The Approach to Pseudarthrosis After Adult Spinal Deformity Surgery: Is a Multiple-Rod Construct Necessary?

STUDY DESIGN: Retrospective study. OBJECTIVES: Our goal was to evaluate the rate of rod fracture and persistent pseudarthrosis in cohorts of patients treated with a dual rod or multiple-rod construct in revision surgery for pseudarthrosis. METHODS: A dual rod construct was used in 23 patients, and a multiple rod construct in 24 patients, spanning the pseudarthrosis level. Two-year fusion grading, and rates of pseudarthrosis and implant failure, were assessed. RESULTS: There were no differences in patient or surgical characteristics between the groups: (2- rod construct: Age 60 ± 14, Levels 10 ± 5, 3-column osteotomy:17%; multiple-rod construct: Age: 62 ± 11, Levels 9 ± 4, 3-column osteotomy:30%). Patients in the multiple rod construct were transfused a greater volume of packed red blood cells (pRBCs) intraoperatively (2.6 ± 2.9 vs. 1.1 ± 1.5 U, p < 0.0001). At 2 year follow up there was no difference in fusion grades at the previous level of pseudarthrosis, the rate of rod fracture or pseudarthrosis between the 2 groups, or rate of reoperation for pseudarthrosis, rod fracture, wound infection, hardware prominence, or PJK/PJF. CONCLUSIONS: Our data demonstrate no difference in fusion grade, or rates of rod fracture and revision at 2 years, after utilizing a dual rod versus multiple rod construct in revision surgery for pseudarthrosis. The low complication rates seen with either configuration warrant further investigation of the optimal instrumentation configuration.

Case Start Timing of Adult Spinal Deformity Surgeries: Does the Wait Matter?

BACKGROUND: Adult spinal deformity (ASD) surgery can entail complex reconstructive procedures. It is unclear whether there is any effect of case start time on outcomes. We sought to evaluate the effects of case start time and day of the week on 90-day complication, readmission, and revision rates after ASD surgery. METHODS: This is a retrospective study of 1040 ASD patients from a single institution. We collected start times and day of the week for cases from 2011 to 2018. Early start was designated as any case starting either before or at 7:30 am or between 7:30 and 11 am; late start was designated as any case starting at 11 am or later. Outcome measures include 90-day complication, revision, and readmission rates. RESULTS: A total of 1040 ASD patients (age, 46 ± 23 years; body mass index, 25 ± 7; American Society of Anesthesiologists classification, 2.5 ± 0.6; levels fused, 10 ± 4; three column osteotomy (3CO), 13%) were included. There was no association between surgery day of the week and length of stay, 90-day complication, readmission, or reoperation rates in the adjusted analyses. Late start cases had higher rates of 90-day readmission (10.5% vs 6.0%, P = 0.02), reoperation (11.9% vs 6.6%, P = 0.008), and neurologic injury (5.2% vs 2.1%, P = 0.019). Subanalysis of neurologic complications demonstrated that there was a higher rate of postoperative radiculopathy (P = 0.007) and residual central or foraminal stenosis (P = 0.029) in late start cases. A late start time was predictive of increased risk for 90-day readmission (OR 1.8, P = 0.02), unplanned reoperation (OR 1.9, P = 0.009), and neurologic complication (OR 2.1, P = 0.046). CONCLUSIONS: A late OR start time was predictive of increased risk for neurologic complication, 90-day readmission, and unplanned reoperation. The well-established protocols for first start OR times for elective ASD surgery may decrease outcome risk and reduce variability in complication rates. CLINICAL RELEVANCE: Understanding the impact of start time on outcomes and complications after ASD surgery is helpful for surgeons in preoperative planning and for institutions and hospitals' allocation of operating room staff and resources.

Pseudarthrosis and Rod Fracture Rates After Transforaminal Lumbar Interbody Fusion at the Caudal Levels of Long Constructs for Adult Spinal Deformity Surgery.

BACKGROUND: Interbody fusion at the caudal levels of long constructs for adult spinal deformity (ASD) surgery is used to promote fusion and secure a solid foundation for maintenance of deformity correction. We sought to evaluate long-term pseudarthrosis, rod fracture, and revision rates for TLIF performed at the base of a long construct for ASD. METHODS: We reviewed 316 patients who underwent TLIF as a component of ASD surgery for medical comorbidities, surgical characteristics, and rate of unplanned reoperation for pseudarthrosis or instrumentation failure at the TLIF level. Fusion grading was assessed after revision surgery for pseudarthrosis at the TLIF level. RESULTS: Rate of pseudarthrosis at the TLIF level was 9.8% (31/316), and rate of rod fractures was 7.9% (25/316). The rate of revision surgery at the TLIF level was 8.9% (28/316), and surgery was performed at a mean of 20.4 ± 16 months from the index procedure. Current smoking status (odds ratio 3.34, P = 0.037) was predictive of pseudarthrosis at the TLIF site. At a mean follow-up of 43 ± 12 months after revision surgery, all patients had achieved bony union at the TLIF site. CONCLUSIONS: At 3-year follow-up, the rate of pseudarthrosis after TLIF performed at the base of a long fusion for ASD was 9.8%, and the rate of revision surgery to address pseudarthrosis and/or rod fracture was 8.9%. All patients were successfully treated with revision interbody fusion or posterior augmentation of the fusion mass, without need for further revision procedures at the TLIF level.

