinic discharges were included 18/03/06e31/03/06. Patients with osteoporotic fractures were identified and analysed (site of #, previous fragility fractures, risk factors, BMD measurement, prescription of Ca supplements and biphosphonates when indicated)
Volume 10, 2007
Abstracts
fracture risk is of interest. This study evaluated the reliability and reproducibility of height measurements among technologists in a clinical DXA laboratory setting. Fifty subjects referred for BMD testing were recruited to have their height measured a total of six times, twice each by three technologists. Participants were measured in stockinged- or bare-feet with a ruler affixed to an exam room wall to the nearest 1/16th inch. A triangle was used to square the measurements to the wall, and participants were repositioned between measurements. The average patient height was 63.9 inches (range 58.1e69.7). Mean height measurements between the three technologists were not significantly different by ANOVA (p 5 0.15). CV of between-technologist precision was 0.42%, with a least significant change (LSC) of 0.75 inches. Within-subject precision was good for all 3 technologists, with one tech (C) slightly more precise than the other two (p 5 0.0087).
has not been reported following TKA using the GE dedicated knee application software. Subjects underwent TKA with an uncemented tantalum (HedrocelÒ) tibial base plate and a cemented CoCr cruciate-retaining femoral component. Scans were performed six weeks post-surgery with a GE Healthcare Lunar Prodigy densitometer (software version 11.1). Fourteen subjects were measured 3 times in the supine position, repositioning between scans. Three user-designed regions-of-interest (ROI) in the proximal tibial metaphysics were selected. ROIs 1 and 2 were adjacent rectangles measuring 4.7 1.6 cm centered below the base plate and each included one of two base plate pegs. ROI 3 (6.0 1.5 cm) was centered directly below ROIs 1 and 2 and extended beyond the tibial outer margins. Average (SD) age, height and weight of 12 males and 2 females was 56.2 (7.4) years, 179.3 (7.3) cm, 102.9 (17.9) kg, respectively. BMD precision error measured using the root-mean-square method ranged from 3.0% to 3.6% for each of the three regions, with slightly better precision (2.8% error) for the three sites combined. Precision errors indicate that anticipated BMD changes greater than 8 10%, depending on ROI, would be detected as a significant change from baseline in an individual patient. Periprosthetic tibial BMD is a valid methodology as a research tool to study tibial bone density following TKA.
Poster Number 163 Poster Number 161
Patient Education
IS A PATIENT-FOCUSED POSTER ABOUT DUAL-ENERGY X-RAY ABSORPTIOMETRY (DXA) USEFUL FOR PATIENT EDUCATION? SL Morgan, MD, RD, CCD, Professor of Nutrition Sciences and Medicine, University of Alabama at Birmingham N Nunnally, RT (R), CDT, DXA Technologist, The Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL; L Burroughs, RT (R), CDT, DXA Technologist, The UAB Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL; MB Hager, Clinic Nurse-Team Leader, The Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL; N Norris, RN, BSN, CNOR, Director TKC Clinical Services, The Osteoporosis Prevention and Treatment Clinic, The Kirklin Clinic, The University of Alabama at Birmingham, Birmingham, AL We developed a patient-focused poster which was placed on the wall of both dualenergy x-ray absorptiometry (DXA) rooms so that it was easily visualized by a patient lying on the DXA table. The poster defined osteoporosis and discussed DXA scans, vertebral fracture analysis (VFA) and T-scores with many visual examples. Exemption from IRB approval was obtained to do a survey of our DXA population about the poster s usefulness. After completion of a DXA scan, patients were randomly asked if they would complete a survey by the DXA technologists from September 1eOctober 31, 2006. 242 surveys were completed. The mean age of the respondents was 58.6 years, 84.4% were female; 31% indicated that they have a diagnosis of osteopenia or osteoporosis, 33% were currently taking a medication for osteoporosis/osteopenia and 7.9% had fractures after the age of 45 not related to trauma. 67.8% of individuals stated that they did notice the poster. 40.9% of the patients indicated that the poster information was easy to understand and 16.94% said that the poster was somewhat easy to understand. 31.8% stated that the poster improved their understanding about the diagnosis of osteoporosis and 19.83% stated that the poster somewhat improved their understanding of osteoporosis. 34.7% stated that they will be more likely to talk to their physician about their bones and 10.7% said they were somewhat more likely to talk to their physician. We conclude that patient education posters on the wall of DXA rooms are useful for teaching DXA patients.
