Sagittal radiographic parameters demonstrate weak correlations with pretreatment patient-reported health-related quality of life measures in symptomatic de novo degenerative lumbar scoliosis: a European multicenter analysis

Stiffness-related disability following long segmental posterior instrumentation and fusion: is it influenced by postoperative spinopelvic alignment?

PURPOSE

The aims of this study were to investigate the correlations between Chinese version of Lumbar Stiffness Disability Index (C-LSDI) and other clinical outcomes, and to identify the factors independently affecting stiffness-related disability after long-segment fusion in patients with degenerative lumbar scoliosis (DLS).

METHODS

We performed a retrospective study of 118 consecutive surgically treated DLS cases at a single institute. Pre- and post-operative radiological parameters and postoperative health related quality of life (HRQOL) were examined to determine their correlation coefficients with postoperative C-LSDI. Patients were divided into two groups by the medium number of postoperative C-LSDI: low-stiffness group (C-LSDI < 48 points) and high-stiffness group (C-LSDI ≥ 48 points). Subsequently, differences between the two groups were assessed, and the presumed factors affecting C-LSDI evaluation were further analyzed.

RESULTS

Coronal parameters and global sagittal parameters showed significant correlations with postoperative C-LSDI. The correlation coefficients between C-LSDI and Oswestry Disability Index (ODI), Japanese Orthopedic Association-29 (JOA-29), the Scoliosis Research Society-22 questionnaire (SRS-22) Function, and the Short Form-36 Health Survey (SF-36) Physical Component Scores were over 0.5. In multiple linear regression, postoperative sagittal vertical axis (β = 0.084, p = 0.025), fusion levels (β = 2.13, p = 0.012), and body mass index (β = 0.867, p = 0.022) were independent related factors for C-LSDI.

CONCLUSION

This study showed that all HRQOLs demonstrated the varying degree of correlations with C-LSDI, of which the ODI, JOA-29, SRS-22 Function, and SF-36 PCS were most relevant, with moderate strength of associations.Moreover, longer fusion levels, higher BMI, and greater postoperative SVA independently affect C-LSDI after long segmental posterior instrumentation and fusion for DLS.

Spino-pelvic parameters and back pain in patients without coronal deformity or history of spinal surgery: A cross-sectional analysis

BACKGROUND

During the last two decades, there has been a growing interest in spinal sagittal alignment. Most published studies have focused on the role of spinopelvic parameters in patients with adult spinal deformity or in those with previous spinal fusion.

OBJECTIVE

The aim of this study was to explore possible association between disability related to back pain and spinopelvic parameters in the absence of coronal deformity or previous spinal surgery.

METHODS

In the setting of a larger study involving patients with low back pain (LBP), those without previous surgery or spinal deformity in the coronal plane were selected. A total of 52 patients (mean age 59 years, range 21-86, 23 men and 29 women) were found. The visual analogic scale (VAS) and Oswestry Disability Index questionnaire (ODI) were recorded. Surgimap software was used to measure the sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), and lumbar lordosis (LL). Statistical analysis was performed with SPSS Statistics software. Pearson or Spearman correlation were the test of choice depending on the specific variables.

RESULTS

A statistically significant association was found between SVA and ODI (r 0.59, p< 0.03). Increased pelvic tilt was also associated with more severe disability related to back pain (r 0.48, p< 0.03). PI-LL mismatch showed moderate association with disability and severity of back pain, although this association did not reach statistical significance (r 0.52, p< 0.08).

CONCLUSION

Our findings suggest that sagittal misalignment may be related with more severe disability and back pain in patients with minor or null deformity in the coronal plane.

The kickstand rod technique for correction of coronal malalignment in patients with adult spinal deformity: a systematic review and pooled analysis of 97 cases

Coronal malalignment (CM) has recently gained focus as a key predictor of functional outcomes in patients with adult spinal deformity (ASD). The kickstand rod technique has been described as a novel technique for CM correction using an accessory rod on the convex side of the deformity. This review aimed to evaluate the surgical technique and outcomes of corrective surgery using this technique. The literature search was conducted on three databases (PubMed, EMBASE, and Scopus). After reviewing the search results, six studies were shortlisted for data extraction and pooled analysis. Weighted means for surgical duration, length of stay, amount of coronal correction, and sagittal parameters were calculated. The studies included in the review were published between 2018 and 2023, with a total sample size of 97 patients. The mean age of the study cohort was 61.1 years, with female preponderance. The mean operative time was 333.6 minutes. The mean correction of CM was 5.1 cm (95% confidence interval [CI], 3.6-6.6), the mean sagittal correction was 5.6 cm (95% CI, 4.1-7.1), and the mean change in lumbar lordosis was 17° (95% CI, 10.4-24.1). Preoperative coronal imbalance and mean correction achieved postoperatively were directly related with age. The reoperation rate was 13.2%. The kickstand rod technique compares favorably with conventional techniques such as asymmetric osteotomies in CM management. This technique provides an additional accessory rod that helps increase construct stiffness. Because of limited data, definitive conclusions cannot be drawn from this review; however, this technique is a valuable tool for a surgeon dealing with ASD.

Early Experience with Prone Lateral Interbody Fusion in Deformity Correction: A Single-Institution Experience

Background/Objectives: Lateral spine surgery offers effective minimally invasive deformity correction, but traditional approaches often involve separate anterior, lateral, and posterior procedures. The prone lateral technique streamlines this process by allowing single-position access for lateral and posterior surgery, potentially benefiting from the lordosing effect of prone positioning. While previous studies have compared prone lateral to direct lateral for adult degenerative diseases, this retrospective review focuses on the outcomes of adult deformity patients undergoing prone lateral interbody fusion. Methods: Ten adult patients underwent single-position prone lateral surgery for spine deformity correction, with a mean follow-up of 18 months. Results: Results showed significant improvements: sagittal vertical axis decreased by 2.4 cm, lumbar lordosis increased by 9.1°, pelvic tilt improved by 3.3°, segmental lordosis across the fusion construct increased by 12.2°, and coronal Cobb angle improved by 6.3°. These benefits remained consistent over the follow-up period. Correlational analysis showed a positive association between improvements in PROs and SVA and SL. When compared to hybrid approaches, prone lateral yielded greater improvements in SVA. Conclusions: Prone lateral surgery demonstrated favorable outcomes with reasonable perioperative risks. However, further research comparing this technique with standard minimally invasive lateral approaches, hybrid, and open approaches is warranted for a comprehensive evaluation.

