Outcomes of operative treatment for adult spinal deformity: a prospective multicenter assessment with mean 4-year follow-up

Benchmark Values for Construct Survival and Complications by Type of ASD Surgery

OBJECTIVE

The aim of this study was to provide benchmarks for the rates of complications by type of surgery performed.

STUDY DESIGN

Prospective multicenter database.

BACKGROUND

We have previously examined overall construct survival and complication rates for ASD surgery. However, the relationship between type of surgery and construct survival warrants more detailed assessment.

MATERIALS AND METHODS

Eight surgical scenarios were defined based on the levels treated, previous fusion status [primary (P) vs. revision (R)], and three-column osteotomy use (3CO): short lumbar fusion, LT-pelvis with 5 to 12 levels treated (P, R, or 3CO), UT-pelvis with 13 levels treated (P, R, or 3CO), and thoracic to lumbar fusion without pelvic fixation, representing 92.4% of the case in the cohort. Complication rates for each type were calculated and Kaplan-Meier curves with multivariate Cox regression analysis was used to evaluate the effect of the case characteristics on construct survival rate, while controlling for patient profile.

RESULTS

A total of 1073 of 1494 patients eligible for 2-year follow-up (71.8%) were captured. Survival curves for major complications (with or without reoperation), while controlling for demographics differed significantly among surgical types ( P <0.001). Fusion procedures short of the pelvis had the best survival rate, while UT-pelvis with 3CO had the worst survival rate. Longer fusions and more invasive operations were associated with lower 2-year complication-free survival, however, there were no significant associations between type of surgery and renal, cardiac, infection, wound, gastrointestinal, pulmonary, implant malposition, or neurological complications (all P >0.5).

CONCLUSIONS

This study suggests that there is an inherent increased risk of complication for some types of ASD surgery independent of patient profile. The results of this paper can be used to produce a surgery-adjusted benchmark for ASD surgery with regard to complications and survival. Such a tool can have very impactful applications for surgical decision-making and more informed patient counseling.

LEVEL OF EVIDENCE

Level III.

Self-image in spinal deformity: a state-of-the-art review

PURPOSE

To review the current literature surrounding the assessment of self-image in pediatric and adult spinal deformity.

METHODS

The literature were reviewed for studies examining patient-reported outcome measurements (PROM) and self-image in pediatric and adult spinal deformity. PROM performance metrics were collected and described. The relationships between self-image PROM and patient outcomes, including satisfaction, were described.

RESULTS

Several self-image PROM exist, including the Scoliosis Research Society-22r (SRS-22r) self-image domain, the Body Image Disturbance Questionnaire (BIDQ), and the Spinal Appearance Questionnaire (SAQ). The most commonly used is the self-image domain of the SRS-22r. It is validated in adult and pediatric spinal deformity and is correlated with patient desire for surgery and satisfaction after surgery. This domain is limited by floor and ceiling effects.

CONCLUSION

Self-image assessment is critical to both pediatric and adult spinal deformity surgeries. The SRS-22r self-image domain is the most frequently reported PROM for this health domain. While valid in both surgical cohorts, this PROM is affected by floor and ceiling effects which limits the ability to discriminate between health states. Given the overall importance of this domain to patients with spinal deformity further efforts are needed to improve discrimination without gross increases in PROM question burden, which may limit broad acceptance and use.

Revision of Harrington rod constructs: a single-center's experience with this homogenous adult spinal deformity population at a minimum 2-year follow-up

PURPOSE

To evaluate radiographic and clinical outcomes following revision surgery after HRC fusions.

METHODS

Single-institution, retrospective study of patients revised following HRC with minimum 2-year follow-up post-revision. Demographics, perioperative information, radiographic parameters, complications, and Oswestry disability index (ODI) scores were collected. Radiographic parameters included global alignment, coronal and sagittal measurements pre and postoperatively, as well as final follow-up time points.

