Demographic characteristics of patients receiving 2- and 3-level posterolateral lumbar fusion.
| Variables | 2-Level Fusion (N = 557) | 3-Level Fusion (N = 287) |
| Age, mean ± SD | 61.74 ± 12.05 | 63.71 ± 11.57 |
| Gender: men, n (%) | 277 (50.0%) | 128 (44.9%) |
| Race: White, n (%) | 482 (87.2%) | 264 (93.0%) |
| Body mass index, mean ± SD | 31.23 ± 6.68 | 30.67 ± 6.44 |
| Comorbidities, n (%) | ||
| 1 or 2 Comorbidities | 319 (57.3%) | 165 (57.5%) |
| >2 Comorbidities | 153 (27.5%) | 87 (30.3%) |
| Coronary artery disease | 99 (23.6%) | 53 (22.9%) |
| Hypertension | 350 (62.8%) | 193 (67.2%) |
| Congestive heart failure | 17 (3.1%) | 10 (3.5%) |
| Chronic obstructive pulmonary disease | 31 (5.6%) | 10 (3.5%) |
| Osteoporosis | 17 (4.1%) | 14 (6.1%) |
| Diabetes | 142 (25.5%) | 72 (25.1%) |
| Active smoker, n (%) | 88 (15.8%) | 51 (17.8%) |
| Preoperative anticoagulation/antiplatelet usage, n (%) | 13 (3.1%) | 8 (3.5%) |
| Insurance, n (%) | ||
| Private | 237 (42.5%) | 95 (33.1%) |
| Medicare/Medicaid/Tenncare | 265 (47.6%) | 171 (59.6%) |
| Veterans Affairs/Government (includes Tricare) | 38 (6.8%) | 15 (5.2%) |
| Uninsured/not available | 7 (1.3%) | 3 (1.0%) |
| Currently employed, n (%) | 191 (34.4%) | 67 (23.3%) |
| Intend to return to work, n (%) | 183 (95.8%) | 59 (89.4%) |
| Preoperative ambulation, n (%) | ||
| With assistance | 179 (32.3%) | 96 (33.4%) |
| Independent | 371 (66.8%) | 189 (65.9%) |
| Wheelchair bound | 5 (0.9%) | 2 (0.7%) |
| Duration of symptoms, n (%) | ||
| <3 mo | 33 (7.6%) | 15 (6.5%) |
| 3–12 mo | 141 (32.4%) | 67 (29.1%) |
| >12 mo | 261 (60.0%) | 148 (64.3%) |
| Diagnosis, n (%) | ||
| Stenosis | 132 (24.0%) | 66 (23.6%) |
| Herniated disc | 11 (2.0%) | 10 (3.6%) |
| Fracture | 29 (5.3%) | 14 (5.0%) |
| Deformity/scoliosis | 43 (7.8%) | 60 (21.4%) |
| Spondylolisthesis | 280 (51.0%) | 97 (34.6%) |
| Pseudarthrosis | 30 (5.5%) | 22 (7.9%) |
| Other | 22 (4.0%) | 11 (4.0%) |
| Revision, n (%) | 214 (38.4%) | 135 (47.0%) |
| Reason for revision, n (%) | ||
| Adjacent segment disease | 68 (38.4%) | 43 (38.4%) |
| Pseudarthrosis/instrumentation failure | 34 (19.2%) | 30 (26.8%) |
| Same level recurrent stenosis | 53 (29.9%) | 26 (23.2%) |
| Same level recurrent disc herniation | 16 (9.0%) | 6 (5.4%) |
| Other | 6 (3.4%) | 7 (6.3%) |