Christopher Shaffrey | University of Virginia (original) (raw)
Papers by Christopher Shaffrey
Neurosurgical Focus
S ome prior reports have suggested that the use of recombinant human bone morphogenetic protein-2... more S ome prior reports have suggested that the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusion (ACF) may be beneficial in select patients with risk factors for developing pseudarthrosis. 1 However, other reports have provided evidence to suggest that there is potential for high complication rates (e.g., hematoma/seroma, cervical swelling, dysphagia) when using rhBMP-2 for ACF. 2 As such, there are currently no clear guidelines or definitive recommendations regarding the usage of rhBMP-2 in patients undergoing ACF. The explanation for some of the discrepancies from prior rhBMP-2/ACF reports is likely multifactorial but could potentially be attributed to nonstandardized dosing and delivery of rhBMP-2. 1-4 To address this important topic, Mendenhall et al. performed a retrospective study to evaluate the safety and efficacy of low-dose rhBMP-2 for use in patients undergoing ACF (both anterior cervical discectomy and corpectomy). 5 The authors hypothesized that the higher doses of rhBMP-2 used in prior ACF studies may have led to the higher complication rates observed. In this study, Mendenhall and colleagues included a total of 198 patients (62 [31%] were smokers) who underwent stand-alone ACF (median of 2 levels fused; mean rhBMP-2 dose 0.50 ± 0.09 mg/level; both contained and noncontained delivery devices were used). The authors reported associated complications and fusion rates with a minimum of 1 year of radiographic follow-up. Briefly, 22 (11%) patients experienced dysphagia, 11 (6%) patients experienced cervical swelling, 2 (1%) patients underwent washout for hematoma, 1 (0.5%) patient had washout for seroma, 2 (1%) patients had pseudarthrosis requiring posterior cervical fusion, and 3 (2%) patients experienced a new postoperative neurological deficit (which was reported to have recovered by the last follow-up). Regarding rates of arthrodesis, study results demonstrated that 190 (96%) patients had solid arthrodesis over an average of 15 months of follow-up (with no statistically significant difference in fusion rates between smokers and nonsmokers). After carefully analyzing these study results, the authors
Neurosurgery
BACKGROUND Lateral (ie, coronal) vertebral listhesis may contribute to disability in adult scolio... more BACKGROUND Lateral (ie, coronal) vertebral listhesis may contribute to disability in adult scoliosis patients. OBJECTIVE To assess for a correlation between lateral listhesis and disability among patients with adult scoliosis. METHODS This was a retrospective multi-center analysis of prospectively collected data. Patients eligible for a minimum of 2-yr follow-up and with coronal plane deformity (defined as maximum Cobb angle ≥20º) were included (n = 724). Outcome measures were Oswestry Disability Index (ODI) and leg pain numeric scale rating. Lateral thoracolumbar listhesis was measured as the maximum vertebral listhesis as a percent of the superior endplate across T1-L5 levels. Linear and logistic regression was utilized, as appropriate. Multivariable analyses adjusted for demographics, comorbidities, surgical invasiveness, maximum Cobb angle, and T1-PA. Minimally clinically important difference (MCID) in ODI was defined as 12.8. RESULTS In total, 724 adult patients were assessed. ...
