Table 2.

Demographics for Included Studies Comparing Early (≤24 Hours) and Late (>24 Hours) Decompression.

Author (Year), Study Design (Risk of Bias), Follow-up	Demographics	Baseline Neurological Status	Patient Characteristics	Intervention(s) and Co-intervention(s)	Inclusion/Exclusion
Cervical SCI
Fehlings (2012) STASCIS trial (multicenter) Prospective cohort (moderately low risk of bias) Follow-up: 6 months (70.9%, n = 222/313; Early: 72.0%, n = 131/182; Late: 69.5%, n = 91/131)	Early (<24 hours) N = 182 Mean age (±SD): 45.0 ± 17.2 years Male: 76.9% Late (≥24 hours) N = 131 Mean age (±SD): 50.7 ± 15.9 years Male: 73.3%	Initial neurologic exam at presentation (within 24 hrs. of admission) ASIA grade, n (%) Early A: 65 (35.7) B: 40 (22.0) C: 32 (17.6) D: 45 (24.7) Late A: 36 (27.5) B: 14 (10.7) C: 34 (26.0) D: 47 (35.9)	Level of injury between C2 and T1 Cause of injury was a MVA or fall in >75% of patients in both groups No patient had a head injury (GCS ≤ 13) or significant polytrauma Charlson Comorbidity Index ≥ 1, n (%) Early: 40 (22.0), Late: 30 (26.0)	Interventions Decompression with instrumented fusion Approach (anterior vs posterior) and number of levels decompressed were left at the discretion of the spinal surgeon Co-interventions Steroids at hospital admission: 62.0% (n = 194); significantly higher proportion administered in the early vs the late group (P = .04) Methylprednisolone use was left at the discretion of the treating team All patients underwent a postoperative rehabilitation regimen, tailored to individual and injury specific factors	Inclusion: Male or female Ages 16–80 years Initial GCS > 13 Initial AIS grade A–D Cervical spinal cord compression confirmed by MRI or CT myelography Neurological level of injury between C2 and T1 Exclusion: Cognitive impairment preventing accurate neurologic assessment Penetrating injuries to the neck Pregnancy Preinjury major neurologic deficits or disease (ie, ischemic stroke, Parkinson’s disease) Life-threatening injuries which prevent early decompression of the spinal cord Arrival at health center >24 hours after SCI Surgery >7 days after SCI
Cervical and thoracolumbar SCI
Bourassa-Moreau (2013) Retrospective cohort (moderately high risk of bias) Follow-up: Mean NR; acute hospital stay only (97.2%, n = 419/431)	Overall N = 431 Mean age (±SD): 41.8 ± 17.6 years Males: 77.7% Early (<24 hours) N = 90 Mean age (±SD): 37.0 ± 15.9 years Males: 82.2% Late I (24-72 hours) N = 231 Mean age (±SD): 40.7 ± 17.3 years Males: 78.4% Late II (>72 hours) N = 110 Mean age (±SD): 47.9 ± 18.0 years Males: 72.7%	Initial assessment time was not reported ASIA grade, n (%) Overall A: 197 (45.7) B: 71 (16.5) C: 61 (14.2) D: 102 (23.7) Early A: 55 (61.1) B: 16 (17.8) C: 8 (8.9) D: 11 (12.2) Late I A: 109 (47.2) B: 42 (18.2) C: 38 (16.5) D: 42 (18.2) Late II A: 33 (30.0) B: 13 (11.8) C: 15 (13.6) D: 49 (44.5)	Levels from C1 to L2 Paraplegia, n (%) Overall: 227 (52.7), Early: 61 (67.8), Late I: 130 (56.3), Late II: 36 (32.7) Traumatic brain injury, n (%) Overall: 140 (32.5), Early: 33 (36.7), Late I: 76 (37.7), Late II: 31 (28.2) Charlson Comorbidity Index (mean ± SD) Overall: 0.22 ± 0.68, Early: 0.10 ± 0.37, Late I: 0.19 ± 0.60, Late II: 0.38 ± 0.96 ISS (mean ± SD) Overall: 26.2 ± 10.2, Early: 28.2 ± 10.2, Late I: 26.6 ± 10.0, Late II: 23.5 ± 10.3	Intervention Surgical decompression (not otherwise specified) Co-interventions NR Administration of methylprednisolone not accounted for due to lack of information	Inclusion: Spinal fracture, dislocation or fracture-dislocation from C1 to L2 Clinical evidence of SCI (AIS A, B, C, and D) Age ≥16 years Spine surgery performed at our center Exclusion: Penetrating trauma to the spine Nonsurgical management Central cord syndrome or absence of acute spine injury Unknown neurologic assessment Associated neurologic disorders that preclude neurologic assessment, including severe traumatic brain injury
Thoracolumbar SCI
