Browsing by Subject "adult spinal deformity"
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Item Open Access Adult revision surgery of prior hook-and-rod wire instrumentation for idiopathic scoliosis.(Neurosurgical focus: Video, 2020-01) Burke, Rebecca M; Buell, Thomas J; Maggio, Dominic M; Yener, Ulas; Yen, Chun-Po; Shaffrey, Christopher I; Smith, Justin SAdolescent idiopathic scoliosis patients treated with spinal fusion may develop adjacent segment disease and curve progression into adulthood. Revision operations can be challenging, especially for adult patients treated with outdated instrumentation such as sublaminar hooks and/or wires. The authors demonstrate revision lumbar spine surgery in a 38-year-old female with scoliosis progression from junctional degeneration below a prior T5-L3 posterior instrumented arthrodesis with a hook-and-rod wire system. They also demonstrate safe application of an ultrasonic bone scalpel for completion of a Smith-Petersen osteotomy. The patient provided written, informed consent for all material presented in this case demonstration. The video can be found here: https://youtu.be/3PmaFtNcqKc.Item Open Access An Economic Analysis of Early and Late Complications After Adult Spinal Deformity Correction.(Global spine journal, 2024-04) Williamson, Tyler K; Owusu-Sarpong, Stephane; Imbo, Bailey; Krol, Oscar; Tretiakov, Peter; Joujon-Roche, Rachel; Ahmad, Salman; Bennett-Caso, Claudia; Schoenfeld, Andrew J; Lebovic, Jordan; Vira, Shaleen; Diebo, Bassel; Lafage, Renaud; Lafage, Virginie; Passias, Peter GStudy design/setting
Retrospective cohort.Objective
Adult spinal deformity (ASD) corrective surgery is often a highly invasive procedure portending patients to both immediate and long-term complications. Therefore, we sought to compare the economic impact of certain complications before and after 2 years.Methods
ASD patients with minimum 3-year data included. Complication groups were defined as follows: any complication, major, medical, mechanical, radiographic, and reoperation. Complications stratified by occurrence before or after 2 years postoperatively. Published methods converted ODI to SF-6D to QALYs. Cost was calculated using CMS.gov definitions. Marginalized means for utility gained and cost-per-QALY were calculated via ANCOVA controlling for significant confounders.Results
244 patients included. Before 2Y, complication rates: 76% ≥1 complication, 18% major, 26% required reoperation. After 2Y, complication rates: 32% ≥1 complication, 4% major, 2.5% required reoperation. Major complications after 2 years had worse cost-utility (.320 vs .441, P = .1). Patients suffering mechanical complications accrued the highest overall cost ($130,482.22), followed by infection and PJF for complications before 2 years. Patients suffering a mechanical complication after 2 years had lower cost-utility ($109,197.71 vs $130,482.22, P = .041). Patients developing PJF after 2 years accrued a better cost-utility ($77,227.84 vs $96,873.57; P = .038), compared to PJF before 2 years.Conclusion
Mechanical complications had the single greatest impact on cost-utility after adult spinal deformity surgery, but less so after 2 years. Understanding the cost-utility of specific interventions at certain timepoints may mitigate economic burden and prophylactic efforts should strategically be made against early mechanical complications.Item Open Access Are We Focused on the Wrong Early Postoperative Quality Metrics? Optimal Realignment Outweighs Perioperative Risk in Adult Spinal Deformity Surgery.(Journal of clinical medicine, 2023-08) Passias, Peter G; Williamson, Tyler K; Mir, Jamshaid M; Smith, Justin S; Lafage, Virginie; Lafage, Renaud; Line, Breton; Daniels, Alan H; Gum, Jeffrey L; Schoenfeld, Andrew J; Hamilton, David Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert; Mundis, Gregory M; Diebo, Bassel; Kebaish, Khaled M; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Klineberg, Eric O; Ames, Christopher P; Hart, Robert A; Burton, Douglas C; Schwab, Frank J; Shaffrey, Christopher I; Bess, Shay; On Behalf Of The International Spine Study GroupBackground
While reimbursement is centered on 90-day outcomes, many patients may still achieve optimal, long-term outcomes following adult spinal deformity (ASD) surgery despite transient short-term complications.Objective
Compare long-term clinical success and cost-utility between patients achieving optimal realignment and suboptimally aligned peers.Study design/setting
Retrospective cohort study of a prospectively collected multicenter database.Methods
ASD patients with two-year (2Y) data included. Groups were propensity score matched (PSM) for age, frailty, body mass index (BMI), Charlson Comorbidity Index (CCI), and baseline deformity. Optimal radiographic criteria are defined as meeting low deformity in all three (Scoliosis Research Society) SRS-Schwab parameters or being proportioned in Global Alignment and Proportionality (GAP). Cost-per-QALY was calculated for each time point. Multivariable logistic regression analysis and ANCOVA (analysis of covariance) adjusting for baseline disability and deformity (pelvic incidence (PI), pelvic incidence minus lumbar lordosis (PI-LL)) were used to determine the significance of surgical details, complications, clinical outcomes, and cost-utility.Results
A total of 930 patients were considered. Following PSM, 253 "optimal" (O) and 253 "not optimal" (NO) patients were assessed. The O group underwent more invasive procedures and had more levels fused. Analysis of complications by two years showed that the O group suffered less overall major (38% vs. 52%, p = 0.021) and major mechanical complications (12% vs. 22%, p = 0.002), and less reoperations (23% vs. 33%, p = 0.008). Adjusted analysis revealed O patients more often met MCID (minimal clinically important difference) in SF-36 PCS, SRS-22 Pain, and Appearance. Cost-utility-adjusted analysis determined that the O group generated better cost-utility by one year and maintained lower overall cost and costs per QALY (both p < 0.001) at two years.Conclusions
