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Justin K. Scheer, Taemin Oh, Justin S. Smith, Christopher I. Shaffrey, Alan H. Daniels, Daniel M. Sciubba, D. Kojo Hamilton, Themistocles S. Protopsaltis, Peter G. Passias, Robert A. Hart, Douglas C. Burton, Shay Bess, Renaud Lafage, Virginie Lafage, Frank Schwab, Eric O. Klineberg, Christopher P. Ames and the International Spine Study Group

OBJECTIVE

Pseudarthrosis can occur following adult spinal deformity (ASD) surgery and can lead to instrumentation failure, recurrent pain, and ultimately revision surgery. In addition, it is one of the most expensive complications of ASD surgery. Risk factors contributing to pseudarthrosis in ASD have been described; however, a preoperative model predicting the development of pseudarthrosis does not exist. The goal of this study was to create a preoperative predictive model for pseudarthrosis based on demographic, radiographic, and surgical factors.

METHODS

A retrospective review of a prospectively maintained, multicenter ASD database was conducted. Study inclusion criteria consisted of adult patients (age ≥ 18 years) with spinal deformity and surgery for the ASD. From among 82 variables assessed, 21 were used for model building after applying collinearity testing, redundancy, and univariable predictor importance ≥ 0.90. Variables included demographic data along with comorbidities, modifiable surgical variables, baseline coronal and sagittal radiographic parameters, and baseline scores for health-related quality of life measures. Patients groups were determined according to their Lenke radiographic fusion type at the 2-year follow-up: bilateral or unilateral fusion (union) or pseudarthrosis (nonunion). A decision tree was constructed, and internal validation was accomplished via bootstrapped training and testing data sets. Accuracy and the area under the receiver operating characteristic curve (AUC) were calculated to evaluate the model.

RESULTS

A total of 336 patients were included in the study (nonunion: 105, union: 231). The model was 91.3% accurate with an AUC of 0.94. From 82 initial variables, the top 21 covered a wide range of areas including preoperative alignment, comorbidities, patient demographics, and surgical use of graft material.

CONCLUSIONS

A model for predicting the development of pseudarthrosis at the 2-year follow-up was successfully created. This model is the first of its kind for complex predictive analytics in the development of pseudarthrosis for patients with ASD undergoing surgical correction and can aid in clinical decision-making for potential preventative strategies.

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Thomas J. Buell, Davis G. Taylor, Ching-Jen Chen, Christopher I. Shaffrey, Justin S. Smith and Shay Bess

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Cecilia L. Dalle Ore, Darryl Lau, Jessica L. Davis, Michael M. Safaee and Christopher P. Ames

Juvenile ossifying fibroma (JOF) is a rare benign bone tumor that occurs most frequently in the craniofacial bones of children and young adults. There are few case reports that describe its involvement outside the craniofacial skeleton, especially within the spinal column. While JOF is classified as a benign lesion, it may be locally aggressive and demonstrate a high propensity for recurrence, even after resection. Definitive surgical management may be challenging in naive cases, but it is particularly challenging in recurrent cases and when extensive spinal reconstruction is warranted. In this report, the authors describe the diagnosis and surgical management of a 29-year-old man who presented with a large recurrent sacral trabecular-subtype JOF. A review of literature regarding JOFs, management of recurrent primary spinal tumors, and sacral reconstruction are discussed.

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Darryl Lau, Joseph A. Osorio, Vedat Deviren and Christopher P. Ames

OBJECTIVE

Three-column osteotomies are increasingly being used in the elderly population to correct rigid spinal deformities. There is hesitation, however, in performing the technique in older patients because of the high risk for blood loss, longer operative times, and complications. This study assesses whether age alone is an independent risk factor for complications and length of stay.

METHODS

All patients with thoracolumbar adult spinal deformity (ASD) who underwent 3-column osteotomy (vertebral column resection or pedicle subtraction osteotomy) performed by the senior author from 2006 to 2016 were identified. Demographics, clinical baseline, and surgical details were collected. Outcomes of interest included perioperative complication, ICU stay, and hospital stay. Bivariate and multivariate analyses were used to assess the association of age with outcomes of interest.