Spine Deformity
Informed decision making for operative treatment of the skeletally mature adolescent idiopathic s... more Informed decision making for operative treatment of the skeletally mature adolescent idiopathic scoliosis (AIS) patient meeting surgical indications requires a discussion of differences in operative morbidity in adult scoliosis versus AIS. This study evaluated differences in operative data and outcomes between AIS and adult scoliosis patients based on an estimated natural history of curve progression. Twenty-eight adult scoliosis patients (43.7 ± 15.8 years; 93% F) were 1:2 matched with 56 (Risser 4/5) AIS patients (15.7 ± 2.1 years) based on gender and curve type as vetted by 5 surgeons' consensus in committee. Curve progression of 0.3°/year for the first 10 years following skeletal maturity and a 0.5°/year thereafter was assumed to estimate curve progression from AIS to adulthood for the adult counterpart. Operative data, complications, and quality of life (Scoliosis Research Society [SRS-22r] questionnaire) measures were evaluated, with a minimum 2-year follow-up. Postoperative major Cobb and percentage correction were similar between adult versus AIS, whereas operative time, percentage estimated blood loss (EBL; % total blood volume), length of hospital stay (LOS), and total spine levels fused were greater for adult patients (p < .05). No difference was found in EBL, operative time, or LOS when normalized by levels fused. Ten (36%) adult scoliosis patients were fused to the pelvis compared with none in AIS (p < .0001). Major complication rate was higher for adult versus AIS (25% vs. 5.4%; p < .05). Preoperative SRS-22r scores were worse for adult patients; however, they demonstrated greater improvement in SRS-22r than the AIS cohort at final follow-up. A higher percentage of adult patients reached the MCID in self-image domain than the AIS patients (92.3% vs. 61.8%; p = .0040). Treatment of the adult scoliosis patient who has undergone an estimated natural history of progression is characterized by greater levels fused, operative time, and higher complication rates than the AIS counterpart. Longer-term follow-up of AIS is needed to define the benefits of early intervention of relatively asymptomatic adolescent patients versus late treatment of symptomatic disease in the adult.
SPINE
Retrospective review of prospective multicenter database. To identify an optimal set of factors p... more Retrospective review of prospective multicenter database. To identify an optimal set of factors predicting the risk of PJF while taking the time dependency of PJF and those factors into account. Surgical correction of adult spinal deformity (ASD) can be complex and therefore, may come with high revision rates due to proximal junctional failure (PJF). 763 operative ASD patients with a minimum of 1-year follow-up were included. PJF was defined as any type of proximal junctional kyphosis (PJK) requiring revision surgery. Time-dependent ROC curves were estimated with corresponding Cox proportional hazard models. The predictive abilities of demographic, surgical, radiographic parameters and their possible combinations were assessed sequentially. The area under the curve (AUC) was used to evaluate models' performance. PJF occurred in 42 patients (6%), with a median time to revision of approximately one year. Larger preoperative pelvic tilt (PT) (Hazard ratio [HR]=1.044, p = 0.034) significantly increased the risk of PJF. With respect to changes in the radiographic parameters at 6-week post-surgery, larger differences in pelvic incidence-lumbar lordosis (PI-LL) mismatch (HR = 0.924, p = 0.002) decreased risk of PJF. The combination of demographic, surgical and radiographic parameters has the best predictive ability for the occurrence of PJF (AUC = 0.863), followed by demographic along with radiographic parameters (AUC = 0.859). Both models' predictive ability was preserved over time. Over correction increased the risk of PJF. Radiographic along with demographic parameters have shown the approximately equivalent predictive ability for PJF over time as with the addition of surgical parameters. Radiographic rather than surgical factors may of particular importance in predicting the development of PJF over time. These results set the groundwork for risk stratification and corresponding prophylactic interventions for patients undergoing ASD surgery. 4.
SPINE
This study retrospectively analyzes prospectively collected data. Here we aim to determine the in... more This study retrospectively analyzes prospectively collected data. Here we aim to determine the influence of preoperative and 12-month mJOA on satisfaction; and understand the change in mJOA severity classification after surgical management of DCM. Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease resulting from cervical cord compression. The natural progression of DCM is variable; some patients experience periods of stability, while others rapidly deteriorate following disease onset. The modified Japanese Orthopedic Association (mJOA) is commonly used to grade and categorize myelopathy symptoms, but its association with post-operative satisfaction has not been previously explored. The QOD (Quality and Outcomes Database) was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥ 14), moderate (9 to 13), or severe (< 9) categories on the mJOA scores. A McNemar-Bowker test was used to assess whether a significant proportion of patients changed mJOA category between preoperative and 12 months postoperative. A multivariable proportional odds ordinal logistic regression model was fitted with 12-month satisfaction as the outcome of interest. We identified 1963 patients who underwent elective surgery for DCM and completed 12-months follow-ups. Comparing mJOA severity level preoperatively and at 12 months revealed that 55% remained in the same category, 37% improved, and 7% moved to a worse category. After adjusting for baseline and surgery-specific variables, the 12-month mJOA category had the highest impact on patient satisfaction (p < .001). Patient satisfaction is an indispensable tool for measuring quality of care following spine surgery. In this sample, 12-month mJOA category, regardless of preop mJOA, was significantly correlated with satisfaction. Given these findings, it is important to advise patients of the probability that surgery will change their mJOA severity classification and the changes required to achieve post-operative satisfaction. 3.
