title: Adaptation of the lateral distal femur DXA scan technique to adults with disabilities.
abstract: The technique that best addresses the challenges of assessing bone mineral density in children with neuromuscular impairments is a dual-energy X-ray absorptiometry (DXA) scan of the lateral distal femur. The purpose of this study was to adapt this technique to adults with neuromuscular impairments and to assess the reproducibility of these measurements. Thirty-one adults with cerebral palsy had both distal femurs scanned twice, with the subject removed and then repositioned between each scan (62 distal femurs, 124 scans). Each scan was independently analyzed twice by 3 different technologists of varying experience with DXA (744 analyses). Precision of duplicate analyses of the same scan was good (range: 0.4%-2.3%) and depended on both the specific region of interest and the experience of the technologist. Precision was reduced when comparing duplicate scans, ranging from 7% in the metaphyseal (cancellous) region to 2.5% in the diaphyseal (cortical) region. The least significant change was determined as recommended by the International Society for Clinical Densitometry for each technologist and each region of interest. Obtaining reliable, reproducible, and clinically relevant assessments of bone mineral density in adults with neuromuscular impairments can be challenging. The technique of obtaining DXA scans of the lateral distal femur can be successfully applied to this population but requires a commitment to developing the necessary expertise.
authors.affiliation: Department of Orthopaedics, University of North Carolina, Chapel Hill, NC, USA; Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Henderson
authors.affiliation: Department of Orthopaedics, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Henderson
authors.affiliation: Department of Biomedical Research, Nemours/A. I. duPont Hospital for Children, Wilmington, DE, USA; Department of Medical Imaging, Nemours/A. I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: Heidi H
authors.initials: HH
authors.lastname: Kecskemethy
authors.affiliation: Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Sebastian T
authors.initials: ST
authors.lastname: Hidalgo
authors.affiliation: Imaging Technologist, Gillette Children's Specialty Care, St. Paul, MN, USA.
authors.forename: Beth Ann
authors.initials: BA
authors.lastname: Nikolova
authors.affiliation: Adult and Pediatric Endocrinology, Gillette Children's Specialty Care, St. Paul, MN, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Sheridan
authors.affiliation: Department of Medical Imaging, Nemours/A. I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: H Theodore
authors.initials: HT
authors.lastname: Harcke
authors.affiliation: Division of Neuromuscular Therapy, Department of Allied Health Sciences, School of Medicine, Center for Human Movement Science, University of North Carolina, Chapel Hill, NC, USA. Electronic address: dthorpe54@gmail.com.
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Thorpe
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D015519:Bone Density; D002983:Clinical Competence / Q000592:standards; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009468:Neuromuscular Diseases / Q000503:physiopathology; D056888:Patient Positioning / Q000379:methods*; D058996:Quality Improvement; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods / Q000592:standards; D015203:Reproducibility of Results
keywords: Adults; DXA scan; cerebral palsy; distal femur; skeletal fragility