Measurement of Neck-Shaft Angle Using CT Scout View in Healthy Jordanian Adults - A Reliability and Agreement Study
Ibrahim Altubasi *
Department of Physiotherapy, School of Rehabilitation Sciences, The University of Jordan, Amman 11942, Jordan.
Hayat Hamzeh
Department of Physiotherapy, School of Rehabilitation Sciences, The University of Jordan, Amman 11942, Jordan.
Mohammad Madi
Department of Physiotherapy and Occupational Therapy, Faculty of Applied Health Sciences, Hashemite University, Zarqa 13133, Jordan.
*Author to whom correspondence should be addressed.
Abstract
Aims: To report estimates of the reliability and agreement of a new method for measuring the femoral Neck-shaft angle in the Jordanian population. The neck-shaft angle is an important anatomical indicator in orthopedics of the hip. While there are different approaches to measuring the neck-shaft angle in the literature, there is no agreement on the best technique used for measurement. CT scout view was used in this study to provide a promising alternative.
Study Design: Observational reliability and agreement study.
Places and Duration of the Study: Department of physiotherapy, school of rehabilitation science, University of Jordan and University of Jordan Hospital between March 2014 and October 2015.
Methodology: Two independent raters calculated the neck-shaft angle on each hip of 50 pelvic CT scout images of healthy adults to determine inter-rater reliability. One rater performed the measurement twice to determine the intra-rater reliability. Intra-class correlation coefficients were used to examine relative reliability. The standard error of measurement (SEM) and 95% minimal detectable change (MDC) were calculated to examine absolute reliability.
Results: The mean value of all angle measurements was 131.3. Intra-class correlation coefficients were 0.726 and 0.63 for inter and intra-rater measurements respectively. SEM and MDC for inter-rater measurements were 2.69 and 7.46 respectively. For intra-rater measurements, they were 2.84 and 7.86 respectively.
Conclusion: The new method proposed in this study for measuring the neck-shaft angle showed good reliability and small measurement error.
Keywords: Neck-shaft angle, reliability, CT scout images, standard error of measurement, minimal detectable change.