Demographics of study participants.
| Characteristics | n (%) |
| No. of patients | 97 |
| No. of levels | 161 |
| No. of PTP levels | |
| 1 | 55 (57) |
| 2 | 29 (30) |
| 3 | 6 (6) |
| 4 | 7 (7) |
| No. of PTP levels | |
| 2 | 29 (30) |
| 3 | 6 (6) |
| 4 | 7 (7) |
| Total No. of levels fused | |
| 1 | 40 (41) |
| 2 | 25 (26) |
| 3 | 15 (16) |
| 4 | 15 (16) |
| 5+ | 2 (2) |
| Level of PTP | |
| L1−L2 | 18 (11) |
| L2−L3 | 34 (21) |
| L3−L4 | 53 (33) |
| L4−L5 | 56 (35) |
| No. of transforaminal lumbar interbody fusion levels | |
| 0 | 76 (79) |
| 1 | 15 (16) |
| 2 | 5 (5) |
| 3 | 1 (1) |
| No. of anterior lumbar interbody fusion levels | |
| 0 | 94 (97) |
| 1 | 2 (2) |
| 2 | 1 (1) |
| Gender, female | 54 (56) |
| Age, y, mean (SD) | 62 (11) |
| Body mass index, mean (SD) | 30 (7) |
| Comorbidities | |
| Hypertension | 69 (71) |
| Hyperlipidemia | 42 (43) |
| Diabetes | 18 (19) |
| Coronary artery disease | 9 (9) |
| Congestive heart failure | 1 (1) |
| Chronic obstructive pulmonary disease | 11 (11) |
| Chronic kidney disease | 6 (6) |
| ASA classification | |
| 1 | 2 (2) |
| 2 | 58 (60) |
| 3 | 37 (37) |
Abbreviations: ASA, American Society of Anesthesiology; PTP, prone transpsoas.
Note: Data presented as n (%) unless otherwise indicated.