Austrian Pain Intervention Centers

Linz and Baden/Vienna

www.schmerz.cc

The influence of BMI and gender on pain decrease and medication usage after Facet – Medial Branch or SI Joint Lateral Branch Neurotomy (cooled RF-

SInergy) in case of Facetjoint or SI Joint mediated low back pain.A large Case series of low back pain RF Treatment

(The Austrian Experience)Wolfgang Stelzer, MD,* Dominik Stelzer,MD* ,Valentin Stelzer*,Mag.,Monika Braune, MD,*;

Christine Duller, Univ. Prof., MMag. DI. Dr.§

www.schmerz.cc

Austrian Pain Intervention Centers Linz and Baden/Vienna

Objective

This retrospective study was designed to illustrate the general outcome after radiofrequency neurotomy of lumbar medial branches and rami posterior of the SI Joint in patients with low back pain 1, 6 and 12 months after treatment. Outcomes were stratified by BMI, gender and age to determine their effect on the reduction of opioids and NSAIDS.

Subjects and Setting

164 patients with chronic low back pain who underwent treatment with RF medial branch and/or cooled RF LBN. Three pain clinics Austria

Design

• The records of 164 patients with chronic low back pain who underwent treatment with RF medial branch Neurotomy (parallel needle technique) and/or cooled RF LBN in case of SI Joint mediated low back pain were identified. Subjects were selected for treatment based on physical examination and positive response (>50% pain relief) to an lumbar medial branch block/Ramus dorsalis L5 block or intraarticular SIJ block.

• Lumbar medial branches L3 and L4 and the ramus dorsalis L5 were lesioned in „ISIS“ parallel needle technique (N=36). Cooled RF LBN involved lesioning the L5 dorsal ramus and lateral to the S1, S2, and S3 posterior sacral foraminal apertures (N=87).

Design

• Visual analog scale (VAS) pain scores, quality of life, BMI, medication usage, and satisfaction with pain management were collected before the procedure, at 1 month postprocedure (N = 164), and again after 6 (N= 75) and 12 months (N=89) postprocedure.

• Parallel needle technique (ISIS technique)

RF Technique lumbar Facet Joint medial branch

Technique SIJ

Total of 9 lesions were created during the procedure: one at the L5 dorsal ramus, 3 lateral to the S1 and S2 sacral foramina, and 2 lateral to the S3 sacral foramen.

Methods

All subjects qualified for treatment based on physical examination and positive response to testblock. Data collected included; Visual Analog Scale pain scores, quality of life, BMI, medication usage, and satisfaction with pain management before procedure, at 1, 6 and 12 months.

• For tests of normality of the data, the Kolmogorov-Smirnov-Test (KS-test) as well as the Shapiro-Wilks-Test (SW-test) were used. As both tests showed significant results and therefore assumption of normal distribution did not hold for our variables, a test on differences in location were made by the nonparametric Wilcoxon Test.

• In many cases (if requirements of central limit theorem were fulfilled) we also conducted an additional paired t-test.

• summarized VAS for the whole sample before treatment (prae), one month after treatment (mts) as well as later after treatment (6 or 12 months) and shows the number of cases, the estimators for mean and standard deviation, and the two-sided p-values for tests of normality (both Kolmogorv-Smirnov-test and Shapiro-Wilks-test)

prae mts yr

Cases 130 161 163

Estimators

mean 8,004 4,273 4,304

standard deviation 1,42 2,18 2,49

p-values (2-sided)

KS-Test 0,001 0,000 0,000

SW-Test 0,000 0,000 0,000

VAS

 

•All analyses were performed using SPSS version 22. Descriptive statistics were used to give in data summary of variables illustrating: the number of cases, mean, standard deviation (SD), minimum, maximum and all quartiles (i.e. 0.25 percentile, median, 0.75 percentile). Tables of confidence intervals contain information on the mean, standard deviation (SD), standard error (SE), upper and lower bound of the interval, as well as the two sided p-value for a t-test (test value 0).

•All statistical tests were conducted on a significance level of alpha = 5%.

Statistical Analysis

• All 857 treated patients (09/2012-06/2014) were sent a questionnaire (with self-addressed return envelope) after 6 months, and 12 months ( 09/2013-12/2014) .

• 193 sent back the form . (22,5%)

• 29 Exclusion Criterias (false filled out form, other health problems like internal deseases,..)

• 31 with some missing data and

• 131 completly filled form with all dataThere were no severe or moderate complications during or after the procedures.

Statistical Analysis

Results

• VAS decrease of 4 points on 10 point scale (8 to 4) was demonstratedafter 6 months and 4.5 after 12 months. Lower medication usage was demonstrated with a decrease in opioids by 40%, and NSAIDS by 60%. Decrease in reported pain was shown to last for 12 months.Data illustrate significant better outcomes for patients with BMI lower than 30.Nogender specific difference in decrease in VAS. All reported complications were mild and spontaneously resolved.

VAS Reduction total group

The results indicate a reduction in all groups 1, 6 and 12 months after treatment and a small increase between 6 and 12 months (4.082 up to 4.556).