Strong Association of Depression and Anxiety With the Presence of Back Pain While Impact of Spinal Imaging Findings is Limited: Analysis of an MRI Cohort Study

Development of back pain is multifactorial, and it is not well understood which factors are the main drivers of the disease. We therefore applied a machine-learning approach to an existing large cohort study data set and sought to identify and rank the most important contributors to the presence of back pain amongst the documented parameters of the cohort. Data from 399 participants in the KORA-MRI (Cooperative health research in the region Augsburg-magnetic resonance imaging) (Cooperative Health Research in the Region Augsburg) study was analyzed. The data set included MRI images of the whole body, including the spine, metabolic, sociodemographic, anthropometric, and cardiovascular data. The presence of back pain was one of the documented items in this data set. Applying a machine-learning approach to this preexisting data set, we sought to identify the variables that were most strongly associated with back pain. Mediation analysis was performed to evaluate the underlying mechanisms of the identified associations. We found that depression and anxiety were the 2 most selected predictors for back pain in our model. Additionally, body mass index, spinal canal width and disc generation, medium and heavy physical work as well as cardiovascular factors were among the top 10 most selected predictors. Using mediation analysis, we found that the effects of anxiety and depression on the presence of back pain were mainly direct effects that were not mediated by spinal imaging. In summary, we found that psychological factors were the most important predictors of back pain in our cohort. This supports the notion that back pain should be treated in a personalized multidimensional framework. PERSPECTIVE: This article presents a wholistic approach to the problem of back pain. We found that depression and anxiety were the top predictors of back pain in our cohort. This strengthens the case for a multidimensional treatment approach to back pain, possibly with a special emphasis on psychological factors.

Measuring Outcomes in Spinal Deformity Surgery

Outcome assessment in adult spinal deformity has evolved from radiographic analysis of curve correction to patient-centered perception of health-related quality-of-life. Oswestry Disability Index and the Scoliosis Research Society-22 Patient Questionnaire are the predominantly used patient-reported outcome (PRO) measurements for deformity surgery. Correction of sagittal alignment correlates with improved PRO. Functional outcomes and accelerometer measurements represent newer methods of measuring outcomes but have not yet been widely adopted or validated. Further adoption of a minimum set of core outcome domains will help facilitate international comparisons and benchmarking, and ultimately enhance value-based healthcare.

Focusing on the amount of immediate changes in spinopelvic radiographic parameters to predict the amount of mid-term improvement of quality of life in adult degenerative scoliosis patients with surgery

INTRODUCTION

Surgery is still an effective treatment option for adult degenerative scoliosis (ADS), but how to predict patients' significant amount of the improvement in quality of life remains unclear. The previous studies included an inhomogeneous population. This study aimed to report the results about concentrating on the amount of immediate changes in spinopelvic radiographic parameters to predict the amount of mid-term improvement in quality of life in ADS patients.

MATERIALS AND METHODS

Pre-operative and immediately post-operative radiographic parameters included Cobb angle, coronal vertical axis (CVA), sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI) and LL/PI matching (PI-LL). Quality of life scores were evaluated pre-operatively and at the final follow-up using Oswestry Disability Index (ODI) and visual analogue scale (VAS). The amount of immediate changes in spinopelvic radiographic parameters (Δ) and the amount of mid-term improvement in quality of life (Δ) were defined, respectively.

RESULTS

Patients showed significant change in radiographic parameters, ODI and VAS pre- and post-surgery, except CVA and PI. Univariate analysis showed a significant correlation between ΔTK, ΔLL, ΔCVA and the amount of mid-term improvement in quality of life, but multivariate analysis did not get a significant result. Univariate and multivariate analyses showed that ΔSVA was still a significant predictor of ΔVAS and ΔODI. The changes in the other radiographic parameters were not significant. The equations were developed by linear regression: ΔODI = 0.162 × ΔSVA - 21.592, ΔVAS = 0.034 × ΔSVA - 2.828. In the ROC curve for ΔSVA in the detection of a strong ΔODI or ΔVAS, the cut-off value of ΔSVA was - 19.855 mm and - 15.405 mm, respectively.

CONCLUSIONS

This study shows that ΔSVA can predict the amount of mid-term improvement in quality of life in ADS patients. The changes in the other radiographic parameters were not significant. Two equations were yielded to estimate ΔODI and ΔVAS. ΔSVA has respective cut-off value to predict ΔODI and ΔVAS.

Isokinetic strength assessment of trunk muscle and its relationship with spinal-pelvic parameters in patients with degenerative spinal deformity

BACKGROUND

The incidence rate of degenerative spinal deformity (DSD) has gradually increased in the elderly. Currently, the relationship between the functional status of trunk muscle and the spinal-pelvic parameters of DSD patients remains unclear.

OBJECTIVE

This paper aims to explore the relationship between the two factors and provide new clues for exploring the mechanism of the occurrence and development of DSD.

METHODS

A total of 41 DSD patients treated in our hospital (DSD group) and 35 healthy volunteers (control group) were selected. Muscle strength was evaluated using an IsoMed-2000 isokinetic dynamometer, and the trunk flexor and extensor peak torque (PT) of subjects was measured at a low, medium, and high angular velocity of 30∘/s, 60∘/s, and 120∘/s, respectively. Hand grip strength (HGS) was assessed using an electronic grip dynamometer and Surgimap software was used to measure the spinal-pelvic parameters, including the sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence rate (PI), and PI-LL, and the relationship between trunk muscle function and various parameters was analyzed.

RESULTS

Under the three angular velocities, the flexor and extensor PT values in the DSD group were lower than those in the control group, and only the extensor PT showed a statistically significant difference (P< 0.05). There was no significant difference in HGS between the two groups (P> 0.05). In the DSD group, the extensor PT at 30∘/s was significantly negatively correlated with SVA (P< 0.05). At 60∘/s and 120∘/s, the extensor PT was significantly negatively correlated with SVA and PT (P< 0.05).

CONCLUSION

Trunk extensor strength is significantly lower in DSD patients than in normal controls. The decline in trunk extensor strength in DSD patients is a type of local muscle dysfunction more closely related to the deformity, which is likely involved in the compensatory mechanism of DSD and may reflect the overall imbalance of the trunk.

Use of the Global Alignment and Proportion score to predict postoperative health-related quality of life in adult spinal deformity surgery

OBJECTIVE

The purpose of this study was to validate the Global Alignment and Proportion (GAP) score as a predictor of health-related quality of life (HRQOL) outcomes for patients undergoing adult spinal deformity (ASD) surgery.

METHODS

This was a retrospective cohort study of patients with ASD undergoing long-segment spine fusions (≥ 5 vertebrae fused) at a single institution over a 2-year period (n = 85). Radiographic parameters were measured at preoperative, 6-week postoperative, 1-year postoperative, and 2-year postoperative visits. GAP scores were calculated using 4 sagittal parameters: relative pelvic version, relative lumbar lordosis, lordosis distribution index, and relative spinopelvic alignment. Patients were stratified into 3 GAP categories at each time point: proportioned (score 0-2), moderately disproportioned (score 3-6), and severely disproportioned (score ≥ 7). HRQOL outcomes were collected at preoperative, 1-year postoperative, and 2-year postoperative visits; these measures included patient self-reported outcome measures (i.e., PROMIS), Scoliosis Research Society-22 spinal deformity questionnaire (SRS-22), and Oswestry Disability Index (ODI) scores.

