Purpose
Major peri-operative complications for adult spinal deformity (ASD) surgery remain common. However, risk factors have not been clearly defined. Our objective was to identify patient and ...surgical parameters that correlate with the development of major peri-operative complications with ASD surgery.
Methods
This is a multi-center, retrospective, consecutive, case–control series of surgically treated ASD patients. All patients undergoing surgical treatment for ASD at eight centers were retrospectively reviewed. Each center identified 10 patients with major peri-operative complications. Randomization tables were used to select a comparably sized control group of patients operated during the same time period that they did not suffer major complications. The two groups were analyzed for differences in clinical and surgical factors. Analysis was restricted to non-instrumentation related complications.
Results
At least one major complication occurred in 80 of 953 patients (8.4 %), including 72 patients with non-instrumentation related complications. There were no significant differences between the complications and control groups based on the demographics, ASA grade, co-morbidities, body mass index, prior surgeries, pre-operative anemia, smoking, operative time or ICU stay (
p
> 0.05). Hospital stay was significantly longer for the complications group (14.4 vs. 7.9 days,
p
= 0.001). The complications group had higher percentages of staged procedures (46 vs. 37 %,
p
= 0.011) and combined anterior–posterior approaches (56 vs. 32 %,
p
= 0.011) compared with the control group.
Conclusion
The major peri-operative complication rate was 8.4 % for 953 surgically treated ASD patients. Significantly higher rates of complications were associated with staged and combined anterior–posterior surgeries. None of the patient factors assessed were significantly associated with the occurrence of major peri-operative complications. Improved understanding of risk profiles and procedure-related parameters may be useful for patient counseling and efforts to reduce complication rates.
Purpose
In past decades, the role of sagittal alignment has been widely demonstrated in the setting of spinal conditions. As several parameters can be affected, identifying the driver of the ...deformity is the cornerstone of a successful treatment approach. Despite the importance of restoring sagittal alignment for optimizing outcome, this task remains challenging. Self-learning computers and optimized algorithms are of great interest in spine surgery as in that they facilitate better planning and prediction of postoperative alignment. Nowadays, computer-assisted tools are part of surgeons’ daily practice; however, the use of such tools remains to be time-consuming.
Methods: Narrative review and results
Computer-assisted methods for the prediction of postoperative alignment consist of a three step analysis: identification of anatomical landmark, definition of alignment objectives, and simulation of surgery. Recently, complex rules for the prediction of alignment have been proposed. Even though this kind of work leads to more personalized objectives, the number of parameters involved renders it difficult for clinical use, stressing the importance of developing computer-assisted tools. The evolution of our current technology, including machine learning and other types of advanced algorithms, will provide powerful tools that could be useful in improving surgical outcomes and alignment prediction. These tools can combine different types of advanced technologies, such as image recognition and shape modeling, and using this technique, computer-assisted methods are able to predict spinal shape. The development of powerful computer-assisted methods involves the integration of several sources of information such as radiographic parameters (X-rays, MRI, CT scan, etc.), demographic information, and unusual non-osseous parameters (muscle quality, proprioception, gait analysis data). In using a larger set of data, these methods will aim to mimic what is actually done by spine surgeons, leading to real tailor-made solutions.
Conclusion
Integrating newer technology can change the current way of planning/simulating surgery. The use of powerful computer-assisted tools that are able to integrate several parameters and learn from experience can change the traditional way of selecting treatment pathways and counseling patients. However, there is still much work to be done to reach a desired level as noted in other orthopedic fields, such as hip surgery. Many of these tools already exist in non-medical fields and their adaptation to spine surgery is of considerable interest.
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
Despite adequate correction, the pelvis may fail to readjust, deemed pelvic nonresponse (PNR). To assess alignment outcomes PNR, proximal junctional kyphosis (PJK), postoperative cervical deformity ...(CD) following adult spinal deformity (ASD) surgery utilizing different realignment strategies.
ASD patients with two-year data were included. PNR defined as undercorrected in age-adjusted pelvic tilt (PT) at six weeks and maintained at two years. Patients classified by alignment utilities: (a) improvement in Scoliosis Research Society-Schwab sagittal vertical axis, (b) matching in age-adjusted pelvic incidence-lumbar lordosis, (c) matching in Roussouly, (d) aligning Global Alignment and Proportionality (GAP) score. Multivariable regression analyses, controlling for age, baseline deformity, and surgical factors, assessed rates of PNR, PJK, and CD development following realignment.