Fewer late complications (mechanical and reoperations) are seen in optimally aligned patients, leading to better long-term cost-utility overall. Therefore, the current focus on avoiding short-term complications may be counterproductive, as achieving optimal surgical correction is critical for long-term success.Item Open Access Assessing the Impact of Radiographic Realignment on Adult Spinal Deformity Patients with Sacroiliac Joint Pain at Presentation.(Journal of clinical medicine, 2024-06) Onafowokan, Oluwatobi O; Tretiakov, Peter; Lorentz, Nathan; Galetta, Matthew; Das, Ankita; Mir, Jamshaid; Roberts, Timothy; Passias, Peter GBackground: Adult spinal deformity (ASD) patients with concurrent sacroiliac joint (SIJ) pain are susceptible to worse postoperative outcomes. There is scarce literature on the impact of ASD realignment surgery on SIJ pain. Methods: Patients undergoing ASD realignment surgery were included and stratified by the presence of SIJ pain at the baseline (SIJP+) or SIJ pain absence (SIJP-). Mean comparison tests via ANOVA were used to assess baseline differences between both cohorts. Multivariable regression analyses analyzed factors associated with SIJ pain resolution/persistence, factoring in BMI, frailty, disability, and deformity. Results: A total of 464 patients were included, with 30.8% forming the SIJP+ cohort. At the baseline (BL), SIJP+ had worse disability scores, more severe deformity, higher BMI, higher frailty scores, and an increased magnitude of lower limb compensation. SIJP+ patients had higher mechanical complication (14.7 vs. 8.2%, p = 0.024) and reoperation rates (32.4 vs. 20.2%, p = 0.011) at 2 years. SIJP+ patients who subsequently underwent SI fusion achieved disability score outcomes similar to those of their SIJ- counterparts. Multivariable regression analysis revealed that SIJP+ patients who were aligned in the GAP lordosis distribution index were more likely to report symptom resolution at six weeks (OR 1.56, 95% CI: 1.02-2.37, p = 0.039), 1 year (OR 3.21, 2.49-5.33), and 2 years (OR 3.43, 2.41-7.12). SIJP- patients who did not report symptom resolution by 1 year and 2 years were more likely to demonstrate PI-LL > 5° (OR 1.36, 1.07-2.39, p = 0.045) and SVA > 20 mm (OR 1.62, 1.24-1.71 p = 0.017). Conclusions: SIJ pain in ASD patients may result in worsened pain and disability at presentation. Symptom resolution may be achieved in affected patients by adequate postoperative lumbar lordosis restoration.Item Open Access Calibration of a comprehensive predictive model for the development of proximal junctional kyphosis and failure in adult spinal deformity patients with consideration of contemporary goals and techniques.(Journal of neurosurgery. Spine, 2023-06) Tretiakov, Peter S; Lafage, Renaud; Smith, Justin S; Line, Breton G; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey; Protopsaltis, Themistocles; Hamilton, D Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert K; Mundis, Gregory; Nunley, Pierce D; Klineberg, Eric O; Kebaish, Khaled; Lewis, Stephen; Lenke, Lawrence; Hostin, Richard; Gupta, Munish C; Ames, Christopher P; Hart, Robert A; Burton, Douglas; Shaffrey, Christopher I; Schwab, Frank; Bess, Shay; Kim, Han Jo; Lafage, Virginie; Passias, Peter GObjective
The objective of this study was to calibrate an updated predictive model incorporating novel clinical, radiographic, and prophylactic measures to assess the risk of proximal junctional kyphosis (PJK) and failure (PJF).Methods
Operative patients with adult spinal deformity (ASD) and baseline and 2-year postoperative data were included. PJK was defined as ≥ 10° in sagittal Cobb angle between the inferior uppermost instrumented vertebra (UIV) endplate and superior endplate of the UIV + 2 vertebrae. PJF was radiographically defined as a proximal junctional sagittal Cobb angle ≥ 15° with the presence of structural failure and/or mechanical instability, or PJK with reoperation. Backstep conditional binary supervised learning models assessed baseline demographic, clinical, and surgical information to predict the occurrence of PJK and PJF. Internal cross validation of the model was performed via a 70%/30% cohort split. Conditional inference tree analysis determined thresholds at an alpha level of 0.05.Results
Seven hundred seventy-nine patients with ASD (mean 59.87 ± 14.24 years, 78% female, mean BMI 27.78 ± 6.02 kg/m2, mean Charlson Comorbidity Index 1.74 ± 1.71) were included. PJK developed in 50.2% of patients, and 10.5% developed PJF by their last recorded visit. The six most significant demographic, radiographic, surgical, and postoperative predictors of PJK/PJF were baseline age ≥ 74 years, baseline sagittal age-adjusted score (SAAS) T1 pelvic angle modifier > 1, baseline SAAS pelvic tilt modifier > 0, levels fused > 10, nonuse of prophylaxis measures, and 6-week SAAS pelvic incidence minus lumbar lordosis modifier > 1 (all p < 0.015). Overall, the model was deemed significant (p < 0.001), and internally validated receiver operating characteristic analysis returned an area under the curve of 0.923, indicating robust model fit.Conclusions
PJK and PJF remain critical concerns in ASD surgery, and efforts to reduce the occurrence of PJK and PJF have resulted in the development of novel prophylactic techniques and enhanced clinical and radiographic selection criteria. This study demonstrates a validated model incorporating such techniques that may allow for the prediction of clinically significant PJK and PJF, and thus assist in optimizing patient selection, enhancing intraoperative decision making, and reducing postoperative complications in ASD surgery.Item Open Access Complication rate evolution across a 10-year enrollment period of a prospective multicenter database.(Journal of neurosurgery. Spine, 2021-12) Lafage, Renaud; Fong, Alex M; Klineberg, Eric; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Burton, Douglas; Kim, Han Jo; Elysee, Jonathan; Mundis, Gregory M; Passias, Peter; Gupta, Munish; Hostin, Richard; Schwab, Frank; Lafage, VirginieObjective
Adult spinal deformity is a complex pathology that benefits greatly from surgical treatment. Despite continuous innovation, little is known regarding continuous changes in surgical techniques and the complications rate. The objective of the current study was to investigate the evolution of the patient profiles and surgical complications across a single prospective multicenter database.Methods
This study is a retrospective review of a prospective, multicenter database of surgically treated patients with adult spinal deformity (thoracic kyphosis > 60°, sagittal vertical axis > 5 cm, pelvic tilt > 25°, or Cobb angle > 20°) with a minimum 2-year follow-up. Patients were stratified into 3 equal groups by date of surgery. The three groups' demographic data, preoperative data, surgical information, and complications were then compared. A moving average of 320 patients was used to visualize and investigate the evolution of the complication across the enrollment period.Results