RESULTS

A total of 300 patients were included, and 38.3% were male. The mean age was 63.7 years: 10.3% of patients were younger than 50 years, 36.0% were 50–64 years, 45.7% were 65–79 years, and 8.0% were 80 years or older. The overall mean EBL was 1999 ml. The overall perioperative complication rate was 24.7%: 18.0% had a medical complication and 7.0% had a surgical complication. There were no perioperative or 30-day deaths. Age was associated with overall complications (p = 0.002) and medical-specific complications (p < 0.001); there were higher rates of overall and medical complications with increased age: 9.7% and 6.5%, respectively, for patients younger than 50 years; 16.7% and 10.2%, respectively, for patients 50–64 years; 31.4% and 22.6%, respectively, for patients 65–79 years; and 41.7% and 41.7%, respectively, for patients 80 years or older. However, after adjusting for relevant covariates on multivariate analysis, age was not an independent factor for perioperative complications. Surgical complication rates were similar among the 4 age groups. Longer ICU and total hospital stays were observed in older age groups, and age was an independent factor associated with longer ICU stay (p = 0.028) and total hospital stay (p = 0.003). ICU stays among the 4 age groups were 1.6, 2.3, 2.0, and 3.2 days for patients younger than 50 years, 50–64 years, 65–79 years, and 80 years or older, respectively. The total hospital stays stratified by age were 7.3, 7.7, 8.2, and 11.0 days for patients younger than 50 years, 50–64 years, 65–79 years, and 80 years or older, respectively.

CONCLUSIONS

Older age was associated with higher perioperative complication rates, but age alone was not an independent risk factor for complications following the 3-column osteotomy for ASD. Comorbidities and other unknown variables that come with age are likely what put these patients at higher risk for complications. Older age, however, is independently associated with longer ICU and hospital stays.

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Michael M. Safaee, Vedat Deviren, Cecilia Dalle Ore, Justin K. Scheer, Darryl Lau, Joseph A. Osorio, Fred Nicholls and Christopher P. Ames

OBJECTIVE

Proximal junctional kyphosis (PJK) is a well-recognized, yet incompletely defined, complication of adult spinal deformity surgery. There is no standardized definition for PJK, but most studies describe PJK as an increase in the proximal junctional angle (PJA) of greater than 10°–20°. Ligament augmentation is a novel strategy for PJK reduction that provides strength to the upper instrumented vertebra (UIV) and adjacent segments while also reducing junctional stress at those levels.

METHODS

In this study, ligament augmentation was used in a consecutive series of adult spinal deformity patients at a single institution. Patient demographics, including age; sex; indication for surgery; revision surgery; surgical approach; and use of 3-column osteotomies, vertebroplasty, or hook fixation at the UIV, were collected. The PJA was measured preoperatively and at last follow-up using 36-inch radiographs. Data on change in PJA and need for revision surgery were collected. Univariate and multivariate analyses were performed to identify factors associated with change in PJA and proximal junctional failure (PJF), defined as PJK requiring surgical correction.

RESULTS

A total of 200 consecutive patients were included: 100 patients before implementation of ligament augmentation and 100 patients after implementation of this technique. The mean age of the ligament augmentation cohort was 66 years, and 67% of patients were women. Over half of these cases (51%) were revision surgeries, with 38% involving a combined anterior or lateral and posterior approach. The mean change in PJA was 6° in the ligament augmentation group compared with 14° in the control group (p < 0.001). Eighty-four patients had a change in PJA of less than 10°. In a multivariate linear regression model, age (p = 0.016), use of hook fixation at the UIV (p = 0.045), and use of ligament augmentation (p < 0.001) were associated with a change in PJA. In a separate model, only ligament augmentation (OR 0.193, p = 0.012) showed a significant association with PJF.

CONCLUSIONS

Ligament augmentation represents a novel technique for the prevention of PJK and PJF. Compared with a well-matched historical cohort, ligament augmentation is associated with a significant decrease in PJK and PJF. These data support the implementation of ligament augmentation in surgery for adult spinal deformity, particularly in patients with a high risk of developing PJK and PJF.

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Michael M. Safaee, Cecilia L. Dalle Ore, Corinna C. Zygourakis, Vedat Deviren and Christopher P. Ames

OBJECTIVE

Proximal junctional kyphosis (PJK) is a well-recognized complication of surgery for adult spinal deformity and is characterized by increased kyphosis at the upper instrumented vertebra (UIV). PJK prevention strategies have the potential to decrease morbidity and cost by reducing rates of proximal junctional failure (PJF), which the authors define as radiographic PJK plus clinical sequelae requiring revision surgery.

METHODS

The authors performed an analysis of 195 consecutive patients with adult spinal deformity. Age, sex, levels fused, upper instrumented vertebra (UIV), use of 3-column osteotomy, pelvic fixation, and mean time to follow-up were collected. The authors also reviewed operative reports to assess for the use of surgical adjuncts targeted toward PJK prevention, including ligament augmentation, hook fixation, and vertebroplasty. The cost of surgery, including direct and total costs, was also assessed at index surgery and revision surgery. Only revision surgery for PJF was included.

