Prognosis Following Surgery for SCI

In the acute period of traumatic SCI, interventions are aimed primarily at preserving or improving long-term function. Although recovery of neurologic function after injury is notoriously difficult to predict, much work has gone into identifying prognostic factors that might help guide individual expectations for long-term function. In general, prognosis and neurological outcome are described using outcomes tools including changes in the AIS motor score, and the Frankel grade, which is general measure of functional independence.

Author Year

Country
Research Design
Score
Total Sample Size

Methods Outcome
Razaq et al. (2018)

Pakistan

Case Series

N=149

Population: Mean age=32±13.1 yr; Gender: male=117, female=32; Level of injury: C3–C4=3, C4–C5=2, C5–C6=7, C6–C7=7, C7–T1=1; Severity of injury: ASIA A=65, B=12, C=59, D=13.

Intervention: A retrospective review to assess neurological recovery in terms of ASIA grading in individuals with traumatic SCI. Outcome measures were assessed preoperatively and at six mo follow-up.

Outcome measures: Cause of injury; ASIA score.

Chronicity: All participants were operated on within 24 hr after injury.

1.     The majority of individuals presented with fall (64.4%), while the remainder presented with motor vehicular accidents (35.6%).

2.     The AISA grading at six mo was ASIA A=40.9%, B=2.7%, C=17.4%, D=22.1%. E=16.8%.

3.     Overall neurological improvement was observed in 45% of individuals.

4.     Improvement of one ASIA grade was observed in 32.9% of individuals, while a two-grade improvement was observed in 11.4% of individuals and three grades in 7%.

Abdel Fatah (2017)

Egypt

Case Series

N=53

Population: Mean age=39.4 yr; Gender: male=22, female=31; Level of injury: T10=4, T11=7, T12=31, L1=11; Severity of injury: AISA A=6, B=18, C=29.

Intervention: A retrospective review of walking recovery after surgical management of traumatic burst fractures at the thoracolumbar junction in paraplegic individuals.

Outcome measures: Walking ability.

Chronicity: The mean time from injury to surgical intervention was 9.3 hr and the mean length of hospital stay was 21.6 days.

1.     All individuals with L1 fracture and 70.96% of individuals with T12 fracture regained the ability to walk, however, all the individuals with T10 and T11 fractures did not regain walking ability 12 mo after surgery.

1.     The severity of SCI and walking ability was related to the spinal level of fracture.

Park et al. 2017

Korea

Case Series

N=73

Population: Mean age=44.2 yr; Gender: male=58, female=15; Level of injury: C2–C7; Severity of injury: AISA A-D.

Intervention: A retrospective review of the prognostic factors affecting the outcomes of decompression surgery in individuals with SCI.
Outcome measures: Early intervention; Sex; Age; Surgical level; American Spinal Injury Association (ASIA) score; Blood Pressure (BP); Mean Arterial Pressure (MAP); Cord compression; Steroid use; Surgery time; Estimated blood loss measured after surgery and at 3 mo.

Chronicity: The mean time from injury to surgery and length of hospital stay was not reported.

1.     The MAP, AIS before surgery and BP were significant prognostic factors affecting recovery in the immediate post-operative period (p<0.001, p=0.033, p=0.004), while early decompression, sex, age, surgical level, maximal cord compression, use of steroids, surgery time and EBL were not significant (p>0.05).

2.     In the late recovery period, three mo after surgery, the AIS before surgery, BP, and MAP were significant prognostic factors affecting recovery (p=0.006, p=0.004, p=0.003), while early decompression, sex, age, surgical level, maximal cord compression, use of steroids, surgery time, and EBL were not significant (p>0.05).

Konomi et al. (2018)

Japan

Case Control

N=78

Population:  Mean age=67 yr; Gender: male=66, female=12; Level of injury: C3–C6; Severity of injury: Not reported.

Intervention: The effectiveness of decompression surgery for individuals with traumatic cervical SCI and pre-existing cord compression ≥40% (n=32) or <40% (n=46) was compared.

Outcome measures: American Spinal Injury Association (ASIA) score; Barthel index; SCIM.

Chronicity: Individuals underwent surgery on average 27 days after injury. The mean duration of hospital stay was 46 days.

1.     In the severe compression group (≥40%), AIS grade improvement >2 was observed in 30% of individuals with surgical treatment, although it was not observed in any individual without surgery.