A total of 928/1260 (73.7%) patients completed their 2-year follow-up, with an enrollment rate of 7.7 ± 4.1 patients per month. Across the enrollment period (2008-2018) patients became older (mean age increased from 56.7 to 64.3 years) and sicker (median Charlson Comorbidity Index rose from 1.46 to 2.08), with more pure sagittal deformity (type N). Changes in surgical treatment included an increased use of interbody fusion, more anterior column release, and a decrease in the 3-column osteotomy rate, shorter fusion, and more supplemental rods and bone morphogenetic protein use. There was a significant decrease in major complications associated with a reoperation (from 27.4% to 17.1%) driven by a decrease in radiographic failures (from 12.3% to 5.2%), despite a small increase in neurological complications. The overall complication rate has decreased over time, with the lowest rate of any complication (51.8%) during the period from August 2014 to March 2017. Major complications associated with reoperation decreased rapidly in the 2014-2015. Major complications not associated with reoperation had the lowest level (21.0%) between February 2014 and October 2016.Conclusions
Despite an increase in complexity of cases, complication rates did not increase and the rate of complications leading to reoperation decreased. These improvements reflect the changes in practice (supplemental rod, proximal junctional kyphosis prophylaxis, bone morphogenetic protein use, anterior correction) to ensure maintenance of status or improved outcomes.Item Open Access Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery.(Global Spine J, 2023-12-11) Passias, Peter G; Williamson, Tyler K; Kummer, Nicholas A; Pellisé, Ferran; Lafage, Virginie; Lafage, Renaud; Serra-Burriel, Miguel; Smith, Justin S; Line, Breton; Vira, Shaleen; Gum, Jeffrey L; Haddad, Sleiman; Sánchez Pérez-Grueso, Francisco Javier; Schoenfeld, Andrew J; Daniels, Alan H; Chou, Dean; Klineberg, Eric O; Gupta, Munish C; Kebaish, Khaled M; Kelly, Michael P; Hart, Robert A; Burton, Douglas C; Kleinstück, Frank; Obeid, Ibrahim; Shaffrey, Christopher I; Alanay, Ahmet; Ames, Christopher P; Schwab, Frank J; Hostin, Richard A; Bess, Shay; International Spine Study GroupSTUDY DESIGN/SETTING: Retrospective cohort study. OBJECTIVE: Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery. METHODS: ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility. RESULTS: By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001). CONCLUSIONS: The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.Item Open Access Economic burden of nonoperative treatment of adult spinal deformity.(J Neurosurg Spine, 2023-12-01) Passias, Peter G; Ahmad, Waleed; Dave, Pooja; Lafage, Renaud; Lafage, Virginie; Mir, Jamshaid; Klineberg, Eric O; Kabeish, Khaled M; Gum, Jeffrey L; Line, Breton G; Hart, Robert; Burton, Douglas; Smith, Justin S; Ames, Christopher P; Shaffrey, Christopher I; Schwab, Frank; Hostin, Richard; Buell, Thomas; Hamilton, D Kojo; Bess, ShayOBJECTIVE: The purpose of this study was to investigate the cost utility of nonoperative treatment for adult spinal deformity (ASD). METHODS: Nonoperatively and operatively treated patients who met database criteria for ASD and in whom complete radiographic and health-related quality of life data at baseline and at 2 years were available were included. A cost analysis was completed on the PearlDiver database assessing the average cost of nonoperative treatment prior to surgical intervention based on previously published treatments (NSAIDs, narcotics, muscle relaxants, epidural steroid injections, physical therapy, and chiropractor). Utility data were calculated using the Oswestry Disability Index (ODI) converted to SF-6D with published conversion methods. Quality-adjusted life years (QALYs) used a 3% discount rate to account for residual decline in life expectancy (78.7 years). Minor and major comorbidities and complications were assessed according to the CMS.gov manual's definitions. Successful nonoperative treatment was defined as a gain in the minimum clinically importance difference (MCID) in both ODI and Scoliosis Research Society (SRS)-pain scores, and failure was defined as a loss in MCID or conversion to operative treatment. Patients with baseline ODI ≤ 20 and continued ODI of ≤ 20 at 2 years were considered nonoperative successful maintenance. The average utilization of nonoperative treatment and cost were applied to the ASD cohort. RESULTS: A total of 824 patients were included (mean age 58.24 years, 81% female, mean body mass index 27.2 kg/m2). Overall, 75.5% of patients were in the operative and 24.5% were in the nonoperative cohort. At baseline patients in the operative cohort were significantly older, had a greater body mass index, increased pelvic tilt, and increased pelvic incidence-lumbar lordosis mismatch (all p < 0.05). With respect to deformity, patients in the operative group had higher rates of severe (i.e., ++) sagittal deformity according to SRS-Schwab modifiers for pelvic tilt, sagittal vertical axis, and pelvic incidence-lumbar lordosis mismatch (p < 0.05). At 2 years, patients in the operative cohort showed significantly increased rates of a gain in MCID for physical component summary of SF-36, ODI, and SRS-activity, SRS-pain, SRS-appearance, and SRS-mental scores. Cost analysis showed the average cost of nonoperative treatment 2 years prior to surgical intervention to be $2041. Overall, at 2 years patients in the nonoperative cohort had again in ODI of 0.36, did not show a gain in QALYs, and nonoperative treatment was determined to be cost-ineffective. However, a subset of patients in this cohort underwent successful maintenance treatment and had a decrease in ODI of 1.1 and a gain in utility of 0.006 at 2 years. If utility gained for this cohort was sustained to full life expectancy, patients' cost per QALY was $18,934 compared to a cost per QALY gained of $70,690.79 for posterior-only and $48,273.49 for combined approach in patients in the operative cohort. CONCLUSIONS: Patients with ASD undergoing operative treatment at baseline had greater sagittal deformity and greater improvement in health-related quality of life postoperatively compared to patients treated nonoperatively. Additionally, patients in the nonoperative cohort overall had an increase in ODI and did not show improvement in utility gained. Patients in the nonoperative cohort who had low disability and sagittal deformity underwent successful maintenance and cost-effective treatment.Item Open Access Incremental benefits of circumferential minimally invasive surgery for increasingly frail patients with adult spinal deformity.(Journal of neurosurgery. Spine, 2023-04) Passias, Peter G; Tretiakov, Peter S; Nunley, Pierce D; Wang, Michael Y; Park, Paul; Kanter, Adam S; Okonkwo, David O; Eastlack, Robert K; Mundis, Gregory M; Chou, Dean; Agarwal, Nitin; Fessler, Richard G; Uribe, Juan S; Anand, Neel; Than, Khoi D; Brusko, Gregory; Fu, Kai-Ming; Turner, Jay D; Le, Vivian P; Line, Breton G; Ames, Christopher P; Smith, Justin S; Shaffrey, Christopher I; Hart, Robert A; Burton, Douglas; Lafage, Renaud; Lafage, Virginie; Schwab, Frank; Bess, Shay; Mummaneni, Praveen VObjective