RESULTS

Overall, 42% of cases were revision surgeries and 96.5% of patients underwent fusion to the sacrum. The mean preoperative GAP score significantly improved from preoperative (7.84) to immediate postoperative (3.31) assessment (p < 0.001). Similarly, the percentage of patients categorized as proportioned improved from 9.4% at preoperative to 45.9% at immediate postoperative evaluation. The preoperative GAP score or category was not significantly associated with any preoperative HRQOL outcome metrics. The immediate postoperative GAP score was not correlated with any 1-year HRQOL outcomes. However, the immediate postoperative GAP score was significantly associated with 2-year SRS-22 outcomes, including SRS-22 function (r = -0.35, p < 0.01), self-image (r = -0.27, p = 0.044), and subtotal (r = -0.35, p < 0.01) scores. As compared to severely disproportioned patients, proportioned patients had better SRS-22 pain (4.08 vs 3.17, p = 0.04), satisfaction (4.40 vs 3.50, p = 0.02), and subtotal (4.01 vs 3.27, p = 0.036) scores. The immediate postoperative GAP score was also significantly associated with 2-year PROMIS outcomes, including PROMIS pain (r = 0.31, p = 0.023) and physical function (r = -0.35, p < 0.01) scores. As compared to severely disproportioned patients, proportioned patients had better PROMIS pain (53.18 vs 63.60, p = 0.025) and physical function (41.66 vs 34.18, p = 0.017) scores. Postoperative GAP score or category did not predict any ODI outcomes.

CONCLUSIONS

The postoperative GAP score is a predictor of long-term HRQOL outcomes following ASD surgery, and proportioned patients are more likely to have less pain and be satisfied with their surgery. However, the postoperative GAP score does not predict outcomes as measured by ODI.

Static and dynamic stabilometric force platform study of spinopelvic anterior sagittal imbalance

BACKGROUND DATA

Anterior sagittal imbalance (ASI) is a severity factor in spinal pathology. Stabilometric study of the dynamic position of the center of pressure (CoP) assesses orthostatic control. These analyses provide the energy expenditure used for this control.

HYPOTHESIS

Stabilometric signs are associated with ASI indicate increased energy expenditure.

PATIENTS AND METHODS

Healthy male volunteers were subjected to reversible ASI induced by wearing a kyphotic thermoformed thoracolumbar corset. The deformation was assessed by C7 tilt on EOS whole-spine views. Static and dynamic posturographic force platform study was performed under conditions of anteroposterior and mediolateral instability. Mean CoP position (X_mean, Y_mean) was studied on statokinesigram, with scatter assessed as confidence ellipse (CE). Path length according to CE surface (LAS) indicated energy expenditure. The stabilogram quantified displacement over time as lengths (L_x, L_y) and amplitudes (A_x, A_y).

RESULTS

The corset significantly increased C7 tilt (p<0.0001). This did not significantly change mean CoP positions (X_mean and Y_mean), but LAS was significantly increased (p=0.003). Static tests showed changes in L_y (p=0.0008) and A_x (p=0.003), and dynamic tests showed changes in L_y (p<0.0001), L_x (p<0.0001), A_x (p<0.0001), A_y (p<0.05) and CE (p<0.004).

DISCUSSION

Posturographic parameters were impacted by inducing ASI in healthy subjects. Significant differences were seen in stabilography, CE and LAS, were greater on dynamic testing, and correlated with radiologic sagittal balance. Force platforms can reveal increased energy expenditure in maintaining posture.

LEVEL OF EVIDENCE

II; Single-center prospective study involving healthy volunteers.

Transcranial Motor-evoked Potentials for Intraoperative Nerve Root Monitoring During Adult Spinal Deformity Surgery: A Prospective Multicenter Study

STUDY DESIGN

A prospective, multicenter study.

OBJECTIVE

This study clarified the uses and limitations of transcranial motor-evoked potentials (Tc-MEPs) for nerve root monitoring during adult spinal deformity (ASD) surgeries.

SUMMARY OF BACKGROUND DATA

Whether Tc-MEPs can detect nerve root injuries (NRIs) in ASD surgeries remains controversial.

MATERIALS AND METHODS

We prospectively analyzed neuromonitoring data from 14 institutions between 2017 and 2020. The subjects were ASD patients surgically treated with posterior corrective fusion using multichannel Tc-MEPs. An alert was defined as a decrease of ≥70% in the Tc-MEP's waveform amplitude from baseline, and NRI was considered as meeting the focal Tc-MEP alerts shortly following surgical procedures with postoperative nerve root symptoms in the selected muscles.

RESULTS

A total of 311 patients with ASD (262 women and 49 men) and a mean age of 65.5 years were analyzed. Tc-MEP results revealed 47 cases (15.1%) of alerts, including 25 alerts after 10 deformity corrections, six three-column osteotomies, four interbody fusions, three pedicle screw placements or two decompressions, and 22 alerts regardless of surgical maneuvers. Postoperatively, 14 patients (4.5%) had neurological deterioration considered to be all NRI, 11 true positives, and three false negatives (FN). Two FN did not reach a 70% loss of baseline (46% and 65% loss of baseline) and one was not monitored at target muscles. Multivariate logistic regression analysis revealed that risk factors of NRI were preexisting motor weakness ( P <0.001, odds ratio=10.41) and three-column osteotomies ( P =0.008, odds ratio=7.397).

CONCLUSIONS

Nerve root injuries in our ASD cohort were partially predictable using multichannel Tc-MEPs with a 70% decrease in amplitude as an alarm threshold. We propose that future research should evaluate the efficacy of an idealized warning threshold (e.g., 50%) and a more detailed evoked muscle selection, in reducing false negatives.

Clinical impact of short limited lumbar fusion for adult spinal deformity with postural and radiological abnormalities

Extensive surgical spinopelvic fusion for patients with adult spinal deformity (ASD) to achieve optimal radiological parameters should be avoided. The aim of this study was to review clinical and imaging findings in patients with ASD with postural and radiological abnormalities who underwent a novel three-level limited lumbar fusion as two-stage surgery in an attempt to propose a better tolerated alternative to spinopelvic long fusion to the pelvis. The subjects were 26 patients with a minimum follow-up period of 2 years. Cobb angle, C7 sagittal vertical axis, and pelvic incidence (PI) minus lumbar lordosis (LL) were significantly improved after surgery and maintained at follow-up. Most radiological parameters were corrected with lateral interbody fusion (LIF) as the initial surgery, and few with posterior fusion. PI-LL remained high after limited lumbar fusion, but scores on patient-based questionnaires and sagittal and coronal tilt in gait analysis improved. In cases with postoperative progression of proximal junctional kyphosis (11.5%), residual L1-L2 local kyphosis after LIF was the most significant radiological feature. In some cases of ASD with postural abnormalities, short limited lumbar fusion gives sufficient postoperative clinical improvement with preservation of spinal mobility and activities of daily living. The range of fixation should be determined based on radiological parameters after LIF to avoid postoperative complications.

Determining the relationship between preoperative mental health scores and postoperative outcomes in adult spinal deformity surgeries

OBJECTIVE

The objective of this study was to examine the relationship between the mental health domain of the refined 22-item Scoliosis Research Society Outcome Questionnaire (SRS) and various postoperative outcome measures in the adult spinal deformity (ASD) population. Given the scale and involved nature of deformity surgery, some surgeons have proposed that preoperative mental health scores (MHSs) may assist in screening out poor surgical candidates. In this study, the authors aimed to further assess the SRS MHS as a preoperative metric and its association with postoperative outcomes and to comment on its potential use in patient selection and optimization for ASD surgery.