RESULTS

26 patients were included with a mean follow-up of 3.3 ± 1.1 years. Mean age was 55.5 ± 7.8 years, BMI 25.2 ± 5.8, and 22 (85%) were females. Instrumented levels increased from 9.7 ± 2.8 to 16.0 ± 2.2. Five (19.2%) patients underwent lumbar pedicle subtraction osteotomies, and 23 (88.4%) had interbody fusions. Patients significantly improved in all radiographic parameters at immediate and final follow-up (p < 0.005), except for thoracic kyphosis and pelvic incidence (p > 0.05). Correction was maintained from immediate postop to final follow-up (p > 0.05). 20 (76.9%) of patients experienced a complication at some point within the follow-up period with the most common being a lumbar nerve root deficit (n = 7). However, only one patient had a nerve root deficit at final follow-up, that being a 4/5 unilateral anterior tibialis function. 5 (19.2%) patients required further revision within a mean of 1.8 ± 1.1 years. On average, patients had an improvement in ODI score by final follow-up (35.6 ± 16.8 vs 25.4 ± 19.8, p = 0.035).

CONCLUSION

Patients revised for HRCs significantly improve, both clinically and radiographically by final follow-up. This group did have a propensity for distal lumbar root neurological issues, which were common but all patients except for one, recovered to full strength by two-year follow-up.

Patient-specific rods in adult spinal deformity: a systematic review

PURPOSE

The purpose of this review was to evaluate the effectiveness of patient-specific rods for adult spinal deformity.

METHODS

A systematic review of the literature was performed through an electronic search of the PubMed, Scopus, and Web of Science databases. Human studies between 2012 and 2023 were included. Sample size, sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), operation time, blood loss, follow-up duration, and complications were recorded for each study when available.

RESULTS

Seven studies with a total of 304 adult spinal deformity patients of various etiologies were included. All studies reported SVA, and PT; two studies did not report PI-LL. Four studies reported planned radiographic outcomes. Two found a significant association between preoperative plan and postoperative outcome in all three outcomes. One found a significant association for PI-LL alone. The fourth found no significant associations. SVA improved in six of seven studies, PI-LL improved in all five, and three of seven studies found improved postoperative PT. Significance of these results varied greatly by study.

CONCLUSION

Preliminary evidence suggests potential benefits of PSRs in achieving optimal spino-pelvic parameters in ASD surgery. Nevertheless, conclusions regarding the superiority of PSRs over traditional rods must be judiciously drawn, given the heterogeneity of patients and study methodologies, potential confounding variables, and the absence of robust randomized controlled trials. Future investigations should concentrate on enhancing preoperative planning, standardizing surgical methodologies, isolating specific patient subgroups, and head-to-head comparisons with traditional rods to fully elucidate the impact of PSRs in ASD surgery.

Identifying Correlation Among Patient-Reported Outcome Measures: A Study of PROMIS-29, ODI, and VAS in Adult Spinal Deformity Patients

BACKGROUND

Adult spinal deformity (ASD) is becoming increasingly common in aging populations. Patient-reported outcome measures (PROMs) are self-reported patient surveys administered pre- and postoperatively that provide insight into patient improvement. We aim to compare 3 of the most utilized PROMs: PROMIS-29, Oswestry Disability Index (ODI), and Visual Analogue Scale (VAS), to investigate whether they provide unique and independent assessments of patient outcomes when assessed longitudinally.

METHODS

We retrospectively reviewed a database of ASD at UT Southwestern Medical Center between 2016 and 2021. Adult patients (>18 years old) were included if they underwent long-segment (>4 levels) thoracolumbar fusion. PROMIS-29, ODI, and VAS scores were collected preoperatively and at 3-, 6-, 12-, 18-, 24-, 30-, and 36-month follow-ups. Scores were recorded ±1 month of the time points. Pearson correlation coefficients for each PROM were then calculated in a pairwise fashion.

RESULTS

A total of 163 patients were included in our analysis. ODI and VAS showed significant covariance, with VAS Neck and VAS Back having Pearson coefficients of 0.95 and 0.94, respectively. ODI and PROMIS-29 also showed significant covariance, with Physical Function and ODI showing a Pearson coefficient of 0.95. PROMIS-29 and VAS demonstrated less correlation regarding Pain and Physical Function; however, they showed a significantly high Pearson coefficient when comparing VAS Back with PROMIS-29 Sleep and Pain Intensity (r = 0.97 and r = 0.96, respectively).

