title: Comparison of lifts versus tape measure in determining leg length discrepancy.
abstract: OBJECTIVE
  To evaluate the validity (accuracy) and reliability of 2 commonly used clinical methods, 1 indirect (lifts) and 1 direct (tape measure), for assessment of leg length discrepancy (LLD) in comparison to radiograph.
  
  
  METHODS
  Twenty subjects suspected of having LLD participated in this study. Two clinical methods, 1 direct using a tape measure and 1 indirect using lifts, were standardized and carried out by 4 examiners. Difference in height of the femoral heads on standing pelvic radiograph was measured and served as the gold standard.
  
  
  RESULTS
  The intraclass correlation coefficient assessing interobserver reliability was 0.737 for lifts and 0.477 for tape measure. The remainder of the analysis is based on the average of the measurements by the 4 examiners. Pearson correlation coefficients were 0.93 for the lifts and 0.75 for the tape measure method. Paired sample t tests showed difference in means of 2 mm (p = 0.051) for lifts and -5 mm (p = 0.007) for tape measure compared with radiograph. Sensitivity and specificity were 55% and 89% for lifts and 45% and 56% for tape measure, respectively, using > 5 mm as the definition for LLD. The wrong leg was identified as being shorter in 1 out of 20 subjects using lifts versus 7 out of 20 using tape measure.
  
  
  CONCLUSIONS
  The indirect standing method of LLD measurement using lifts had superior validity, interobserver reliability, and specificity in comparison with radiograph over the direct supine method using tape measure. Both clinical methods underestimated LLD compared with radiograph.
authors.affiliation: From the Division of Rheumatology, Department of Medicine, and the Department of Radiology, and the Department of Health Care and Epidemiology, University of British Columbia (UBC); Pacific Arthritis Center, Vancouver, British Columbia, Canada.M. Badii, MD, MHSc, Division of Rheumatology, Department of Medicine, UBC; A.N. Wade, BSc Candidate, Research Associate, Pacific Arthritis Center; D.R. Collins, MD, Division of Rheumatology, Department of Medicine, UBC; S. Nicolaou, Department of Radiology, UBC; B.J. Kobza, MPT, Physiotherapy, Pacific Arthritis Center; J.A. Kopec, MD, PhD, Department of Health Care and Epidemiology, UBC.
authors.forename: Maziar
authors.initials: M
authors.lastname: Badii
authors.affiliation: From the Division of Rheumatology, Department of Medicine, and the Department of Radiology, and the Department of Health Care and Epidemiology, University of British Columbia (UBC); Pacific Arthritis Center, Vancouver, British Columbia, Canada.M. Badii, MD, MHSc, Division of Rheumatology, Department of Medicine, UBC; A.N. Wade, BSc Candidate, Research Associate, Pacific Arthritis Center; D.R. Collins, MD, Division of Rheumatology, Department of Medicine, UBC; S. Nicolaou, Department of Radiology, UBC; B.J. Kobza, MPT, Physiotherapy, Pacific Arthritis Center; J.A. Kopec, MD, PhD, Department of Health Care and Epidemiology, UBC. a.nicolewade@gmail.com.
authors.forename: A Nicole
authors.initials: AN
authors.lastname: Wade
authors.affiliation: From the Division of Rheumatology, Department of Medicine, and the Department of Radiology, and the Department of Health Care and Epidemiology, University of British Columbia (UBC); Pacific Arthritis Center, Vancouver, British Columbia, Canada.M. Badii, MD, MHSc, Division of Rheumatology, Department of Medicine, UBC; A.N. Wade, BSc Candidate, Research Associate, Pacific Arthritis Center; D.R. Collins, MD, Division of Rheumatology, Department of Medicine, UBC; S. Nicolaou, Department of Radiology, UBC; B.J. Kobza, MPT, Physiotherapy, Pacific Arthritis Center; J.A. Kopec, MD, PhD, Department of Health Care and Epidemiology, UBC.
authors.forename: David R
authors.initials: DR
authors.lastname: Collins
authors.affiliation: From the Division of Rheumatology, Department of Medicine, and the Department of Radiology, and the Department of Health Care and Epidemiology, University of British Columbia (UBC); Pacific Arthritis Center, Vancouver, British Columbia, Canada.M. Badii, MD, MHSc, Division of Rheumatology, Department of Medicine, UBC; A.N. Wade, BSc Candidate, Research Associate, Pacific Arthritis Center; D.R. Collins, MD, Division of Rheumatology, Department of Medicine, UBC; S. Nicolaou, Department of Radiology, UBC; B.J. Kobza, MPT, Physiotherapy, Pacific Arthritis Center; J.A. Kopec, MD, PhD, Department of Health Care and Epidemiology, UBC.
authors.forename: Savvakis
authors.initials: S
authors.lastname: Nicolaou
authors.affiliation: From the Division of Rheumatology, Department of Medicine, and the Department of Radiology, and the Department of Health Care and Epidemiology, University of British Columbia (UBC); Pacific Arthritis Center, Vancouver, British Columbia, Canada.M. Badii, MD, MHSc, Division of Rheumatology, Department of Medicine, UBC; A.N. Wade, BSc Candidate, Research Associate, Pacific Arthritis Center; D.R. Collins, MD, Division of Rheumatology, Department of Medicine, UBC; S. Nicolaou, Department of Radiology, UBC; B.J. Kobza, MPT, Physiotherapy, Pacific Arthritis Center; J.A. Kopec, MD, PhD, Department of Health Care and Epidemiology, UBC.
authors.forename: B Jacek
authors.initials: BJ
authors.lastname: Kobza
authors.affiliation: From the Division of Rheumatology, Department of Medicine, and the Department of Radiology, and the Department of Health Care and Epidemiology, University of British Columbia (UBC); Pacific Arthritis Center, Vancouver, British Columbia, Canada.M. Badii, MD, MHSc, Division of Rheumatology, Department of Medicine, UBC; A.N. Wade, BSc Candidate, Research Associate, Pacific Arthritis Center; D.R. Collins, MD, Division of Rheumatology, Department of Medicine, UBC; S. Nicolaou, Department of Radiology, UBC; B.J. Kobza, MPT, Physiotherapy, Pacific Arthritis Center; J.A. Kopec, MD, PhD, Department of Health Care and Epidemiology, UBC.
authors.forename: Jacek A
authors.initials: JA
authors.lastname: Kopec
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D035843:Biomedical Research / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D007866:Leg / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D007870:Leg Length Inequality / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010388:Pelvis / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011187:Posture; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: CLINICAL METHODS; LEG LENGTH DISCREPANCY; RADIOGRAPH