Not Frail and Elderly: How Invasive Can We Go in This Different Type of Adult Spinal Deformity Patient?

STUDY DESIGN: Retrospective review of a single-center spine database. OBJECTIVE: Investigate the intersections of chronological age and physiological age via frailty to determine the influence of surgical invasiveness on patient outcomes. SUMMARY OF BACKGROUND DATA: Frailty is a well-established factor in preoperative risk stratification and prediction of postoperative outcomes. The surgical profile of operative patients with adult spinal deformity (ASD) who present as elderly and not frail (NF) has yet to be investigated. Our aim was to examine the surgical profile and outcomes of patients with ASD who were NF and elderly. METHODS: Patients with ASD 18 years or older, four or greater levels fused, with baseline (BL) and follow-up data were included. Patients were categorized by ASD frailty index: NF, Frail (F), severely frail (SF]. An elderly patient was defined as 70 years or older. Patients were grouped into NF/elderly and F/elderly. SRS-Schwab modifiers were assessed at BL and 1 year (0, +, ++). Logistic regression analysis assessed the relationship between increasing invasiveness, no reoperations, or major complications, and improvement in SRS-Schwab modifiers [Good Outcome]. Decision tree analysis assessed thresholds for an invasiveness risk/benefit cutoff point. RESULTS: A total of 598 patients with ASD included (55.3 yr, 59.7% F, 28.3 kg/m2). 29.8% of patients were older than 70 years. At BL, 51.3% of patients were NF, 37.5% F, and 11.2% SF. Sixty-sis (11%) patients were NF and elderly. About 24.2% of NF-elderly patients improved in SRS-Schwab by 1 year and had no reoperation or complication postoperatively. Binary regression analysis found a relationship between worsening SRS-Schwab, postop complication, and reoperation with invasiveness score (odds ratio: 1.056 [1.01-1.102], P = 0.011). Risk/benefit cut-off was 10 (P = 0.004). Patients below this threshold were 7.9 (2.2-28.4) times more likely to have a Good Outcome. 156 patients were elderly and F/SF with 16.7% having good outcome, with a risk/benefit cut-off point of less than 8 (4.4 [2.2-9.0], P < 0.001). CONCLUSION: Frailty status impacted the balance of surgical invasiveness relative to operative risk in an inverse manner, whereas the opposite was seen amongst elderly patients with a frailty status less than their chronologic age. Surgeons should perhaps consider incorporation of frailty status over age status when determining realignment plans in patients of advanced age.Level of Evidence: 3.

Clinical photographs in the assessment of adult spinal deformity: a comparison to radiographic parameters.

OBJECTIVE: The goal of this study was to reliably predict sagittal and coronal spinal alignment with clinical photographs by using markers placed at easily localized anatomical landmarks. METHODS: A consecutive series of patients with adult spinal deformity were enrolled from a single center. Full-length standing radiographs were obtained at the baseline visit. Clinical photographs were taken with reflective markers placed overlying C2, S1, the greater trochanter, and each posterior-superior iliac spine. Sagittal radiographic parameters were C2 pelvic angle (CPA), T1 pelvic angle (TPA), and pelvic tilt. Coronal radiographic parameters were pelvic obliquity and T1 coronal tilt. Linear regressions were performed to evaluate the relationship between radiographic parameters and their photographic "equivalents." The data were reanalyzed after stratifying the cohort into low-body mass index (BMI) (< 30) and high-BMI (≥ 30) groups. Interobserver and intraobserver reliability was assessed for clinical measures via intraclass correlation coefficients (ICCs). RESULTS: A total of 38 patients were enrolled (mean age 61 years, mean BMI 27.4 kg/m2, 63% female). All regression models were significant, but sagittal parameters were more closely correlated to photographic parameters than coronal measurements. TPA and CPA had the strongest associations with their photographic equivalents (both r2 = 0.59, p < 0.001). Radiographic and clinical parameters tended to be more strongly correlated in the low-BMI group. Clinical measures of TPA and CPA had high intraobserver reliability (all ICC > 0.99, p < 0.001) and interobserver reliability (both ICC > 0.99, p < 0.001). CONCLUSIONS: The photographic measures of spinal deformity developed in this study were highly correlated with their radiographic counterparts and had high inter- and intraobserver reliability. Clinical photography can not only reduce radiation exposure in patients with adult spinal deformity, but also be used to assess deformity when full-spine radiographs are unavailable.

Operative versus nonoperative treatment for adult symptomatic lumbar scoliosis at 5-year follow-up: durability of outcomes and impact of treatment-related serious adverse events.