CONCLUSIONS

All 3 PROMs demonstrated significant correlation over 36 months, indicating that simultaneous administration of each during follow-up is redundant. The measure that provided the least unique information was ODI, as both VAS and PROMIS-29 demonstrated similar progression and assessed additional metrics. PROMIS-29 provided the same information as VAS and ODI, with extra facets of patient-reported outcomes, indicating that it may be a more comprehensive measure of longitudinal patient improvement.

Analysis of Personalized Interbody Implants in the Surgical Treatment of Adult Spinal Deformity

STUDY DESIGN

Multicenter cohort.

OBJECTIVES

A report from the International Spine Study Group (ISSG) noted that surgeons failed to achieve alignment goals in nearly two-thirds of 266 complex adult deformity surgery (CADS) cases. We assess whether personalized interbody spacers are associated with improved rates of achieving goal alignment following adult spinal deformity (ASD) surgery.

METHODS

ASD patients were included if their surgery utilized 3D-printed personalized interbody spacer(s) and they met ISSG CADS inclusion criteria. Planned alignment was personalized by the surgeon during interbody planning. Planned vs achieved alignment was assessed and compared with the ISSG CADS series that used stock interbodies.

RESULTS

For 65 patients with personalized interbodies, 62% were women, mean age was 70.3 years (SD = 8.3), mean instrumented levels was 9.9 (SD = 4.1), and the mean number of personalized interbodies per patient was 2.2 (SD = .8). Segmental alignment was achieved close to plan for levels with personalized interbodies, with mean difference between goal and achieved as follows: intervertebral lordosis = .9° (SD = 5.2°), intervertebral coronal angle = .1° (SD = 4.7°), and posterior disc height = -0.1 mm (SD = 2.3 mm). Achieved pelvic incidence-to-lumbar lordosis mismatch (PI-LL) correlated significantly with goal PI-LL (r = .668, P < .001). Compared with the ISSG CADS cohort, utilization of personalized interbodies resulted in significant improvement in achieving PI-LL <5° of plan (P = .046) and showed a significant reduction in cases with PI-LL >15° of plan (P = .012).

CONCLUSIONS

This study supports use of personalized interbodies as a means of better achieving goal segmental sagittal and coronal alignment and significantly improving achievement of goal PI-LL compared with stock devices.

Adult Cervical Deformity Patients Have Higher Baseline Frailty, Disability, and Comorbidities Compared With Complex Adult Thoracolumbar Deformity Patients: A Comparative Cohort Study of 616 Patients

STUDY DESIGN

Multicenter comparative cohort.

OBJECTIVE

Studies have shown markedly higher rates of complications and all-cause mortality following surgery for adult cervical deformity (ACD) compared with adult thoracolumbar deformity (ATLD), though the reasons for these differences remain unclear. Our objectives were to compare baseline frailty, disability, and comorbidities between ACD and complex ATLD patients undergoing surgery.

METHODS

Two multicenter prospective adult spinal deformity registries were queried, one ATLD and one ACD. Baseline clinical and frailty measures were compared between the cohorts.

RESULTS

616 patients were identified (107 ACD and 509 ATLD). These groups had similar mean age (64.6 vs 60.8 years, respectively, P = .07). ACD patients were less likely to be women (51.9% vs 69.5%, P < .001) and had greater Charlson Comorbidity Index (1.5 vs .9, P < .001) and ASA grade (2.7 vs 2.4, P < .001). ACD patients had worse VR-12 Physical Component Score (PCS, 25.7 vs 29.9, P < .001) and PROMIS Physical Function Score (33.3 vs 35.3, P = .031). All frailty measures were significantly worse for ACD patients, including hand dynamometer (44.6 vs 55.6 lbs, P < .001), CSHA Clinical Frailty Score (CFS, 4.0 vs 3.2, P < .001), and Edmonton Frailty Scale (EFS, 5.15 vs 3.21, P < .001). Greater proportions of ACD patients were frail (22.9% vs 5.7%) or vulnerable (15.6% vs 10.9%) based on EFS (P < .001).

CONCLUSIONS

Compared with ATLD patients, ACD patients had worse baseline characteristics on all measures assessed (comorbidities/disability/frailty). These differences may help account for greater risk of complications and all-cause mortality previously observed in ACD patients and facilitate strategies for better preoperative optimization.