Circumferential minimally invasive surgery (cMIS) may provide incremental benefits compared with open surgery for patients with increasing frailty status by decreasing peri- and postoperative complications.Methods
Operative patients with adult spinal deformity (ASD) ≥ 18 years old with baseline and 2-year postoperative data were assessed. With propensity score matching, patients who underwent cMIS (cMIS group) were matched with similar patients who underwent open surgery (open group) based on baseline BMI, C7-S1 sagittal vertical axis, pelvic incidence to lumbar lordosis mismatch, and S1 pelvic tilt. The Passias modified ASD frailty index (mASD-FI) was used to determine patient frailty stratification as not frail, frail, or severely frail. Baseline and postoperative factors were assessed using two-way analysis of covariance (ANCOVA) and multivariate ANCOVA while controlling for baseline age, Charlson Comorbidity Index (CCI) score, and number of levels fused.Results
After propensity score matching, 170 ASD patients (mean age 62.71 ± 13.64 years, 75.0% female, mean BMI 29.25 ± 6.60 kg/m2) were included, split evenly between the cMIS and open groups. Surgically, patients in the open group had higher numbers of posterior levels fused (p = 0.021) and were more likely to undergo three-column osteotomies (p > 0.05). Perioperatively, cMIS patients had lower intraoperative blood loss and decreased use of cell saver across frailty groups (with adjustment for baseline age, CCI score, and levels fused), as well as fewer perioperative complications (p < 0.001). Adjusted analysis also revealed that compared to open patients, increasingly frail patients in the cMIS group were also more likely to demonstrate greater improvement in 1- and 2-year postoperative scores for the Oswestry Disability Index, SRS-36 (total), EQ-5D and SF-36 (all p < 0.05). With regard to postoperative complications, increasingly frail patients in the cMIS group were also noted to experience significantly fewer complications overall (p = 0.036) and fewer major intraoperative complications (p = 0.039). The cMIS patients were also less likely to need a reoperation than their open group counterparts (p = 0.043).Conclusions
Surgery performed with a cMIS technique may offer acceptable outcomes, with diminishment of perioperative complications and mitigation of catastrophic outcomes, in increasingly frail patients who may not be candidates for surgery using traditional open techniques. However, further studies should be performed to investigate the long-term impact of less optimal alignment in this population.Item Open Access Individual differences in postoperative recovery trajectories for adult symptomatic lumbar scoliosis(JOURNAL OF NEUROSURGERY-SPINE, 2022) Greenberg, Jacob K; Kelly, Michael P; Landman, Joshua M; Zhang, Justin K; Bess, Shay; Smith, Justin S; Lenke, Lawrence G; Shaffrey, Christopher I; Bridwell, Keith HItem Open Access Individual differences in postoperative recovery trajectories for adult symptomatic lumbar scoliosis.(Journal of neurosurgery. Spine, 2022-03) Greenberg, Jacob K; Kelly, Michael P; Landman, Joshua M; Zhang, Justin K; Bess, Shay; Smith, Justin S; Lenke, Lawrence G; Shaffrey, Christopher I; Bridwell, Keith HObjective
The Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) trial demonstrated the benefit of adult symptomatic lumbar scoliosis (ASLS) surgery. However, the extent to which individuals differ in their postoperative recovery trajectories is unknown. This study's objective was to evaluate variability in and factors moderating recovery trajectories after ASLS surgery.Methods
The authors used longitudinal, multilevel models to analyze postoperative recovery trajectories following ASLS surgery. Study outcomes included the Oswestry Disability Index (ODI) score and Scoliosis Research Society-22 (SRS-22) subscore, which were measured every 3 months until 2 years postoperatively. The authors evaluated the influence of preoperative disability level, along with other potential trajectory moderators, including radiographic, comorbidity, pain/function, demographic, and surgical factors. The impact of different parameters was measured using the R2, which represented the amount of variability in ODI/SRS-22 explained by each model. The R2 ranged from 0 (no variability explained) to 1 (100% of variability explained).Results
Among 178 patients, there was substantial variability in recovery trajectories. Applying the average trajectory to each patient explained only 15% of the variability in ODI and 21% of the variability in SRS-22 subscore. Differences in preoperative disability (ODI/SRS-22) had the strongest influence on recovery trajectories, with patients having moderate disability experiencing the greatest and most rapid improvement after surgery. Reflecting this impact, accounting for the preoperative ODI/SRS-22 level explained an additional 56%-57% of variability in recovery trajectory, while differences in the rate of postoperative change explained another 7%-9%. Among the effect moderators tested, pain/function variables-such as visual analog scale back pain score-had the biggest impact, explaining 21%-25% of variability in trajectories. Radiographic parameters were the least influential, explaining only 3%-6% more variance than models with time alone. The authors identified several significant trajectory moderators in the final model, such as significant adverse events and the number of levels fused.Conclusions
