Holz Sara Christensen, Sehgal Nalini
University of Wisconsin School of Medicine and Public Health, Madison, WI.
Pain Physician. 2016 Mar;19(3):163-72.
Facet joint pain is a common cause of low back pain. There are no physical exam findings that provide a reliable diagnosis. Diagnosis is made by medial branch block injections (MBB). Once the source of pain has been determined, radiofrequency neurotomy (RFN) can be performed. Previous studies have shown that RFN reduces level of pain and improves function. No study has tried to correlate MBB results with outcomes after RFN.
(1) Estimate percentage decrease in pain, decrease in analgesic use, and increase in activity tolerance after facet joint radiofrequency neurotomy (2) Determine correlation between percentage pain relief or duration of pain relief after MBB and RFN outcomes.
Retrospective review of patients undergoing RFN, who had = 70% pain relief on 2 sets of MBB with 0.5 - 1 mL of 2% lidocaine (MBB 1) and 0.75% bupivacaine (MBB 2). IRB approval was obtained before data collection began.
All patients undergoing RFN between 12/06-1/10 at University Spine and Pain clinics.
Subgroup analysis was performed based on response to MBB, a)100% pain relief and <100% pain relief after MBB 1 and 2 and a) those with > 8 hours and = 8 hours pain relief after MBB 1 and 2. Correlational analysis was conducted to determine the correlation between a) percent pain relief after MBB1 and 2 and percent change in pain after RFN and b) duration of pain relief after MBB 1 and 2 and percent change in pain relief after RFN.
Pain intensity, disability index, analgesic use, and patient perception of benefit.
Mean improvement of Disability scores at 3 months was 12.63 (P = 0.001), percent pain relief was 47.68% (P = 0.001). Patients with 100% pain relief after MBB 1 had greater improvement of disability scores (P = 0.008). Those with > 8 hours pain relief after MBB 1 had greater reduction in pain (P = 0.014). Pearson correlation analysis showed no correlation between percent pain relief or duration of pain relief after MBB and percent pain relief after RFN.
This was a small observational study with short-term follow up.
Patients had improved disability scores and decreased pain after RFN. No correlation was seen between results on MBB and pain relief after RFN. It is still unclear how many medial branch blocks are needed and the criteria for MBB results before proceeding to RFN.
小关节疼痛是腰痛的常见原因。没有体格检查结果能够提供可靠的诊断。诊断通过内侧支阻滞注射（MBB）来进行。一旦确定了疼痛来源，就可以进行射频神经切断术（RFN）。既往研究表明，RFN可减轻疼痛程度并改善功能。尚无研究试图将MBB结果与RFN后的疗效相关联。
（1）评估小关节射频神经切断术后疼痛减轻的百分比、镇痛药使用的减少以及活动耐量的增加；（2）确定MBB后疼痛缓解百分比或疼痛缓解持续时间与RFN疗效之间的相关性。
对接受RFN的患者进行回顾性研究，这些患者在两组分别注射0.5 - 1 mL 2%利多卡因（MBB 1）和0.75%布比卡因（MBB 2）的MBB中疼痛缓解率≥70%。在开始数据收集前获得了机构审查委员会（IRB）的批准。
大学脊柱与疼痛诊所2006年12月至2010年1月期间所有接受RFN的患者。
根据对MBB的反应进行亚组分析，a）MBB 1和2后100%疼痛缓解和<100%疼痛缓解，以及a）MBB 1和2后疼痛缓解>8小时和≤8小时的患者。进行相关性分析以确定a）MBB 1和2后疼痛缓解百分比与RFN后疼痛变化百分比之间以及b）MBB 1和2后疼痛缓解持续时间与RFN后疼痛缓解变化百分比之间的相关性。
疼痛强度、残疾指数、镇痛药使用以及患者对疗效的感知。
3个月时残疾评分的平均改善为12.63（P = 0.001），疼痛缓解百分比为47.68%（P = 0.001）。MBB 1后疼痛完全缓解的患者残疾评分改善更大（P = 0.008）。MBB 1后疼痛缓解>8小时的患者疼痛减轻更明显（P = 0.014）。Pearson相关性分析显示，MBB后疼痛缓解百分比或疼痛缓解持续时间与RFN后疼痛缓解百分比之间无相关性。
这是一项短期随访的小型观察性研究。
RFN后患者的残疾评分得到改善，疼痛减轻。MBB结果与RFN后疼痛缓解之间未发现相关性。在进行RFN之前，仍不清楚需要多少次内侧支阻滞以及MBB结果的标准。