METHODS

The authors conducted a retrospective study of 100 consecutive patients who had undergone primary or revision ASD surgery at a single academic institution between 2015 and 2019. Each patient had a minimum 2-year follow-up. Patients were categorized on the basis of their baseline mental health per the SRS mental health domain, with a score < 4 indicating low baseline mental health (LMH) and a score ≥ 4 indicating high baseline mental health (HMH). Baseline and follow-up SRS and Oswestry Disability Index scores, surgical procedures, lengths of stay, discharge locations, intraoperative or postoperative complications, and other outcome metrics were then compared between the HMH and LMH groups, as well as these groups stratified by an age ≤ 45 and > 45 years.

RESULTS

Among patients aged ≤ 45 and those aged > 45, the LMH group had significantly worse baseline health-related quality-of-life (HRQOL) metrics in nearly all domains. The LMH group also had an increased median estimated blood loss (EBL; 1200 vs 800 ml, p = 0.0026) and longer average surgical duration (8.3 ± 2.8 vs 6.9 ± 2.6 hours, p = 0.014). Both LMH and HMH groups had significant improvements in nearly all HRQOL measures postoperatively. Despite their worse preoperative HRQOL baseline, patients in the LMH group actually improved the most and reached the same HRQOL endpoints as those in the HMH group.

CONCLUSIONS

While patients with lower baseline MHSs may require slightly longer hospital courses or more frequent discharges to rehabilitation facilities, these patients actually attain greater absolute improvements from their preoperative baseline and surprisingly have the same postoperative HRQOL metrics as the patients with high MHSs, despite their poorer starting point. This finding suggests that patients with LMH may be uniquely positioned to substantially benefit from surgical intervention and improve their HRQOL scores and thus should be considered for ASD surgery to an extent similar to patients with HMH.

Ability of Visual Analogue Scale to predict Oswestry Disability Index improvement and surgical treatment decision in patients with adult spinal deformity

Introduction

The effect of pain on HRQoL scores in ASD patients is not well studied. Disability is a major factor on decision and outcomes. On the other hand, little is known about the effect of perceived and reported pain on these parameters, especially in the elderly population. We hypothesized that baseline back and leg pain would not affect the treatment decision whereas may have a negative effect on outcomes.

Research question

To determine the correlation between preoperative ODI and VAS scores; and to identify the effect of baseline VAS score on treatment decision and ODI improvement following treatment.

Material and methods

In this retrospective study, patients with a follow-up duration of minimum 2 years were enrolled from a prospective multicentric ASD database. Pearson and Spearman correlation tests were used to evaluate the correlation between ODI and VAS scores; univariate binary logistic regression method was used to analyze the effect of VAS on treatment decision as well as the outcomes.

Results

1050 patients (mean age 48.2) were analyzed. Baseline ODI and back, leg pain VAS scores were significantly correlated (P ​< ​0.001). One unit increase in baseline back and leg pain VAS scores, increased the probability of improvement in ODI by 1.219 (P ​= ​0.016) and 1.182 times (P ​= ​0.029), respectively in surgically treated patients; and reduced it by 0.894 times (P ​= ​0.012) for conservatively treated patients. For patients >70 years old, one-unit increase in baseline leg pain VAS score increased the probability of deciding on surgical treatment by 1.121 times (p ​= ​0.016).

Discussion and conclusions

Preoperative back and leg pain VAS scores were found to be significantly correlated with the preoperative ODI scores. Additionally, preoperative baseline back and leg pain VAS scores were useful in predicting the improvement in disability as assessed by ODI. Another important finding was that, higher baseline leg pain (but not back pain) VAS scores increased the rate of elderly patients preferring surgical treatment.

Preoperative Patient-reported Outcomes are not Associated With Sagittal and Spinopelvic Alignment in Degenerative Lumbar Spondylolisthesis

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

The aim of this study was to evaluate whether sagittal and spinopelvic alignment correlate with preoperative patient-reported outcomes (PROs) in degenerative lumbar spondylolisthesis (DLS) with spinal stenosis.

SUMMARY OF BACKGROUND DATA

Positive global sagittal balance and spinopelvic malalignment are strongly correlated with symptom severity in adult spinal deformity, but this correlation has not been evaluated in DLS.

METHODS

Patients were enrolled in the Canadian Spine Outcomes Research Network (CSORN) prospective DLS study at seven centers between January 2015 and May 2018. Correlation was assessed between the following preoperative PROs: Oswestry Disability Index (ODI), numeric rating scale (NRS) leg pain, and NRS back pain and the following preoperative sagittal radiographic parameters SS, PT, PI, SVA, LL, TK, T1SPI, T9SPI, and PI-LL. Patients were further divided into groups based on spinopelvic alignment: Group 1 PI-LL<10°; Group 2 PI-LL ≥10° with PT <30°; and Group 3 PI-LL ≥10° with PT ≥30°. Preoperative PROs were compared among these three groups and were further stratified by those with SVA <50 mm and SVA ≥50 mm.

RESULTS

A total of 320 patients (61% female) with mean age of 66.1 years were included. Mean (SD) preoperative PROs were: NRS leg pain 7.4 (2.1), NRS back pain 7.1 (2.0), and ODI 45.5 (14.5). Preoperative radiographic parameters included: SVA 27.1 (33.4) mm, LL 45.7 (13.4°), PI 57.6 (11.9), and PI-LL 11.8 (14.0°). Weak but statistically significant correlations were observed between leg pain and PT (r = -0.114) and PI (ρ = -0.130), and T9SPI with back pain ( r  = 0.130). No significant differences were observed among the three groups stratified by PI-LL and PT. No significant differences in PROs were observed between patients with SVA <50 mm compared to those with SVA ≥50 mm.

CONCLUSION

Sagittal and spinopelvic malalignment do not appear to significantly influence baseline PROs in patients with DLS.

LEVEL OF EVIDENCE

Prognostic level II.

Risk factors for coronal oblique take-off following adult spinal deformity surgery using lateral lumbar interbody fusion and open posterior corrective fusion

PURPOSE

To evaluate risk factors associated with oblique take-off (OT) following lateral lumbar interbody fusion (LLIF) for adult spinal deformity.

METHODS

Thirty-nine consecutive patients (mean age 67.9 years) with scoliosis of the lumbar curve (> 30°) were evaluated. Multilevel LLIF, followed by open thoraco-pelvic posterior corrective fusion after 1 week, was performed. We defined OT as a distance of > 25 mm between the C7 plumb line and the central sacral vertical line and examined risk factors by dividing the patients into the OT and non-OT groups.

RESULTS

OT occurred in 11 patients (28%), all showing a tilt to the convex side. The correction rate of the lumbar curve was approximately 70% range for both groups, which indicated good correction. Preoperative radiographs showed a high L1-central sacral vertical line in the standing position; high L5 tilt in the supine position; high L3, L4, and L5 tilts to the convex side in the supine-bending position; and a high L4 vertebral wedge on the convex side in OT cases. Multiple logistic regression analysis showed that an L4 tilt to the concave side in the bending position was the most effective predictor of OT (odds ratio = 1.104, P = 0.047). For a cutoff value of 16°, the sensitivity and specificity were 73% and 61%, respectively, according to the receiver operating characteristic curve analysis (area under the curve = 0.73).

