Table 4.
Factors Associated with Treatment Outcome after Facet Block and Radiofrequency Denervation
| Characteristic | Negative 1-Month Outcome after Facet Block (N = 203) |
Positive 1-Month Outcome after Facet Block (N = 24) |
P Value* | Negative 3-Month Outcome after Radiofrequency Denervation (N = 74) |
Positive 3-Month Outcome after Radiofrequency Denervation (N = 60) |
P Value |
|---|---|---|---|---|---|---|
| Age (mean ± SD) | 48±14 | 46±11 | 0.640 | 48±14 | 46±14 | 0.441 |
| Female (n, %) | 71 (35%) | 7 (29%) | 0.571 | 25 (33%) | 23 (38%) | 0.546 |
| Duration of pain in years (mean ± SD) | 7±7 | 5±5 | 0.473† | 7±7 | 6±5 | 0.852† |
| Levels (mean ± SD) | 2.1±0.5 | 2.0±0.6 | 0.723† | 2.1±0.5 | 2.1±0.4 | 0.816† |
| Bilateral (n, %) | 133 (66%) | 16 (64%) | 0.911 | 51 (68%) | 36 (60%) | 0.335 |
| Opioid use (n, %) | 33 (16%) | 2 (8%) | 0.586† | 16 (21%) | 6 (10%) | 0.178 |
| Military status (n, %) | 0.434 | 0.388 | ||||
| Officer | 31 (15%) | 2 (8%) | 9 (12%) | 12 (20%) | ||
| Enlisted | 69 (34%) | 11 (48%) | 27 (36%) | 22 (37%) | ||
| Civilian | 103(51%) | 11 (44%) | 39 (52%) | 26 (43%) | ||
| Disability, worker’s compensation, or medical board‡ | 34 (17%) | 2 (8%) | 0.385† | 18 (24%) | 7 (12%) | 0.067 |
| Inciting event (n, %) | ||||||
| Motor vehicle collision | 9 (4%) | 1 (4%) | > 0.999† | 2 (3%) | 3 (5%) | 0.655† |
| Fall | 9 (4%) | 2 (8%) | 0.328† | 2 (3%) | 3 (5%) | 0.655† |
| Work related | 31 (15%) | 3 (13%) | > 0.999† | 8 (11%) | 9 (15%) | 0.451 |
| Sports | 23 (11%) | 3 (13%) | 0.744† | 10 (13%) | 10 (16%) | 0.588 |
| Other | 17 (8%) | 2 (8%) | > 0.999† | 10 (13%) | 4 (7%) | 0.262† |
| None | 116 (57%) | 13 (54%) | 0.781 | 43 (57%) | 32 (53%) | 0.642 |
| Concomitant pain condition (n, %) | ||||||
| Neck pain | 39 (19%) | 6 (25%) | 0.501 | 12 (16%) | 11 (18%) | 0.720 |
| Arthralgia | 75 (37%) | 5 (21%) | 0.118 | 30 (40%) | 16 (27%) | 0.104 |
| Headache | 13 (6%) | 1 (4%) | > 0.999† | 5 (7%) | 3 (5%) | 0.732† |
| Neuropathic | 6 (3%) | 2 (8%) | 0.202† | 1 (1%) | 3 (5%) | 0.323† |
| Other | 29 (14%) | 0 | 0.051† | 6 (8%) | 6 (10%) | 0.685 |
| None | 79 (39%) | 13 (54%) | 0.150 | 32 (43%) | 29 (48%) | 0.511 |
| Coexisting psychiatric condition (n, %) | ||||||
| Mood | 40 (20%) | 5 (21%) | 0.896 | 19 (25%) | 11 (18%) | 0.331 |
| Anxiety | 36 (18%) | 4 (17%) | > 0.999† | 17 (23%) | 9 (15%) | 0.262 |
| PTSD§ | 18 (9%) | 3 (13%) | 0.472† | 7 (9%) | 4 (7%) | 0.754† |
| Substance abuse§ | 4 (2%) | 1 (4%) | 0.431† | 2 (3%) | 3 (5%) | 0.655† |
| Other | 7 (3%) | 0 | > 0.999† | 2 (3%) | 2 (3%) | > 0.999† |
| None | 133 (66%) | 16 (67%) | 0.911 | 47 (63%) | 41 (68%) | 0.492 |
| Deployment related (n, %) | 22 (11%) | 2 (8%) | 0.701 | 6 (8%) | 8 (13%) | 0.325 |
| Traumatic brain injury (n, %) | 10 (5%) | 1 (4%) | > 0.999† | 3 (4%) | 4 (7%) | 0.487 |
| Smoking (n, %) | 32 (16%) | 5 (21%) | 0.525 | 10 (13%) | 9 (15%) | 0.782 |
| Average NRS back pain (mean ± SD) | 5.4±1.5 | 4.9±1.6 | 0.090† | 5.2±1.5 | 5.4±1.6 | 0.439† |
| Worst NRS back pain (mean ± SD) | 8.1±1.4 | 7.7± 1.5± | 0.210† | 8.1±1.4 | 8.0±1.6 | 0.979† |
| Oswestry disability score (mean ± SD) | 33±13 | 30±13 | 0.014† | 35±14 | 30±12 | 0.138† |
| Percent relief from diagnostic | (n = 158) | (n = 21) | 0.016 | (n = 42) | (n = 50) | 0.864 |
| block (mean ± SD)∥ | 44±32% | 60±32% | 74±15% | 73±17% | ||
| Percent relief from diagnostic | (n = 202) | (n = 24) | 0.037 | (n = 74) | (n = 60) | 0.004 |
| block (mean ± SD)# | 46±32% | 61±32% | 56±31% | 70±21% |
*
For continuous variables, P values for parametric tests are shown, except for nonparametric data, for which P values for the nonparametric tests are shown, as denoted below.
†
Based on nonparametric test.
‡
Service members with a medical condition that renders them unfit for duty enter an integrated disability evaluation system to determine their eligibility to remain on active duty (i.e., equivalent to a civilian disability hearing).
§
Denotes controlled or inactive.
∥
Excludes group III patients.
#
Includes group III patients.
NRS = numerical rating scale; PTSD = posttraumatic stress disorder.