Rahimi-Movghar (2014) RCT (moderately low risk of bias) Follow-up: Early 1 month: 87.5% (n = 14/16) 3 months: 56.3% (n = 9/16) 6 months: 87.5% (14/16) 12 months: 93.8% (15/16) Late 1 month: 73.7% (14/19) 3 months: 63.2% (12/19) 6 months: 78.9% (15/19) 12 months: 94.7% (18/19)	Early (<24 hours) N = 16 Mean age (±SD): 31.7 ± 9.1 years Male: 69.0% Mean time to surgery (± SD): 18.9 ± 4.75 hours Late (24–72 hours) N = 19 Mean age (±SD): 37.8 ± 13.70 years Male: 74.0% Mean time to surgery (± SD): 45.0 ± 11.93 hours	Initial neurologic examinations performed on admission, preoperatively, immediately after surgery, and at 1, 3, 6, and 12-months follow-ups ASIA grade, n (%) Early A: 7 (44.0) B: 1 (6.0) C: 4 (25.0) D: 4 (25.0) Late A: 9 (47.0) B: 5 (26.0) C: 1 (5.0) D: 4 (21.0)	Thoracic/throacolumbar compression Cause of trauma, n (%) Early: Automobile crashes: 4 (25), Motorcycle crashes: 3 (19), Fall: 7 (44), Other: 2 (12), Late: Automobile crashes: 14 (74), Motorcycle crashes: 2 (10), Fall: 3 (16), Other: 0 Baseline AIS grade, n (%) Early: A: 7 (44), B: 1 (6), C: 4 (25), D: 4 (25), Late: A: 9 (47), B: 5 (26), C: 1 (5), D: 4 (21) Mean length of hospitalization (± SD) Early: 7.0 ± 7.13 days Late: 9.0 ± 8.28 days	Interventions Decompression with spinal fusion and fixation Co-interventions Standard spinal immobilization and resuscitation techniques Intravenous methylprednisolone based on recommendations from National Acute Spinal Cord Injury Studies Gastrointestinal prophylaxis	Inclusion: >18 years old TSCI between T1 and L1 Hemodynamic stability Evidence of spinal cord/conus medullaris compression and/or MRI signal change Hospital admission before 24 hours of injury Exclusion: Initial AIS grade E No cord compression on MRI Spinal shock An injury involving more than 2 adjacent vertebral levels Inability to provide informed consent Any cognitive deficit Major and current psychiatric illness Significant concurrent traumatic brain injury Major concurrent medical disease Pre-injury major neurologic deficits or disease Ankylosing spondylitis Penetrating thoracolumbar injuries Pregnancy Life-threatening injuries preventing early cord decompression Criminals under indictment Incarceration Substance abuse
Cervical and thoracic and lumbosacral SCI
Dvorak (2015) Prospective cohort (moderately high risk of bias) Rick Hansen Spinal Cord Injury Registry Follow-up: NR	Overall N = 888 Mean age (range): 45.7 (76) years Male: 76.5% Mean time to surgery (±SD): 60.4 ± 80 hours Early (<24 hours) N = 355 Average age: NR Male: NR Late (24–168 hours) N = 533 Average age: NR Male: NR	Initial neurologic exam performed within 72 hours of injury ASIA grade, n (%) Overall A: 292 (38.8) B: 90 (12) C: 138 (18.4) D: 232 (30.9)	Neurological level of injury, n (%) Overall: High cervical (C1-C4): 190 (26.5), Low cervical (C5-T1): 257 (35.8), Thoracic (T2-T10): 120 (16.7), Thoracolumbar (T11-L2): 151 (21.0) Severity of injury, n (%) Overall: AIS A: 292 (38.8), AIS B: 90 (12), AIS C: 138 (18.4), AIS D: 232 (30.9)	Interventions Combination of either stabilization and/or decompression Co-interventions NR	Inclusion: Participants in the RHSCIR Acute SCI Surgery <1 month post-injury Exclusion: GCS <14 Timing of surgery and neurological examinations unspecified Failure to provide consent
Wilson (2012) Prospective cohort (moderately high risk of bias) Ontario Spinal Cord Registry Follow-up: Acute care discharge: Mean 24.8 ± 29.2 days (97.6%, n = 82/84) Inpatient rehabilitation discharge: Mean 89.6 ± 47.4 days (65.4%, n = 55/84; Early: 62.9%, n = 22/35; Late: 67.3%, n = 33/49)	Overall N = 84 Mean age: 45.3 years Males: 80.1% Early (<24 hours) N = 35 Mean age: 41.6 years Males: 83% Mean time to surgery (±SD): 12.7 ± 4.9 hours Late (≥24 hours) N = 49 Mean age: 47.9 years Males: 78% Mean time to surgery (±SD): 155.0 ± 236.7 hours	Initial assessment at acute-care admission ASIA grade, n (%) Early A: 18 (51) B: 6 (17) C: 5 (14) D: 6 (17) Late A: 15 (31) B: 3 (6) C: 6 (12) D: 25 (51)	Neurological level of injury, n (%) Early: