STUDY DESIGN.Retrospective analysis.
OBJECTIVE.Determine whether deformity corrections should vary by pelvic incidence (PI).
SUMMARY OF BACKGROUND DATA.Alignment targets for deformity correction have ...been reported for various radiographic parameters. The T1 pelvic-angle (TPA) has gained in applications for adult spinal deformity (ASD) surgical-planning since it directly measures spinal alignment separate from pelvic- and lower-extremity compensation. Recent studies have demonstrated that ASD corrections should be age specific.
METHODS.A prospective database of consecutive ASD patients was analyzed in conjunction with a normative spine database. Clinical measures of disability included the Oswestry Disability Index (ODI) and Short Form 36 Survey (SF-36) Physical Component Score (PCS). Baseline relationships between TPA, age, PI, and ODI/SF-36 PCS scores were analyzed in the ASD and asymptomatic patients. Linear regression modeling was used to determine alignment targets based on PI and age-specific normative SF-36-PCS values.
RESULTS.Nine hundred three ASD patients (mean 53.7 yr) and 111 normative subjects (mean 50.7 yr) were included. Patients were subanalyzed by PIlow, medium, high (<40, 40–75, >75); and ageelderly (>65 yr, n = 375), middle age (45–65 yr, n = 387), and young (18–45 yr, n = 141). TPA and SRS-Schwab parameters correlated with age and PI in ASD and normative subjects (r = 0.42, P < 0.0001). ODI correlated with PCS (r = 0.71, P < 0.0001). Linear regression analysis using age-normative SF-36-PCS values demonstrated that ideal spinopelvic alignment is less strict with increasing PI and age.
CONCLUSION.Targets for ASD correction should vary by age and PI. This is demonstrated in both asymptomatic and ASD subjects. Using age-normative SF-36 PCS values, alignment targets are described for different age and PI categories. High-PI patients do not require as rigorous realignments to attain age-specific normative levels of health status. As such, sagittal spinal alignment targets increase with increasing age as well as PI.Level of Evidence3
Retrospective review of a cervical deformity database.
This study aimed to develop a model that can predict the postoperative distal junctional kyphosis angle (DJKA) using preoperative and ...postoperative radiographic measurements.
Distal junctional kyphosis (DJK) is a complication following cervical deformity correction that can reduce of patient quality of life and functional status. Although researchers have identified the risk factors for DJK, no model has been proposed to predict the magnitude of DJK.
The DJKA was defined as the Cobb angle from the lower instrumented vertebra (LIV) to LIV-2 with traditional DJK having a DJKA change >10°. Models were trained using 66.6% of the randomly selected patients and validated in the remaining 33.3%. Preoperative and postoperative radiographic parameters associated with DJK were identified and ranked using a conditional variable importance table. Linear regression models were developed using the factors most strongly associated with postoperative DJKA.
A total of 131 patients were included with a mean follow-up duration of 14±8 months. The mean postoperative DJKA was 14.6±14° and occurred in 35% of the patients. No significant differences between the training and validation cohort were observed. The variables most associated with postoperative DJK were: preoperative DJKA (DJKApre), postoperative C2-LIV, and change in cervical lordosis (∆CL). The model identified the following equation as predictive of DJKA: DJKA=9.365+(0.123×∆CL)-(0.315×∆C2-LIV)-(0.054×DJKApre). The predicted and actual postoperative DJKA values were highly correlated ( R =0.871, R2 =0.759, P <0.001).
The variables that most increased the DJKA were the preoperative DJKA, postoperative alignment within the construct, and change in cervical lordosis. Future studies can build upon the model developed to be applied in a clinical setting when planning for cervical deformity correction.
Retrospective cohort.
To examine the validity of the Oswestry Disability Index (ODI) in patients with adult spinal deformity (ASD) treated with surgery.
The ODI is a patient-reported outcome measure ...of low back pain and disability. Although nearly ubiquitous in ASD research, the measure has not been validated in this patient population.
