Gregory W. Poorman

Hospital Readmission Within 2 Years Following Adult Thoracolumbar Spinal Deformity Surgery: Prevalence, Predictors, and Effect on Patient-derived Outcome Measures

Study Design. A retrospective review of prospective multicenter database. Objective. The aim of this study was to identify factors influencing readmission, reoperation, and the impact on health-related quality of life outcomes (HRQoLs) in adult spinal deformity (ASD) surgery. Summary of Background Data. Many ASD patients experience complications requiring readmission. It is important to identify baseline/operative factors leading to rehospitalizations and reoperation, which may impact outcomes. Methods. Inclusion criteria: ASD surgical patients (age >18 yrs, major coronal Cobb ≥20°, sagittal vertical axis ≥5 cm, pelvic tilt ≥25°, and/or thoracic kyphosis >60°) with complete baseline, 1-, and 2-year follow-up. Patients were grouped on the basis of readmission occurrence (yes/no) and type [medical (no reoperation) vs. surgical (revision surgery)]. Readmissions caused by infections requiring surgical treatment (e.g., deep infections) were considered reoperations. Univariate and multivariate analyses determined readmission and reoperation predictors. Repeated measures mixed models evaluated readmission impact on HRQoLs at 1 and 2 years. Results. Three hundred thirty-four patients were included: 76 (22.8%) readmissions, involving 65 (85.5% of 76) reoperations (surgical readmission) and 11 (14.5% of 76) medical readmissions. The most common surgical readmission indication (n = 65) was implant complications (36.9%; rod breakage n = 13); the most common medical readmission indication was infection (36.4%, n = 4), treated with antibiotics. Noninfectious medical readmission (n = 7) included pleural effusion, deep vein thrombosis (DVT), intraoperative blood loss, neurologic, and unspecified. Readmission predictors: increased number of major peri-operative complications [odds ratio (OR) 5.13, P = 0.014], infection presence (OR 25.02, P = 0.001), implant complications (OR 6.12, P < 0.001), and radiographic complications (DJK, proximal junctional kyphosis, pseudoarthrosis, sagittal/coronal imbalance) (OR 16.94, P < 0.001). HRQoL analysis revealed overall improvement of the full cohort (P < 0.01), though the 76 readmitted improved less overall and at each time point P < 0.001) except in 6-week MCS (P = 0.14). Conclusion. Major peri-operative, implant, radiographic, and infection complications during index were associated with increased readmission odds. Implant complications most frequently caused surgical readmissions. Readmitted patients improved in outcome scores, although less compared with the nonreadmitted cohort, yet displayed reduced 6-week SF-36 Mental Component Summary. Level of Evidence: 3

Comparative analysis of perioperative complications between a multicenter prospective cervical deformity database and the Nationwide Inpatient Sample database

BACKGROUND CONTEXT Complication rates for adult cervical deformity are poorly characterized given the complexity and heterogeneity of cases. PURPOSE To compare perioperative complication rates following adult cervical deformity corrective surgery between a prospective multicenter database for patients with cervical deformity (PCD) and the Nationwide Inpatient Sample (NIS). STUDY DESIGN/SETTING Retrospective review of prospective databases. PATIENT SAMPLE A total of 11,501 adult patients with cervical deformity (11,379 patients from the NIS and 122 patients from the PCD database). OUTCOME MEASURES Perioperative medical and surgical complications. METHODS The NIS was queried (2001-2013) for cervical deformity discharges for patients ≥18 years undergoing cervical fusions using International Classification of Disease, Ninth Revision (ICD-9) coding. Patients ≥18 years from the PCD database (2013-2015) were selected. Equivalent complications were identified and rates were compared. Bonferroni correction (p<.004) was used for Pearson chi-square. Binary logistic regression was used to evaluate differences in complication rates between databases. RESULTS A total of 11,379 patients from the NIS database and 122 patiens from the PCD database were identified. Patients from the PCD database were older (62.49 vs. 55.15, p<.001) but displayed similar gender distribution. Intraoperative complication rate was higher in the PCD (39.3%) group than in the NIS (9.2%, p<.001) database. The PCD database had an increased risk of reporting overall complications than the NIS (odds ratio: 2.81, confidence interval: 1.81-4.38). Only device-related complications were greater in the NIS (7.1% vs. 1.1%, p=.007). Patients from the PCD database displayed higher rates of the following complications: peripheral vascular (0.8% vs. 0.1%, p=.001), gastrointestinal (GI) (2.5% vs. 0.2%, p<.001), infection (8.2% vs. 0.5%, p<.001), dural tear (4.1% vs. 0.6%, p<.001), and dysphagia (9.8% vs. 1.9%, p<.001). Genitourinary, wound, and deep veinthrombosis (DVT) complications were similar between databases (p>.004). Based on surgicalapproach, the PCD reported higher GI and neurologic complication rates for combined anterior-posterior procedures (p<.001). For posterior-only procedures, the NIS had more device-related complications (12.4% vs. 0.1%, p=.003), whereas PCD had more infections (9.3% vs. 0.7%, p<.001). CONCLUSIONS Analysis of the surgeon-maintained cervical database revealed higher overall and individual complication rates and higher data granularity. The nationwide database may underestimate complications of patients with adult cervical deformity (ACD) particularly in regard to perioperative surgical details owing to coding and deformity generalizations. The surgeon-maintained database captures the surgical details, but may underestimate some medical complications.

