Quality metrics in adult spinal deformity surgery over the last decade: a combined analysis of the largest prospective multicenter data sets

OBJECTIVE The reported rate of complications and cost of adult spinal deformity (ASD) surgery, associated with an exponential increase in the number of surgeries, cause alarm among healthcare payers and providers worldwide. The authors conjointly analyzed the largest prospective available ASD data sets to define trends in quality-of-care indicators (complications, reinterventions, and health-related quality of life [HRQOL] outcomes) since 2010. METHODS This is an observational prospective longitudinal cohort study. Patients underwent surgery between January 2010 and December 2016, with > 2 years of follow-up data. Demographic, surgical, radiological, and HRQOL (i.e., Oswestry Disability Index, SF-36, Scoliosis Research Society-22r) data obtained preoperatively and at 3, 6, 12, and 24 months after surgery were evaluated. Trends and changes in indicators were analyzed using local regression (i.e., locally estimated scatterplot smoothing [LOESS]) and adjusted odds ratio (OR). RESULTS Of the 2286 patients included in the 2 registries, 1520 underwent surgery between 2010 and 2016. A total of 1151 (75.7%) patients who were treated surgically at 23 centers in 5 countries met inclusion criteria. Patient recruitment increased progressively (2010–2011 vs 2015–2016: OR 1.64, p < 0.01), whereas baseline clinical characteristics (age, American Society of Anesthesiologists class, HRQOL scores, sagittal deformity) did not change. Since 2010 there has been a sustained reduction in major and minor postoperative complications observed at 90 days (major: OR 0.59; minor: OR 0.65; p < 0.01); at 1 year (major: OR 0.52; minor: 0.75; p < 0.01); and at 2 years of follow-up (major: OR 0.4; minor: 0.80; p < 0.01) as well as in the 2-year reintervention rate (OR 0.41, p < 0.01). Simultaneously, there has been a slight improvement in the correction of sagittal deformity (i.e., pelvic incidence–lumbar lordosis mismatch: OR 1.11, p = 0.19) and a greater gain in quality of life (i.e., Oswestry Disability Index 26% vs 40%, p = 0.02; Scoliosis Research Society-22r, self-image domain OR 1.16, p = 0.13), and these are associated with a progressive reduction of surgical aggressiveness (number of fused segments: OR 0.81, p < 0.01; percent pelvic fixation: OR 0.66, p < 0.01; percent 3-column osteotomies: OR 0.63, p < 0.01). CONCLUSIONS The best available data show a robust global improvement in quality metrics in ASD surgery over the last decade. Surgical complications and reoperations have been reduced by half, while improvement in disability increased and correction rates were maintained, in patients with similar baseline characteristics.

Correlation of Paraspinal Muscle Mass With Decompensation of Sagittal Adult Spinal Deformity After Setting of Fatigue Post 10-Minute Walk

Objective: The purpose of this study was to investigate the changes in spinopelvic parameters before and after the setting of muscle fatigue along with its correlation with pre-existing paraspinal and psoas muscle mass.Methods: Single-center retrospective review of prospectively collected data was conducted on 145-adults with symptomatic loss of lumbar lordosis (LL). Radiographs were taken before and after walking for 10 minutes. Magnetic resonance imaging was used to calculate paraspinal muscle (PSM) cross-sectional area (CSA), mean signal intensity, fatty infiltration (FI), and lean muscle mass at thoracolumbar junction (T12) and lower lumbar level (L4). Psoas CSA was calculated at L3. Patients were divided into 2 groups namely compensated sagittal deformity (CSD) (SVA ≤ 4 cm, PT > 20°) and decompensated sagittal deformity (DSD) (SVA > 4 cm, PT > 20°) based on prewalk measurements.Results: Initial mean SVA was 1.8 cm and 11 cm for CSD and DSD respectively (p < 0.01). After walking, significant deteriorations in SVA, PT–LL (p < 0.01) were observed in CSD without significant change in thoracic kyphosis (TK). All sagittal parameters in DSD deteriorated significantly. DSD group had significantly poorer PSM quality at T12 and L4 compared to CSD group. In CSD group, sagittal decompensation correlated with muscle quality, i.e. , decreases in LL (ΔLL) correlated with CSA of PSM/vertebral body (VB) at L4 (r = -0.412, p = 0.046) while increases in TK (ΔTK) correlated with CSA of PSM/VB at T12 (r = 0.477, p = 0.018). ΔSVA and ΔPT correlated with FI at L4 (r = 0.577, p = 0.003 and r = -0.407, p = 0.048, respectively). DSD group, had weak correlations (-0.3 < r < -0.1) between changes in sagittal and PSM parameters.Conclusion: PSM quality in adults with spinal deformity correlates with patients’ ability to maintain an upright posture and sagittal decompensation after walking for 10 minutes.