2.     SCIM improvement rate at discharge was 60% in the surgical group and 20% in the non-surgical treatment group.

3.     In the minor compression group (<40%), AIS grade improvement >2 was observed in 18% of individuals with surgical treatment and 11% without surgery.

4.     The SCIM improvement rate at discharge was 52% in the surgical treatment group and 43% in the non-surgical treatment group.

Biglari et al. (2016)

Germany

Cohort

N=51

Population: Early intervention (n=29): Mean age=38.2±17.9 yr; Gender: male=25, female=4; Level of injury: cervical=12, thoracic=10, lumbar=7; Severity of injury: AISA A=13, B=8, C=7, D=1.

Late intervention (n=22): Mean age=50.2±18.9 yr; Gender: male=15, female=7; Level of injury: cervical=10, thoracic=6, lumbar=6; Severity of injury: AISA A=11, B=3, C=4; D=4.

Intervention: Individuals with SCI received early (within the first four hr) or late (between four and 24 hr) surgical decompression to determine if either improves neurological outcomes. Outcome measures were assessed at the time of admission and 6 mo after trauma or longer depending on the time of release.

Outcome measures: American Spinal Injury Association (ASIA) score.

Chronicity: All individuals received early stabilization and decompression within 24 hr.

1. No significant difference in neurologic function, measured with ASIA score, was found between cohorts (p>0.05).
Kreinest et al. (2016)

Germany

Case Series

N=133

Population: Mean age=50.5±21.2 yr; Gender: male=104, female=29; Level of injury: C3–L4; Severity of injury: not reported.

Intervention: A retrospective review to analyze the influence of previous comorbidities and common complications on motor function outcome in individuals with traumatic spinal cord injury that received early surgical intervention.

Outcome measures: Motor function; Complications.

Chronicity: The mean time from injury to surgery was 22.1±56.6 hr. The mean length of hospital stay was 122.8±100.4 days.

1.     Motor function improved from 51.5±24.8 to 60.1±25 (improvement: 25.7%).

2.     The most common complications were urinary tract infection and pneumonia.

3.     A significant relationship between a lack of previous spinal comorbidities and increased motor function was observed (p<0.05).

4.     No other comorbidities or complications showed a significant effect on motor function outcome.

Jug et al. (2015)

Slovenia

Cohort

N=48

Population: Early intervention (n=26): Mean age=44 yr; Gender: male=18, female=8; Level of injury: C3–C4=1, C4–C5=4, C5–C6=5, C6–C7=10, C7–T1=2; Severity of injury: AISA A=13, B=5, C=4.

Late intervention (n=22): Mean age=52 yr; Gender: male=16, female=6; Level of injury: C3–C4=3, C4–C5=2, C5–C6=7, C6–C7=7, C7–T1=1; Severity of injury: AISA A=4, B=1, C=15.

Intervention: Individuals with SCI received surgical decompression and instrumented fusion early (within 8 hr) or late (between eight and 24 hr) after injury to determine if either improves neurological outcomes.  Outcome measures were assessed at baseline and at six mo follow up.

Outcome measures: American Spinal Injury Association (ASIA) score; Complications.

Chronicity: All individuals received early stabilization and decompression within 24 hr.

1.     At the six mo follow up, a significant improvement of at least two AIS grades was found in 45.5% of individuals in the early intervention compared to 10% of the late intervention cohort (p=0.017).

2.     A significant improvement in ASIA motor score was found in the early intervention (38.5) compared to the late (15.0) (p=0.0468).

3.     The odds of an at least two-grade AIS improvement were 106% higher for individuals in the early intervention than for individuals in the late intervention (OR=11.08, p=0.004).

4.     No significant differences in rate of complications was found between cohorts.

Lehre et al. (2015)

Norway

Case Series

N=146

Population: Mean age=31.7 yr; Gender: male=129, female=17; Level of injury: lumbar=60, cervical=50, thoracic=32, combined=4; Severity of injury: AISA A=32.2%, B/C/D=46.6%, E=21.2%.

Intervention: A retrospective review of outcomes after surgical treatment for SCI.

Outcome measures: Mortality; Neurological status; Quality of life; Complications.

Chronicity: Not reported.