Outcomes of open staged corrective surgery in the setting of adult spinal deformity

BACKGROUND CONTEXT Adult spinal deformity (ASD) represents a constellation of complex malalignments affecting the spinal column. Corrective surgical procedures aimed at improving ASD can be equally challenging, and commonly require multiple index procedures and potential revisions before definitive management. There is a paucity of data comparing the outcomes of same-day(simultaneous [SIM]) and 2-day (staged [STA]) procedures for long spinal fusions for ASD. Using a large patient cohort with surgeon- and patient-reported outcomes will be particularly useful in determining the utility and effect of staging long spinal fusions for ASD. PURPOSE This study aimed to compare intraoperative, perioperative, and 2-year outcomes of STA and SIM procedures correcting ASD. STUDY DESIGN This is a retrospective analysis of a prospective multicenter database. PATIENT SAMPLE A total of 142 patients (71 STA, 71 SIM) were included. OUTCOME MEASURES Primary outcome measures were intra- and perioperative (6 weeks) complication rates. Secondary outcome measures were 2-year thoracolumbar and spinopelvic radiographic parameters, 2-year health-related quality of life (HRQoL) changes (Oswestry Disability Index [ODI] and Short Form-36 [SF-36]), and 2-year complication rates. METHODS Inclusion criteria included patients with ASD ≥18 years with 6-week and 2-year follow-up. Propensity score matching identified similar patients undergoing STA or SIM long spinal fusions based on surgical invasiveness, pelvic tilt, and sagittal vertical axis (SVA). Complications, HRQoL scores (Scoliosis Research Society-22 Patient Questionnaire [SRS-22r], SF-36, ODI), and patient characteristics were compared across and within treatment groups at follow-up with analysis of variance (ANOVA) and paired t tests at three surgical stages: intraoperatively, perioperatively (6 weeks), and postoperatively (>6 weeks). RESULTS A total of 142 patients were included (71 STA, 71 SIM). Matching STA and SIM groups based on degree of deformity and surgical invasiveness created two groups similar in overall correction of the surgery. Patients undergoing STA underwent more anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) procedures, whereas patients undergoing SIM had longer fusions. Charlson comorbidity index and revision status were similar between groups (p>.05). Staging procedures had significantly more complications causing reoperation (STA: 47% vs. SIM: 8%, p=.021), and had a greater number of perioperative complications requiring a return to the operating room (OR) (STA: 9.9% vs. SIM: 1.4%, p=.029). There was no difference in intraoperative complications, mortality, or perioperative infection or wound complications (p>.05) between the two procedures. At 2-year follow-up, incidence of revision surgery was higher in STA (STA: 21.1% vs. SIM: 8.5%, p=.033). CONCLUSION Staged spinal fusions, which add ALIFs and LLIFs to the procedure, compared with similar-correction SIM procedures, result in similar intraoperative complication incidence, but significantly higher rates of peri- and postoperative complications leading to revision. Functional outcomes, radiographic parameters, and mortality were similar. This will aid surgeons in their determination of the optimal treatment for such complex procedures.

