Table 6. Complications and Subsequent Surgeries between the Two Surgical Groups.
| Outcomes | N of studies | Minimally invasive group | Open group | OR (95% CI) | ||
|---|---|---|---|---|---|---|
| N of OR events (%) | Total N of patients | N of events (%) | Total N of patients | |||
| Surgical-site complications | ||||||
| Overall | 7 | 5 (1.7) | 302 | 13 (4.5) | 289 | 0.4 (0.2 to 1.1) |
| Infection | 6 | 3 (1.2) | 260 | 13 (5.3) | 246 | 0.3 (0.1 to 0.9)* |
| Surgical-site infection | 3 | 0 (0.0) | 159 | 5 (3.3) | 152 | 0.2 (0.02 to 0.9)† |
| Superficial wound infection | 3 | 2 (2.0) | 101 | 7 (7.4) | 94 | 0.3 (0.02 to 1.4) |
| Deep wound infection | 1 | 1 (3.1) | 32 | 1 (3.4) | 29 | 0.9 (0.05 to 15.1) |
| Hematoma | 2 | 2 (2.5) | 79 | 0 (0.0) | 73 | 2.8 (0.3 to 27.6) |
| Neurological complications | ||||||
| Overall | 7 | 13 (4.5) | 288 | 13 (4.7) | 278 | 0.8 (0.4 to 1.8) |
| Dural tear/CSF leak | 7 | 12 (4.2) | 288 | 11 (4.0) | 278 | 0.9 (0.4 to 2.1) |
| Nerve root injury (L5 root paresis) | 1 | 1 (5.6) | 18 | 0 (0.0) | 18 | 3.2 (0.1 to 83.2) |
| Postoperative radiculopathy (transient L3 radicular pain) | 2 | 0 (0.0) | 55 | 2 (4.2) | 48 | 0.3 (0.03 to 2.9) |
| Hardware complications | ||||||
| Overall | 6 | 14 (5.4) | 258 | 9 (3.6) | 250 | 1.2 (0.5 to 2.6) |
| Screw-related complications | 6 | 8 (3.1) | 258 | 2 (0.8) | 250 | 1.8 (0.6 to 5.8) |
| Screw malposition | 4 | 4 (2.0) | 196 | 2 (1.0) | 194 | 1.1 (0.3 to 5.1) |
| Screw loosening | 1 | 2 (11.1) | 18 | 0 (0.0) | 18 | 5.6 (0.3 to 125.4) |
| Screw breakage | 1 | 1 (5.6) | 18 | 0 (0.0) | 18 | 3.2 (0.1 to 83.2) |
| Overlong screw | 1 | 1 (2.3) | 44 | 0 (0.0) | 38 | 2.7 (0.1 to 67.1) |
| Cage-related complications | 3 | 5 (4.1) | 122 | 7 (5.9) | 119 | 0.7 (0.2 to 2.2) |
| Cage migration | 2 | 5 (4.8) | 104 | 6 (5.9) | 101 | 0.8 (0.2 to 2.7) |
| Cage fracture during insertion | 1 | 0 (0.0) | 18 | 1 (5.6) | 18 | 0.3 (0.01 to 8.3) |
| Graft dislodgement | 1 | 1 (2.4) | 42 | 0 (0.0) | 43 | 3.1 (0.1 to 79.4) |
| Pseudarthrosis | 9 | 12 (3.3) | 363 | 9 (2.6) | 344 | 1.2 (0.5 to 2.9) |
| Other complications | ||||||
| Overall | 3 | 3 (2.4) | 127 | 7 (5.8) | 120 | 0.6 (0.2 to 1.9) |
| Deep vein thrombosis | 1 | 0 (0.0) | 37 | 1 (3.3) | 30 | 0.3 (0.01 to 6.7) |
| Myocardial infarction | 1 | 0 (0.0) | 72 | 1 (1.4) | 72 | 0.3 (0.01 to 8.2) |
| Pneumonia | 1 | 1 (1.4) | 72 | 1 (1.4) | 72 | 1.0 (0.06 to 16.3) |
| Paralytic ileus | 1 | 0 (0.0) | 37 | 3 (10) | 30 | 0.1 (0.005 to 2.1) |
| Urinary tract infection | 1 | 1 (2.7) | 37 | 0 (0.0) | 30 | 2.5 (0.1 to 63.8) |
| Postoperative anemia | 1 | 0 (0.0) | 72 | 1 (1.4) | 72 | 0.3 (0.01 to 8.2) |
| Brachial plexus injury due to positioning | 1 | 1 (5.6) | 18 | 0 (0.0) | 18 | 3.2 (0.1 to 83.2) |
| Subsequent surgeries‡ | ||||||
| Overall | 6 | 11 (4.4) | 251 | 9 (3.7) | 242 | 0.9 (0.4 to 2.3) |
| Revision | 4 | 5 (2.6) | 196 | 2 (1.0) | 194 | 1.1 (0.3 to 4.5) |
| Revision for malpositioned screw | 4 | 4 (2.0) | 196 | 2 (1.0) | 194 | |
| Revision for migrated cage | 1 | 1 (3.1) | 32 | 0 (0.0) | 29 | |
| Removal for pseudarthrosis | 3 | 3 (3.4) | 87 | 3 (3.9) | 77 | 1.3 (0.2 to 7.9) |
| Reoperation | 4 | 3 (1.5) | 196 | 4 (2.1) | 194 | 0.6 (0.1 to 2.8) |
| Reoperation for graft dislodgement | 1 | 1 (2.4) | 42 | 0 (0.0) | 43 | |
| Reoperation for surgical-site infection | 2 | 0 (0.0) | 122 | 3 (2.5) | 122 | |
| Reoperation for deep wound infection | 1 | 1 (3.1) | 32 | 1 (3.4) | 29 | |
| Reoperation for hematoma | 1 | 1 (2.4) | 42 | 0 (0.0) | 43 | |
| Supplemental fixation | 0 | 0 (0.0) | 0 | 0 (0.0) | 0 | |
N, number; OR, odds ratio; CI, confidence interval; CSF, cerebrospinal fluid.
*p=0.02, †p=0.04, ‡Complications lead to a subsequent surgical intervention. Subsequent surgical intervention was categorized as follows: a revision is a procedure that adjusts or in any way modifies or removes part of the original implant configuration, with or without replacement of a component; a revision may also include adjusting the position of the original configuration (revision for migrated cage, removal of screws, etc.). A removal is a procedure where all of the original system configuration are removed with or without replacement (removal for pain at operative site but after fusion, for pseudarthrosis, etc.). A reoperation is any surgical procedure at the involved level(s) that does not removal, modification, or addition of any components to the system. A supplemental fixation is a procedure in which additional instrumentation not under study in the protocol is implanted.