Peripheral DXA
EFFECT OF PTH THERAPY ON RADIOGRAPHIC TEXTURE ANALYSIS (RTA) OF THE DENSITOMETRIC HEEL IMAGES Tamara Vokes, MD, Associate Professor of Endocrinology, University of Chicago Kristen Kasza, Department of Health Studies, University of Chicago; Joel Wilkie, Department of Radiology, University of Chicago; Ann Pham, Department of Medicine, University of Chicago; Maryellen Giger Purpose: RTA is a new method for non-invasive assessment of bone structure from computerized analysis of the pattern of bone radiographs. We have reported that RTA performed on high resolution (0.2 mm) calcaneal images from the peripheral densitometer differentiates patients with and without fractures. In this study we investigated whether RTA can detect changes in bone structure during anabolic therapy for osteoporosis. Methods: We measured the BMD of the lumbar spine, proximal femur and heel, and performed RTA on densitometric heel images at 0, 6, 12 and 18 months during treatment of osteoporotic postmenopausal women with 1,84 PTH or placebo (10 per group). All subjects received calcium and vitamin D supplementation. For statistical analysis we used repeated measures ANOVA with time as within-subject and treatment as between-subject factor. Results: The BMD did not change in placebo treated patients but increased at some sites in PTH group resulting in significant difference between groups (treatment-time interaction) for spine (p 5 0.03), and total hip (p 5 0.05), but not for femoral neck and heel. RTA features also showed significant difference between groups for Minkowski fractal (a measure of roughness-smoothness of the texture pattern, p 5 0.01), and for RMS (root mean square variation, the difference in the contrast between light and dark areas, p 5 0.03). Conclusion: These preliminary findings suggest that RTA performed on high resolution densitometric images may be a sensitive way of examining changes in bone structure during treatment of osteoporosis, at least with anabolic agents.
Poster Number 165
Prevention and Treatment of Osteoporosis
FRACTURE CLINIC MANAGEMENT OF OSTEOPOROTIC FRAGILITY FRACTURES
Poster Number 162
Peripheral DXA
PRECISION OF PERIPROSTHETIC BMD AFTER TOTAL KNEE ARTHROPLASTY C Simonelli, MD, CCD, Director, HealthEast Osteoporosis Care and Assoc. MC Schoeller, HealthEast Osteoporosis Care; AK Harrison, Dept. of Surgery, University of Minnesota; TJ Gioe, Adjunct Professor of Surgery, University of Minnesota We report the precision of DXA in measuring peri-prosthetic bone of the tibia following total knee arthroplasty (TKA). DXA is a useful technique for quantifying periprosthetic BMD changes around proximal femoral implants, but precision data
Journal of Clinical Densitometry
Rafid Al-Mahfoudh, MBChB, Surgical SHO Mersey Deanery, UK Purpose: To determine the demographics of patients with fragility fractures attending # clinic. To ascertain if the NICE guidelines for managing fragility # are being followed. To determine how to improve the practice, policies and care pathways for patients with osteoporotic fragility fractures. Methods: Prospective study. 2 weeks of # clinic discharges were included 18/03/06e31/03/06. Patients with osteoporotic fractures were identified and analysed (site of #, previous fragility fractures, risk factors, BMD measurement, prescription of Ca supplements and biphosphonates when indicated)
Volume 10, 2007