Accuracy of physical examination for chronic lumbar radiculopathy
1 Bindal Legekontor, Terråk, Norway
2 Department of Physical Medicine and Rehabilitation, University Hospital of North Norway, Tromsø, Norway
3 Department of Ophthalmology and Neurosurgery, University Hospital of North Norway, Tromsø, Norway
4 The Norwegian Registry for Spine Surgery (NORspine), North Norway Regional Health Authority, Tromsø, Norway
5 Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
6 Department of Neurosurgery, The Neuroscience Centre, Rigshospitalet, Copenhagen, Denmark
7 Department of Community Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
8 Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
9 Department of Neurosurgery, St Olavs University Hospital, Trondheim, Norway
10 Department of Neurology, University Hospital of North Norway, Tromsø, Norway
11 Department of Psychology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
12 Section for Back Surgery, Orthopaedic Department, Oslo University Hospital, Oslo, Norway
13 Centre for Clinical Governance Research, Australian Institute of Health Innovation, University of New South Wales, Sydney, NSW, Australia
BMC Musculoskeletal Disorders 2013, 14:206 doi:10.1186/1471-2474-14-206Published: 9 July 2013
Clinical examination of patients with chronic lumbar radiculopathy aims to clarify whether there is nerve root impingement. The aims of this study were to investigate the association between findings at clinical examination and nerve root impingement, to evaluate the accuracy of clinical index tests in a specialised care setting, and to see whether imaging clarifies the cause of chronic radicular pain.
A total of 116 patients referred with symptoms of lumbar radiculopathy lasting more than 12 weeks and at least one positive index test were included. The tests were the straight leg raising test, and tests for motor muscle strength, dermatome sensory loss, and reflex impairment. Magnetic resonance imaging (n = 109) or computer tomography (n = 7) were imaging reference standards. Images were analysed at the level of single nerve root(s), and nerve root impingement was classified as present or absent. Sensitivities, specificities, and positive and negative likelihood ratios (LR) for detection of nerve root impingement were calculated for each individual index test. An overall clinical evaluation, concluding on the level and side of the radiculopathy, was performed.
The prevalence of disc herniation was 77.8%. The diagnostic accuracy of individual index tests was low with no tests reaching positive LR >4.0 or negative LR <0.4. The overall clinical evaluation was slightly more accurate, with a positive LR of 6.28 (95% CI 1.06–37.21) for L4, 1.74 (95% CI 1.04–2.93) for L5, and 1.29 (95% CI 0.97–1.72) for S1 nerve root impingement. An overall clinical evaluation, concluding on the level and side of the radiculopathy was also performed, and receiver operating characteristic (ROC) analysis with area under the curve (AUC) calculation for diagnostic accuracy of this evaluation was performed.
The accuracy of individual clinical index tests used to predict imaging findings of nerve root impingement in patients with chronic lumbar radiculopathy is low when applied in specialised care, but clinicians’ overall evaluation improves diagnostic accuracy slightly. The tests are not very helpful in clarifying the cause of radicular pain, and are therefore inaccurate for guidance in the diagnostic workup of the patients. The study population was highly selected and therefore the results from this study should not be generalised to unselected patient populations in primary care nor to even more selected surgical populations.