OBJECTIVE: Although short-term adult symptomatic lumbar scoliosis (ASLS) studies favor operative over nonoperative treatment, longer outcomes are critical for assessment of treatment durability, especially for operative treatment, because the majority of implant failures and nonunions present between 2 and 5 years after surgery. The objectives of this study were to assess the durability of treatment outcomes for operative versus nonoperative treatment of ASLS, to report the rates and types of associated serious adverse events (SAEs), and to determine the potential impact of treatment-related SAEs on outcomes. METHODS: The ASLS-1 (Adult Symptomatic Lumbar Scoliosis-1) trial is an NIH-sponsored multicenter prospective study to assess operative versus nonoperative ASLS treatment. Patients were 40-80 years of age and had ASLS (Cobb angle ≥ 30° and Oswestry Disability Index [ODI] ≥ 20 or Scoliosis Research Society [SRS]-22 subscore ≤ 4.0 in the Pain, Function, and/or Self-Image domains). Patients receiving operative and nonoperative treatment were compared using as-treated analysis, and the impact of related SAEs was assessed. Primary outcome measures were ODI and SRS-22. RESULTS: The 286 patients with ASLS (107 with nonoperative treatment, 179 with operative treatment) had 2-year and 5-year follow-up rates of 90% (n = 256) and 74% (n = 211), respectively. At 5 years, compared with patients treated nonoperatively, those who underwent surgery had greater improvement in ODI (mean difference -15.2 [95% CI -18.7 to -11.7]) and SRS-22 subscore (mean difference 0.63 [95% CI 0.48-0.78]) (p < 0.001), with treatment effects (TEs) exceeding the minimum detectable measurement difference (MDMD) for ODI (7) and SRS-22 subscore (0.4). TEs at 5 years remained as favorable as 2-year TEs (ODI -13.9, SRS-22 0.52). For patients in the operative group, the incidence rates of treatment-related SAEs during the first 2 years and 2-5 years after surgery were 22.38 and 8.17 per 100 person-years, respectively. At 5 years, patients in the operative group who had 1 treatment-related SAE still had significantly greater improvement, with TEs (ODI -12.2, SRS-22 0.53; p < 0.001) exceeding the MDMD. Twelve patients who received surgery and who had 2 or more treatment-related SAEs had greater improvement than nonsurgically treated patients based on ODI (TE -8.34, p = 0.017) and SRS-22 (TE 0.32, p = 0.029), but the SRS-22 TE did not exceed the MDMD. CONCLUSIONS: The significantly greater improvement of operative versus nonoperative treatment for ASLS at 2 years was durably maintained at the 5-year follow-up. Patients in the operative cohort with a treatment-related SAE still had greater improvement than patients in the nonoperative cohort. These findings have important implications for patient counseling and future cost-effectiveness assessments.

The Ankle-Pelvic Angle (APA) and Global Lower Extremity Angle (GLA): Summary Measurements of Pelvic and Lower Extremity Compensation.

BACKGROUND: Adult sagittal spinal deformity (SSD) leads to the recruitment of compensatory mechanisms to maintain standing balance. After regional spinal compensation is exhausted, lower extremity compensation is recruited. Knee flexion, ankle flexion, and sacrofemoral angle increase to drive pelvic shift posterior and increase pelvic tilt. We aim to describe 2 summary angles termed ankle-pelvic angle (APA) and global lower extremity angle (GLA) that incorporate all aspects of lower extremity and pelvic compensation in a comprehensive measurement that can simplify radiographic analysis. METHODS: Full-body sagittal stereotactic radiographs were retrospectively collected and digitally analyzed. Spinal and lower extremity alignment were quantified with existing measures. Two angles-APA and GLA-were drawn as geometrically complementary angles to T1-pelvic angle (TPA) and global sagittal axis (GSA), respectively. Regression analysis was used to represent the predictive relationship between TPA and APA and between GSA and GLA. RESULTS: A total of 518 propensity score-matched patient records were available for analysis. Patients with lower extremity compensation had higher APA (21.83° versus 19.47°, P = .007) and GLA (6.03° versus 1.19°, P < .001) than those without compensation. APA and GLA demonstrated strong correlation with TPA (r = 0.81) and GSA (r = 0.77), respectively. Furthermore, the change between preoperative and postoperative values were strongly correlative between ΔAPA and ΔTPA (r = 0.71) and between ΔGLA and ΔGSA (r = 0.77). APA above 20.6° and GLA above 3.6° were indicative of lower extremity compensation. Patients with increased GLA values had significantly higher Oswestry Disability Index scores (48.67 versus 41.04, P = .005). CONCLUSIONS: TPA and GSA are measures of global spinal alignment and APA and GLA, respectively, and are geometrically complementary angles that vary proportionately to SSD and balance the body. APA and GLA increase in SSD patients with lower extremity compensation and decrease with corrective surgery. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: APA and GLA offer a concise and simple method of communicating pelvic and lower extremity compensation.

Complications After Adult Spinal Deformity Surgeries: All Are Not Created Equal.