CONCLUSION

OT occurred in 28% of adult scoliosis patients following LLIF. An L4 tilt > 16° to the concave side in the bending position was the most valuable risk factor.

LEVEL OF EVIDENCE

IV.

A Retrospective Analysis of the L3-4 Disc and Spinopelvic Parameters on Outcomes in Thoracolumbar Fusion: Was Art Steffee Right?

OBJECTIVE

To determine if the L3-4 disc angle may be a surrogate marker for global lumbar alignment in thoracolumbar fusion surgery. To explore the relationship between radiographic and patient-reported outcomes (PROs) after thoracolumbar fusion surgery.

METHODS

Retrospective chart review was conducted on patients who had undergone a lumbar fusion involving levels from T9 to pelvis. EuroQol-Five Dimension (EQ-5D) scores and adverse events including adjacent segment disease and degeneration, pseudoarthrosis, proximal junctional kyphosis, stenosis, and reoperation were collected. Pre- and postoperative spinopelvic parameters were measured on weight-bearing radiographs, with the L3-4 disc angle of novel interest. Univariate logistic and linear regression were performed to assess the associations of radiographic parameters with adverse event incidence and improvement in EQ-5D, respectively.

RESULTS

182 patients met inclusion criteria. Univariable analysis revealed that increased magnitude of L3-4 disc angle, anterior pelvic tilt, and pelvic incidence measures are associated with increased likelihood of developing postoperative adverse events. Conversely, increased lumbar lordosis demonstrated a decreased incidence of developing a postoperative adverse event. Linear regression showed that radiographic parameters did not significantly correlate with postoperative EQ-5D scores although scores were significantly improved post-fusion in all dimensions except Self-care (P = 0.51).

CONCLUSIONS

L3-4 disc angle magnitude may serve as a surrogate marker of global lumbar alignment. Degree of spinopelvic alignment did not correlate to improvement in EQ-5D score in the present study, suggesting that quality of life metric change may not be a sensitive or specific marker of post-fusion alignment.

Sagittal balance: from theory to clinical practice

Adequate sagittal balance (SB) is essential to maintain an upright, efficient, and painless posture. It has been shown that sagittal profile alterations affect quality of life of patients with a similar or even greater impact than chronic disease.

Evaluation of the SB has gained much relevance in recent years, with recognition of its importance in the evaluation of spinal pathology.

This review summarizes the basic principles of SB, aiming to obtain a practical, simple and understandable evaluation of the sagittal profile of a patient.

SB is a dynamic process that involves a varying degree of energy expenditure. Distinguishing between a balanced, compensated imbalance or decompensated imbalanced patient, is relevant to diagnosis and therapeutic decision-making.

Cite this article: EFORT Open Rev 2021;6:1193-1202. DOI: 10.1302/2058-5241.6.210062

Radiographic outcomes and complications after L4 or L5 pedicle subtraction osteotomy for fixed sagittal malalignment in 102 adult spinal deformity patients with a minimum 2-year follow-up

PURPOSE

The objective of this retrospective study was to provide the radiographic outcomes and complications for pedicle subtraction osteotomy (PSO) performed at the low lumbar spine, i.e., L4 or L5 for ASD patients with fixed sagittal malalignment.

METHODS

ASD patients who underwent L4 or L5 PSO with a minimum 2-year follow-up were included. Preoperative and postoperative radiographs, and complications were collected. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), thoracic kyphosis (TK), sagittal vertical axis (SVA), spinal lordosis (SL) ratio and global tilt (GT) on standing long-cassette radiographs.

RESULTS

A total of 102 patients from 2 spinal centers were analyzed. 66 patients underwent PSO at L4 and 36 patients at L5. From preoperatively to the final follow-up, significant improvements occurred in LL (from - 31° to - 52°), SVA (from 13 to 5 cm), and GT (from 44° to 27°) (all, p < 0.05). 12 patients had transient neurological deficits, and 8 patients had persistent neurological deficit. 23 patients underwent revision for PJK (2), pseudarthrosis (10), neurological deficit (2), epidural hematoma (1), or deep surgical site infection (8). No PJK was observed in any of the patients with L5 PSO.

CONCLUSIONS

PSO at the level of L4 or L5 remains a challenging technique but with an acceptable rate of complications and revisions. It enables correction of fixed sagittal malalignment in ASD patients with a globally satisfactory outcome. In comparison with L4 PSO, L5 PSO patients did not show PJK as a mechanical complication. Distal lumbar PSO at the level of L5 may represent one of the factors that may help preventing the proximal junctional kyphosis complication.

Coronal Correction Using Kickstand Rods for Adult Thoracolumbar/Lumbar Scoliosis: Case Series With Analysis of Early Outcomes and Complications

BACKGROUND

The "kickstand rod technique" has been recently described for achieving and maintaining coronal correction in adult spinal deformity (ASD). Kickstand rods span scoliotic lumbar spine from the thoracolumbar junction proximally to a "kickstand iliac screw" distally. Using the iliac wing as a base, kickstand distraction produces powerful corrective forces. Limited literature exists for this technique, and its associated outcomes and complications are unknown.

OBJECTIVE

To assess alignment changes, early outcomes, and complications associated with kickstand rod distraction for ASD.

METHODS

Consecutive ASD patients treated with kickstand distraction at our institution were retrospectively analyzed.

RESULTS

The cohort comprised 19 patients (mean age: 67 yr; 79% women; 63% prior fusion) with mean follow-up 21 wk (range: 2-72 wk). All patients had posterior-only approach surgery with tri-iliac fixation (third iliac screw for the kickstand) for mean fusion length 12 levels. Three-column osteotomy and lumbar transforaminal lumbar interbody fusion were performed in 5 (26%) and 15 (79%) patients, respectively. Postoperative alignment improved significantly (coronal balance: 8 to 1 cm [P < .001]; major curve: 37° to 12° [P < .001]; fractional curve: 20° to 10° [P < .001]; sagittal balance: 11 to 4 cm [P < .001]; pelvic incidence to lumbar lordosis mismatch: 38° to 9° [P < .001]). Pain Numerical Rating Scale scores improved significantly (back: 7.2 to 4.2 [P = .001]; leg: 5.9 to 1.7 [P = .001]). No instrumentation complications occurred. Motor weakness persisted in 1 patient. There were 3 reoperations (1-PJK, 1-wound dehiscence, and 1-overcorrection).

CONCLUSION

Among 19 ASD patients treated with kickstand rod distraction, alignment, and back/leg pain improved significantly following surgery. Complication rates were reasonable.

Comparative Study between Transforaminal Lumbar Interbody Fusion and Posterolateral Fusion for Treatment of Spondylolisthesis: Clinical Outcomes and Spino-Pelvic Sagittal Balance Parameters

Objective This retrospective study aims to compare the clinical and radiological outcomes of posterolateral fusion (PLF) with transforaminal lumbar interbody fusion (TLIF + PLF) for the treatment of patients with low-grade spondylolisthesis.