The Interobserver and Intraobserver Reliability of the Sanders Classification Versus the Risser Stage.

Background: Estimation of skeletal maturity, classically performed using Risser sign, plays a crucial role in the treatment of AIS. Recent data, however, has shown the simplified Tanner-Whitehouse (Sanders) classification, based on an anteriorposterior (AP) hand radiographs, to correlate more closely to the rapid growth phase and thus curve progression. This study evaluated the interobserver and intraobserver reliability of the Sanders and Risser classifications among clinicians at different levels of training. Methods: Twenty AP scoliosis radiographs and 20 AP hand radiographs were randomized and distributed to 11 graders. The graders consisted of 3 orthopaedic residents, 3 spine fellows, 3 spine surgeons, and 1 radiologist. The graders were then asked to classify the radiographs according to the Sanders and Risser classifications. There were 3 rounds of grading, each done 3 weeks apart. The overall &kgr; coefficient was then calculated for each system to evaluate the interobserver and intraobserver reliability. Results: For all graders the average &kgr; coefficient for the interobserver and intraobserver reliability of the Sanders classification was 0.54 and 0.62, respectively, and 0.46 and 0.49 for the Risser classification. With respect to spine attendings alone, the average &kgr; coefficient for the interobserver and intraobserver reliability of Sanders classification was 0.72 and 0.77, respectively, and 0.46 and 0.67 for the Risser classification. Conclusions: Our study demonstrated that the Sanders classification had moderate reliability with respect to physicians at various levels of training and had good reliability with respect to attending spine surgeons. Interestingly, the Risser staging was found to have less interobserver and intraobserver reliability overall. The Sanders classification is a reliable and reproducible system and should be in the armamentarium of surgeons who treat adolescent idiopathic scoliosis. Level of evidence: Level III.

Morbidity of Adult Spinal Deformity Surgery in Elderly Has Declined Over Time

Study Design. A retrospective review of a prospectively collected database, the Nationwide Inpatient Sample (NIS), years 2003 to 2012. Objectives. The aim of this study was to examine trends in the management of scoliosis in elderly (age >75 yrs) patients from 2003 to 2012. Summary of Background Data. Scoliosis incidence rises with increasing age, and age has been shown to be an independent risk factor for surgical complications in scoliosis surgery. Previous studies have displayed increasing surgical frequency on elderly scoliotic patients in the last decade, but have not investigated complications in the same years. Methods. ICD-9 coding identified elderly (age ≥75 yrs) patients with a primary diagnosis of scoliosis undergoing lumbar fusion or decompression. Analysis of variance (ANOVA) comparisons and linear trend analysis described changes from 2003 to 2012 in surgical invasiveness (Mirza scale: levels fused/decompressed/instrumented and by approach), intraoperative complications, and Charlson Comorbidity Index (CCI). Secondary outcome measures included cost and discharge outcomes. Results. Eight thousand one elderly patients with ASD from 2003 to 2012 were included for analysis. Fusion incidence increased on average 13.8% per year (P < 0.001), surgical invasiveness by Mirza scale increased from 2.0 in 2003 to 5.9 in 2012 (P < 0.001), and CCI increased from 0.77 to 1.44 (p < 0.001). Over the same interval, elderly patients undergoing fusion displayed overall reduction in complications (excluding anemia)—from 26.7% to 8.6% (P < 0.001); specifically, surgical complications decreased from 11.7% to 0.7% (P < 0.001) and respiratory complications decreased from 6.7% to 1.4% (P = 0.004). Conclusion. From 2003 to 2012, surgical management of ASD in the elderly population increased in incidence and complexity, while number of patient comorbidities increased and in-hospital morbidity decreased. This may indicate increased willingness of surgeons to operate on elderly patients, and reflect a development of overall understanding of deformity in the past decade. Level of Evidence: 3

A novel index for quantifying the risk of early complications for patients undergoing cervical spine surgeries