BACKGROUND: Data on timing of complications are important for accurate quality assessments. We sought to better define pre- and postdischarge complications occurring within 90 days of adult spinal deformity (ASD) surgery and quantify the effect of multiple complications on recovery. METHODS: We performed a review of 1040 patients who underwent ASD surgery (age: 46 ± 23; body mass index: 25 ± 7, American Society of Anesthesiologists [ASA] score: 2.5 ± 0.6, levels: 10 ± 4, revision: 9%, 3-column osteotomy: 13%). We assessed pre- and postdischarge complications and risk factors for isolated versus multiple complications, as well as the impact of multiple complications. RESULTS: The 90-day complication rate was 17.7%. 85 patients (8.2%) developed a predischarge complication, most commonly ileus (12%), and pulmonary embolism (PE; 7.1%). The most common causes of predischarge unplanned reoperation were neurologic injury (12.9%) and surgical site drainage (8.2%). Predictors of a predischarge complication included smoking (odds ratio [OR]: 2.2, P = .02), higher ASA (OR: 1.8, P = .008), hypertension (HTN; OR: 2.0, P = .004), and iliac fixation (OR: 4.3, P < .001). Ninety-nine patients (9.5%) developed a postdischarge complication, most commonly infection (34%), instrumentation failure (13.4%), and proximal junctional failure (10.4%). Predictors of postdischarge complications included chronic obstructive pulmonary disease (OR: 3.6, P < .0001), congestive heart failure (OR: 4.4, P = .016), HTN (OR: 2.3, P < .0001), and multiple rod construct (OR: 1.8, P = .02). Patients who developed multiple complications (9.3%) had a longer length of stay, and increased risk for readmission and unplanned reoperation. CONCLUSIONS: Knowledge regarding timing of postoperative complications in relation to discharge may better inform quality improvement measures. PE and implant-related complications play a prominent role in perioperative complications and need for readmission, with several modifiable risk factors identified. LEVEL OF EVIDENCE: Level 3. CLINICAL RELEVANCE: Advances in surgical techniques and instrumentation have improved postoperative radiographic and clinical outcomes after ASD surgery. The rate of complications after complex ASD surgery remains high, both at early postoperative and long term follow-up. This study reviews complications within 90 days of surgery, with an assessment of patient and surgical risk factors. We found that modifiable risk factors for early complications after ASD surgery include COPD, and current smoking. The data presented in this study also provide surgeons with knowledge of the most common complications encountered after ASD surgery, to aid in preoperative patient discussion.

Residual lumbar hyperlordosis is associated with worsened hip status 5 years after scoliosis correction in non-ambulant patients with cerebral palsy.

BACKGROUND: Cerebral palsy (CP) is a static encephalopathy with progressive musculoskeletal pathology. Non-ambulant children (GMFCS IV and V) with CP have high rates of spastic hip disease and neuromuscular scoliosis. The effect of spinal fusion and spinal deformity on hip dislocation following total hip arthroplasty has been well studied, however in CP this remains largely unknown. This study aimed to identify factors associated with worsening postoperative hip status (WHS) following corrective spinal fusion in children with GMFCS IV and V CP. METHODS: Retrospective review of GMFSC IV and V CP patients in a prospective multicenter database undergoing spinal fusion, with 5 years follow-up. WHS was determined by permutations of baseline (BL), 1 year, 2 years, and 5 years hip status and defined by a change from an enlocated hip at BL that became subluxated, dislocated or resected post-op, or a subluxated hip that became dislocated or resected. Hip status was analyzed against patient demographics, hip position, surgical variables, and coronal and sagittal spinal alignment parameters. Cutoff values for parameters at which the relationship with hip status was significant was determined using receiver operating characteristic curves. Logistic regression determined odds ratios for predictors of WHS. RESULTS: Eighty four patients were included. 37 (44%) had WHS postoperatively. ROC analysis and logistic regression demonstrated that the only spinopelvic alignment parameter that significantly correlated with WHS was lumbar hyperlordosis (T12-L5) > 60° (p = 0.028), OR = 2.77 (CI 1.10-6.94). All patients showed an increase in pre-to-postop LL. Change in LL pre-to-postop was no different between groups (p = 0.318), however the WHS group was more lordotic at BL and postop (pre44°/post58° vs pre32°/post51° in the no change group). Age, sex, Risser, hip position, levels fused, coronal parameters, global sagittal alignment (SVA), thoracic kyphosis, and reoperation were not associated with WHS. CONCLUSION: Postoperative hyperlordosis(> 60°) is a risk factor for WHS at 5 years after spinal fusion in non-ambulant CP patients. WHS likely relates to anterior pelvic tilt and functional acetabular retroversion due to hyperlordosis, as well as loss of protective lumbopelvic motion causing anterior femoracetabular impingement. LEVEL OF EVIDENCE: III.

Age and Gender Confound PROMIS Scores in Spine Patients With Back and Neck Pain.

STUDY DESIGN: This was a single-center retrospective review. OBJECTIVES: To explore how age and gender affect PROMIS scores compared with traditional health-related quality of life (HRQL) in spine patients. METHODS: Patients presenting with a primary complaint of back pain (BP) or neck pain (NP) were included. Legacy HRQLs were Oswestry Disability Index (ODI), Neck Disability Index (NDI), and Visual Analogue Scale (VAS). PROMIS Physical Function (PF), Pain Intensity (Int), and Pain Interference (Inf) were also administered to patients in a clinical setting. Patients were grouped by chief complaint, age (18-44, 45-64, 65+ years) and gender. Two parallel analyses were conducted to identify the effects of age and gender on patient-reported outcomes. Age groups were compared after propensity-score matching by VAS-pain and gender. Separately, genders were compared after propensity-score matching by age and VAS-pain. RESULTS: A total of 484 BP and 128 NP patients were matched into gender cohorts (n = 201 in each BP group, 46 in each NP group). Among BP patients, female patients demonstrated worse disability by ODI (44.15 vs 38.45, P = .005); PROMIS-PF did not differ by gender. Among NP patients, neither legacy HRQLs nor PROMIS differed by gender when controlling for NP and age. BP and NP patients were matched into age cohorts (n = 135 in each BP group and n = 14 in each BP group). Among BP patients, ANOVA revealed differences between groups when controlling for BP and gender: ODI (P < .001), PROMIS-PF (P = .018), PROMIS-Int (P < .001) PROMIS-Inf (P < .001). Among NP patients, matched age groups differed significantly in terms of NDI (P = .032) and PROMIS-PF (P = .022) but not PROMIS-Int or PROMIS-Inf. CONCLUSIONS: Age and gender confound traditional HRQLs as well as PROMIS domains. However, PROMIS offers age and gender-specific scores, which traditional HRQLs lack.