A registry of patients with ASD was queried for baseline and 1-year PROM data, including the ODI, the Scoliosis Research Society-22r (SRS-22r), and the Patient Reported Outcomes Measurement Information System-Pain Interference (PI) and Physical Function (PF) CATs. Internal reliability was assessed with Cronbach alpha, where values ≥0.7 are considered reliable. Validity was assessed with Spearman correlation coefficients calculated for the ODI against validated Patient-Reported Outcomes Measurement Information System (PROMIS)-PI and PF, and legacy measures SRS-Pain and SRS-Activity. Responsiveness to change was measured with the adjusted effect size.
A total of 325 patients were enrolled, with 208 completing baseline and 1-year patient-reported outcome measures. The majority (149, 72%) were females and White (193, 93%), median Charlson Comorbidity Index 0 (interquartile range: 0-2). The majority of cases included sagittal plane deformity mean T1PA: 24.2° (13.9). Cronbach alpha showed excellent internal reliability (baseline = 0.89, 1 yr = 0.90). ODI was valid, with strong correlations between PROMIS-PI, PROMIS-PF, SRS-Pain, and SRS-Activity at baseline and 1-year follow-up. All measures were responsive to change, with the ODI showing greater responsiveness than PROMIS-PI, PROMIS-PF, and SRS-Activity.
The ODI is a valid measure of disability as measured by pain and function in patients with ASD. It is responsive to change in a manner not different from validated PROMIS-CAT or the SRS-22r legacy measure. It is multidimensional, however, as it assesses both pain and function simultaneously. It does not measure disability related to self-image and may not account for all disease-related disability in patients with ASD.
Over the past 3 decades the sagittal plane has received increasing attention from the scientific community and spine surgeons alike. There remains a lack of clear and concise methods for ...incorporating surgical techniques and radiographic parameters to achieve the best possible outcome on a patient-specific level. This article proposes a new method for a treatment approach to sagittal malalignment by incorporating new digital tools for surgical planning. This technique offers a consistent approach to adult spinal deformity with sagittal-plane components, and can permit optimization in consistently achieving proper postoperative spinopelvic alignment.
Previous studies have characterized utilization rates and cost of adult spinal deformity (ASD) surgery, but the differences between these factors in commercially insured and Medicare populations are ...not well studied.
To identify predictors of increased payments for ASD surgery in commercially insured and Medicare populations.
We identified adult patients who underwent fusion for ASD, 2007 to 2015, in 20% Medicare inpatient file (n = 21 614) and MarketScan commercial insurance database (n = 38 789). Patient age, sex, race, insurance type, geographical region, Charlson Comorbidity Index, and length of stay were collected. Outcomes included predictors of increased payments, surgical utilization rates, total cost (calculated using Medicare charges and hospital-specific charge-to-cost ratios), and total Medicare and commercial payments for ASD.
Rates of fusion increased from 9.0 to 8.4 per 10 000 in 2007 to 20.7 and 18.2 per 10 000 in 2015 in commercial and Medicare populations, respectively. The Medicare median total charges increased from $88 106 to $144 367 (compound annual growth rate, CAGR: 5.6%), and the median total cost increased from $31 846 to $39 852 (CAGR: 2.5%). Commercial median total payments increased from $58 164 in 2007 to $64 634 in 2015 (CAGR: 1.2%) while Medicare median total payments decreased from $31 415 in 2007 to $25 959 in 2015 (CAGR: -2.1%). The Northeast and Western regions were associated with higher payments in both populations, but there is substantial state-level variation.
Rate of ASD surgery increased from 2007 to 2015 among commercial and Medicare beneficiaries. Despite increasing costs, Medicare payments decreased. Age, length of stay, and BMP usage were associated with increased payments for ASD surgery in both populations.