Results

Results

Medication Usage

• It could be shown that in all groups the patients required less medication for pain management in the follow up period. For all patients, 106/164 (64.7%) needed less medication, just 1/164 (0. 7%) needed more. NSAIDS reduction was possible for 48/78 (62%), in the opioid users group 14/37 (38%) were able to reduce or stop the medication after treatment.

Results

sorted by area (lumbar facets and SI Joint)

• The results are nearly equal between patients treated on the lumbar medial branches ( 18G, 1cm active tip, parallel technique) and SI Joint (cooled RF Treatment, Halyard Health) for VAS (Table 2), and medication usage (NSAIDS and opiodis)

Percentiles

25. 50. 75.

LWS 6 prae 11 7,7 1,7 7,0 8,0 9,0

mts 11 4,8 1,9 3,0 5,0 5,0

yr 11 3,0 2,8 1,0 1,5 5,0

12 prae 24 7,9 1,3 7,0 8,0 8,0

mts 24 4,2 2,1 3,0 3,5 5,9

yr 24 4,8 2,3 2,6 5,0 7,0

ISG 6 prae 35 8,2 1,4 7,0 8,0 9,5

mts 34 4,1 2,1 3,0 3,3 5,3

yr 35 4,6 2,5 2,0 4,5 6,5

12 prae 52 8,0 1,5 7,0 8,0 9,0

mts 51 4,1 2,2 2,0 3,0 6,0

yr 52 4,5 2,7 2,0 5,0 6,8

Group VAS N Mean SD

Results

BMI Dependence • Separated in two groups (BMI <30

and BMI > 30) a difference is noted in VAS decrease and quality of life

Results

Confidence Interval

• The 95% Confidence Interval of difference VAS pre versus 1 month 3,3 -4,2 ;

• VAS pre versus 6/12month 3,1-4,1,this shows that patients have a 95% probability to get a pain decrease about 3,1-4,1 points on the VAS Scale after treatment.

lower upper

prae - 1 mth 3,74 2,56 0,23 3,29 4,19 0,000

prae - 6/12 mth 3,62 2,79 0,25 3,14 4,11 0,000

1 mth - 6/12 mth -0,08 2,74 0,22 -0,51 0,34 0,697

SESDMeanVAS Difference95% CI

p-value

Results

The Influence of Sex

• In an analysis of VAS decrease by gender, our results are approximately the same in the male (n=53) and female (n=106) group (Tbl.6).

• Analysis of satisfaction (“quality of life” better/equal/worse) the results reveal high satisfaction in the female group.

• The durability of pain relief reported in this study is consistent with other studies of RF neurotomy for SIJ- mediated low back pain and lumbar facet joint mediated low back pain[1],[2],[3],[4],[5] The decreases in chronic pain and medication usage may suggest the use of RF treatment in case of low back pain as a proper treatment option as well as the probability of 95% to have a VAS decrease of 3-4 points on the NAS (0-10) scale. Pain decrease can be shown for at least 12 months.

• [1] Patel, Nilesh, et al. "A Randomized, Placebo Controlled Study to Assess the Efficacy of Lateral Branch Neurotomy for ‐Chronic Sacroiliac Joint Pain." Pain Medicine 13.3 (2012): 383-398.

• [2] Schofferman J, Kine G. Effectiveness of repeated radiofrequency neurotomy for lumbar facet pain. Spine 2004;29(21):2471–3.

• [3] Hagg O, Fritzell P, Nordwall A. The clinical importance of changes in outcome scores after treatment for chronic low back pain. Eur Spine J 2003;12(1):12–20.

• [4] Patel N, Gross A, Brown L, Gekht G. A randomized, placebo controlled study to assess the efficacy of lateral branch denervation for chronic sacroiliac joint pain. Pain Med 2012;13:383–98.

• [5] Nikolai Bogduk, MD, PhD, DSc, Paul Dreyfuss, MD,ayantilal Govind, MB, ChB, Mmed; Pain Med. 2009;10:1035-1045,A Narrative Review of Lumbar Medial Branch Neurotomy for theTreatment of Back Pain

Conclusions

Conclusions

• Limitations of this study are those that apply to all retrospective studies: no control group to account for confounders, such as the placebo effect, but the results are better than what we would expect for the placebo effect; difficulty of a small percentage of subjects to fill out the questionnaire and return it to the investigative staff; and missing data for some subjects.

• The decreases in chronic pain and medication usage may suggest that the use of Radio Frequency treatment would serve as the first option in standard of care for the treatment of low back pain with a 95% probability of a significant decrease in pain (3-4 points on the NAS 0-10 scale) that may last for at least 12 months.

Conclusions

• The results of lumbar medial branch neurotomy with the parallel needle technique seem to be as good as the results achieved with the SI Joint mediated low back pain with the cooled RF-Probe (Halyard Health)

• Overall, the authors have determined that treatment with RF methods for patients with chronic low back pain is a safe, durable effective long term pain and analgesic reduction treatment option. Public insurance should be motivated to provide for reimbursement as a safe and reliable method for the treatment of low back pain.

Austrian Pain Intervention Centers

Linz and Baden/Vienna

www.schmerz.cc