Faculty Bibliography

Background/UNASSIGNED:Risk of death is important in counseling patients and improving quality of care. Incidence of death in cervical surgery is not firmly established due to its rarity and limited sample sizes, particularly in the context of different surgeries, demographics, and risk factors. Particularly, different patient risk profiles may have varying degrees of risk in terms of surgeries, comorbidities, and demographics. This study aims to use a large patient cohort available on a national database to study the prevalence of death associated with cervical spine surgery. Methods/UNASSIGNED:< .05 differences relative to overall cohort. Results/UNASSIGNED:< .001. Conclusion/UNASSIGNED:In 342 477 cervical spine surgery patients an overall mortality rate of 0.32% was reported. The rate was 3.91% in a cohort of 5933 patients with congestive heart failure and 3.79% in a cohort of 6947 patients with paraplegia. These findings are consistent with previous estimates and may help counsel patients and improve in-hospital safety. Level of Evidence/UNASSIGNED:3.

Background/UNASSIGNED:Effects of nonoperative treatments on surgical outcomes for patients who failed conservative management for cervical spine pathologies remain unknown. The objective is to describe conservative modality use in patients indicated for surgery for degenerative cervical spine conditions and its impact on perioperative outcomes. Methods/UNASSIGNED:tests were performed to determine differences between groups and impact on outcomes. Results/UNASSIGNED: < .05). Conclusions/UNASSIGNED:Radiculopathy patients receiving epidurals returned to work after 1 year more frequently. PT was associated with shorter hospitalizations, greater SF-36 bodily pain norm and physical component score improvements, and increased return-to-work rates after 1 and 2 years. No statistically significant nonoperative treatment was associated with return-to-work rate in myelopathy patients. Clinical Relevance/UNASSIGNED:These findings suggest certain preoperative conservative treatment modalities are associated with improved outcomes in radiculopathy patients.

STUDY DESIGN/METHODS:Consensus-building using the Delphi and nominal group technique. OBJECTIVE:To establish best practice guidelines using formal techniques of consensus building among a group of experienced spinal deformity surgeons to avert wrong-level spinal deformity surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Numerous previous studies have demonstrated that wrong-level spinal deformity occurs at a substantial rate, with more than half of all spine surgeons reporting direct or indirect experience operating on the wrong levels. Nevertheless, currently, guidelines to avert wrong-level spinal deformity surgery have not been developed. METHODS:The Delphi process and nominal group technique were used to formally derive consensus among 16 fellowship-trained spine surgeons. Surgeons were surveyed for current practices, presented with the results of a systematic review, and asked to vote anonymously for or against item inclusion during three iterative rounds. Agreement of 80% or higher was considered consensus. Items near consensus (70% to 80% agreement) were probed in detail using the nominal group technique in a facilitated group meeting. RESULTS:Participants had a mean of 13.4 years of practice (range: 2-32 years) and 103.1 (range: 50-250) annual spinal deformity surgeries, with a combined total of 24,200 procedures. Consensus was reached for the creation of best practice guidelines (BPGs) consisting of 17 interventions to avert wrong-level surgery. A final checklist consisting of preoperative and intraoperative methods, including standardized vertebral-level counting and optimal imaging criteria, was supported by 100% of participants. CONCLUSION/CONCLUSIONS:We developed consensus-based best practice guidelines for the prevention of wrong-vertebral-level surgery. This can serve as a tool to reduce the variability in preoperative and intraoperative practices and guide research regarding the effectiveness of such interventions on the incidence of wrong-level surgery. LEVEL OF EVIDENCE/METHODS:Level V.

Minimally invasive surgical (MIS) techniques offer promising improvements in the management of thoracolumbar trauma. Recent advances in MIS techniques and instrumentation for degenerative conditions have heralded a growing interest in employing these techniques for thoracolumbar trauma. Specifically, surgeons have applied these techniques to help manage flexion- and extension-distraction injuries, neurologically intact burst fractures, and cases of damage control. Minimally invasive surgical techniques offer a means to decrease blood loss, shorten operative time, reduce infection risk, and shorten hospital stays. Herein, we review thoracolumbar minimally invasive surgery with an emphasis on thoracolumbar trauma classification, minimally invasive spinal stabilization, surgical indications, patient outcomes, technical considerations, and potential complications.