Abstract Background context Whereas the costs of primary surgery, revisions, and selected complications for adult spinal deformity (ASD) have been individually reported in the literature, the total ...costs over several years after surgery have not been assessed. The determinants of such costs are also not well understood in the literature. Purpose This study analyzes the total hospital costs and operating room (OR) costs of ASD surgery through extended follow-up. Study design/setting Single-center retrospective analysis of consecutive surgical patients. Patient sample Four hundred eighty-four consecutive patients undergoing surgical treatment for ASD from January 2005 through January 2011 with minimum three levels fused. Outcome measures Costs were collected from hospital administrative data on the total hospital costs incurred for the operation and any related readmissions, expressed in 2010 dollars and discounted at 3.5% per year. Detailed data on OR costs, including implants and biologics, were also collected. Methods We performed a series of paired t tests and Wilcoxon signed-rank tests for differences in total hospital costs over different follow-up periods. The goal of these tests was to identify a time period over which average costs plateau and remain relatively constant over time. Generalized linear model regression was used to estimate the effect of patient and surgical factors on hospital inpatient costs, with different models estimated for different follow-up periods. A similar regression analysis was performed separately for OR costs and all other hospital costs. Results Patients were predominantly women (n=415 or 86%) with an average age of 48 (18–82) years and an average follow-up of 4.8 (2–8) years. Total hospital costs averaged $120,394, with primary surgery averaging $103,143 and total readmission costs averaging $67,262 per patient with a readmission (n=130 or 27% of all patients). Operating room costs averaged $70,514 per patient, constituting the majority (59%) of total hospital costs. Average total hospital costs across all patients significantly increased (p<.01) after primary surgery, from $111,807 at 1-year follow-up to $126,323 at 4-year follow-up. Regression results also revealed physician preference as the largest determinant of OR costs, accounting for $14,780 of otherwise unexplained OR cost differences across patients, with no significant physician effects on all other non-OR costs (p<.05). Conclusions The incidence of readmissions increased the average cost of ASD surgery by more than 70%, illustrating the financial burden of revisions/reoperations; however, the cost burden resulting from readmissions appeared to taper off within 5 years after surgery. The estimated impact of physician preference on OR costs also highlights the variation in current practice and the opportunity for large cost reductions via a more standardized approach in the use of implants and biologics.
Retrospective review of a multicenter database of consecutive patients undergoing 3-column osteotomy for treatment of adult spinal deformity (ASD).
To rigorously develop a T1 pelvic angle (TPA) ...categorization paradigm and use it to assess the surgical management of patients with ASD.
TPA, the angle between the hips-T1 line and hips-S1 endplate line, is a novel spinopelvic parameter that assesses the combined effect of a loss of lordosis on trunk inclination and pelvic retroversion.
A prospective, multicenter database of consecutive patients with ASD was queried to identify the severe deformity threshold and meaningful change values for TPA by correlation with Oswestry Disability Index. A separate multicenter, consecutive, retrospective database of patients with ASD treated with single lumbar 3-column osteotomy was then analyzed at baseline, 3-month, and 1-year follow-up. Subjects were classified into well-aligned or poorly aligned groups at 3 months on the basis of TPA. Patients "deteriorated" if they lost more than 1 meaningful change in TPA between 3 months and 1 year and had TPA more than deformity threshold at 1 year.
The severe deformity threshold for TPA was 20° (Oswestry Disability Index > 40) and the meaningful change was 4.1° (Oswestry Disability Index change = 15). Review of the 3-column osteotomy database identified 179 patients with preoperative severe deformity; 63 were well-aligned (TPA < 15.9°) and 73 were poorly aligned (TPA > 20°) at 3-month follow-up. This newly developed TPA categorization mechanism grouped patients in a manner comparable with the Scoliosis Research Society-Schwab Classification. Subjects who were well-aligned at 3 months had less severe baseline deformity, but received more correction, than poorly aligned subjects. Four well-aligned patients and 13 poorly aligned patients deteriorated between 3 months and 1 year after surgery.
TPA accounts for sagittal vertical axis and pelvic tilt and shows great promise as a classification tool. Longitudinal analysis demonstrated undercorrection among patients with more severe preoperative deformity. We propose a surgical target of 10° for TPA.
4.
Abstract
BACKGROUND:
Global sagittal malalignment is significantly correlated with health-related quality-of-life scores in the setting of spinal deformity. In order to address rigid deformity ...patterns, the use of spinal osteotomies has seen a substantial increase. Unfortunately, variations of established techniques and hybrid combinations of osteotomies have made comparisons of outcomes difficult.
OBJECTIVE:
To propose a classification system of anatomically-based spinal osteotomies and provide a common language among spine specialists.