RESULTS

The mean age of the cohort was 64 years (range 25–84 years); 135 (69%) patients were female. The mean number of levels fused was 10 (range 2–18) with the UIV as follows: 2 cervical (1%), 73 upper thoracic (37%), 108 lower thoracic (55%), and 12 lumbar (6%). Ligament augmentation was used in 99 cases (51%), hook fixation in 60 cases (31%), and vertebroplasty in 71 cases (36%). PJF occurred in 18 cases (9%). Univariate analysis found that ligament augmentation and hook fixation were associated with decreased rates of PJF. However, in a multivariate model that also incorporated age, sex, and UIV, only ligament augmentation maintained a significant association with PJF reduction (OR 0.196, 95% CI 0.050–0.774; p = 0.020). Patients with ligament augmentation, compared with those without, had a higher cost of index surgery, but ligament augmentation was overall cost effective and produced significant cost savings. In sensitivity analyses in which we independently varied the reduction in PJF, cost of ligament augmentation, and cost of reoperation by ± 50%, ligament augmentation remained a cost-effective strategy for PJF prevention.

CONCLUSIONS

Prevention strategies for PJK/PJF are limited, and their cost-effectiveness has yet to be established. The authors present the results of 195 patients with adult spinal deformity and show that ligament augmentation is associated with significant reductions in PJF in both univariate and multivariate analyses, and that this intervention is cost-effective. Future studies will need to determine if these clinical results are reproducible, but for high-risk cases, these data suggest an important role of ligament augmentation for PJF prevention and cost savings.

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Junseok Bae, Alexander A. Theologis, Russell Strom, Bobby Tay, Shane Burch, Sigurd Berven, Praveen V. Mummaneni, Dean Chou, Christopher P. Ames and Vedat Deviren

OBJECTIVE

Surgical treatment of adult spinal deformity (ASD) is an effective endeavor that can be accomplished using a variety of surgical strategies. Here, the authors assess and compare radiographic data, complications, and health-related quality-of-life (HRQoL) outcome scores among patients with ASD who underwent a posterior spinal fixation (PSF)–only approach, a posterior approach combined with lateral lumbar interbody fusion (LLIF+PSF), or a posterior approach combined with anterior lumbar interbody fusion (ALIF+PSF).

METHODS

The medical records of consecutive adults who underwent thoracolumbar fusion for ASD between 2003 and 2013 at a single institution were reviewed. Included were patients who underwent instrumentation from the pelvis to L-1 or above, had a sagittal vertical axis (SVA) of < 10 cm, and underwent a minimum of 2 years’ follow-up. Those who underwent a 3-column osteotomy were excluded. Three groups of patients were compared on the basis of the procedure performed, LLIF+PSF, ALIF+PSF, and PSF only. Perioperative spinal deformity parameters, complications, and HRQoL outcome scores (Oswestry Disability Index [ODI], Scoliosis Research Society 22-question Questionnaire [SRS-22], 36-Item Short Form Health Survey [SF-36], visual analog scale [VAS] for back/leg pain) from each group were assessed and compared with each other using ANOVA. The minimal clinically important differences used were −1.2 (VAS back pain), −1.6 (VAS leg pain), −15 (ODI), 0.587/0.375/0.8/0.42 (SRS-22 pain/function/self-image/mental health), and 5.2 (SF-36, physical component summary).

RESULTS

A total of 221 patients (58 LLIF, 91 ALIF, 72 PSF only) met the inclusion criteria. Average deformities consisted of a SVA of < 10 cm, a pelvic incidence–lumbar lordosis (LL) mismatch of > 10°, a pelvic tilt of > 20°, a lumbar Cobb angle of > 20°, and a thoracic Cobb angle of > 15°. Preoperative SVA, LL, pelvic incidence–LL mismatch, and lumbar and thoracic Cobb angles were similar among the groups. Patients in the PSF-only group had more comorbidities, those in the ALIF+PSF group were, on average, younger and had a lower body mass index than those in the LLIF+PSF group, and patients in the LLIF+PSF group had a significantly higher mean number of interbody fusion levels than those in the ALIF+PSF and PSF-only groups. At final follow-up, all radiographic parameters and the mean numbers of complications were similar among the groups. Patients in the LLIF+PSF group had proximal junctional kyphosis that required revision surgery significantly less often and fewer proximal junctional fractures and vertebral slips. All preoperative HRQoL scores were similar among the groups. After surgery, the LLIF+PSF group had a significantly lower ODI score, higher SRS-22 self-image/total scores, and greater achievement of the minimal clinically important difference for the SRS-22 pain score.

