The Accuracy of the Physical Examination for the Diagnosis of Midlumbar and Low Lumbar Nerve Root Impingement

Division of Research, New England Baptist Hospital, Boston, MA, USA.
Spine (Impact Factor: 2.3). 01/2011; 36(1):63-73. DOI: 10.1097/BRS.0b013e3181c953cc
Source: PubMed


Cross-sectional study with prospective recruitment. OBJECTIVE.: To determine the accuracy of the physical examination for the diagnosis of midlumbar nerve root impingement (L2, L3, or L4), low lumbar nerve root impingement (L5 or S1) and level-specific lumbar nerve root impingement on magnetic resonance imaging, using individual tests and combinations of tests.
The sensitivity and specificity of the physical examination for the localization of nerve root impingement has not been previously studied.
Sensitivities, specificities, and likelihood ratios (LRs) were calculated for the ability of individual tests and test combinations to predict the presence or absence of nerve root impingement at midlumbar, low lumbar, and specific nerve root levels.
LRs ≥5.0 indicate moderate to large changes from pre-test probability of nerve root impingement to post-test probability. For the diagnosis of midlumbar impingement, the femoral stretch test (FST), crossed FST, medial ankle pinprick sensation, and patellar reflex testing demonstrated LRs ≥5.0 (LR ∞). LRs ≥5.0 were observed with the combinations of FST and either patellar reflex testing (LR 7.0; 95% confidence interval [CI] 2.3-21) or the sit-to-stand test (LR ∞). For the diagnosis of low lumbar impingement, the Achilles reflex test demonstrated an LR ≥5.0 (LR 7.1; 95% CI 0.96-53); test combinations did not increase LRs. For the diagnosis of level-specific impingement, LRs ≥5.0 were observed for anterior thigh sensation at L2 (LR 13; 95% CI 1.8-87); FST at L3 (LR 5.7; 95% CI 2.3-4.4); patellar reflex testing (LR 7.7; 95% CI 1.7-35), medial ankle sensation (LR ∞), or crossed FST (LR 13; 95% CI 1.8-87) at L4; and hip abductor strength at L5 (LR 11; 95% CI 1.3-84). Test combinations increased LRs for level-specific root impingement at the L4 level only.
Individual physical examination tests may provide clinical information that substantially alters the likelihood that midlumbar impingement, low lumbar impingement, or level-specific impingement is present. Test combinations improve diagnostic accuracy for midlum-bar impingement.