Methodology A total of 77 adult patients ≥18 years with low-grade spondylolisthesis, Meyerding grades I and II, were assigned into two groups: 36 patients treated with PLF and 41 patients treated with TLIF + PLF. The PLF group is composed of the patients that were operated with pedicle screw and the TLIF + PLF group is composed of the ones that were operated with fixation and TILF by autografting. Clinical evaluation was performed using the spino-pelvic sagittal balance, Numeric Rating Scale, Oswestry Disability Index, blood loss, operation times, and postoperative hospital stay of the PLF vs TLIF groups. The incidences of postoperative low back pain and radicular pain in the two groups were also recorded. Radiography was performed preoperatively and postoperatively to assess spino-pelvic parameters.

Results Significant restoration of spino-pelvic sagittal balance was observed in the TLIF group after surgery, and all spino-pelvic sagittal balance parameters showed significant improvement in the TLIF group after surgery, while in the PLF group, all spino-pelvic sagittal parameters had improved except the segmental angle lordosis (p = 0.316), which showed no significant difference after surgery in the PLF group. Postoperative pelvic incidence and pelvic tilt significantly improved in the TLIF group in comparison to PLF groups. Hence, TLIF can achieve better postoperative spino-pelvic sagittal balance parameters than PLF. There was no difference in the complication rates for each group. Both groups achieved significant improvement in postoperative clinical outcomes, and there was no significant difference in the incidence of postoperative low back pain or radicular pain between the two groups.

Conclusion Both surgical procedures PLF and TLIF were effective. PLF and TLIF can result in improved clinical and radiological outcomes for patients treated for low-grade spondylolisthesis. TLIF can achieve better restoration of spino-pelvic sagittal balance parameters than PLF alone.

Prospective investigation of Oswestry Disability Index and short form 36 subscale scores related to sagittal and coronal parameters in patients with degenerative lumbar scoliosis

PURPOSE

This study investigated relationships of Oswestry Disability Index (ODI) and Short Form 36 (SF-36) total and subscale scores with global spinal parameters in patients with degenerative lumbar scoliosis (DLS).

METHODS

This was a prospective single-center study of 126 consecutive patients with DLS. Disability was evaluated using the ODI and SF-36 total and subscale scores. Sagittal and coronal parameters were measured. Pearson's correlation analysis was performed to determine relationships between disability and radiographic parameters.

RESULTS

The study population included 76 women and 15 men (mean age, 70.2 ± 8.4 years). Mean Cobb angle was 18.9° ± 8.0°. The ODI total score and SF-36 physical component score were only correlated with coronal parameters. ODI pain intensity, personal care, lifting, sitting, and sex life domains were only correlated with coronal parameters. The walking, standing, social life, and traveling domain scores were correlated with coronal and sagittal parameters. The SF-36 bodily pain and vitality domain scores were only correlated with coronal parameters. The SF-36 physical function domain score was correlated with both coronal and sagittal parameters. Among the clinical and radiographic parameters, the personal care score and the coronal vertical-axis had the strongest correlation (r = 0.425), although the r² value was only 0.18.

CONCLUSIONS

ODI total score and most of the subscale scores were significantly, but weakly correlated with coronal parameters. Sagittal parameters were only correlated with some of the ODI and SF-36 subscale scores. Analysis using ODI and SF-36 subscale scores may aid in understanding and treatment of disability in patients with DLS.

Risk Factors Associated With Failure to Reach Minimal Clinically Important Difference After Correction Surgery in Patients With Degenerative Lumbar Scoliosis

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to evaluate the factors affecting health-related quality of life (HRQOL) after surgery in patients with degenerative lumbar scoliosis (DLS) by minimum clinically important difference (MCID).

SUMMARY OF BACKGROUND DATA

MCID has been introduced in the adult spinal deformity to quantify the absolute minimum change that can be considered a success. There are limited data available to identify factors affecting reaching MCID after DLS surgery.

METHODS

This study reviewed a cohort of 123 DLS patients after correction surgery and with a minimum 2-year follow-up (FU). Inclusion criteria included age ≥40 and minimum five vertebrae fused and the availability of Scoliosis Research Society (SRS)-22 scores and radiographic data at baseline (BL) and FU. Using a multivariate analysis, two groups were compared to identify possible risk factors: those who reached MCID in the all four SRS domains (N = 65) at the last FU and those who missed MCID (N = 58).

RESULTS

At baseline, patients differed significantly from matched normative data in all SRS-22 domains. The baseline HRQOL was comparable in reached MCID and missed MCID group patients (P > 0.05). The HRQOL scores at FU were significantly higher than those at baseline. Of 123 included patients, 77.2% (N = 95), 72.4% (N = 89), 76.4% (N = 94), and 89.4% (N = 110) reached MCID in SRS pain, activity, appearance, and mental domain, respectively. Pelvic incidence (PI) >55°, lumbar lordosis (LL) loss >4.65°, coronal imbalance at FU, sagittal vertical axis (SVA) at FU >80 mm, and presence of proximal junctional kyphosis (PJK) and distal junctional problem (DJP) had negative effects on the recovery process.

CONCLUSION

Factors affecting reaching MCID after surgery for DLS were higher PI, LL loss, coronal imbalance, severe sagittal imbalance, and the occurrence of PJK and DJP.

LEVEL OF EVIDENCE

4.

Lumbar Muscle Fat Content Has More Correlations with Living Quality than Sagittal Vertical Axis in Elderly Patients with Degenerative Lumbar Disorders

Purpose

As the most poorly tolerated and debilitating form of spinal malalignment, sagittal imbalance is becoming an increasingly recognized cause of pain and disability in adults. However, there is evidence showing that sagittal imbalance has a weak or no correlation with health-related quality-of-life (HRQoL) outcomes. The objective of this study was to describe the direct factor associated with HRQoL in terms of Oswestry Disability Index (ODI) assessment.

Patients and Methods

This study retrospectively evaluated the clinical and radiographic information of 179 elderly patients with degenerative lumbar disorders and suboptimal sagittal standing posture (sagittal vertical axis>50 mm). Patient-reported outcomes were assessed using ODI. Patients with ODI≥40% were assigned to Group D (disability), while those with ODI<40% were assigned to Group ND (non-disability).

Results

Compared with Group ND (n=104), patients in Group D (n=75) had greater thoracolumbar kyphosis, pelvic incidence-lumbar lordosis (PI-LL), sagittal vertical axis (SVA), T1 pelvic angle, and fat infiltration, and smaller LL and muscle mass ratio. Pearson analysis revealed a high correlation between the percentage of fat infiltrated and ODI (r=768, P<0.01) and moderate correlation between SVA and ODI (r=0.408, P<0.001). Linear regression results indicated that fat infiltration was an independent factor associated with ODI. ODI significantly correlated with SVA in patients with major fat infiltration (r=0.328, P=0.001), while having no correlation with SVA in those with moderate or minor fat infiltration (r=0.083, P=0.464).

Conclusion

Lumbar muscle fat infiltration is an independent factor associated with the living quality in terms of ODI assessment in the elderly population with degenerative lumbar disorders, which has more correlations with ODI scores than the sagittal imbalance. The relationship between HRQoL outcomes and sagittal imbalance depends on the quality of lumbar muscle.

The effect of age, BMI, and bone mineral density on the various lumbar vertebral measurements in females

PURPOSE

Healthy spinal balance is dependent on spinal sagittal alignment. It is evaluated by several spinopelvic measures. The objective of this study is to investigate the effect of age and body mass index and the bone mineral density on the several vertebral measures and sagittal spinopelvic measurements.