Characteristics and Trends of the Most Cited Spine Publications.

STUDY DESIGN: Bibliometric literature review. OBJECTIVE: The aim of this study was to recognize and analyze the most frequently cited manuscripts published in the journal Spine. SUMMARY OF BACKGROUND DATA: Although the journal Spine is considered a premiere location for distributing influential spine research, no previous study has evaluated which of their publications have had the most impact. Knowledge and appreciation of the most influential Spine publications can guide and inspire future research endeavors. METHODS: Using the Scopus database, the 100 most cited articles published in Spine were accessed. The frequency of citations, year of publication, country of origin, level-of-evidence (LOE), article type, and contributing authors/institutions were recorded. The 10 most cited articles (per year) from the past decade were also determined. RESULTS: "Guidelines For The Process Of Cross-Cultural Adaptation Of Self-Report Measures" by Beaton DE was the most cited article with 2960 citations. 2000 to 2009 (n = 46) was the most productive period. A LOE of III (n = 35) followed by II (n = 34) were the most common. Deyo RA (n = 8), Bombardier C (n = 6), and Waddell G (n = 6) produced the most articles. University of Washington (n = 8) and University of Toronto (n = 8) ranked first for institutional output. Clinical Outcome (n = 28) was the most recurring article topic. The United States (n = 51) ranked first for country of origin. CONCLUSION: Using citation analysis as an objective proxy for influence, certain publications can be distinguished from others due to their lasting impact and recognition from peers. Of the top cited Spine publications, many pertained to clinical outcomes (28%) and had a LOE of I, II, or III (60%). Although older publications have had longer time to accrue citations, those in the most recent decade comprise this list almost 2:1. Knowledge of these "classic" publications allows for a better overall understanding of the diagnosis, management, and future direction of spine health care.Level of Evidence: 3.

The Relationship Between 3-dimensional Spinal Alignment, Thoracic Volume, and Pulmonary Function in Surgical Correction of Adolescent Idiopathic Scoliosis: A 5-year Follow-up Study.

STUDY DESIGN: Retrospective review of a prospective multicenter database. OBJECTIVE: The aim of this study was to study the effects of thoracic kyphosis (TK) restoration in adolescent idiopathic scoliosis (AIS) Type 1 and 2 curves on postoperative thoracic volume (TV) and pulmonary function. SUMMARY OF BACKGROUND DATA: Surgical correction of AIS is advocated to preserve or improve pulmonary function, prevent progressive deformity and pain, and improve self-appearance. Restoration of sagittal and 3D alignment, particularly TK, has become increasingly emphasized in efforts to improve pulmonary function, TVs, sagittal balance, and prevent adjacent-segment degeneration and deformity. METHODS: AIS patients 10 to 21years undergoing surgical correction of Lenke Type 1 and 2 curves with baseline, 1-erect-postoperative, and 5-year (5Y) postoperative visits including stereoradiographic assessment and pulmonary function tests (PFTs) were included. 3D-radiographic analysis was performed to assess spinal-alignment, chest-wall, and rib-cage dimensions at each time point. Outcome variables were analyzed between time points with one-way analysis of variance and between variables with linear regression analysis. RESULTS: Thirty-nine patients (37 females, 14.4 ± 2.2 years) were included. 3D-spinal-alignment analyses demonstrated significant reduction in preoperative to first-erect thoracic and lumbar Cobb-angles, an increase in TK:T2-12 (19.67°-39.69°) and TK:T5-12 (9.47°-28.05°), and reduction in apical vertebral rotation (AVR) (P < 0.001 for all). Spinal-alignment remained stable from 1-erect to 5Y. 3D rib-cage analysis demonstrated small reductions in baseline to first-erect depth (145-139 mm), width (235-232 mm), and increase in height (219-230 mm, P < 0.01), but no significant change in volume (5161-5222 cm,P = 0.184). From 1-erect to 5Y, significant increases in depth, width, height, and volume (all P < 0.001) occurred. PFTs showed preoperative to 5Y improvement in first second of Forced Expiratory Volume (FEV1) (2.74-2.98 L, P = 0.005) and forced vital capacity (FVC) (3.23-3.47 L, P = 0.008); however, total lung capacity (TLC) did not change (P = 0.517). Percent-predicted TLC decreased (Pre: 101.3% to 5Y: 89.3%, P < 0.001); however, percent-predicted forced expiratory volume and FVC did not (P = 0.112 and P = 0.068). CONCLUSION: Although TK increases, coronal-Cobb and AVR decrease postoperatively; these do not directly influence TV, which increases from 1-erect to 5Y due to growth, corresponding with increases in FEV1 and FVC at 5Y; however, surgical restoration of kyphosis does not directly improve pulmonary function. LEVEL OF EVIDENCE: 3.

Efficacy of intraoperative cell salvage in spine surgery: a meta-analysis.