1.     Twenty-five individuals (17.1%) were confirmed dead and 85 individuals (58.2%) were alive.

2.     Eight out of 47 individuals (17%) with a complete injury and 29 out of 68 individuals (42.6%) with an incomplete injury showed neurological improvement.

3.     The reported incidences of pressure wounds, recurrent urinary tract infections, pneumonia, and thromboembolic events were 22.5%, 13.5%, 5.6% and 1.1% respectively.

4.     No significant differences were observed in quality of life.

Kawano et al. (2010)

Japan

Prospective Control Trial

N=54

Population: Surgery (SG, n=17): Mean age: 61.4 yr; Gender: males=11, females=6; Level of injury range: C3-C6; Level of severity: AIS B=3, C=14.

Conservative Compression (CC, n=17): Mean age: 64.6 yr; Gender: males=15, females=2; Level of injury range: C3-C6; Level of severity: AIS B=5, C=12.

Conservative Mild Compression (MC, n=20): Mean age: 61.3 yr; Gender: males=18, females=2; Level of injury range: C3-C6; Level of severity: AIS B=4, C=16.

Intervention: Individuals with cervical spinal cord compression without bone and disc injury were assigned to either a surgical treatment group or a conservative treatment group. Outcomes were assessed at baseline, 2 wk, 3 mo, 6 mo, and 1 yr after injury.

Outcome Measures: American Spinal Injury Association (ASIA) Motor Score.

1.     The mean ASIA motor scores were 25.1 points (SG) and 27.1 (CC), at the time of admission; 41.0 (SG), 42.5 (CC), at 2 wk; 61.8 (SG), 61.2 (CC), at 3 mo; 64.2 (SG), 63.0 (CC), at 6 mo; 65.1 (SG), 64.1 (CC), at 1 yr. There was no significant difference in the recovery process.

2.     The mean ASIA motor score of the MC group was 25.0 at admission, 38.3 at 2 wk, 60.8 at 3 mo, 64.0 at 6 mo, and 64.9 at 1 yr. Not significantly different from the SG or CC groups.

Singhal et al. (2008)

UK

Case Series

NInitial=57, NFinal=37

Population: Mean age: 40.8 yr; Gender: males=43, females=14; Injury etiology: motor vehicle accident=17, fall=15, sports=2, assaults=2; Level of injury: C2-C7; Level of severity: Frankel B=25, C=7, D=5.

Intervention: Individuals with traumatic cervical SCI who underwent surgery were retrospectively analyzed. Follow-up time was >12 mo.

Outcome Measures: Frankel Grade.

1.     Of the 25 individuals with Frankel Grade B, 14 improved to C, six improved to D, and five remained the same.

2.     Of the seven individuals with Frankel Grade C, all improved to D.

3.     Of the five individuals with Frankel Grade D, one improved to E and four remained the same.

McKinley et al. (2004)

USA

Case Series

N=54

Population: Nonsurgical (NS, n=176): Mean age: 42.8 yr; Gender: males=149, females=27; Injury etiology: motor vehicle accident=89, falls=52, sports=7, medical complication=17, violence=2, other=9; Level of severity: incomplete paraplegia=34, complete paraplegia=34, incomplete tetraplegia=73, complete tetraplegia=35. Early Surgical (ES, n=307): Mean age: 36.7 yr; Gender: males=228, females=79; Injury etiology: motor vehicle accident=175, falls=75, sports=29, medical complication=4, violence=3, other=21; Level of severity: incomplete paraplegia=65, complete paraplegia=93, incomplete tetraplegia=82, complete tetraplegia=67; Time since injury range: <72 hr. Late Surgical (LS, n=296): Mean age: 35.6 yr; Gender: males=237, females=59; Injury etiology: motor vehicle accident=148, falls=93, sports=35, medical complication=1, violence=3, other=16; Level of severity: incomplete paraplegia=40, complete paraplegia=85, incomplete tetraplegia=101, complete tetraplegia=70; Time since injury range: >72 hr.

Intervention: Individuals with spinal cord injury were retrospectively analyzed based on timing of surgery. Outcomes were assessed at baseline and 1 yr after injury.

Outcome Measures: American Spinal Injury Association (ASIA) Motor Score, Length of Stay (LOS), Cost, Complications, Neurologic Levels, AIS Grade, Functional Independence Measure (FIM) Motor.

1.     ASIA motor score improvements were significantly greater in the NS group compared to both the ES and LS groups (p<0.05).