A total of 686 patients met the inclusion criteria. Rates of postoperative PJK and CD were not significant in the PNR group (both P >0.15). PNR patients less often met substantial clinical benefit in Oswestry Disability Index by two years odds ratio: 0.6 (0.4-0.98). Patients overcorrected in age-adjusted pelvic incidence-lumbar lordosis, matching Roussouly, or proportioned in GAP at six weeks had lower rates of PNR (all P <0.001). Incremental addition of classifications led to 0% occurrence of PNR, PJK, and CD. Stratifying by baseline PT severity, Low and moderate deformity demonstrated the least incidence of PNR (7.7%) when proportioning in GAP at six weeks, while severe PT benefited most from matching in Roussouly (all P <0.05).
Following ASD corrective surgery, 24.9% of patients showed residual pelvic malalignment. This occurrence was often accompanied by undercorrection of lumbopelvic mismatch and less improvement of pain. However, overcorrection in any strategy incurred higher rates of PJK. We recommend surgeons identify a middle ground using one, or more, of the available classifications to inform correction goals in this regard.
III.
Currently, the functional status of patients undergoing spine surgery is assessed with quality-of-life questionnaires, and a more objective and quantifiable assessment method is lacking. Dr. Jean ...Dubousset conceptually proposed a four-component functional test, but to our knowledge, reference values derived from asymptomatic individuals have not yet been reported, and these are needed to assess the test's clinical utility in patients with spinal deformities.
(1) What are the reference values for the Dubousset Functional Test (DFT) in asymptomatic people? (2) Is there a correlation between demographic variables such as age and BMI and performance of the DFT among asymptomatic people?
This single-institution prospective study was performed from January 1, 2018 to May 31, 2018. Asymptomatic volunteers were recruited from our college of medicine and hospital staff to participate in the DFT. Included participants did not report any musculoskeletal problems or trauma within 5 years. Additionally, they did not report any history of lower limb fracture, THA, TKA, or patellofemoral arthroplasty. Patients were also excluded if they reported any active medical comorbidities. Demographic data collected included age, sex, BMI, and self-reported race. Sixty-five asymptomatic volunteers were included in this study. Their mean age was 42 ± 15 years; 27 of the 65 participants (42%) were women. Their mean BMI was 26 ± 5 kg/m. The racial distribution of the participants was 34% white (22 of 65 participants), 25% black (16 of 65 participants), 15% Asian (10 of 65 participants), 9% subcontinental Indian (six of 65 participants), 6% Latino (four of 65 participants), and 10% other (seven of 65 participants). In a controlled setting, participants completed the DFT after verbal instruction and demonstration of each test, and all participants were video recorded. The four test components included the Up and Walking Test (unassisted sit-to-stand from a chair, walk forward/backward 5 meters no turn, then unassisted stand-to-sit), Steps Test (ascend three steps, turn, descend three steps), Down and Sitting Test (stand-to-ground, followed by ground-to-stand, with assistance as needed), and Dual-Tasking Test (walk 5 meters forwards and back while counting down from 50 by 2). Tests were timed, and data were collected from video recordings to ensure consistency. Reference values for the DFT were determined via a descriptive analysis, and we calculated the mean, SD, 95% CI, median, and range of time taken to complete each test component, with univariate comparisons between men and women for each component. Linear correlations between age and BMI and test components were studied, and the frequency of verbal and physical pausing and adverse events was noted.
The Up and Walking Test was completed in a mean of 15 seconds (95% CI, 14-16), the Steps Test was completed in 6.3 seconds (95% CI, 6.0-6.6), the Down and Sitting Test was completed in 6.0 seconds (95% CI, 5.4-6.6), and the Dual-Tasking Test was performed in 13 seconds (95% CI, 12-14). The length of time it took to complete the Down and Sitting (r = 0.529; p = 0.001), Up and Walking (r = 0.429; p = 0.001), and Steps (r = 0.356; p = 0.014) components increased with as the volunteer's age increased. No correlation was found between age and the time taken to complete the Dual-Tasking Test (r = 0.134; p = 0.289). Similarly, the length of time it took to complete the Down and Sitting (r = 0.372; p = 0.005), Up and Walking (r = 0.289; p = 0.032), and Steps (r = 0.366; p = 0.013) components increased with increasing BMI; no correlation was found between the Dual-Tasking Test's time and BMI (r = 0.078; p = 0.539).
We found that the DFT could be completed by asymptomatic volunteers in approximately 1 minute, although it took longer for older patients and patients with higher BMI.
We believe, but did not show, that the DFT might be useful in assessing patients with spinal deformities. The normal values we calculated should be compared in future studies with those of patients before and after undergoing spine surgery to determine whether this test has practical clinical utility. The DFT provides objective metrics to assess function and balance that are easy to obtain, and the test requires no special equipment.
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 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.
BACKGROUND:Prospective trials of enhanced recovery after spine surgery are lacking. We tested the hypothesis that an enhanced recovery pathway improves quality of recovery after one- to two-level ...lumbar fusion.