OBJECTIVE: Intraoperative cell salvage systems, or cell savers, are widely used for the management of blood loss in patients undergoing spine surgery. However, recent studies report conflicting evidence of their efficacy. The purpose of the meta-analysis was to investigate the efficacy of cell savers in reducing blood transfusion requirements in patients undergoing spine surgery. METHODS: Both retrospective and prospective studies that investigated the efficacy of cell savers in reducing transfusion requirements in spine surgery patients when compared with control patients were identified from MEDLINE, Embase, Cochrane Collaboration Library, Google Scholar, and Scopus databases. Outcome data extracted included number of patients receiving allogenic transfusions (transfusion rate); units of allogenic transfusions; postoperative hemoglobin; costs; operative time; and complications. RevMan 5 software was used to perform statistical analyses. A random-effects model was used to calculate pooled odds ratios (with 95% CIs) and weighted mean differences (WMDs [95% CI]) for dichotomous and continuous variables, respectively. RESULTS: Eighteen studies with 2815 patients in total were included in the meta-analysis. During spine surgery, the use of intraoperative cell salvage did not reduce the intraoperative (OR 0.66 [95% CI 0.30, 1.41]), postoperative (OR -0.57 [95% CI 0.20, 1.59]), or total transfusion (OR 0.92 [95% CI 0.43, 1.98]) rate. There was a reduction in the number of allogenic units transfused intraoperatively by a mean of 0.81 (95% CI -1.15, -0.48). However, there were no differences in the number of units transfused postoperatively (WMD -0.02 [95% CI -0.41, 0.38]) or the total units transfused (WMD 0.08 [95% CI -1.06, 1.22]). There were also no differences in operative time (WMD 19.36 [95% CI -2.43, 42.15]) or complications reported (OR 0.79 [95% CI 0.46, 1.37]) between groups. A difference in postoperative hemoglobin (WMD 0.54 [95% CI 0.11, 0.98]) between both groups was observed. CONCLUSIONS: Cell saver is efficacious at reducing intraoperative allogenic units transfused. There is no difference in transfusion rates, postoperative units transfused, and the total number of units transfused. Further cost analysis studies are necessary to evaluate the cost-effectiveness of this method of blood conservation.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: meta-analysis; strength of recommendation: low.

Decision Tree-based Modelling for Identification of Predictors of Blood Loss and Transfusion Requirement After Adult Spinal Deformity Surgery.

BACKGROUND: Multilevel fusions and complex osteotomies to restore global alignment in adult spinal deformity (ASD) surgery can lead to increased operative time and blood loss. In this regard, we assessed factors predictive of perioperative blood product transfusion in patients undergoing long posterior spinal fusion for ASD. METHODS: A single-institution retrospective review was conducted on 909 patients with ASD, age > 18 years, who underwent surgery for ASD with greater than 4 levels fused. Using conditional inference tree analysis, a machine learning methodology, we sought to predict the combination of variables that best predicted increased risk for intraoperative percent blood volume lost and perioperative blood product transfusion. RESULTS: Among the 909 patients included in the study, 377 (41.5%) received red blood cell (RBC) transfusion. The conditional inference tree analysis identified greater than 13 levels fused, American Society of Anesthesiologists (ASA) score > 1, a history of hypertension, 3-column osteotomy, pelvic fixation, and operative time > 8 hours, as significant risk factors for perioperative RBC transfusion. The best predictors for the subgroup with the highest risk for intraoperative percent blood volume lost (subgroup mean: 53.1% ± 42.9%) were greater than 13 levels fused, ASA score > 1, preoperative hemoglobin < 13.6 g/dL, 3-column osteotomy, posterior column osteotomy, and pelvic fixation. Patients who underwent major blood transfusion intraoperatively had significantly longer length of stay (8.5 days) versus those who did not (6.1 days) (P < .0001). The overall 90-day complication rate in patients who underwent major blood transfusion intraoperatively was 49%, compared with 19% in those who did not (P < .0001). By multivariate regression analysis, patients with a preoperative hemoglobin > 13.0 were less likely to require major blood transfusion (odds ratio: 0.52, P = .046). CONCLUSIONS: Using a supervised learning technique, this study demonstrates that greater than 13 levels fused, ASA score > 1, 3-column osteotomy, and pelvic fixation are consistent risk factors for increased intraoperative percent blood volume lost and perioperative RBC transfusion. The addition of having a preoperative hemoglobin < 13.6 g/dL or undergoing a posterior column osteotomy conferred the highest risk for intraoperative blood loss. This information can assist spinal deformity surgeons in identifying at-risk individuals and allocating healthcare resources. LEVEL OF EVIDENCE: 3.

PROMIS is superior to established outcome measures in capturing disability resulting from sagittal malalignment in patients with back pain.

