Laslett Mark, McDonald Barry, Aprill Charles N, Tropp Hans, Oberg Birgitta
PhysioSouth, Moorhouse Medical Centre, 3 Pilgrim Place, Christchurch, 8002, New Zealand.
Spine J. 2006 Jul-Aug;6(4):370-9. doi: 10.1016/j.spinee.2006.01.004.
Only controlled intra-articular zygapophyseal joint (ZJ) injections or medial branch blocks can diagnose ZJ-mediated low back pain. The low prevalence of ZJ pain implies that identification of clinical predictors of a positive response to a screening block is needed.
To estimate the predictive power of clinical findings in relation to pain reduction after screening ZJ blocks.
As part of a wider prospective blinded study investigating diagnostic accuracy of clinical variables, a secondary analysis was carried out to seek evidence of variables potentially valuable as predictors of screening ZJ block outcomes.
Chronic low back pain patients received screening ZJ blocks (n=151) with 120 patients included in the analysis after exclusions.
Pain intensity was measured using a 100-mm visual analog scale, and responses were categorized according to 75% through 95% or more pain reduction in 5% increments.
Patients completed pain drawings, questionnaires, and a clinical examination before screening lumbar ZJ blocks. History, demographic and clinical variables were evaluated in cross tabulation and regression analyses with diagnostic accuracy values calculated for variables and variable clusters in relation to different pain reduction standards.
At the 75% pain reduction standard, 24.5% responded to screening ZJ blocks and 10.8% responded at the 95% standard. The centralization phenomenon is not associated with pain reduction using any standard. No variables were useful predictors of post-ZJ block pain reduction of less than 90%. Seven clinical findings were associated with 95% pain reduction after blocks. Five useful clinical prediction rules (CPRs) were found for ruling out a 95% pain reduction (100% sensitivity), and one CPR had a likelihood ratio of 9.7, producing a fivefold improvement in posttest probability.
A negative extension rotation test, the centralization phenomenon, and four CPRs effectively rule out pain ablation after screening ZJ block. One CPR generates a fivefold improvement in posttest probability of a negative or positive response to ZJ block.
只有关节内控制性小关节突关节（ZJ）注射或内侧支阻滞才能诊断ZJ介导的下腰痛。ZJ疼痛的低患病率意味着需要识别筛查阻滞阳性反应的临床预测因素。
评估与筛查ZJ阻滞后疼痛减轻相关的临床发现的预测能力。
作为一项更广泛的前瞻性盲法研究的一部分，该研究调查临床变量的诊断准确性，进行了二次分析以寻找可能作为筛查ZJ阻滞结果预测指标的变量的证据。
慢性下腰痛患者接受筛查ZJ阻滞（n = 151），排除后120例患者纳入分析。
使用100毫米视觉模拟量表测量疼痛强度，并根据疼痛减轻75%至95%或更多（以5%递增）对反应进行分类。
患者在筛查腰椎ZJ阻滞前完成疼痛绘图、问卷调查和临床检查。对病史、人口统计学和临床变量进行交叉表分析和回归分析，并计算与不同疼痛减轻标准相关的变量和变量集群的诊断准确性值。
在疼痛减轻75%的标准下，24.5%的患者对筛查ZJ阻滞有反应，在95%的标准下，10.8%的患者有反应。集中现象与使用任何标准的疼痛减轻均无关。没有变量可有效预测ZJ阻滞后疼痛减轻小于90%的情况。七项临床发现与阻滞后95%的疼痛减轻相关。发现了五条有用的临床预测规则（CPR）用于排除95%的疼痛减轻（敏感性100%），一条CPR的似然比为9.7，使检验后概率提高了五倍。
阴性伸展旋转试验、集中现象和四条CPR可有效排除筛查ZJ阻滞后的疼痛消除。一条CPR使ZJ阻滞阴性或阳性反应的检验后概率提高了五倍。
