The Role of Thoracic Medial Branch Blocks in Managing Chronic Mid and Upper Back Pain: A Randomized, Double-Blind, Active-Control Trial with a 2-Year Followup

Table 2

Comparison of numeric rating scale for pain and Oswestry Disability Index score summaries at four time points.

Time points	Numeric pain rating scale		Oswestry disability index
	Mean ± SD		Mean ± SD
	Group I (𝑁=50)	Group II (𝑁=50)	Group I (𝑁=50)	Group II (𝑁=50)
Baseline	7.9±0.9	7.8±1.0	27.1±6.6	27.5±5.8
3 months	3.1^∗±0.9(94%)	3.1^∗±0.7(96%)	13.0^∗±4.9(80%)	11.6^∗±3.7(88%)
6 months	3.0^∗±0.9(94%)	3.2^∗±0.8(94%)	13.0^∗±4.2(78%)	11.9^∗±3.8(82%)
12 months	3.2^∗±0.9(90%)	3.1^∗±1.0(90%)	12.0^∗±4.0(80%)	11.8^∗±3.9(84%)
18 months	3.0^∗±1.0(88%)	3.1^∗±0.9(90%)	12.1^∗±4.9(80%)	11.7^∗±3.9(82%)
24 months	3.1^∗±1.2(86%)	3.1^∗±1.0(88%)	11.7^∗±4.9(82%)	11.0^∗±4.2(86%)
Group difference	0.964		0.560
Time difference	0.000		0.000
Group by time interaction	0.884		0.112

^∗Significant difference with baseline values within the group (P < 0.05).
() Illustrates proportion with significant pain relief (≥50%) from baseline.
Group I = bupivacaine only.
Group II = bupivacaine and steroid.