ASLS patients have highly variable postoperative recovery trajectories, although most reach steady state at 12 months. Preoperative disability was the most important influence, although other factors, such as number of levels fused, also impacted recovery.Item Open Access Patient and procedural risk factors for decline in lower-extremity motor scores following adult spinal deformity surgery.(Journal of neurosurgery. Spine, 2023-04) Mohanty, Sarthak; Hassan, Fthimnir M; Lenke, Lawrence G; Burton, Douglas; Daniels, Alan H; Gupta, Munish C; Kebaish, Khaled M; Kelly, Michael; Kim, Han Jo; Klineberg, Eric O; Passias, Peter G; Protopsaltis, Themistocles; Schwab, Frank; Shaffrey, Christopher I; Smith, Justin S; Line, Breton G; Lafage, Renaud; Lafage, Virginie; Bess, ShayObjective
The purpose of this study was to discern factors that differentiate patients who experience postoperative lower-extremity motor function decline in the early postoperative period.Methods
Adult spinal deformity (ASD) patients who were enrolled in a multicenter, observational, and prospectively collected study from 2018 to 2021 at 18 spinal deformity centers in North America were queried. Eligible participants met at least one of the following radiographic and/or procedural inclusion criteria: pelvic incidence minus lumbar lordosis (PI-LL) ≥ 25°, T1 pelvic angle (T1PA) ≥ 30°, sagittal vertical axis (SVA) ≥ 15 cm, thoracic scoliosis ≥ 70°, thoracolumbar scoliosis ≥ 50°, global coronal malalignment ≥ 7 cm, 3-column osteotomy, spinal fusion ≥ 12 levels, and/or age ≥ 65 years with ≥ 7 levels of instrumentation. Patients with an inflammatory or autoimmune disease and those who were incarcerated or pregnant were excluded, as were non-English speakers. Only patients with baseline and 6-week postoperative lower-extremity motor score (LEMS) were analyzed. Patient information, including demographic data, operative data, patient-reported outcomes, and radiographic parameters, were collected. Univariate and multivariable logistic regression models were built to quantify the degree to which a patient's postoperative LEMS decline was related to demographic and clinical characteristics.Results
In total, 205 patients (mean age 61.5 years, mean total instrumented levels 12.6, 67.3% female, 54.2% primary cases, 79.5% with pelvic fixation) were evaluated. Of these 205 patients, 32 (15.5%) experienced LEMS decline in the perioperative period. These patients were older (p = 0.0014) and had greater BMI (p = 0.0176), higher frailty scores (p = 0.047), longer operating room times (p = 0.033), and greater estimated blood loss (p < 0.0001), and they were more frequently observed to have intraoperative neurophysiological monitoring (IONM) changes (p = 0.018). The deteriorated cohort had greater C7SVA at baseline (p = 0.0028) but were comparable in terms of all other radiographic parameters. No radiographic differences were seen between the groups at the 6-week visit; however, the deteriorated cohort experienced greater change in PI-LL (p < 0.0001), lumbar lordosis (p = 0.0461), C7SVA (p = 0.0004), and T1PA (p < 0.0001). Multivariate logistic regression demonstrated that the presence of IONM changes and each degree of negative change in T1PA conferred 3.71 (95% CI 1.01-13.42) and 1.09 (1.01-1.19) greater odds of postoperative LEMS deterioration, respectively.Conclusions
In this study, 15.6% of ASD patients incurred LEMS decline in the perioperative period. The magnitude of change in global sagittal alignment, specifically T1PA, was the strongest independent predictor of LEMS decline, which has implications for surgical planning, patient counseling, and clinical research.Item Open Access Predictive role of global spinopelvic alignment and upper instrumented vertebra level in symptomatic proximal junctional kyphosis in adult spinal deformity.(Journal of neurosurgery. Spine, 2023-08) Ye, Jichao; Gupta, Sachin; Farooqi, Ali S; Yin, Tsung; Soroceanu, Alex; Schwab, Frank J; Lafage, Virginie; Kelly, Michael P; Kebaish, Khaled; Hostin, Richard; Gum, Jeffrey L; Smith, Justin S; Shaffrey, Christopher I; Scheer, Justin K; Protopsaltis, Themistocles S; Passias, Peter G; Klineberg, Eric O; Kim, Han Jo; Hart, Robert A; Hamilton, D Kojo; Ames, Christopher P; Gupta, Munish CObjective
The authors of this study sought to evaluate the predictive role of global sagittal alignment and upper instrumented vertebra (UIV) level in symptomatic proximal junctional kyphosis (PJK) among patients with adult spinal deformity (ASD).Methods
Data on ASD patients who had undergone fusion of ≥ 5 vertebrae from 2008 to 2018 and with a minimum follow-up of 1 year were obtained from a prospectively collected multicenter database and evaluated (n = 1312). Radiographs were obtained preoperatively and at 6 weeks, 6 months, 1 year, 2 years, and 3 years postoperatively. The 22-Item Scoliosis Research Society Patient Questionnaire Revised (SRS-22r) scores were collected preoperatively, 1 year postoperatively, and 2 years postoperatively. Symptomatic PJK was defined as a kyphotic increase > 20° in the Cobb angle from the UIV to the UIV+2. At 6 weeks postoperatively, sagittal parameters were evaluated and patients were categorized by global alignment and proportion (GAP) score/category and SRS-Schwab sagittal modifiers. Patients were stratified by UIV level: upper thoracic (UT) UIV ≥ T8 or lower thoracic (LT) UIV ≤ T9.Results
Patients who developed symptomatic PJK (n = 260) had worse 1-year postoperative SRS-22r mental health (3.70 vs 3.86) and total (3.56 vs 3.67) scores, as well as worse 2-year postoperative self-image (3.45 vs 3.65) and satisfaction (4.03 vs 4.22) scores (all p ≤ 0.04). In the whole study cohort, patients with PJK had less pelvic incidence-lumbar lordosis (PI-LL) mismatch (-0.24° vs 3.29°, p < 0.001) but no difference in their GAP score/category or SRS-Schwab sagittal modifiers compared with the patients without PJK. Regression showed a higher risk of PJK with a pelvic tilt (PT) grade ++ (OR 2.35) and less risk with a PI-LL grade ++ (OR 0.35; both p < 0.01). When specifically analyzing the LT UIV cohort, patients with PJK had a higher GAP score (5.66 vs 4.79), greater PT (23.02° vs 20.90°), and less PI-LL mismatch (1.61° vs 4.45°; all p ≤ 0.02). PJK patients were less likely to be proportioned postoperatively (17.6% vs 30.0%, p = 0.015), and regression demonstrated a greater PJK risk with severe disproportion (OR 1.98) and a PT grade ++ (OR 3.15) but less risk with a PI-LL grade ++ (OR 0.45; all p ≤ 0.01). When specifically evaluating the UT UIV cohort, the PJK patients had less PI-LL mismatch (-2.11° vs 1.45°) but no difference in their GAP score/category. Regression showed a greater PJK risk with a PT grade + (OR 1.58) and a decreased risk with a PI-LL grade ++ (OR 0.21; both p < 0.05).Conclusions
