Posterior disk displacement: morphologic assessment and measurement reliability--cervical spine.

BACKGROUND: Magnetic resonance imaging (MRI) is often used to assess for disk displacement after manipulation, but limited information about the true incidence of iatrogenic herniations exists. Preliminary data must be obtained concerning the size of different types of displacement to further assess this relationship. The reliability of chiropractic radiologists in assessing disks, and a comparison of measuring devices should be evaluated. OBJECTIVE: To identify average measurements for normal and displaced disks and to assess the reliability of measurements by chiropractic radiologists. STUDY DESIGN: Intraobserver and interobserver reliability study assessing cervical disk displacement on MRI scans. METHODS: Three evaluators assessed the disks on 106 MRI scans. Six categories were assessed and compared. Thirty-seven scans were reassessed for intraobserver comparisons. Interobserver and intraobserver variations and measurement-device correlations were determined. RESULTS: Interexaminer measurement reliability for the 2 devices was 0.80 to 0.84. Intraexaminer reliability ranged from 0.58 to 0.94. Interexaminer and intraexaminer agreement for the presence of disk displacement was 86% (kappa = 0.69) and 78% to 85% (kappa = 0.50-0.67), respectively; for the presence of osteophytes, 92% (kappa = 0.54) and 86% to 95% (kappa = 0.60-0.80); and for the classification of disk displacements, 76% (kappa = 0.53) and 73% to 80% (kappa 0.44-0.61). Distinguishing between normal versus bulged disks demonstrated the greatest classification disagreement. Clear size differences between the types of disk displacement were noted. The ruler and digitizer correlation coefficient was 0.96. CONCLUSIONS: Interexaminer and intraexaminer agreement were good to very good concerning measurements and fair to good concerning disk assessments. Different disk displacement types demonstrated obvious mean size differences. No significant mean difference in measurements between the ruler and the digitizer was noted.

Posterior disk displacement: morphologic assessment and measurement reliability-lumbar spine.

BACKGROUND: Magnetic resonance imaging is often used to assess for disk displacement after manipulation, but limited information about the true incidence of iatrogenic herniations exists. To design a study that evaluates for a causal relationship, preliminary data must be obtained relating to the size of different types of disk displacement. The reliability of chiropractic radiologists in assessing disks and a comparison of different measuring devices should also be evaluated. OBJECTIVE: To identify average measurements for normal and displaced disks and to assess the reliability of measurements by chiropractic radiologists. STUDY DESIGN: Intraobserver and interobserver reliability study assessing disk displacement on magnetic resonance scans. METHODS: Three evaluators assessed the disks on 122 magnetic resonance scans from two imaging centers. Six categories were graded, and digitizer and ruler measurements were compared. Forty-four scans were reassessed for intraobserver agreement. Intraobserver and interobserver variations were measured with intraclass correlation coefficient and kappa statistical analysis. Measurement device correlation was assessed with Pearson's r. RESULTS: Clear size differences between different types of disk displacement were noted. Interexaminer measurement reliability was 0.78 to 0.84. Agreement concerning the presence of disk displacement was 85% (kappa = 0.68), and the classification of disk displacements was 76% (kappa = 0.60). Intraexaminer measurement reliability was 0.40 to 0.49. Intraexaminer agreement concerning the presence of disk displacement was 76% (kappa = 0.52), and the classification of disk displacements was 62% to 69% (kappa = 0.38 to 0.46). Normal versus bulged disk distinctions demonstrated the most disagreement. The ruler and digitizer correlation coefficient was 0.968. CONCLUSIONS: Different disk types demonstrated distinct size averages. Interexaminer agreement was good concerning disk assessment and measurements. Intraexaminer agreement was lower than expected. A millimetric ruler is an acceptable alternative to digital measurement devices.

Interexaminer reliability of the palpation of trigger points in the trunk and lower limb muscles.

OBJECTIVES: To determine the interexaminer reliability of palpation of three characteristics of trigger points (taut band, local twitch response, and referred pain) in patients with subacute low back pain, to determine whether training in palpation would improve reliability, and whether there was a difference between the physiatric and chiropractic physicians. DESIGN: Reliability study. SETTING: Whittier Health Campus, Los Angeles College of Chiropractic. PARTICIPANTS: Twenty-six nonsymptomatic individuals and 26 individuals with subacute low back pain. INTERVENTION: Twenty muscles per individual were first palpated by an expert and then randomly by four physician examiners. MAIN OUTCOME MEASURES: Palpation findings. RESULTS: Kappa scores for palpation of taut bands, local twitch responses, and referred pain were .215, .123, and .342, respectively, between the expert and the trained examiners, and .050, .118, and .326, respectively, between the expert and the untrained examiners. Kappa scores for agreement for palpation of taut bands, twitch responses, and referred pain were .108, -.001, and .435, respectively, among the nonexpert, trained examiners, and -.019, .022, and .320, respectively, among the nonexpert, untrained examiners. CONCLUSIONS: Among nonexpert physicians, physiatric or chiropractic, trigger point palpation is not reliable for detecting taut band and local twitch response, and only marginally reliable for referred pain after training.