Minimally Invasive Direct Decompression for Lumbar Spinal Stenosis: Impact of Multiple Prior Epidural Steroid Injections

Figures & data

Table 1. Baseline demographics and clinical characteristics.

Characteristic	≤1 ESI, n = 75	≥2 ESIs, n = 70	Total, n = 145	p-value for difference across ESI cohorts
Age (years)   Mean (SD)   Range	72.8 (9.9) 40–92	72.6 (9.3) 48–91	72.7 (9.6) 40–92	0.914
Gender (%, n)   Female   Male	53.3 (40) 46.7 (35)	54.3 (38) 45.7 (32)	53.8 (78) 46.2 (67)	0.909
Presenting comorbidities (%, n)   Bulging disc   Herniated disc   Facet arthropathy   Facet hypertrophy   Foraminal narrowing   Lateral recess narrowing   DDD   Osteophytes   Other	73.3 (55) 24.0 (18) 76.0 (57) 53.3 (40) 56.0 (42) 42.7 (32) 53.3 (40) 12.0 (9) 53.3 (40)	82.9 (58) 14.3 (10) 72.9 (51) 51.4 (36) 54.3 (38) 52.9 (37) 62.9 (44) 12.9 (9) 65.7 (46)	77.9 (113) 19.3 (28) 74.5 (108) 52.4 (76) 55.2 (80) 47.6 (69) 57.9 (84) 12.4 (18) 59.3 (86)	0.167 0.139 0.664 0.819 0.836 0.220 0.246 0.876 0.129

DDD: Degenerative disc disease; ESI: Epidural steroid injection; SD: Standard deviation.

Table 2. mild procedure data.

mild procedure	≤1 ESI, n = 75	≥2 ESIs, n = 70	Total, n = 145	p-value for difference across ESI
Level treated   T12–L1   L1–L2   L2–L3   L3–L4   L4–L5   L5–S1	1.3 (1) 4.0 (3) 25.3 (19) 73.3 (55) 76.0 (57) 6.7 (5)	0 (0) 0 (0) 24.3 (17) 72.9 (51) 78.6 (55) 12.9 (9)	0.7 (1) 2.1 (3) 24.8 (36) 73.1 (106) 77.2 (112) 9.7 (14)	0.332 0.091 0.884 0.949 0.712 0.207
Number of levels treated   1 Level   2 Levels   3 Levels	21.3 (16) 68.0 (51) 10.7 (8)	22.9 (16) 60.0 (42) 17.1 (12)	22.1 (32) 64.1 (93) 13.8 (20)	0.472

ESI: Epidural steroid injection.

Table 3. VAS scores.

Follow-up	≤1 ESI, n = 75	≥2 ESI, n = 70	p-value
Baseline (mean, SD)	7.81 (1.38)	7.48 (1.27)	0.132
1-week follow-up (mean, SD)   p-value within group	4.41 (2.07) <0.0001	4.22 (2.10) <0.0001	0.642
3-month follow-up (mean, SD)   p-value within group	4.83 (2.59) <0.0001	4.56 (2.53) <0.0001	0.559

ESI: Epidural steroid injection; SD: Standard deviation.

Figure 1. Comparison of mean VAS scores at baseline, 1-week and 3-month follow-up.

ESI: Epidural steroid injection.

Figure 2. Recommended algorithm reflecting mild therapy as the primary bridge between conservative care and more invasive surgical treatments for patients with neurogenic claudication and hypertrophic ligamentum flavum.

ESI: Epidural steroid injection.