Sagittal Plane Deformities in Children with SMA2 following Posterior Spinal Instrumentation

This is a retrospective radiographic review to assess post-operative sagittal plane deformities in patients with Spinal Muscular Atrophy type 2 that had been treated with posterior spinal instrumentation. Thirty-two patients with a history of either spinal fusion (N = 20) or growing rods (N = 12) were identified with an average of 7.6 (2.1–16.6) years post-operative follow-up. Forty percent (13/32) of the patients were identified as having obvious “tucked chin” (N = 4), “tipped trunk” (N = 9), or both (N = 3). Sacral incidence was the only parameter that was statistically significant change between pre-operative or immediate post-operative measurements (66.9° vs. 55.2° p = 0.03). However, at final follow-up, the post-operative thoracic kyphosis had decreased over time in those that developed a subsequent sagittal deformity (24.2°) whereas it increased in those that did not (44.7°, p = 0.008). This decrease in thoracic kyphosis throughout the instrumented levels, resulted in a greater lordotic imbalance (30.4° vs. 5.6°, p = 0.001) throughout the instrumented levels in the group that developed the subsequent cervical or pelvic sagittal deformities. In conclusion, sagittal plane deformities commonly develop outside the instrumented levels in children with SMA type 2 following posterior spinal instrumentation and may be the result of lordotic imbalance that occurs through continued anterior growth following posterior instrumentation.

Outcomes of Surgical Treatment for One Hundred Thirty-Eight Patients With Severe Sagittal Deformity at a Minimum 2-Year Follow-up: A Case Series

BACKGROUND Operative treatment of adult spinal deformity (ASD) can be very challenging with high complication rates. It is well established that patients benefit from such treatment; however, the surgical outcomes for patients with severe sagittal deformity have not been reported. OBJECTIVE To report the outcomes of patients undergoing surgical correction for severe sagittal deformity. METHODS Retrospective review of a prospective, multicenter ASD database. Inclusion criteria: operative patients age ≥18, sagittal vertical axis (SVA) ≥15 cm, mismatch between pelvic incidence and lumbar lordosis (PI-LL) ≥30°, and/or lumbar kyphosis ≥5° with minimum 2 yr follow-up. Health-related quality of life (HRQOL) scores including minimal clinically important difference (MCID)/substantial clinical benefit (SCB), sagittal and coronal radiographic values, demographic, frailty, surgical, and complication data were collected. Comparisons between 2 yr postoperative and baseline HRQOL/radiographic data were made. P &lt; .05 was significant. RESULTS A total of 138 patients were included from 502 operative patients (54.3% Female, Average (Avg) age 63.3 ± 11.5 yr). Avg operating room (OR) time 386.2 ± 136.5 min, estimated blood loss (EBL) 1829.8 ± 1474.6 cc. A total of 71(51.4%) had prior fusion. A total of 89.9% were posterior fusion only. Mean posterior levels fused 11.5 ± 4.1. A total of 44.9% had a 3-column osteotomy. All 2 yr postoperative radiographic parameters were significantly improved compared to baseline (P &lt; .001 for all). All 2yr HRQOL measures were significantly improved compared to baseline (P &lt; .004 for all). A total of 46.6% to 73.8% of patients met either MCID/SCB for all HRQOL. A total of 74.6% of patients had at least 1 complication, 11.6% had 4 or more complications, 33.3% had minimum 1 major complication, and 42(30.4%) had a postop revision. CONCLUSION Patients with severe sagittal malalignment benefit from surgical correction at 2 yr postoperative both radiographically and clinically despite having a high complication rate.