INTRODUCTION: Patient reported outcomes measurement information system (PROMIS) is a quality of life metric that has gained increased popularity due to computer adaptive testing. Previous studies have shown that PROMIS correlates with Oswestry Disability Index (ODI) in patients with back pain and takes significantly less time to complete. However, the ability of PROMIS to capture disability from spinal malalignment relative to established metrics is unknown. The aim of the present study is to validate the correlation between ODI and PROMIS in patients with back pain, analyze correlations of PROMIS and legacy metrics to sagittal alignment, and identify major drivers of PROMIS scores and ODI in patients with back pain. METHODS: A retrospective review was conducted of a prospectively collected outcome measures database (PROMIS, ODI, VAS Back, VAS Leg, VAS Neck, and VAS Arm) of spine patients > 18 years. Inclusion criteria for the present study was a chief complaint of back pain and full length weight bearing X-rays within 30 days of health related quality of life (HRQL) completion. Demographic information, radiographic alignment, psychiatric diagnoses, and comorbidities were recorded. PROMIS metrics were correlated to legacy metrics (ODI and VAS). Next, outcome metrics were correlated with sagittal alignment variables T1 Pelvic Angle (TPA), SVA, PT, and PI-LL. Patients were grouped based on the presence of spinal deformity (defined radiographically as any one of SVA > 4 cm, PI-LL > 10°, PT > 20°) and mean HRQL scores were investigated for the adult spinal deformity (ASD) and non-ASD groups. Finally, drivers of PROMIS PF scores and ODI scores were determined using multiple stepwise regression. RESULTS: 150 patients met inclusion criteria including 60 patients with ASD and 90 patients without. For the whole cohort, PROMIS PF correlated with ODI (r = - 0.651, p < 0.001), VAS Back (r = - 0.260, p = 0.014) and Charleson Comorbidity Index (r = - 0.336, p < 0.001). PROMIS PF had higher correlations than ODI for each sagittal alignment parameter tested, including TPA, SVA, PT, and PI-LL. When patients with ASD were compared to non-ASD patients, the PROMIS score was different between the groups but the ODI and VAS scores were not. Finally, stepwise linear regression showed that SVA, PI-LL, and VAS Leg were significant drivers of PROMIS PF (r2 = 0.406, p < 0.001). VAS Leg and VAS Back were significant contributors to ODI (r2 = 0.376, p < 0.001). CONCLUSIONS: In a cohort of 150 patients with back pain, PROMIS correlated strongly with legacy outcome metrics, including VAS and ODI. PROMIS PF correlated more strongly with sagittal malalignment than ODI. Additionally, patients with spinal deformity had significantly worse PROMIS PF scores but similar ODI scores as patients without ASD. Finally, sagittal alignment was found to be a significant driver of PROMIS PF scores but not ODI scores. PROMIS PF should be utilized as a disability assessment tool in patients with spinal deformity due to ease of use, strong correlations with legacy metrics, and ability to capture disability resulting from sagittal alignment.

Predictors of long-term opioid dependence in transforaminal lumbar interbody fusion with a focus on pre-operative opioid usage.

PURPOSE: Predictors of long-term opioid usage in TLIF patients have not been previously explored in the literature. We examined the effect of pre-operative narcotic use in addition to other predictors of the pattern and duration of post-operative narcotic usage. METHODS: We conducted a retrospective cohort study at a single academic institution of patients undergoing a one- or two-level primary TLIF between 2014 and 2017. Total oral morphine milligram equivalents (MMEs) for inpatient use were calculated and used as the common unit of comparison. RESULTS: A multivariate binary logistic regression (R2 = 0.547, specificity 95%, sensitivity 58%) demonstrated that a psychiatric or chronic pain diagnosis (OR 3.95, p = 0.013, 95% CI 1.34-11.6), pre-operative opioid use (OR 8.65, p < 0.001, 95% CI 2.59-29.0), ASA class (OR 2.95, p = 0.025, 95% CI 1.14-7.63), and inpatient total MME (1.002, p < 0.001, 95% CI 1.001-1.003) were positive predictors of prolonged opioid use at 6-month follow-up, while inpatient muscle relaxant use (OR 0.327, p = 0.049, 95% CI 0.108-0.994) decreased the probability of prolonged opioid use. Patients in the pre-operative opioid use group had a significantly higher rate of opioid usage at 6 weeks (79% vs. 46%, p < 0.001), 3 months (51% vs. 14%, p < 0.001), and 6 months (40% vs. 5%, p < 0.001). CONCLUSIONS: Pre-operative opioid usage is associated with higher total inpatient opioid use and a significantly higher risk of long-term opiate usage at 6 months. Approximately 40% of pre-operative narcotic users will continue to consume narcotics at 6-month follow-up, compared with 5% of narcotic-naïve patients. These slides can be retrieved under Electronic Supplementary Material.

MRI Radiological Predictors of Requiring Microscopic Lumbar Discectomy After Lumbar Disc Herniation.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate radiological differences in lumbar disc herniations (herniated nucleus pulposus [HNP]) between patients receiving microscopic lumbar discectomy (MLD) and nonoperative patients. METHODS: Patients with primary treatment for an HNP at a single academic institution between November 2012 to March 2017 were divided into MLD and nonoperative treatment groups. Using magnetic resonance imaging (MRI), axial HNP area; axial canal area; HNP canal compromise; HNP cephalad/caudal migration and HNP MRI signal (black, gray, or mixed) were measured. T test and chi-square analyses compared differences in the groups, binary logistic regression analysis determined odds ratios (ORs), and decision tree analysis compared the cutoff values for risk factors. RESULTS: A total of 285 patients (78 MLD, 207 nonoperative) were included. Risk factors for MLD treatment included larger axial HNP area (P < .01, OR = 1.01), caudal migration, and migration magnitude (P < .05, OR = 1.90; P < .01, OR = 1.14), and gray HNP MRI signal (P < .01, OR = 5.42). Cutoff values for risks included axial HNP area (70.52 mm2, OR = 2.66, P < .01), HNP canal compromise (20.0%, OR = 3.29, P < .01), and cephalad/caudal migration (6.8 mm, OR = 2.43, P < .01). MLD risk for those with gray HNP MRI signal (67.6% alone) increased when combined with axial HNP area >70.52 mm2 (75.5%, P = .01) and HNP canal compromise >20.0% (71.1%, P = .05) cutoffs. MLD risk in patients with cephalad/caudal migration >6.8 mm (40.5% alone) increased when combined with axial HNP area and HNP canal compromise (52.4%, 50%; P < .01). CONCLUSION: Patients who underwent MLD treatment had significantly different axial HNP area, frequency of caudal migration, magnitude of cephalad/caudal migration, and disc herniation MRI signal compared to patients with nonoperative treatment.