OBJECTIVE It is becoming increasingly necessary for surgeons to provide evidence supporting cost-effectiveness of surgical treatment for cervical spine pathology. Anticipating surgical risk is critical in accurately evaluating the risk/benefit balance of such treatment. Determining the risk and cost-effectiveness of surgery, complications, revision procedures, and mortality rates are the most significant limitations. The purpose of this study was to determine independent risk factors for medical complications (MCs), surgical complications (SCs), revisions, and mortality rates following surgery for patients with cervical spine pathology. The most relevant risk factors were used to structure an index that will help quantify risk and anticipate failure for such procedures. METHODS The authors of this study performed a retrospective review of the National Inpatient Sample (NIS) database for patients treated surgically for cervical spine pathology between 2001 and 2010. Multivariate models were performed to calculate the odds ratio (OR) of the independent risk factors that led to MCs and repeated for SCs, revisions, and mortality. The models controlled for age (< and > 65 years old), sex, race, revision status (except for revision analysis), surgical approach, number of levels fused/re-fused (2-3, 4-8, ≥ 9), and osteotomy utilization. ORs were weighted based on their predictive category: 2 times for revision surgery predictors and 4 times for mortality predictors. Fifty points were distributed among the predictors based on their cumulative OR to establish a risk index. RESULTS Discharges for 362,989 patients with cervical spine pathology were identified. The mean age was 52.65 years, and 49.47% of patients were women. Independent risk factors included medical comorbidities, surgical parameters, and demographic factors. Medical comorbidities included the following: pulmonary circulation disorder, coagulopathy, metastatic cancer, renal failure, congestive heart failure, alcohol abuse, neurological disorder, nonmetastatic cancer, liver disease, rheumatoid arthritis/collagen vascular diseases, and chronic blood loss/anemia. Surgical parameters included posterior approach to fusion/re-fusion, ≥ 9 levels fused/re-fused, corpectomy, 4-8 levels fused/re-fused, and osteotomy; demographic variables included age ≥ 65 years. These factors increased the risk of at least 1 of MC, SC, revision, or mortality (risk of death). A total of 50 points were distributed among the factors based on the cumulative risk ratio of every factor in proportion to the total risk ratios. CONCLUSIONS This study proposed an index to quantify the potential risk of morbidity and mortality prior to surgical intervention for patients with cervical spine pathology. This index may be useful for surgeons in patient counseling efforts as well as for health insurance companies and future socioeconomics studies in assessing surgical risks and benefits for patients undergoing surgical treatment of the cervical spine.

Cervical Alignment Changes in Patients Developing Proximal Junctional Kyphosis Following Surgical Correction of Adult Spinal Deformity

BACKGROUND Proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery is a well-documented complication, but associations between radiographic PJK and cervical malalignment onset remain unexplored. OBJECTIVE To study cervical malalignment in ASD surgical patients that develop PJK. METHODS Retrospective review of prospective multicenter database. Inclusion: primary ASD patients (≥5 levels fused, upper instrumented vertebra [UIV] at T2 or above, and 1-yr minimum follow-up) without baseline cervical deformity (CD), defined as ≥2 of the following criteria: T1 slope minus cervical lordosis < 20°, cervical sagittal vertical axis < 4 cm, C2-C7 cervical lordosis < 10°. PJK presence (<10° change in UIV and UIV + 2 kyphosis) and angle were identified 1 yr postoperative. Propensity score matching between PJK and nonPJK groups controlled for baseline alignment. Preoperative and 1-yr postoperative cervical alignment were compared between PJK and nonPJK patients. RESULTS One hundred sixty-three patients without baseline CD (54.9 yr, 83.9% female) were included. PJK developed in 60 (36.8%) patients, with 27 (45%) having UIV above T7. PJK patients had significantly greater baseline T1 slope in unmatched and propensity score matching comparisons (P < .05). At 1 yr postoperative, PJK patients had significantly higher T1 slope (P < .001), C2-T3 Cobb (P = .04), and C2-T3 sagittal vertical axis (P = .02). New-onset CD rate in PJK patients was 15%, and 16.5% in nonPJK patients (P > .05). Increased PJK magnitude was associated with increasing T1 slope and C2-T3 SVA (P < .05). CONCLUSION Patients who develop PJK following surgical correction of ASD have a 15% incidence of development of new-onset CD. Patients developing PJK following surgical correction of ASD tend to have an increased preoperative T1 slope. Increased progression of C2-T3 Cobb angle and C2-T3 SVA are associated with development of PJK following surgical correction of thoracolumbar deformity.