METHODS

In this cross-sectional study, a total of 89 female patients were grouped according to age (> 70, < 70); to BMI (underweight (< 18.5 kg/m²), normal weight (18.5-25 kg/m²), overweight (25-30 kg/m²); and to spine T scores (normal, osteopenia, and osteoporosis). On lateral lumbar X-ray, lumbar lordosis (LL) angle and pelvic incidence (PI) are measured. On sagittal T2 MRI images, anterior and posterior vertebral heights and foraminal height and area of the L1-L5 segments were measured.

RESULTS

The mean age of the participants was 70.54 ± 6.49. The distribution of the patients in BMI groups and BMD groups were even. Mean lumber lordosis (LL) was 48.27 ± 18.06, and the mean pelvic incidence (PI) was 60.20 ± 15.74. In the younger age group, LL was found to be higher than the older age group. The vertebral and spinopelvic angle measures within the different BMI and BMD groups revealed no difference in between. There were no statistically significant difference in correlation analysis.

CONCLUSION

In this cross-sectional study, the results revealed that younger patients have higher lordosis angle, and normal BMD patients have higher foraminal height and area measures than osteoporotic and osteopenic patients. Obesity seemed not to have any influence on vertebral measures. Spinopelvic parameters seem not to be effected by BMD and BMI.

Association Between Radiographic Spinopelvic Parameters and Health-related Quality of Life in De Novo Degenerative Lumbar Scoliosis and Concomitant Lumbar Spinal Stenosis

STUDY DESIGN

..: A retrospective clinical study of patients who were treated from January 2011 to December 2018 and met our criteria.

OBJECTIVE

..: The aim of this study is to investigate the relationship between radiographic spinopelvic parameters and the health-related quality of life (HRQOL) in pretreatment de novo degenerative lumbar scoliosis (DNDLS) patients with concomitant lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

..: DNDLS has garnered attention because of the increasing aged population. Unlike other types of spine deformities, DNDLS may occur with concomitant LSS. Radiographic spinopelvic parameters are important for evaluating spine alignment in these patients; however, the association between these parameters and the HRQOL is unknown.

METHODS

..: Data from 204 patients diagnosed with DNDLS and concomitant LSS were reviewed. HRQOL was assessed using the visual analog scale (VAS) scores (for the back and leg), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores, and Scoliosis Research Society (SRS)-22 questionnaire (SRS-22). Radiographic spinopelvic parameters were obtained from anteroposterior and lateral x-rays. The relationship between spinopelvic parameters and HRQOL was analyzed by correlation analysis in the overall population.

RESULTS

..: Lumbar lordosis (LL) showed clinical relevance to JOA (r = 0.290), ODI (r = -0.269), SRS-22 pain domain (r = 0.134), SRS-22 function domain (r = 0.257), and VAS for back pain (r = -0.196). There was clinical relevance between T1 pelvic angle (T1PA) and JOA (r = -0.212) and ODI (r = 0.251), sagittal vertical axis (SVA) and JOA (r = -0.211) and SRS-22 function domain (r = -0.229) and ODI (r = 0.215), and L1 pelvic angle (L1PA) and ODI (r = 0.200). HRQOL differences were validated in the SVA and PI-LL groups by SRS-Schwab classification. A significant difference was validated by setting a sagittal balance threshold for SVA, T1PA, T1 sagittal tilt, and L1PA.

CONCLUSION

..: The sagittal radiographic parameters showed a weak correlation with preoperative HRQOL in patients with concomitant DNDLS and LSS. T1PA, T1ST, and L1PA can effectively assess pretreatment HRQOL.

LEVEL OF EVIDENCE

4.

The Natural History of Progression in Adult Spinal Deformity: A Radiographic Analysis

STUDY DESIGN

Historical cohort study.

OBJECTIVE

To evaluate progression in the coronal and sagittal planes in nonsurgical patients with adult spinal deformity (ASD).

METHODS

A retrospective analysis of nonsurgical ASD patients between 2005 and 2017 was performed. Magnitude of the coronal and sagittal planes were compared on the day of presentation and at most recent follow-up. Previous reported prognostic factors for progression in the coronal plane, including the direction of scoliosis, curve magnitude, and the position of the intercrest line (passing through L4 or L5 vertebra), were studied.

RESULTS

Fifty-eight patients were included with a mean follow-up of 59.8 ± 34.5 months. Progression in the coronal plane was seen in 72% of patients. Mean Cobb angle on the day of presentation and most recent follow-up was 37.2 ± 14.6° and 40.8° ± 16.5°, respectively. No significant differences were found in curve progression in left- versus right-sided scoliosis (3.3 ± 7.1 vs 3.7 ± 5.4, P = .81), Cobb angle <30° versus ≥30° (2.6 ± 5.0 vs 4.3 ± 6.5, P = .30), or when the intercrest line passed through L4 rather than L5 vertebra (3.4 ± 5.0° vs 3.8 ± 7.1°, P = .79). No significant differences were found in the sagittal plane between presentation and most recent follow-up.

CONCLUSIONS

This is the first study that describes progression in the coronal and sagittal planes in nonsurgical patients with ASD. Previous reported prognostic factors were not confirmed as truly relevant. Although progression appears to occur, large variation exists and these results may not be directly applicable to the individual patient.

Uncertainty in the Relationship Between Sagittal Alignment and Patient-Reported Outcomes

BACKGROUND

Previous studies have reported correlations and precise quantitative relationships between sagittal alignment and health-related quality-of-life (HRQOL) scores. These studies have not reported the extent of uncertainty in these relationships.

OBJECTIVE

To explore the uncertainty in the overall relationships between sagittal alignment and HRQOL and in the predictions of individual patient pain and disability.

METHODS

A retrospective analysis of all new adult patients with long-cassette radiographs and complete outcomes questionnaires presenting to the senior author from 2012 to 2014 was performed. Univariable maximum a posteriori linear regression analyses using Bayesian methods were performed. High-density probability intervals for mean regression relationships and for individual values were calculated using minimally informative prior distributions.

RESULTS

A total of 134 patients satisfied inclusion criteria and were included. For Oswestry Disability Index (ODI) vs pelvic incidence-lumbar lordosis (LL), the 90% high-density probability interval ranged from -0.04 to 0.23, indicating that both the magnitude and direction of the relationship were uncertain. For both ODI vs sagittal vertical axis and ODI vs LL, there was uncertainty in the magnitude of the slope. Wide regions of uncertainty were also seen for predicting individual patient scores.

CONCLUSION

We report the previously unpublished degree of uncertainty in the mean quantitative relationships between radiographic sagittal alignment and patient-reported outcomes and in individual patient outcomes scores. Based on these results, establishing treatment thresholds or predicting an individual's outcome is unreliable. Further research efforts should be focused on developing multilevel hierarchical models incorporating parameter uncertainty and heterogeneous effects.

Revision strategies for failed adult spinal deformity surgery

PURPOSE

The aim of this study is to analyse the results of revision surgery for failed adult spinal deformity patients and to describe the surgical strategy selection process, based on the identification of the main clinical diagnosis responsible for failure.

