Newman M1,2, Hannink E1,2, Barker K1,2
1Nuffield Orthopaedic Centre, Physiotherapy Research Unit, Oxford, United Kingdom, 2University of Oxford, Nuffield Department for Orthopaedic, Rheumatology and Musculoskeletal Sciences, Oxford, United Kingdom
Background: Kyphosis beyond normal ranges has been associated with a variety of poorer health outcomes. Vertebral fractures due to osteoporosis are a common cause of hyperkyphotic posture. Hyperkyphosis leads to increased spinal loading and risk of further fracture. The gold standard for measurement of thoracic kyphosis is the Cobb angle measured from a radiograph; however it brings with it high costs and exposure to potentially harmful radiation, making it inappropriate in most cases for repeated use in screening or as an outcome measure. Three common alternative tools to measure sagittal plane alignment are: occiput to wall distance (OWD), flexicurve ruler and digital inclinometers. The most clinically useful, reliable and valid non-radiological method for people with osteoporosis and vertebral fractures has yet to be established.
Purpose: To investigate the feasibility and reliability of these 3 commonly used methods of measuring thoracic kyphosis in people with symptomatic osteoporosis with vertebral fracture.
Methods: Forty participants were recruited through specialist osteoporosis clinics. Male and female patients over 18 years were eligible for the study if they had a primary diagnosis of osteoporosis, at least one vertebral fracture and a history of back pain lasting at least 24 hours in the past 12 months. In a repeated measures design, all participants were examined by the same assessor at two time points (7-10 days apart). On the second assessment, the participants were also assessed by a second independent assessor who was blinded to the outcomes of the first assessor. Each clinical measurement (OWD, flexicurve and digital inclinometers) was repeated three times for each participant on each assessment.
Results: The participants' mean (SD) age was 71.4 years (9.5), mean (range) number of vertebral fractures was 3.3 (1-9), and 92.5% were women. From the OWD, 19 participants had measurements of 0 cm (occiput touching wall) on at least one occasion. Kappa statistics were high for OWD intra-rater (K=0.796, p=0.000) and inter-rater reliability (K=0.947, p=0.000); and for measurements over 0 cm, Intraclass Correlation Coefficient (ICC) for intra-rater reliability was 0.84 (21 participants) and for inter-rater reliability was 0.92 (24 participants). The ICC for the first and mean flexicurve measurements all demonstrated high intra-rater (0.91-0.93) and inter-rater reliability (0.81-0.95). The ICC values for the inclinometer angle also demonstrated high intra-rater (0.88-0.89) and inter-rater reliability (0.94).
Conclusion(s): While all measures tested had similarly high reliability, we found the flexicurve ruler to be easy to use for all levels of clinician experience and quick to carry out in this older population. The OWD method had a clear floor effect and the inclinometers may be less sensitive to change as it estimated the angle from endpoints of the thoracic region rather than the curvature itself.
Implications: In a clinical situation, the evaluation of these 3 methods favoured use of the flexicurve ruler. The high reliability of the flexicurve ruler method over a clinically relevant period of time in our study suggests that it may be a useful method of measuring the effects of physical rehabilitation treatments on thoracic posture in people with osteoporotic vertebral fractures.
Keywords: Thoracic kyphosis, Osteoporosis, Vertebral fracture
Funding acknowledgements: HTA Project Number - 10/99/01
Purpose: To investigate the feasibility and reliability of these 3 commonly used methods of measuring thoracic kyphosis in people with symptomatic osteoporosis with vertebral fracture.
Methods: Forty participants were recruited through specialist osteoporosis clinics. Male and female patients over 18 years were eligible for the study if they had a primary diagnosis of osteoporosis, at least one vertebral fracture and a history of back pain lasting at least 24 hours in the past 12 months. In a repeated measures design, all participants were examined by the same assessor at two time points (7-10 days apart). On the second assessment, the participants were also assessed by a second independent assessor who was blinded to the outcomes of the first assessor. Each clinical measurement (OWD, flexicurve and digital inclinometers) was repeated three times for each participant on each assessment.
Results: The participants' mean (SD) age was 71.4 years (9.5), mean (range) number of vertebral fractures was 3.3 (1-9), and 92.5% were women. From the OWD, 19 participants had measurements of 0 cm (occiput touching wall) on at least one occasion. Kappa statistics were high for OWD intra-rater (K=0.796, p=0.000) and inter-rater reliability (K=0.947, p=0.000); and for measurements over 0 cm, Intraclass Correlation Coefficient (ICC) for intra-rater reliability was 0.84 (21 participants) and for inter-rater reliability was 0.92 (24 participants). The ICC for the first and mean flexicurve measurements all demonstrated high intra-rater (0.91-0.93) and inter-rater reliability (0.81-0.95). The ICC values for the inclinometer angle also demonstrated high intra-rater (0.88-0.89) and inter-rater reliability (0.94).
Conclusion(s): While all measures tested had similarly high reliability, we found the flexicurve ruler to be easy to use for all levels of clinician experience and quick to carry out in this older population. The OWD method had a clear floor effect and the inclinometers may be less sensitive to change as it estimated the angle from endpoints of the thoracic region rather than the curvature itself.
Implications: In a clinical situation, the evaluation of these 3 methods favoured use of the flexicurve ruler. The high reliability of the flexicurve ruler method over a clinically relevant period of time in our study suggests that it may be a useful method of measuring the effects of physical rehabilitation treatments on thoracic posture in people with osteoporotic vertebral fractures.
Keywords: Thoracic kyphosis, Osteoporosis, Vertebral fracture
Funding acknowledgements: HTA Project Number - 10/99/01
Topic: Outcome measurement; Musculoskeletal: spine; Older people
Ethics approval required: Yes
Institution: NHS Health Research Authority
Ethics committee: South Central - Hampshire B Research Ethics Committee
Ethics number: 12/SC/0390
All authors, affiliations and abstracts have been published as submitted.