Symptomatic PJK leads to worse patient-reported outcomes and is associated with less postoperative PI-LL mismatch and greater postoperative PT. A worse postoperative GAP score and disproportion are only predictive of symptomatic PJK in patients with an LT UIV.Item Open Access Predictors of pelvic tilt normalization: a multicenter study on the impact of regional and lower-extremity compensation on pelvic alignment after complex adult spinal deformity surgery.(Journal of neurosurgery. Spine, 2024-01) Dave, Pooja; Lafage, Renaud; Smith, Justin S; Line, Breton G; Tretiakov, Peter S; Mir, Jamshaid; Diebo, Bassel; Daniels, Alan H; Gum, Jeffrey L; Hamilton, D Kojo; Buell, Thomas; Than, Khoi D; Fu, Kai-Ming; Scheer, Justin K; Eastlack, Robert; Mullin, Jeffrey P; Mundis, Gregory; Hosogane, Naobumi; Yagi, Mitsuru; Nunley, Pierce; Chou, Dean; Mummaneni, Praveen V; Klineberg, Eric O; Kebaish, Khaled M; Lewis, Stephen; Hostin, Richard A; Gupta, Munish C; Kim, Han Jo; Ames, Christopher P; Hart, Robert A; Lenke, Lawrence G; Shaffrey, Christopher I; Bess, Shay; Schwab, Frank J; Lafage, Virginie; Burton, Douglas C; Passias, Peter GThe objective was to determine the degree of regional decompensation to pelvic tilt (PT) normalization after complex adult spinal deformity (ASD) surgery. Operative ASD patients with 1 year of PT measurements were included. Patients with normalized PT at baseline were excluded. Predicted PT was compared to actual PT, tested for change from baseline, and then compared against age-adjusted, Scoliosis Research Society-Schwab, and global alignment and proportion (GAP) scores. Lower-extremity (LE) parameters included the cranial-hip-sacrum angle, cranial-knee-sacrum angle, and cranial-ankle-sacrum angle. LE compensation was set as the 1-year upper tertile compared with intraoperative baseline. Univariate analyses were used to compare normalized and nonnormalized data against alignment outcomes. Multivariable logistic regression analyses were used to develop a model consisting of significant predictors for normalization related to regional compensation. In total, 156 patients met the inclusion criteria (mean ± SD age 64.6 ± 9.1 years, BMI 27.9 ± 5.6 kg/m2, Charlson Comorbidity Index 1.9 ± 1.6). Patients with normalized PT were more likely to have overcorrected pelvic incidence minus lumbar lordosis and sagittal vertical axis at 6 weeks (p < 0.05). GAP score at 6 weeks was greater for patients with nonnormalized PT (0.6 vs 1.3, p = 0.08). At baseline, 58.5% of patients had compensation in the thoracic and cervical regions. Postoperatively, compensation was maintained by 42% with no change after matching in age-adjusted or GAP score. The patients with nonnormalized PT had increased rates of thoracic and cervical compensation (p < 0.05). Compensation in thoracic kyphosis differed between patients with normalized PT at 6 weeks and those with normalized PT at 1 year (69% vs 35%, p < 0.05). Those who compensated had increased rates of implant complications by 1 year (OR [95% CI] 2.08 [1.32-6.56], p < 0.05). Cervical compensation was maintained at 6 weeks and 1 year (56% vs 43%, p = 0.12), with no difference in implant complications (OR 1.31 [95% CI -2.34 to 1.03], p = 0.09). For the lower extremities at baseline, 61% were compensating. Matching age-adjusted alignment did not eliminate compensation at any joint (all p > 0.05). Patients with nonnormalized PT had higher rates of LE compensation across joints (all p < 0.01). Overall, patients with normalized PT at 1 year had the greatest odds of resolving LE compensation (OR 9.6, p < 0.001). Patients with normalized PT at 1 year had lower rates of implant failure (8.9% vs 19.5%, p < 0.05), rod breakage (1.3% vs 13.8%, p < 0.05), and pseudarthrosis (0% vs 4.6%, p < 0.05) compared with patients with nonnormalized PT. The complication rate was significantly lower for patients with normalized PT at 1 year (56.7% vs 66.1%, p = 0.02), despite comparable health-related quality of life scores. Patients with PT normalization had greater rates of resolution in thoracic and LE compensation, leading to lower rates of complications by 1 year. Thus, consideration of both the lower extremities and thoracic regions in surgical planning is vital to preventing adverse outcomes and maintaining pelvic alignment.Item Open Access Revision Strategies for Harrington Rod Instrumentation: Radiographic Outcomes and Complications.(Global spine journal, 2022-05) Louie, Philip K; Iyer, Sravisht; Khanna, Krishn; Harada, Garrett K; Khalid, Alina; Gupta, Munish; Burton, Douglas; Shaffrey, Christopher; Lafage, Renaud; Lafage, Virginie; Dewald, Christopher J; Schwab, Frank J; Kim, Han JoStudy design
Retrospective case series.Objective
The purpose of this study is to evaluate the clinical and radiographic outcomes following revision surgery following Harrington rod instrumentation.Methods
Patients who underwent revision surgery with a minimum of 1-year follow-up for flatback syndrome following Harrington rod instrumentation for adolescent idiopathic scoliosis were identified from a multicenter dataset. Baseline demographics and intraoperative information were obtained. Preoperative, initial postoperative, and most recent spinopelvic parameters were compared. Postoperative complications and reoperations were subsequently evaluated.Results
A total of 41 patients met the inclusion criteria with an average follow-up of 27.7 months. Overall, 14 patients (34.1%) underwent a combined anterior-posterior fusion, and 27 (65.9%) underwent an osteotomy for correction. Preoperatively, the most common lower instrumented vertebra (LIV) was at L3 and L4 (61%), whereas 85% had a LIV to the pelvis after revision. The mean preoperative pelvic incidence-lumbar lordosis mismatch and C7 sagittal vertical axis were 23.7° and 89.6 mm. This was corrected to 8.1° and 28.9 mm and maintained to 9.04° and 34.4 mm at latest follow-up. Complications included deep wound infection (12.2%), durotomy (14.6%), implant related failures (14.6%), and temporary neurologic deficits (22.0%). Eight patients underwent further revision surgery at an average of 7.4 months after initial revision.Conclusions