Cervical: 14 (40.0), Thoracic: 12 (34.3), Lumbosacral: 9 (25.7), Late: Cervical: 30 (61.2), Thoracic: 9 (18.4), Lumbosacral: 10 (20.4) Cause of trauma, n ((%) Early: MVA: 13 (37.1), Fall: 13 (37.1), Assault: 1 (2.9), Other: 8 (22.9), Late: MVA: 10 (20.4), Fall: 29 (59.2), Assault: 3 (6.1), Other: 7 (14.3)	Interventions Approach, extent of decompression and use of spinal instrumentation made on a case-by-case basis by the attending orthopedic or neurosurgeon Co-interventions All patients received optimal medical support, which included permissive or induced hypertensive therapy for 1 week following injury Methylprednisolone was used per the discretion of the treating team according to the recommendations of the Second National Acute Spinal Cord Injury Study Received methylprednisolone, n/N (%) Early: 3/25 (12), Late: 7/36 (19.4) All patient underwent an individualized post-op rehab protocol in a spinal cord rehab unit	Inclusion: Traumatic SCI Age >16 years Initial AIS grade A-D Spinal cord compression confirmed by MRI or CT myelography Patient or proxy willing to provide consent for enrollment Exclusion: Cognitive impairment preventing accurate neurological assessment Penetrating injuries Pregnancy Pre-injury major neurological deficits or disease (eg, ischemic stroke, Parkinson’s disease) Life-threatening injuries that prevent early decompression of the spinal cord Significant pre-morbid medical illness, including but not limited to myocardial infarction within 3 months; uncompensated heart failure; active systemic cancer; AIDS
Acute central cord injury without instability
Lenehan (2010) Prospective observational dataset (moderately high risk of bias) Spine Trauma Study Group Follow-up: 1 year, % NR	Overall N = 73 Mean age (±SD): 58.2 ± 14.4 years Male: 81.0% Mean time from injury to admission (±SD): 25.6 ± 13.6 hours Mean time from admission to surgery (±SD): 37.7 ± 85.7 hours Early (<24 hours) N = 17 Mean age at injury (±SD): 55.0 ± 14.4 years Male: 82.3% Late (≥24 hours) N = 56 Mean age at injury (±SD): 59.1 ± 14.3 years Male: 80.3%	Timing of initial neurological examination was not reported Comorbidity (%): Overall: None: 57 (78) One: 14 (19) More: 2 (3) Early: Yes: 3 (17.65) No: 14 (82.35) Late: Yes: 13 (23.21) No: 43 (76.79) ASIA Motor Score: Overall (mean ± SD): 25.6 ± 13.6 Overall (median, range): 41.0 (1.0 to 50.0) Early (mean ± SD): 61.1 ± 29.2 Late (mean ± SD): 63.5 ± 25.1 ASIA grade (%): Overall: C: 28 (38) D: 45 (62) Early: C: 9 (52.94) D: 8 (47.06) Late: C: 19 (33.93) D: 37 (66.07)	Mechanism of injury, n (%) Overall: Falls: 46 (63), MVA: 14 (19), Other: 10 (14), Sport: 3 (4), Early: Falls: 9 (52.94), MVA: 4 (23.53), Other: 4 (23.53), Late: Falls: 37 (66.07), MVA: 10 (17.86), Other: 9 (16.07) Surgical approach, n (%) Overall: Anterior: 18 (26), Posterior: 38 (54), Combined: 14 (20), Early: Anterior: 3 (18.75), Posterior: 6 (37.50), Combined: 7 (43.75), Late: Anterior: 15 (27.78), Posterior: 32 (59.26), Combined: 7 (12.96) Mean length of hospital stay (range) Overall: 21 (1-289) days	Interventions Surgical decompression Co-interventions NR	Inclusion: Presenting with acute central cord syndrome Initial AIS grade C or D Sacral sensory sparing Motor score is greater in lower limbs than in the upper limbs Exclusion: Instability secondary to a fracture/fracture dislocation Acute traumatic cervical disc herniation

Abbreviations: AANS, American Association of Neurological Surgeons; AIDS, acquired immunodeficiency syndrome; AIS, ASIA Impairment Score; ASIA, American Spinal Injury Association; CCS, central cord syndrome; CoE, class of evidence; CT, computed tomography; GCS, Glasgow Coma Scale; ISS, Injury Severity Score; MRI, magnetic resonance imaging; MVA, motor vehicle accident; NR, not reported; RCT, randomized controlled trial; RHSCIR, Rick Hansen Spinal Cord Injury Registry; SCI, spinal cord injury; SD, standard deviation; STASCIS, Surgical Timing in Acute Spinal Cord Injury Study; TSCI, traumatic spinal cord injury.