Schwarzer A C, Aprill C N, Derby R, Fortin J, Kine G, Bogduk N
Faculty of Medicine, The University of Newcastle, Callaghan, NSW, 2308 Australia Magnolia Diagnostics, New Orleans, LA 70175-5252 USA Spinecare, Daly City, CA 94015 USA Diagnostic Conservative Management, New Orleans, LA, 70115 USA.
Pain. 1994 Aug;58(2):195-200. doi: 10.1016/0304-3959(94)90199-6.
One hundred and seventy-six consecutive patients with chronic low back pain and no history of previous lumbar surgery were studied to determine the false-positive rate of single diagnostic blocks of the lumbar zygapophysial joints. All patients underwent diagnostic blocks using lignocaine. Those patients who obtained definite or complete relief from these blocks subsequently underwent confirmatory blocks using bupivacaine. Eighty-three patients (47%) had a definite or greater response to the initial, lignocaine injection at one or more levels but only 26 (15%) had a 50% or greater response to a confirmatory injection of 0.5% bupivacaine. Using the response to confirmatory blocks as the criterion standard, the false-positive rate of uncontrolled diagnostic blocks was 38% and the positive predictive value of these blocks was only 31%. Because the positive predictive value of a test is lower when the pre-test probability (prevalence) is low, and because the prevalence of lumbar zygapophysial joint pain is likely to be less than 50%, uncontrolled diagnostic blocks will always be associated with an unacceptably low positive predictive value. These features render uncontrolled diagnostic blocks unreliable for the diagnosis of lumbar zygapophysial joint pain not only in epidemiologic studies but also in any given patient.
对176例慢性下腰痛且无既往腰椎手术史的连续患者进行研究，以确定腰椎关节突关节单次诊断性阻滞的假阳性率。所有患者均使用利多卡因进行诊断性阻滞。那些从这些阻滞中获得明确或完全缓解的患者随后使用布比卡因进行验证性阻滞。83例患者（47%）在一个或多个节段对初始的利多卡因注射有明确或更强的反应，但只有26例（15%）对0.5%布比卡因的验证性注射有50%或更强的反应。以验证性阻滞的反应作为标准，未控制的诊断性阻滞的假阳性率为38%，这些阻滞的阳性预测值仅为31%。由于当检验前概率（患病率）较低时，检验的阳性预测值较低，并且由于腰椎关节突关节疼痛的患病率可能低于50%，未控制的诊断性阻滞总是会有低得令人无法接受的阳性预测值。这些特征使得未控制的诊断性阻滞不仅在流行病学研究中，而且在任何特定患者中，对于腰椎关节突关节疼痛的诊断都不可靠。