Epidemiology and national trends in prevalence and surgical management of metastatic spinal disease

Surgical treatment for spinal metastasis has benefited from improvements in surgical techniques. However, the trends in treatment and outcomes for spinal metastasis surgery have not been well-established in a pediatric population. Patients <20 years old with metastatic spinal tumors undergoing spinal surgery were identified in the KID database. Trends for spinal metastases treatment and patient outcomes were analyzed using weight-adjusted ANOVAs. 333 patients were identified in the KID database. The top five primary diagnoses were metastatic brain/spinal cord tumor (19.8%), metastatic nervous system tumor (15.9%), metastatic bone cancer (13.2%), spinal cord tumor (4.2%), and tumor of ventricles (3.0%). There was an increased incidence of spinal metastasis diagnoses from 2003 to 2012 (88.5-117.9 per 100,000; p < 0.001) and an increased trend in the incidence of surgical treatment for spinal metastasis from 2003 to 2012 (p = 0.014). The average age was 10.19 ± 6.33 years old and 38.4% were female. The average length of stay was 17.34 ± 24.36 days. Average CCI increased over time (2003: 7.87 ± 1.40, 2012: 8.44 ± 1.39; p = 0.006). The most common surgeries were excision of spinal cord/meninges lesions (69.1%) and decompression of spinal canal (38.1%). Length of hospital stay and in-hospital mortality did not change over time (17.34-18.04 days, p = 0.337; 1.6%-2.9%, p = 0.801). 10.5% of patients underwent a posterior fusion and 22.2% had at least one complication (nervous system, respiratory, dysphagia, infection). The overall complication rate remained stable over time (23.4%-21.8%, p = 0.952). Surgical treatment for spinal metastasis in the last decade has increased, though the complication rates, in-hospital mortality, and length of stay have remained stable.

Three types of sagittal alignment regarding compensation in asymptomatic adults: the contribution of the spine and lower limbs

PurposeA 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.MethodsThis 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.ResultsThree 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.ConclusionsThe 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.

Diabetes as an Independent Predictor for Extended Length of Hospital Stay and Increased Adverse Post-Operative Events in Patients Treated Surgically for Cervical Spondylotic Myelopathy

Background Diabetes as an independent driver of peri-operative outcomes, and whether its severity impacts indications is conflicted in the research. The purpose of this study is to evaluate diabetes as a predictor for postoperative outcomes in cervical spondylotic myelopathy (CSM) patients. Methods A retrospective review was performed of patients treated surgically for CSM (ICD-9 721.1) from 2010-2012 in the prospectively-collected American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Outcome measures were length of stay, and the presence of complications. Diabetic patients were stratified based on whether or not their diabetes was insulin- or non-insulin-dependent. Results A total of 5,904 surgical CSM patients were included, 1101 (19%) had diabetes. 722 (65%) were non-insulin-dependent diabetics, and 381 (35%) were insulin-dependent diabetics. Diabetes was found to be an independent predictor of extended LOS (OR: 1.878[2.262-1.559], p<0.001) as well as of developing a complication (OR: 1.666[2.217-1.253], p<0.001) after controlling for associated variables like BMI. Type of diabetes (insulin- vs. non-insulin-dependent) showed little significant difference between the groups (p>0.05), however, patients with insulin-dependent diabetes were associated with an increased incidence of wound complications (p=0.027); severity of diabetes was not associated with any other individual complications. Conclusions Type and severity of diabetes is not a predictor for complication. Diabetes is associated with extended LOS and peri-operative morbidity. Level of evidence: Class 2b. Clinical relevance: Our findings support the view of many spine surgeons, who believe that diabetes has a negative impact on the outcome of surgery for CSM. Our findings support those cohort studies that found an association between diabetes and worst post-operative outcomes following surgical treatment of CSM. These findings lend support to the importance of monitoring preoperative serum glucose levels, as prevention of peri-operative hyperglycemia has been linked to improved postoperative outcomes in spine, joint and colon surgery.