Background/UNASSIGNED:Chiari malformations type 1 (CM-1), a developmental anomaly of the posterior fossa, usually presents in adolescence or early adulthood. There are few studies on the national incidence of CM-1, taking into account outcomes based on concurrent diagnoses. To quantify trends in treatment and associated diagnoses, as retrospective review of the Kid's Inpatient Database (KID) from 2003-2012 was conducted. Methods/UNASSIGNED:-tests for categorical and numerical variables, respectively. Trends in diagnosis, treatments, and outcomes were analyzed using analysis of variance (ANOVA). Results/UNASSIGNED:4.7%). Seven point four percent of patients experienced at least one peri-operative complication (nervous system, dysphagia, respiratory most common). Patients with concurrent hydrocephalus had increased; nervous system, respiratory and urinary complications (P<0.006) and syringomyelia increased the rate of respiratory complications (P=0.037). Conclusions/UNASSIGNED:CM-1 diagnoses have increased in the last decade. Despite the decrease in overall complication rates, fusions are becoming more common and are associated with higher peri-operative complication rates. Commonly associated diagnoses including syringomyelia and hydrocephalus, can dramatically increase complication rates.

BACKGROUND: Adult cervical deformity (ACD) classifications have not been implemented in a prospective ACD population and in conjunction with adult spinal deformity (ASD) classifications. OBJECTIVE: To characterize cervical deformity type and malalignment with 2 classifications (Ames-ACD and Schwab-ASD). METHODS: Retrospective review of a prospective multicenter ACD database. Inclusion: patients >/=18 yr with pre- and postoperative radiographs. Patients were classified with Ames-ACD and Schwab-ASD schemes. Ames-ACD descriptors (C = cervical, CT = cervicothoracic, T = thoracic, S = coronal, CVJ = craniovertebral) and alignment modifiers (cervical sagittal vertical axis [cSVA], T1 slope minus cervical lordosis [TS-CL], modified Japanese Ortphopaedic Association [mJOA] score, horizontal gaze) were assigned. Schwab-ASD curve type stratification and modifier grades were also designated. Deformity and alignment group distributions were compared with Pearson chi 2 /ANOVA. RESULTS: Ames-ACD descriptors in 84 patients: C = 49 (58.3%), CT = 20 (23.8%), T = 9 (10.7%), S = 6 (7.1%). cSVA modifier grades differed in C, CT, and T deformities ( P < .019). In C, TS-CL grade prevalence differed ( P = .031). Among Ames-ACD modifiers, high (1+2) cSVA grades differed across deformities (C = 47.7%, CT = 89.5%, T = 77.8%, S = 50.0%, P = .013). Schwab-ASD curve type and presence (n = 74, T = 2, L = 6, D = 2) differed significantly in S deformities ( P < .001). Higher Schwab-ASD pelvic incidence minus lumbar lordosis grades were less likely in Ames-ACD CT deformities ( P = .027). Higher pelvic tilt grades were greater in high (1+2) cSVA (71.4% vs 36.0%, P = .015) and high (2+3) mJOA (24.0% vs 38.1%, P = .021) scores. Postoperatively, C and CT deformities had a trend toward lower cSVA grades, but only C deformities differed in TS-CL grade prevalence (0 = 31.3%, 1 = 12.2%, 2 = 56.1%, P = .007). CONCLUSION: Cervical deformities displayed higher TS-CL grades and different cSVA grade distributions. Preoperative associations with global alignment modifiers and Ames-ACD descriptors were observed, though only cervical modifiers showed postoperative differences.

BACKGROUND: Global sagittal deformity is an established cause of disability. However, measurements of sagittal alignment are often ignored when patients present with symptoms localizing to the cervical or lumbar spine. OBJECTIVE: To develop scoring scales to predict the risk of sagittal malalignment in patients with only cervical or lumbar spine radiographs. METHODS: A retrospective review of a prospectively maintained multicenter adult spinal deformity database was performed. Primary outcome (sagittal malalignment) was defined as a C7 plumbline >/= 50 mm. Two multivariate logistic regressions were performed using patient characteristics and measurements derived from cervical or lumbar radiographs as covariates. Point scores were assigned to age, body mass index (BMI), and lumbar lordosis or T1 slope by rounding their ss coefficients to the nearest integer. RESULTS: Nine hundred seventy-nine patients were included, with 652 randomly assigned to the derivation cohort (used to build the score) and 327 comprising the validation set. Final cervical score for the primary outcome included BMI >/= 25 (1 point), age >/= 55 yr (2 points), and T1 slope >/= 27 o (2 points). Final lumbar score for the primary outcome included BMI >/= 25 (1 point), age >/= 55 yr (1 point), and lumbar lordosis >/= 45 o (-1 points). High scores for both the cervical and lumbar spine presented with high specificity and positive likelihood ratios of sagittal malalignment. CONCLUSION: We developed scoring scales to predict global sagittal malalignment utilizing clinical covariates and cervical or lumbar radiographs. Patients with high scores may prompt imaging with long-cassette plain films to evaluate for global sagittal imbalance.