METHODS:
The proposed classification system is based on 6 anatomic grades of resection (1 through 6) corresponding to the extent of bone resection and increasing degree of destabilizing potential. In addition, a surgical approach modifier is added (posterior approach or combined anterior and posterior approaches). Reliability of the classification system was evaluated by an analysis of 16 clinical cases, rated 2 times by 8 different readers, and calculation of Fleiss kappa coefficients.
RESULTS:
Intraobserver reliability was classified as "almost perfect"; Fleiss kappa coefficient averaged 0.96 (range, 0.92-1.0) for resection type and 0.90 (0.71-1.0) for the approach modifier. Results from the interobserver reliability for the classification were 0.96 for resection type and 0.88 for the approach modifier.
CONCLUSION:
This proposed anatomically based classification system provides a consistent description of the various osteotomies performed in spinal deformity correction surgery. The reliability study confirmed that the classification is simple and consistent. Further development of its use will provide a common frame for osteotomy assessment and permit comparative analysis of different treatments.
A geoarchaeological study of sediments in the Azraq Oasis, in the Eastern Desert of Jordan, provides information on the fluctuations of the geomorphic and hydrologic systems in this region in ...relation to the local Middle Paleolithic and Upper Paleolithic occupations. The study shows that local geomorphic and hydrological environments fluctuated between marsh, lake and playa (dry lake bed with eolian activity and/or carbonate accumulation). In some instances, local wet conditions correlate with those registered in other regional paleoclimatic records, as is the case of the period comprising MIS 5a and probably early MIS 4. In other cases, however, local wet conditions represented by marsh deposits with hominin occupations are asynchronous with regional wet conditions. This suggests that the Azraq oases may have acted as desert refugia at times of regional adverse climatic conditions. The fact that Azraq represents a potential desert refugia has important consequences for understanding major issues in the Middle Paleolithic of Southwest Asia, namely (1) the arrival, survival, and extinction of populations of both Neanderthals and early modern humans. The location of Azraq at a crossroads between the Levant, the Arabian Peninsula and other regions of the Middle East, is also an important geographic aspect of desert refugia during the critical period of hominin dynamics in the Middle Paleolithic.
A retrospective review of a prospectively collected database.
To assess rates and causes of mortality associated with spine surgery.
Despite the best of care, all surgical procedures have inherent ...risks of complications, including mortality. Defining these risks is important for patient counseling and quality improvement.
The Scoliosis Research Society Morbidity and Mortality database was queried for spinal surgery cases complicated by death from 2004 to 2007, including pediatric (younger than 21 yr) and adult (21 yr or older) patients. Deaths occurring within 60 days and complications within 60 days of surgery that resulted in death were assessed.
A total of 197 mortalities were reported among 108,419 patients (1.8 deaths per 1000 patients). Based on age, rates of death per 1000 patients for adult and pediatric patients were 2.0 and 1.3, respectively. Based on primary diagnosis (available for 107,996 patients), rates of death per 1000 patients were as follows: 0.9 for degenerative (n = 47,393), 1.8 for scoliosis (n = 26,421), 0.9 for spondylolisthesis (n = 11,421), 5.7 for fracture (n = 6706), 4.4 for kyphosis (n = 3600), and 3.3 for other (n = 12,455). The most common causes of mortality included: respiratory/pulmonary causes (n = 83), cardiac causes (n = 41), sepsis (n = 35), stroke (n = 15), and intraoperative blood loss (n = 8). Death occurred prior to hospital discharge for 109 (79%) of 138 deaths for which this information was reported. The specific postoperative day (POD) of death was reported for 94 (48%) patients and included POD 0 (n = 23), POD 1-3 (n = 17), POD 4-14 (n = 30), and POD >14 (n = 24). Increased mortality rates were associated with higher American Society of Anesthesiologists score, spinal fusion, and implants (P < 0.001). Mortality rates increased with age, ranging from 0.9 per 1000 to 34.3 per 1000 for patients aged 20 to 39 years and 90 years or older, respectively.
This study provides rates and causes of mortality associated with spine surgery for a broad range of diagnoses and includes assessments for adult and pediatric patients. These findings may prove valuable for patient counseling and efforts to improve the safety of patient care.
