Table 1.
Baseline Characteristics of the IS Group and the S2AI Group.
| Characteristic | IS (n = 17) | S2AI (n = 46) | P |
|---|---|---|---|
| Age (years), mean ± SD | 64.3 ± 11.4 | 61.5 ± 10.7 | .37 |
| Sex (Female), n (%) | 12 (70.6) | 31 (67.4) | .63 |
| BMI (kg/m2), mean ± SD | 33.0 ± 7.3 | 30.2 ± 6.9 | .17 |
| Follow-up period (months), mean ± SD | 22.9 ± 7.4 | 20.4 ± 10.0 | .36 |
| Smoking, n (%) | 9 (52.9) | 26 (56.5) | .49 |
| Osteoporosis, n (%) | 1 (5.9) | 5 (10.9) | >.99 |
| Osteopenia, n (%) | 4 (23.5) | 11 (23.9) | .72 |
| Prior history of any lumbosacral surgery, n (%) | 14 (82.4) | 39 (84.8) | >.99 |
| Prior history of lumbosacral fusion surgery, n (%) | 7 (41.2) | 12 (26.1) | |
| Primary Diagnosis | |||
| Degenerative scoliosis, n (%) | 11 (64.7) | 26 (56.5) | .77 |
| Adult idiopathic scoliosis, n (%) | 3 (17.6) | 12 (26.1) | .74 |
| Combination, n (%) | 3 (17.6) | 8 (17.4) | >.99 |
| Secondary Diagnosisa | IS (n = 14) | S2AI (n = 39) | |
| PJK secondary to prior lumbosacral surgery, n (%) | 4 (28.6) | 12 (30.8) | >.99 |
| CI secondary to prior lumbosacral surgery, n (%) | 4 (28.6) | 11 (28.2) | >.99 |
| SI secondary to prior lumbosacral surgery, n (%) | 7 (50.0) | 25 (64.1) | .53 |
| Preoperative Symptoms | IS (n = 17) | S2AI (n = 46) | |
| Mechanical back pain, n (%) | 15 (88.2) | 42 (91.3) | .66 |
| Radiculopathy, n (%) | 12 (70.6) | 30 (65.2) | .77 |
| Neurogenic claudication, n (%) | 5 (29.4) | 10 (21.7) | .52 |
| Bladder or bowel dysfunction, n (%) | 0 (0.0) | 1 (2.2) | >.99 |
Abbreviations: IS, iliac screw; S2AI, S2-alar-iliac, BMI, body mass index; PJK, proximal junctional kyphosis; CI, coronal imbalance, SI, sagittal imbalance
aDiagnoses before revision surgery. Some patients had multiple diagnoses.