PURPOSE: A comprehensive understanding of normative sagittal profile is necessary for adult spinal deformity. Roussouly described four sagittal alignment types based on sacral slope, lumbar lordosis, and location of lumbar apex. However, the lower limb, a newly described component of spinal malalignment compensation, is missing from this classification. This study aims to propose a full-body sagittal profile classification in an asymptomatic population based on full-body imaging. METHODS: This is a retrospective analysis of a prospective single-center study of 116 asymptomatic volunteers. Cluster analysis including all sagittal parameters was first performed, and then ANOVA was performed between sub-clusters to eliminate the non-significantly different parameters. This loop was repeated until all parameters were significantly different between each sub-cluster. RESULTS: Three types of full-body sagittal profiles were finalized according to cluster analysis with ten radiographic parameters: hyperlordosis type (77 subjects), neutral type (28 subjects), and compensated type (11 subjects). Radiographic parameters included knee angle, pelvic shift, pelvic angle, PT, PI-LL, C7-S1 SVA, TPA, T1 slope, C2-C7 angle, and C2-C7 SVA. Age was significantly different across compensation types, while BMI and gender were comparable. Age-matched subjects were randomly selected with 11 subjects in each type. ANOVA analysis revealed that all parameters but PT and C2-C7 angle remained significantly different. CONCLUSIONS: The current three compensation types of full-body sagittal profiles in asymptomatic adults included significant changes from cervical region to knee, indicating that subjects should be evaluated with full-length imaging. All three types exist regardless of age, but the distribution may vary.

BACKGROUND CONTEXT: Non-operative management is a common initial treatment for adult spinal deformity (ASD) patients despite reported superiority of surgery with regard to outcomes. Ineffective medical care is a large source of resource drain on the health system. Characterization of ASD patients likely to elect for operative treatment from nonoperative management may allow for more efficient patient counseling and cost savings. PURPOSE: To identify deformity and disability characteristics of ASD patients that ultimately convert to operative treatment compared to those that remain non-operative and those that initially choose surgery. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: 510 ASD patients (189 non-operative, 321 operative) with minimum 2-year follow-up. OUTCOME MEASURES: Oswestry Disability Index (ODI), Short-Form 36 Health Assessment (SF-36), Scoliosis Research Society questionnaire (SRS-22r), and spino-pelvic radiographic alignment. METHODS: Demographic, radiographic and patient-reported outcome measures (PROMs) from a cohort of ASD patients prospectively enrolled into a multi-center database were evaluated. Patients were divided into 3 treatment cohorts: Non-operative (NON=initial non-operative treatment and remained non-operative), Operative (OP=initial operative treatment), and Crossover (CROSS=initial non-operative treatment with subsequent conversion to operative treatment). NON and OP groups were propensity score matched (PSM) to CROSS for to baseline demographics (age, BMI, CCI). Time to crossover was divided into early (<1yr) and late ( >1yr). Outcome measures were compared across and within treatment groups at 4 time points (baseline, 6-week, 1-, and 2-years). RESULTS: Following PSM, 118 patients were included (NON=39, OP=38, CROSS=41). Crossover rate was 21.7% (41/189). Mean time to crossover was 394 days. All groups had similar baseline sagittal alignment, but CROSS had larger PI-LL mismatch than NON (11.9 degrees vs. 3.1 degrees , p=0.032). CROSS and OP had similar baseline PROM scores, however CROSS had worse baseline ODI, PCS, SRS-22r (p<0.05). At time of crossover, CROSS had worse ODI (35.7 vs. 27.8) and SRS Satisfaction (2.6 vs. 3.3) compared to NON (p<0.05). Alignment remained similar for CROSS from baseline to conversion however PROMs (ODI, PCS, SRS Activity/Pain/Total) worsened (p<0.05). Early and late crossover evaluation demonstrated CROSS-early (n=25) had worsening ODI, SRS Activity/Pain at time of crossover (p<0.05). From time of crossover to 2yr follow-up, CROSS-early had less SRS Appearance/Mental improvement compared to OP. Both CROSS-early/late had worse baseline, but greater improvements, in ODI, PCS, SRS Pain/Total compared to NON (p<0.05). Baseline alignment and disability parameters increased crossover odds - Non with Schwab T/L/D curves and ODI>/=40 (OR: 3.05, p=0.031), and Non with high PI-LL modifier grades ('+'/'++') and ODI>/=40 (OR: 5.57, p=0.007) were at increased crossover risk. CONCLUSIONS: High baseline and increasing disability over time drives conversion from non-operative to operative ASD care. CROSS patients had similar spinal deformity but worse PROMs than NON. CROSS achieved similar 2-year outcome scores as OP. Profiling at first visit for patients at risk of crossover may optimize physician counseling and cost savings.