CONCLUSIONS

Satisfactory radiographic outcomes can be achieved similarly and adequately with these 3 surgical approaches for patients with ASD with mild to moderate sagittal deformity. Compared with patients treated with an ALIF+PSF or PSF-only surgical strategy, patients who underwent LLIF+PSF had lower rates of proximal junctional kyphosis and mechanical failure at the upper instrumented vertebra and less back pain, less disability, and better SRS-22 scores.

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Emily K. Miller, Brian J. Neuman, Amit Jain, Alan H. Daniels, Tamir Ailon, Daniel M. Sciubba, Khaled M. Kebaish, Virginie Lafage, Justin K. Scheer, Justin S. Smith, Shay Bess, Christopher I. Shaffrey, Christopher P. Ames and the International Spine Study Group

OBJECTIVE

The goal of this study was to analyze the value of an adult spinal deformity frailty index (ASD-FI) in preoperative risk stratification. Preoperative risk assessment is imperative before procedures known to have high complication rates, such as ASD surgery. Frailty has been associated with risk of complications in trauma surgery, and preoperative frailty assessments could improve the accuracy of risk stratification by providing a comprehensive analysis of patient factors that contribute to an increased risk of complications.

METHODS

Using 40 variables, the authors calculated frailty scores with a validated method for 417 patients (enrolled between 2010 and 2014) with a minimum 2-year follow-up in an ASD database. On the basis of these scores, the authors categorized patients as not frail (NF) (< 0.3 points), frail (0.3–0.5 points), or severely frail (SF) (> 0.5 points). The correlation between frailty category and incidence of complications was analyzed.

RESULTS

The overall mean ASD-FI score was 0.33 (range 0.0–0.8). Compared with NF patients (n = 183), frail patients (n = 158) and SF patients (n = 109) had longer mean hospital stays (1.2 and 1.6 times longer, respectively; p < 0.001). The adjusted odds of experiencing a major intraoperative or postoperative complication were higher for frail patients (OR 2.8) and SF patients ( 4.1) compared with NF patients (p < 0.01). For frail and SF patients, respectively, the adjusted odds of developing proximal junctional kyphosis (OR 2.8 and 3.1) were higher than those for NF patients. The SF patients had higher odds of developing pseudarthrosis (OR 13.0), deep wound infection (OR 8.0), and wound dehiscence (OR 13.4) than NF patients (p < 0.05), and they had 2.1 times greater odds of reoperation (p < 0.05).

CONCLUSIONS

Greater patient frailty, as measured by the ASD-FI, was associated with worse outcome in many common quality and value metrics, including greater risk of major complications, proximal junctional kyphosis, pseudarthrosis, deep wound infection, wound dehiscence, reoperation, and longer hospital stay.

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Gregory W. Poorman, Peter G. Passias, Samantha R. Horn, Nicholas J. Frangella, Alan H. Daniels, D. Kojo Hamilton, Hanjo Kim, Daniel Sciubba, Bassel G. Diebo, Cole A. Bortz, Frank A. Segreto, Michael P. Kelly, Justin S. Smith, Brian J. Neuman, Christopher I. Shaffrey, Virginie LaFage, Renaud LaFage, Christopher P. Ames, Robert Hart, Gregory M. Mundis Jr. and Robert Eastlack

OBJECTIVE

Depression and anxiety have been demonstrated to have negative impacts on outcomes after spine surgery. In patients with cervical deformity (CD), the psychological and physiological burdens of the disease may overlap without clear boundaries. While surgery has a proven record of bringing about significant pain relief and decreased disability, the impact of depression and anxiety on recovery from cervical deformity corrective surgery has not been previously reported on in the literature. The purpose of the present study was to determine the effect of depression and anxiety on patients’ recovery from and improvement after CD surgery.

METHODS

The authors conducted a retrospective review of a prospective, multicenter CD database. Patients with a history of clinical depression, in addition to those with current self-reported anxiety or depression, were defined as depressed (D group). The D group was compared with nondepressed patients (ND group) with a similar baseline deformity determined by propensity score matching of the cervical sagittal vertical axis (cSVA). Baseline demographic, comorbidity, clinical, and radiographic data were compared among patients using t-tests. Improvement of symptoms was recorded at 3 months, 6 months, and 1 year postoperatively. All health-related quality of life (HRQOL) scores collected at these follow-up time points were compared using t-tests.