METHODS:A patient- and assessor-blinded trial of 56 patients randomized to enhanced recovery (17 evidence-based pre-, intra-, and postoperative care elements) or usual care was performed. The primary outcome was Quality of Recovery-40 score (40 to 200 points) at postoperative day 3. Twelve points defined the clinically important difference. Secondary outcomes included Quality of Recovery-40 at days 0 to 2, 14, and 56; time to oral intake and discharge from physical therapy; length of stay; numeric pain scores (0 to 10); opioid consumption (morphine equivalents); duration of intravenous patient-controlled analgesia use; complications; and markers of surgical stress (interleukin 6, cortisol, and C-reactive protein).
RESULTS:The analysis included 25 enhanced recovery patients and 26 usual care patients. Significantly higher Quality of Recovery-40 scores were found in the enhanced recovery group at postoperative day 3 (179 ± 14 vs. 170 ± 16; P = 0.041) without reaching the clinically important difference. There were no significant differences in recovery scores at days 0 (175 ± 16 vs. 162 ± 22; P = 0.059), 1 (174 ± 18 vs. 164 ± 15; P = 0.050), 2 (174 ± 18 vs. 167 ± 17; P = 0.289), 14 (184 ± 13 vs. 180 ± 12; P = 0.500), and 56 (187 ± 14 vs. 190 ± 8; P = 0.801). In the enhanced recovery group, subscores on the Quality of Recovery-40 comfort dimension were higher (longitudinal mean score difference, 4; 95% CI, 1, 7; P = 0.008); time to oral intake (−3 h; 95% CI, −6, −0.5; P = 0.010); and duration of intravenous patient-controlled analgesia (−11 h; 95% CI, −19, −6; P < 0.001) were shorter; opioid consumption was lower at day 1 (−57 mg; 95% CI, −130, −5; P = 0.030) without adversely affecting pain scores (−2; 95% CI, −3, 0; P = 0.005); and C-reactive protein was lower at day 3 (6.1; 95% CI, 3.8, 15.7 vs. 15.9; 95% CI, 6.6, 19.7; P = 0.037).
CONCLUSIONS:Statistically significant gains in early recovery were achieved by an enhanced recovery pathway. However, significant clinical impact was not demonstrated.
STUDY DESIGN.Retrospective analysis.
OBJECTIVE.To define thoracic compensation and investigate its association with postoperative reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK)
...SUMMARY OF BACKGROUND DATA.Adult spinal deformity (ASD) patients recruit compensatory mechanisms like pelvic retroversion and knee flexion. However, thoracic hypokyphosis is a less recognized compensatory mechanism.
METHODS.Patients enrolled in a multicenter ASD registry undergoing fusions to the pelvis with upper instrumented vertebra (UIV) between T9 and L1 were included. Patients were divided into those with postoperative reciprocal thoracic kyphosis (reciprocal kyphosis RKchange in unfused thoracic kyphosis TK ≥15°) with and without PJK and those who maintained thoracic alignment (MT). Thoracic compensation was defined as expected thoracic kyphosis (eTK) minus preoperative TK.
RESULTS.For RK (n = 117), the mean change in unfused TK was 21.7° versus 6.1° for MT (n = 102) and the mean PJK angle change was 17.6° versus 5.7° for MT (all P < 0.001). RK and MT were similar in age, body mass index (BMI), sex, and comorbidities. RK had larger preoperative PI–LL mismatch (30.7 vs. 23.6, P = 0.008) and less preoperative TK (22.3 vs. 30.6, P < 0.001), otherwise sagittal vertical axis (SVA), pelvic tilt (PT), and T1 pelvic angle (TPA) were similar. RK patients had more preoperative thoracic compensation (29.9 vs. 20.0, P < 0.001), more PI–LL correction (29.8 vs. 17.3, P < 0.001), and higher rates of PJK (66% vs. 19%, P < 0.001). There were no differences in preoperative health-related quality of life (HRQOL) except reciprocal kyphosis (RK) had worse Scoliosis Research Society questionnaire (SRS) appearance (2.2 vs. 2.5, P = 0.005). Using a logistic regression model, the only predictor for postoperative reciprocal thoracic kyphosis was more preoperative thoracic compensation. Postoperatively the RK and MT groups were well aligned. Both younger and older (>65 yr) RK patients had greater thoracic compensation than MT counterparts. The eTK was not significantly different from the postoperative TK for the RK group without PJK (P = 0.566).
CONCLUSION.The presence of thoracic compensation in adult spinal deformity is the primary determinant of postoperative reciprocal thoracic kyphosis and these patients have higher rates of proximal junctional kyphosis.Level of Evidence3
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