Implementation and early adaptation of patient-reported outcome measures into an electronic health record: A technical report.

We integrated and optimized patient-reported outcome measures into the electronic health record to provide quantitative, objective data regarding patients' health status, which is important for patient care, payer contracts, and research. With a multidisciplinary team from information technology, clinical informatics, population health, and physician champions, we used formal human-computer interaction techniques and user-centered design to integrate several technology platforms and computerized adaptive testing for the National Institutes of Health Patient-Reported Outcomes Measurement Information System. The patient-reported outcome measure system leverages software frequently used by health systems and provides data for research and clinical care via a mobile-responsive web application using Symfony, with REDCap for configuring assessments and de-identified data storage. The system incorporates Oracle databases and Epic flowsheets. Patients complete patient-reported outcome measures, with data viewable in MyChart and Epic Synopsis Reports. Researchers can access data portals. The highly usable, successful patient-reported outcome measures platform is acceptable to patients and clinicians and achieved 73 percent overall completion rates.

Validation of the recently developed Total Disability Index: a single measure of disability in neck and back pain patients.

OBJECTIVE: Neck and back pain are highly prevalent conditions that account for major disability. The Neck Disability Index (NDI) and Oswestry Disability Index (ODI) are the two most common functional status measures for neck and back pain. However, no single instrument exists to evaluate patients with concurrent neck and back pain. The recently developed Total Disability Index (TDI) combines overlapping elements from the ODI and NDI with the unique items from each. This study aimed to prospectively validate the TDI in patients with spinal deformity, back pain, and/or neck pain. METHODS: This study is a retrospective review of prospectively collected data from a single center. The 14-item TDI, derived from ODI and NDI domains, was administered to consecutive patients presenting to a spine practice. Patients were assessed using the ODI, NDI, and EQ-5D. Validation of internal consistency, test-retest reproducibility, and validity of reconstructed NDI and ODI scores derived from TDI were assessed. RESULTS: A total of 252 patients (mean age 55 years, 56% female) completed initial assessments (back pain, n = 115; neck pain, n = 52; back and neck pain, n = 55; spinal deformity, n = 55; and no pain/deformity, n = 29). Of these patients, 155 completed retests within 14 days. Patients represented a wide range of disability (mean ODI score: 36.3 ± 21.6; NDI score: 30.8 ± 21.8; and TDI score: 34.1 ± 20.0). TDI demonstrated excellent internal consistency (Cronbach's alpha = 0.922) and test-retest reliability (intraclass correlation coefficient = 0.96). Differences between actual and reconstructed scores were not clinically significant. Subanalyses demonstrated TDI's ability to quantify the degree of disability due to back or neck pain in patients complaining of pain in both regions. CONCLUSIONS: The TDI is a valid and reliable disability measure in patients with back and/or neck pain and can capture each spine region's contribution to total disability. The TDI could be a valuable method for total spine assessment in a clinical setting, and its completion is less time consuming than that for both the ODI and NDI.

Minimally Invasive Versus Open Transforaminal Lumbar Interbody Fusion Surgery: An Analysis of Opioids, Nonopioid Analgesics, and Perioperative Characteristics.

STUDY DESIGN: Retrospective study of consecutive patients at a single institution.Objective: Examine the effect of minimally invasive surgery (MIS) versus open transforaminal lumbar interbody fusion (TLIF) surgery on long-term postoperative narcotic consumption. OBJECTIVE: Examine the effect of minimally invasive versus open TLIF on short-term postoperative narcotic consumption. METHODS: Differences between MIS and open TLIF, including inpatient opioid and nonopioid analgesic use, discharge opioid use, and postdischarge duration of narcotic usage were compared using appropriate statistical methods. RESULTS: A total of 172 patients (109 open; 63 MIS) underwent primary TLIF. There was no difference in baseline characteristics. The MIS TLIF cohort had a significantly shorter operative time (223 vs 251 min, P = .006) and length of stay (2.7 vs 3.7 days, P < .001) as well as less estimated blood loss (184 vs 648 mL, P < .001). MIS TLIF had significantly less total inpatient opioid usage (167 vs 255 morphine milligram equivalent [MME], P = .006) and inpatient oxycodone usage (71 vs 105 mg, P = .049). Open TLIF cases required more ongoing opiate usage at 3-month follow-up (36% open vs 21% MIS, P = .041). A subanalysis found that patients who underwent an open TLIF with a history of preoperative opioid use are significantly more likely to remain on opioids at 6-week follow-up (87% vs 65%, P = .027), 3-month follow-up (63% vs 31%, P = .008), and 6-month follow-up (50% vs 21%, P = .018) compared with MIS TLIF. CONCLUSION: Patients undergoing MIS TLIF required less inpatient opioids and had a decreased incidence of opioid dependence at 3-month follow-up. Patients with preoperative opioid use undergoing MIS TLIF are less likely to require long-term opioids.