RESULTS

Sixty-six patients were matched for baseline radiographic parameters: 33 with a history of depression and/or current depression, and 33 without. Depressed patients had similar age, sex, race, and radiographic alignment: cSVA, T-1 slope minus C2–7 lordosis, SVA, and T-1 pelvic angle (p > 0.05). Compared with nondepressed individuals, depressed patients had a higher incidence of osteoporosis (21.2% vs 3.2%, p = 0.028), rheumatoid arthritis (18.2% vs 3.2%, p = 0.012), and connective tissue disorders (18.2% vs 3.2%, p = 0.012). At baseline, the D group had greater neck pain (7.9 of 10 vs 6.6 on a Numeric Rating Scale [NRS], p = 0.015), lower mean EQ-5D scores (68.9 vs 74.7, p < 0.001), but similar Neck Disability Index (NDI) scores (57.5 vs 49.9, p = 0.063) and myelopathy scores (13.4 vs 13.9, p = 0.546). Surgeries performed in either group were similar in terms of number of levels fused, osteotomies performed, and correction achieved (baseline to 3-month measurements) (p < 0.05). At 3 months, EQ-5D scores remained lower in the D group (74.0 vs 78.2, p = 0.044), and NDI scores were similar (48.5 vs 39.0, p = 0.053). However, neck pain improved in the D group (NRS score of 5.0 vs 4.3, p = 0.331), and modified Japanese Orthopaedic Association (mJOA) scores remained similar (14.2 vs 15.0, p = 0.211). At 6 months and 1 year, all HRQOL scores were similar between the 2 cohorts. One-year measurements were as follows: NDI 39.7 vs 40.7 (p = 0.878), NRS neck pain score of 4.1 vs 5.0 (p = 0.326), EQ-5D score of 77.1 vs 78.2 (p = 0.646), and mJOA score of 14.0 vs 14.2 (p = 0.835). Anxiety/depression levels reported on the EQ-5D scale were significantly higher in the depressed cohort at baseline, 3 months, and 6 months (all p < 0.05), but were similar between groups at 1 year postoperatively (1.72 vs 1.53, p = 0.416).

CONCLUSIONS

Clinical depression was observed in many of the study patients with CD. After matching for baseline deformity, depression symptomology resulted in worse baseline EQ-5D and pain scores. Despite these baseline differences, both cohorts achieved similar results in all HRQOL assessments 6 months and 1 year postoperatively, demonstrating no clinical impact of depression on recovery up until 1 year after CD surgery. Thus, a history of depression does not appear to have an impact on recovery from CD surgery.

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Darryl Lau, Andrew K. Chan, Vedat Deverin and Christopher P. Ames

OBJECTIVE

Adult spinal deformity (ASD) develops in the setting of asymmetrical arthritic degeneration, and can also be due to iatrogenic causes, such as prior surgery. Many patients who present with ASD have undergone prior spine surgery with instrumentation. Unfortunately, contemporary studies that evaluate the effect of prior surgery or instrumentation on perioperative outcomes, readmission rates, and need for reoperation are lacking.

METHODS

All ASD patients who underwent a 3-column osteotomy performed by the senior author at the authors’ institution for correction of thoracolumbar spinal deformity between 2006 and 2016 were identified. The authors compared surgical outcomes between primary (first-time) and revision cases. Further subgroup analysis was conducted to investigate the effect of the number of prior surgeries (0, 1, 2, 3, 4, and 5 or more) and the presence of spinal instrumentation on outcomes. Multivariate analysis was used to adjust for relevant and significant confounders.

RESULTS

A total of 300 patients were included; 38.3% of patients were male. The overall perioperative complication rate was 24.7%, and the mean length of hospitalization was 8.2 days. The 90-day readmission rate was 9.0%, and the overall follow-up reoperation rate was 26.7%. There were no significant differences in complication rates (26.6% vs 24.0%, p = 0.645), length of hospitalization (8.7 vs 7.9 days, p = 0.229), readmission rates (11.4% vs 8.1%, p = 0.387), or reoperation rates (26.6% vs 26.7%, p = 0.984) between primary and revision cases. There was no significant difference in wound complications (infections/dehiscence) requiring reoperation (5.1% vs 6.3%, p = 0.683). Subgroup analysis conducted to evaluate the effect of the number of prior spinal surgeries or the presence of spinal instrumentation did not reveal significant differences for the aforementioned surgical outcomes. In adjusted multivariate analysis, there were no significant associations between history of prior surgery (number of prior surgeries and prior instrumentation) and all of the surgical outcomes of interest.

CONCLUSIONS

The findings from this study suggest that patients who have undergone prior spine surgery with or without instrumentation are not at increased risk for perioperative complications, need for readmission, or reoperation following 3-column osteotomy of the thoracolumbar spine.