There are multiple surgical techniques to address symptomatic flatback syndrome in patients with previous Harrington rod instrumentation for adolescent idiopathic scoliosis. At an average of 27.7 months follow-up, pelvic incidence-lumbar lordosis mismatch and C7 sagittal vertical axis can be successfully corrected and maintained. However, complication and reoperation rates remain high.Item Open Access Revision thoracolumbar surgery for flat back deformity: staged ALIF and posterior column osteotomies to avoid three-column osteotomy.(Neurosurgical focus: Video, 2020-01) Marino, Alexandria C; Buell, Thomas J; Burke, Rebecca M; Wang, Tony R; Yen, Chun-Po; Shaffrey, Christopher I; Smith, Justin SThree-column osteotomies (3COs) can achieve significant alignment correction when revising fixed sagittal plane deformities; however, the technique is associated with high complication rates. The authors demonstrate staged anterior-posterior surgery with L5-S1 ALIF (below a prior L3-5 fusion) and multilevel Smith-Petersen osteotomies to circumvent the morbidity associated with 3CO. The patient was a 67-year-old male with three prior lumbar surgeries who presented with back and leg pain. Imaging demonstrated lumbar flat back deformity and sagittal imbalance. The narrated video details key radiological measurements, operative planning and rationale, surgical steps, and outcomes. The patient provided written, informed consent for publication of this illustrative case. The video can be found here: https://youtu.be/wv4W9D9fUPc.Item Open Access Risk Factor Analysis for Proximal Junctional Kyphosis After Adult Spinal Deformity Surgery: A New Simple Scoring System to Identify High-Risk Patients.(Global spine journal, 2020-10) Lafage, Renaud; Beyer, George; Schwab, Frank; Klineberg, Eric; Burton, Douglas; Bess, Shay; Kim, Han Jo; Smith, Justin; Ames, Christopher; Hostin, Richard; Khalife, Marc; Shaffrey, Christopher; Mundis, Gregory; Lafage, VirginieStudy design
Retrospective cohort study.Objective
Develop a simple scoring system to estimate proximal junctional kyphosis (PJK) risk.Methods
A total of 417 adult spinal deformity (ASD) patients (80% females, 57.8 years) with 2-year follow-up were included. PJK was defined as a >10° kyphotic angle between the upper-most instrumented vertebra (UIV) and the vertebrae 2 levels above the UIV (UIV+2). Based on a previous literature review, the following point score was attributed to parameters likely to impact PJK development: age >55 years (1 point), fusion to S1/ilium (1 point), UIV in the upper thoracic spine (UIV-UT: 1 point), UIV in the lower thoracic region (UIV-LT: 2 points), flattening of the thoracic kyphosis (TK) relative to the lumbar lordosis (LL; ie, ▵LL - ▵TK) greater than 10° (1 point).Results
At 2 years, the overall PJK rate was 43%. The odds ratios for each risk factor were the following: age >55 years (2.52), fusion to S1/ilium (5.17), UIV-UT (6.63), UIV-LT (8.24), and ▵LL - ▵TK >10° (1.59). Analysis by risk factor revealed a significant impact on PJK (no PJK vs PJK): age >55 years (28% vs 51%, P < .001), LIV S1/ilium (16.3% vs 51.4%, P < .001), UIV in lower thoracic spine (12.0% vs 38.7% vs 52.9%, P < .001), and a >10° surgical reduction in TK relative to LL increase (40.0% vs 51.5%, P < .001). The PJK rate by point score was as follows: 1 = 17%, 2 = 29%, 3 = 40%, 4 = 53%, and 5 = 69%.Conclusion
A pragmatic scoring system was developed that is tied to the increasing risk of PJK. These findings are helpful for surgical planning and preoperative counseling.Item Open Access Role of obesity in less radiographic correction and worse health-related quality-of-life outcomes following minimally invasive deformity surgery.(Journal of neurosurgery. Spine, 2022-02) Than, Khoi D; Mehta, Vikram A; Le, Vivian; Moss, Jonah R; Park, Paul; Uribe, Juan S; Eastlack, Robert K; Chou, Dean; Fu, Kai-Ming; Wang, Michael Y; Anand, Neel; Passias, Peter G; Shaffrey, Christopher I; Okonkwo, David O; Kanter, Adam S; Nunley, Pierce; Mundis, Gregory M; Fessler, Richard G; Mummaneni, Praveen VObjective
Minimally invasive surgery (MIS) for adult spinal deformity (ASD) can offer deformity correction with less tissue manipulation and damage. However, the impact of obesity on clinical outcomes and radiographic correction following MIS for ASD is poorly understood. The goal of this study was to determine the role, if any, that obesity has on radiographic correction and health-related quality-of-life measures in MIS for ASD.Methods
Data were collected from a multicenter database of MIS for ASD. This was a retrospective review of a prospectively collected database. Patient inclusion criteria were age ≥ 18 years and coronal Cobb angle ≥ 20°, pelvic incidence-lumbar lordosis mismatch ≥ 10°, or sagittal vertical axis (SVA) > 5 cm. A group of patients with body mass index (BMI) < 30 kg/m2 was the control cohort; BMI ≥ 30 kg/m2 was used to define obesity. Obesity cohorts were categorized into BMI 30-34.99 and BMI ≥ 35. All patients had at least 1 year of follow-up. Preoperative and postoperative health-related quality-of-life measures and radiographic parameters, as well as complications, were compared via statistical analysis.Results
A total of 106 patients were available for analysis (69 control, 17 in the BMI 30-34.99 group, and 20 in the BMI ≥ 35 group). The average BMI was 25.24 kg/m2 for the control group versus 32.46 kg/m2 (p < 0.001) and 39.5 kg/m2 (p < 0.001) for the obese groups. Preoperatively, the BMI 30-34.99 group had significantly more prior spine surgery (70.6% vs 42%, p = 0.04) and worse preoperative numeric rating scale leg scores (7.71 vs 5.08, p = 0.001). Postoperatively, the BMI 30-34.99 cohort had worse Oswestry Disability Index scores (33.86 vs 23.55, p = 0.028), greater improvement in numeric rating scale leg scores (-4.88 vs -2.71, p = 0.012), and worse SVA (51.34 vs 26.98, p = 0.042) at 1 year postoperatively. Preoperatively, the BMI ≥ 35 cohort had significantly worse frailty (4.5 vs 3.27, p = 0.001), Oswestry Disability Index scores (52.9 vs 44.83, p = 0.017), and T1 pelvic angle (26.82 vs 20.71, p = 0.038). Postoperatively, after controlling for differences in frailty, the BMI ≥ 35 cohort had significantly less improvement in their Scoliosis Research Society-22 outcomes questionnaire scores (0.603 vs 1.05, p = 0.025), higher SVA (64.71 vs 25.33, p = 0.015) and T1 pelvic angle (22.76 vs 15.48, p = 0.029), and less change in maximum Cobb angle (-3.93 vs -10.71, p = 0.034) at 1 year. The BMI 30-34.99 cohort had significantly more infections (11.8% vs 0%, p = 0.004). The BMI ≥ 35 cohort had significantly more implant complications (30% vs 11.8%, p = 0.014) and revision surgery within 90 days (5% vs 1.4%, p = 0.034).Conclusions