Association of global sagittal deformity with functional disability two years after total hip arthroplasty

Introduction: The relationship between spinopelvic alignment and functional disability after total hip arthroplasty (THA) has not been fully elucidated despite the growing recognition of its importance on patient-reported outcome measures. We aimed to determine whether global sagittal deformity was associated with post-operative disability.Materials and methods: This prospective analysis was based on 208 THAs that were followed up for 2 years. The Hip Disability and Osteoarthritis Outcome Score-Joint Replacement (HOOS-JR) ranging from a scale of 0 (complete joint disability) to 100 (perfect joint health) was utilised to divide eligible patients into two groups with and without disability, using 70 as the threshold. Multivariate analysis was performed to evaluate the factors associated with disability. To identify the cut-off value of the parameters for predicting disability (HOOS-JR <70/100), we used the receiver-operating characteristic curve.Results: The disability (30 hips) and control (178 hips) groups showed a significant difference in body height (p = 0.020), pre-operative T1 pelvic angle divided by pelvic incidence (T1PA/PI) (p = 0.018), pelvic incidence minus lumbar lordosis (p = 0.027), post-operative HOOS-JR (p = 0.010), and satisfaction (p = 0.033). On multivariate analysis, the following factors were associated with persistent disability: T1PA/PI >0.2 (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.19–4.14; p < 0.001) and height <148 cm (OR, 1.26; 95% CI, 1.09–1.48; p = 0.011). The cut-off value of pre-operative T1PA/PI was >0.19 with a sensitivity of 95% and specificity of 85%. Post-operative satisfaction (p < 0.001) and HOOS-JR (p = 0.023) differed between the two groups when the pre-operative cut-off value was chosen as 0.2.Conclusions: A T1PA/PI >0.2 was associated with greater disability after THA. Clinicians should be aware that patient-related factors, including global spinal deformities, particularly in patients with a short stature, can influence THA outcomes at 2 years postoperatively.

A Comprehensive Analysis of the Behavior of Pelvic Incidence After Different Posterior Spinal Procedures in Elderly Patients With Spinal Deformity

Study Design: A retrospective case-control study. Objective: To evaluate the behavior of pelvic incidence (PI) after different posterior spinal procedures in elderly patients with adult spinal deformity (ASD), to determine the potential associated factors with the variability in PI after spinal surgery and to comprehensively analyze its mechanisms. Methods: Elderly patients underwent long fusion to sacrum with and without pelvic fixation were assigned to Group L+P and Group L-P, respectively. In Group L-P, those with severe sagittal deformity were selected as Group A. 20 elderly patients with severe sagittal deformity underwent short lumbar fusion were included as Group B. The following radiographic parameters were evaluated: thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), PI-LL, sagittal vertical axis (SVA), T1 pelvic angle (TPA), and pelvic parameters. PI changing more than 5° (△PI > 5°) was considered as substantially changed. Results: For the whole cohort and in Group L+P, PI were not substantially changed (△PI ≤ 5°) after surgery. Besides the severer sagittal malalignment in patients with △PI > 5° in Group L-P, relatively larger mean age, greater proportion of female and lower preoperative PI were found than those in patients with △PI ≤ 5°. 70.8% of patients had substantial increase of PI in Group A, while only 10% of patients had in Group B ( P < 0.001). Conclusion: PI behaves differently under different conditions in elderly ASD patients. Besides severe sagittal deformity, aging, female and low preoperative PI are also the potential risk factors of PI increasing after long fusion to sacrum.