METHODS

We retrospectively reviewed the clinical and radiological data of 77 consecutive patients treated in a 3-year time (2016-2019) for surgical revision of long fusion (more than five levels fused) for adult spinal deformity in a high-volume spine centre, divided into four groups based on the diagnosis: rod breakage (RB) group, proximal junctional failure (PJF) group, distal junctional failure (DJF) group and loss of correction (LOC) group with symptomatic sagittal or coronal malalignment (including iatrogenic flatback).

RESULTS

Seventy-seven patients met our inclusion criteria, with a female prevalence (66 F vs. 11 M). The mean age at revision surgery was 63. Fused levels before surgery were averagely 12, and revision added averagely two levels to the preexisting fusion area. Clinical status was apparently improved in ODI scores and VAS scores, while it was slightly worsened in SF36 scores. Different diagnosis groups have been addressed with different surgical strategies, according to the different surgical goals: interbody cages and multi-rod construct to improve stiffness and favour bony fusion, "kickstand" rod and "tie" rod to correct coronal and sagittal malalignment, specific rod contouring and proximal hooks in "claw" configuration to reduce mechanical stress at the proximal junctional area. Intraoperative complications occurred in 18% of patients and perioperative complications in 39%.

CONCLUSION

Revision surgery in long fusions for adult spinal deformity is a challenging field. Surgical strategy should always be planned carefully. A successful treatment is a direct consequence of a correct preoperative diagnosis, and surgery should address the primary cause of failure. All the above-mentioned surgical techniques and clinical skills should be part of surgeon's expertise when managing these patients. These slides can be retrieved under Electronic Supplementary Material.

Impact of shift to the concave side of the C7-center sacral vertical line on de novo degenerative lumbar scoliosis progression in elderly volunteers

BACKGROUND

Degenerative lumbar scoliosis (DLS) is one of the most frequent spinal deformities of the aging spine. The purpose of our study was to clarify the independent predictors of pre-existing DLS progression and their influence on the health related quality of life (HRQOL).

METHODS

This study included 356 volunteers (127 men and 229 women; mean age, 72.2 years; follow-up period, 4 years) who underwent musculoskeletal screening. Standing whole-spine radiographic measurements included the Cobb angle of DLS and C7-center sacral vertical line (C7-CSVL; shift to the concave side of the DLS curve indicated a positive value). A baseline Cobb angle ≥10° indicated pre-existing DLS, and Cobb angle deterioration of ≥4° was considered DLS progression. For HRQOL assessment, the Oswestry Disability Index (ODI) was used. Pre-existing DLS cases were divided into progression and non-progression groups.

RESULTS

Among 93 cases (26.1%) with pre-existing DLS at baseline, 23 cases (pre-existing DLS progression group) showed DLS progression. The mean C7-CSVLs were 10.5 and -3.1 mm in the pre-existing progression and non-progression groups, respectively (p < 0.01). The optimal cutoff C7-CSVL length was 5 mm, with high sensitivity and specificity. Multivariate logistic regression analysis showed that a C7-CSVL ≥5 mm (odds ratio, 3.8; 95% CI: 1.42-10.34; p < 0.01) was independently associated with pre-existing DLS progression. ODI scores deteriorated significantly more in the pre-existing progression group than the non-progression group (+9.8% versus +3.9%; p < 0.05).

CONCLUSIONS

Pre-existing DLS progression is associated with a shift to the concave side of C7-CSVL and influences HRQOL deterioration. It is important to assess coronal global alignment for prediction of a DLS progression.

Artificial Intelligence Based Hierarchical Clustering of Patient Types and Intervention Categories in Adult Spinal Deformity Surgery: Towards a New Classification Scheme that Predicts Quality and Value

STUDY DESIGN

Retrospective review of prospectively-collected, multicenter adult spinal deformity (ASD) databases.

OBJECTIVE

To apply artificial intelligence (AI)-based hierarchical clustering as a step toward a classification scheme that optimizes overall quality, value, and safety for ASD surgery.

SUMMARY OF BACKGROUND DATA

Prior ASD classifications have focused on radiographic parameters associated with patient reported outcomes. Recent work suggests there are many other impactful preoperative data points. However, the ability to segregate patient patterns manually based on hundreds of data points is beyond practical application for surgeons. Unsupervised machine-based clustering of patient types alongside surgical options may simplify analysis of ASD patient types, procedures, and outcomes.

METHODS

Two prospective cohorts were queried for surgical ASD patients with baseline, 1-year, and 2-year SRS-22/Oswestry Disability Index/SF-36v2 data. Two dendrograms were fitted, one with surgical features and one with patient characteristics. Both were built with Ward distances and optimized with the gap method. For each possible n patient cluster by m surgery, normalized 2-year improvement and major complication rates were computed.

RESULTS

Five hundred-seventy patients were included. Three optimal patient types were identified: young with coronal plane deformity (YC, n = 195), older with prior spine surgeries (ORev, n = 157), and older without prior spine surgeries (OPrim, n = 218). Osteotomy type, instrumentation and interbody fusion were combined to define four surgical clusters. The intersection of patient-based and surgery-based clusters yielded 12 subgroups, with major complication rates ranging from 0% to 51.8% and 2-year normalized improvement ranging from -0.1% for SF36v2 MCS in cluster [1,3] to 100.2% for SRS self-image score in cluster [2,1].

CONCLUSION

Unsupervised hierarchical clustering can identify data patterns that may augment preoperative decision-making through construction of a 2-year risk-benefit grid. In addition to creating a novel AI-based ASD classification, pattern identification may facilitate treatment optimization by educating surgeons on which treatment patterns yield optimal improvement with lowest risk.

LEVEL OF EVIDENCE

4.

Clinical, Functional, and Radiologic Outcome of Single- and Double-Level Transforaminal Lumbar Interbody Fusion in Patients with Low-Grade Spondylolisthesis

Objective:

The main objective is to determine the functional, clinical, and radiological outcome of patients with low-grade spondylolisthesis undergoing single- or double-level transforaminal lumbar interbody fusion (TLIF).

Materials and Methods:

This quasi-interventional study was conducted during a 2-year period from 2016 to 2018 in Shiraz, Southern Iran. We included all the adult (≥18 years) patients with low-grade spondylolisthesis (Meyerding Grade I and II) who underwent single- or double-level TLIF in our center. The spinopelvic parameters including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and segmental LL (SLL) were measured. The pain intensity and disability were measured utilizing the visual analog scale (VAS) for back and leg pain and Oswestry Disability Index (ODI), respectively, after 1 year.

Results:

Overall, we included a total number of 50 patients with mean age of 54.1 ± 10.48 years. After the surgery, the PI (P = 0.432), PT (P = 0.782), and SS (P = 0.466) were not found to be statistically changed from the baseline. However, we found that single- or double-level TLIF was associated with increased LL (P < 0.001) and SLL (P < 0.001). Regarding the clinical outcome measures, both back (P = 0.001) and leg (P < 0.001) VAS improved after the surgery significantly. In addition, we found that improved leg VAS was positively correlated with improved ODI (r = 0. 634; P < 0.001).

Conclusion:

Single- or double-level TLIF is associated with increased global and SLL along with improved leg and back pain and disability in patients with low-grade spondylolisthesis. Interestingly, improved leg pain is correlated to improved disability in these patients.