Obese patients who undergo MIS for ASD have less correction of their deformity, worse quality-of-life outcomes, more implant complications and infections, and an increased rate of revision surgery compared with their nonobese counterparts, although both groups benefit from surgery. Appropriate counseling should be provided to obese patients.Item Open Access Sacral insufficiency fractures after lumbosacral arthrodesis: salvage lumbopelvic fixation and a proposed management algorithm.(Journal of neurosurgery. Spine, 2020-03-27) Buell, Thomas J; Yener, Ulas; Wang, Tony R; Buchholz, Avery L; Yen, Chun-Po; Shaffrey, Mark E; Shaffrey, Christopher I; Smith, Justin SOBJECTIVE:Sacral insufficiency fracture after lumbosacral (LS) arthrodesis is an uncommon complication. The objective of this study was to report the authors' operative experience managing this complication, review pertinent literature, and propose a treatment algorithm. METHODS:The authors analyzed consecutive adult patients treated at their institution from 2009 to 2018. Patients who underwent surgery for sacral insufficiency fractures after posterior instrumented LS arthrodesis were included. PubMed was queried to identify relevant articles detailing management of this complication. RESULTS:Nine patients with a minimum 6-month follow-up were included (mean age 73 ± 6 years, BMI 30 ± 6 kg/m2, 56% women, mean follow-up 35 months, range 8-96 months). Six patients had osteopenia/osteoporosis (mean dual energy x-ray absorptiometry hip T-score -1.6 ± 0.5) and 3 received treatment. Index LS arthrodesis was performed for spinal stenosis (n = 6), proximal junctional kyphosis (n = 2), degenerative scoliosis (n = 1), and high-grade spondylolisthesis (n = 1). Presenting symptoms of back/leg pain (n = 9) or lower extremity weakness (n = 3) most commonly occurred within 4 weeks of index LS arthrodesis, which prompted CT for fracture diagnosis at a mean of 6 weeks postoperatively. All sacral fractures were adjacent or involved S1 screws and traversed the spinal canal (Denis zone III). H-, U-, or T-type sacral fracture morphology was identified in 7 patients. Most fractures (n = 8) were Roy-Camille type II (anterior displacement with kyphosis). All patients underwent lumbopelvic fixation via a posterior-only approach; mean operative duration and blood loss were 3.3 hours and 850 ml, respectively. Bilateral dual iliac screws were utilized in 8 patients. Back/leg pain and weakness improved postoperatively. Mean sacral fracture anterolisthesis and kyphotic angulation improved (from 8 mm/11° to 4 mm/5°, respectively) and all fractures were healed on radiographic follow-up (mean duration 29 months, range 8-90 months). Two patients underwent revision for rod fractures at 1 and 2 years postoperatively. A literature review found 17 studies describing 87 cases; potential risk factors were osteoporosis, longer fusions, high pelvic incidence (PI), and postoperative PI-to-lumbar lordosis (LL) mismatch. CONCLUSIONS:A high index of suspicion is needed to diagnose sacral insufficiency fracture after LS arthrodesis. A trial of conservative management is reasonable for select patients; potential surgical indications include refractory pain, neurological deficit, fracture nonunion with anterolisthesis or kyphotic angulation, L5-S1 pseudarthrosis, and spinopelvic malalignment. Lumbopelvic fixation with iliac screws may be effective salvage treatment to allow fracture healing and symptom improvement. High-risk patients may benefit from prophylactic lumbopelvic fixation at the time of index LS arthrodesis.Item Open Access Stronger association of objective physical metrics with baseline patient-reported outcome measures than preoperative standing sagittal parameters for adult spinal deformity patients.(Journal of neurosurgery. Spine, 2024-03) Azad, Tej D; Schwab, Frank J; Lafage, Virginie; Soroceanu, Alex; Eastlack, Robert K; Lafage, Renaud; Kebaish, Khaled M; Hart, Robert A; Diebo, Bassel; Kelly, Michael P; Smith, Justin S; Daniels, Alan H; Hamilton, D Kojo; Gupta, Munish; Klineberg, Eric O; Protopsaltis, Themistocles S; Passias, Peter G; Bess, Shay; Gum, Jeffrey L; Hostin, Richard; Lewis, Stephen J; Shaffrey, Christopher I; Burton, Douglas; Lenke, Lawrence G; Ames, Christopher P; Scheer, Justin KObjective
Sagittal alignment measured on standing radiography remains a fundamental component of surgical planning for adult spinal deformity (ASD). However, the relationship between classic sagittal alignment parameters and objective metrics, such as walking time (WT) and grip strength (GS), remains unknown. The objective of this work was to determine if ASD patients with worse baseline sagittal malalignment have worse objective physical metrics and if those metrics have a stronger relationship to patient-reported outcome metrics (PROMs) than standing alignment.Methods
The authors conducted a retrospective review of a multicenter ASD cohort. ASD patients underwent baseline testing with the timed up-and-go 6-m walk test (seconds) and for GS (pounds). Baseline PROMs were surveyed, including Oswestry Disability Index (ODI), Patient-Reported Outcomes Measurement Information System (PROMIS), Scoliosis Research Society (SRS)-22r, and Veterans RAND 12 (VR-12) scores. Standard spinopelvic measurements were obtained (sagittal vertical axis [SVA], pelvic tilt [PT], and mismatch between pelvic incidence and lumbar lordosis [PI-LL], and SRS-Schwab ASD classification). Univariate and multivariable linear regression modeling was performed to interrogate associations between objective physical metrics, sagittal parameters, and PROMs.Results
In total, 494 patients were included, with mean ± SD age 61 ± 14 years, and 68% were female. Average WT was 11.2 ± 6.1 seconds and average GS was 56.6 ± 24.9 lbs. With increasing PT, PI-LL, and SVA quartiles, WT significantly increased (p < 0.05). SRS-Schwab type N patients demonstrated a significantly longer average WT (12.5 ± 6.2 seconds), and type T patients had a significantly shorter WT time (7.9 ± 2.7 seconds, p = 0.03). With increasing PT quartiles, GS significantly decreased (p < 0.05). SRS-Schwab type T patients had a significantly higher average GS (68.8 ± 27.8 lbs), and type L patients had a significantly lower average GS (51.6 ± 20.4 lbs, p = 0.03). In the frailty-adjusted multivariable linear regression analyses, WT was more strongly associated with PROMs than sagittal parameters. GS was more strongly associated with ODI and PROMIS Physical Function scores.Conclusions
The authors observed that increasing baseline sagittal malalignment is associated with slower WT, and possibly weaker GS, in ASD patients. WT has a stronger relationship to PROMs than standing alignment parameters. Objective physical metrics likely offer added value to standard spinopelvic measurements in ASD evaluation and surgical planning.