2.     The LS group had significantly (p<0.05) increased acute care and total LOS and hospital cost along with higher incidence of pneumonia and atelectasis. 3.     There was no significant difference between groups in neurologic levels, AIS grade, or FIM motor efficiency (all p>0.05).

Discussion

Park et al. (2017) performed a prognostic factor analysis to determine variables that might influence prognosis for traumatic SCI. In summary, they found that at one-year follow-up, the presenting neurological status of the individual, as well as their mean arterial pressure during the acute phase of hospital stay, was associated favourably with AIS motor score improvement.

Another potential determinant of neurological outcome is the overall medical state of the individual both before injury, and in terms of their complication profile after injury. Kreinest (2016) retrospectively reviewed a heterogenous series of individuals with SCI and found that long-term AIS motor score changes were adversely affected if the individual had previous spinal co-morbidities such as ankylosing conditions, or significant degenerative conditions. It is unclear whether spinal comorbidities are primary drivers of outcome or whether they may act as a surrogate for increased age, for example. Interestingly, further analysis of these individuals showed that other pre-injury comorbidities, as well as common in-hospital complications such as urinary tract infection and pneumonia, had no effect on AIS motor score improvements in these individuals.

Walking ability is clearly an important functional outcome after traumatic SCI. In a population of individuals with thoracolumbar SCI, Abdel-Fatah (2017) demonstrated that walking ability at one year was strongly related to the level of injury, with T12 and L1 injuries having significantly more function, and T10 and T11-injured individuals not regaining the ability to walk. This may potentially be due narrowing of the spinal canal at T10-11.

Another retrospective review was performed by Razaq (2018) who reported an SCI cohort with mixed neurology, demonstrating an overall AIS motor grade conversion of 45% at follow-up, with AIS A individuals demonstrating a substantially lower chance of improvement than those with incomplete injuries.

Despite the clear focus on early surgical decompression of traumatic SCI for improved outcome, there is some evidence that individuals undergoing delayed treatment can still experience neurological recovery. Konomi et al. (2018) assessed a retrospective cohort of individuals with late surgery and found that those individuals with severe cord compression still demonstrated neurologic improvement (2 or more AIS grades) in 30% of cases when late surgery was performed. This compared favourably to no improvement in the same individuals without surgery. In contrast, the subgroup of individuals with only mild-moderate ongoing cord compression demonstrated similar rates of recovery in surgical vs nonsurgical groups, and this rate was lower (11-18%) than the severe group.

Lehre et al. (2015) report a series of surgical individuals from a resource-limited setting in Ethiopia. In their series, 17% of individuals did not survive to follow-up, but among survivors 17% of complete SCI and 42% of incomplete individuals with SCI demonstrated motor recovery on examination. The authors propose that even in resource-limited settings, individuals can still derive benefit from surgical management of SCI.

McKinley et al. (2004) describe a retrospective comparison between nonsurgical, early surgery, and late surgery with respect to long-term motor improvement. They reported that nonsurgical individuals demonstrated a higher AIS motor score improvement at follow-up, as well as higher scores on the Functional Independence Measure. This was felt to be a confounded result due to the higher proportion of incomplete SCI in the nonsurgical group, who have a greater rehabilitation potential. Otherwise no differences were found with respect to prognosis between early and late surgery.

One well-recognized pattern of SCI is so-called hyperextension injury, which can occur as a dynamic process resulting in cord impingement without structural damage to the spine itself. In terms of AIS motor score improvement, these individuals tend to demonstrate a consistent improvement after 1 year (Kawano et al. 2010), and surgical intervention seems not to affect recovery. This is intuitive as there is not necessarily a structural process to correct in the setting of this injury.

In a (2008) study, Singhal et al. compared the motor recovery of 37 individuals with cervical SCI who were managed conservatively and with surgery. Despite not finding a statistical difference, they did report preservation of sensation below the injury as an important prognostic factor.

Conclusion

There is conflicting level 2, 3, and 4 evidence (based on several mixed studies) that a number of prognostic factors are important in the neurological outcomes after surgery for SCI which may include, but are not limited by, prior neurological and general medical status, mean arterial pressure, spinal co-morbidities, age, complications (e.g., pneumonia, urinary track infections), walking ability, level and completeness of injury, and timing of surgery.