Full-text preview

Available from:
  • Source
    • "Six studies with a total population of 849 patients used radiology as the reference standard to detect a lumbar disc herniation. Three studies evaluated the ability of these tests to diagnose disc herniation at any lumbar spine level [20] [42] [44], whereas the other three studies investigated neurological tests to diagnose specific levels of disc herniation [35] [37] [43]. In the former three studies, sensory testing data were only able to be pooled in a meta-analysis. "
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND CONTEXT: Disc herniation is a common low back pain (LBP) disorder, and several clinical test procedures are routinely employed in its diagnosis. The neurological examination that assesses sensory neuron and motor responses has historically played a role in the differential diagnosis of disc herniation, particularly when radiculopathy is suspected; however, the diagnostic ability of this examination has not been explicitly investigated. PURPOSE: To review the scientific literature to evaluate the diagnostic accuracy of the neurological examination to detect lumbar disc herniation with suspected radiculopathy. STUDY DESIGN: A systematic review and meta-analysis of the literature. METHODS: Six major electronic databases were searched with no date or language restrictions for relevant articles up until March 2011. All diagnostic studies investigating neurological impairments in LBP patients because of lumbar disc herniation were assessed for possible inclusion. Retrieved studies were individually evaluated and assessed for quality using the Quality Assessment of Diagnostic Accuracy Studies tool, and where appropriate, a meta-analysis was performed. RESULTS: A total of 14 studies that investigated three standard neurological examination components, sensory, motor, and reflexes, met the study criteria and were included. Eight distinct meta-analyses were performed that compared the findings of the neurological examination with the reference standard results from surgery, radiology (magnetic resonance imaging, computed tomography, and myelography), and radiological findings at specific lumbar levels of disc herniation. Pooled data for sensory testing demonstrated low diagnostic sensitivity for surgically (0.40) and radiologically (0.32) confirmed disc herniation, and identification of a specific level of disc herniation (0.35), with moderate specificity achieved for all the three reference standards (0.59, 0.72, and 0.64, respectively). Motor testing for paresis demonstrated similarly low pooled diagnostic sensitivities (0.22 and 0.40) and moderate specificity values (0.79 and 0.62) for surgically and radiologically determined disc herniation, whereas motor testing for muscle atrophy resulted in a pooled sensitivity of 0.31 and the specificity was 0.76 for surgically determined disc herniation. For reflex testing, the pooled sensitivities for surgically and radiologically confirmed levels of disc herniation were 0.29 and 0.25, whereas the specificity values were 0.78 and 0.75, respectively. The pooled positive likelihood ratios for all neurological examination components ranged between 1.02 and 1.26. CONCLUSIONS: This systematic review and meta-analysis demonstrate that neurological testing procedures have limited overall diagnostic accuracy in detecting disc herniation with suspected radiculopathy. Pooled diagnostic accuracy values of the tests were poor, whereby all tests demonstrated low sensitivity, moderate specificity, and limited diagnostic accuracy independent of the disc herniation reference standard or the specific level of herniation. The lack of a standardized classification criterion for disc herniation, the variable psychometric properties of the testing procedures, and the complex pathoetiology of lumbar disc herniation with radiculopathy are suggested as possible reasons for these findings.
    Full-text · Article · Mar 2013 · The spine journal: official journal of the North American Spine Society
  • Source
    • "Straight leg raise and femoral nerve traction tests are commonly performed orthopedic maneuvers done to ascertain the presence of a lumbar disc herniation [16,17]. Femoral nerve traction testing has a reported sensitivity of 50% and specificity of 100% for the diagnosis of midlumbar nerve root impingement, and appears to be insensitive and only 50% specific for lower lumbar nerve root impingement [18]. Straight leg raise testing has sensitivity and specificity characteristics of 16% and 31% respectively for midlumbar nerve root impingement. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To present a group of anatomical findings that may have clinical significance. This study is an anatomical case report of combined lumbo-pelvic peripheral nerve and muscular variants. University anatomy laboratory. One cadaveric specimen. During routine cadaveric dissection for a graduate teaching program, unilateral femoral and bilateral sciatic nerve variants were observed in relation to the iliacus and piriformis muscle, respectively. Further dissection of both the femoral nerve and accessory slip of iliacus muscle was performed to fully expose their anatomy. Piercing of the femoral nerve by an accessory iliacus muscle combined with wide variations in sciatic nerve and piriformis muscle presentations may have clinical significance. Combined femoral and sciatic nerve variants should be considered when treatment for a lumbar disc herniation is refractory to care despite positive orthopedic testing.
    Full-text · Article · Oct 2012
  • Source
    • "Participants in both the independent and non-independent groups received a standard battery of physical examination tests which are used commonly in specialty spine care, and are routinely administered in a stereotyped manner in our clinic for the evaluation of lumbosacral radicular pain. Table 1 summarizes the physical examination tests performed; details of the testing methods used in this study are described in depth elsewhere [7-11]. The physical examination consisted of four components: 1) provocative testing, 2) motor strength testing, 3) pinprick sensation testing, and 4) deep tendon reflex testing. "
    [Show abstract] [Hide abstract]
    ABSTRACT: No prior studies have examined systematic bias in the musculoskeletal physical examination. The objective of this study was to assess the effects of bias due to prior knowledge of lumbar spine magnetic resonance imaging findings (MRI) on perceived diagnostic accuracy of the physical examination for lumbar radiculopathy. This was a cross-sectional comparison of the performance characteristics of the physical examination with blinding to MRI results (the 'independent group') with performance in the situation where the physical examination was not blinded to MRI results (the 'non-independent group'). The reference standard was the final diagnostic impression of nerve root impingement by the examining physician. Subjects were recruited from a hospital-based outpatient specialty spine clinic. All adults age 18 and older presenting with lower extremity radiating pain of duration ≤ 12 weeks were evaluated for participation. 154 consecutively recruited subjects with lumbar disk herniation confirmed by lumbar spine MRI were included in this study. Sensitivities and specificities with 95% confidence intervals were calculated in the independent and non-independent groups for the four components of the radiculopathy examination: 1) provocative testing, 2) motor strength testing, 3) pinprick sensory testing, and 4) deep tendon reflex testing. The perceived sensitivity of sensory testing was higher with prior knowledge of MRI results (20% vs. 36%; p = 0.05). Sensitivities and specificities for exam components otherwise showed no statistically significant differences between groups. Prior knowledge of lumbar MRI results may introduce bias into the pinprick sensory testing component of the physical examination for lumbar radiculopathy. No statistically significant effect of bias was seen for other components of the physical examination. The effect of bias due to prior knowledge of lumbar MRI results should be considered when an isolated sensory deficit on examination is used in medical decision-making. Further studies of bias should include surgical clinic populations and other common diagnoses including shoulder, knee and hip pathology.
    Preview · Article · Nov 2010 · BMC Musculoskeletal Disorders
Show more