Journal of neurosurgery. Spine, Jan 10, 2018
OBJECTIVE Achieving appropriate spinopelvic alignment in deformity surgery has been correlated wi... more OBJECTIVE Achieving appropriate spinopelvic alignment in deformity surgery has been correlated with improvement in pain and disability. Minimally invasive surgery (MIS) techniques have been used to treat adult spinal deformity (ASD); however, there is concern for inadequate sagittal plane correction. Because age can influence the degree of sagittal correction required, the purpose of this study was to analyze whether obtaining optimal spinopelvic alignment is required in the elderly to obtain clinical improvement. METHODS A multicenter database of ASD patients was queried. Inclusion criteria were age ≥ 18 years; an MIS component as part of the index procedure; at least one of the following: pelvic tilt (PT) > 20°, sagittal vertical axis (SVA) > 50 mm, pelvic incidence to lumbar lordosis (PI-LL) mismatch > 10°, or coronal curve > 20°; and minimum follow-up of 2 years. Patients were stratified into younger (< 65 years) and older (≥ 65 years) cohorts. Within each cohort,...
World Neurosurgery
Adult spinal deformity (ASD) operations are complex and often require a multi-surgeon team. Simul... more Adult spinal deformity (ASD) operations are complex and often require a multi-surgeon team. Simultaneously, it is the responsibility of academic spine surgeons to train future complex spine surgeons. Our objective was to assess the impact of resident/fellow involvement (RFI) on ASD surgery in four areas: 1) perioperative outcomes, 2) length of stay (LOS), 3) discharge status, and 4) complications. Adults undergoing thoracolumbar spinal deformity correction between 2008 and 2014 were identified in the National Surgical Quality Improvement Program (NSQIP) database. Cases were divided into those with RFI compared to attending(s) only. The outcomes were: operative time, transfusions, LOS, discharge status, and complications. Univariate and multivariable regression modeling was used. Covariates included preoperative comorbidities, specialty, and levels instrumented. A total of 1,471 patients underwent ASD surgery with RFI in 784 (53%) operations. After multivariable regression modeling, RFI was independently associated with longer operations (β=66.01 minutes, 95%CI 35.82-96.19, p<0.001), increased odds of transfusion (OR 2.80, 95%CI 1.81-4.32, p<0.001), longer hospital stay (β=1.76 days, 95% CI 0.18-3.34, p=0.030), and discharge to inpatient rehab or skilled nursing facility (OR 2.02, 95% CI 1.34-3.05, p<0.001). However, RFI was not associated with any increase in major or minor complications. RFI in ASD surgery was associated with increased operative time, additional transfusions, longer LOS, and non-home discharge; however, no increase in major, minor, or severe complications was seen. These data support the continued training of future deformity and complex spine surgeons without fear of worsening complications, yet areas of improvement exist.
Journal of spine surgery (Hong Kong), 2018
Current health-related quality of life (HRQL) metrics used to assess patient outcomes following s... more Current health-related quality of life (HRQL) metrics used to assess patient outcomes following surgical correction of cervical deformity (CD) are not deformity-specific and thus cannot capture all aspects of a patient's deformity and outcomes. The purpose of this study is to evaluate the sensitivity of different HRQL outcome measures in assessing CD patients' outcomes 1-year post-operatively. Retrospective review of prospective multi-center database. Inclusion criteria: CD patients ≥18 yrs with pre- and 1-year post-operative radiographs and HRQLs [modified Japanese Orthopaedic Association (mJOA), EuroQol five-dimensions (EQ-5D), neck disability index (NDI)]. Associations between changes in EQ5D and NDI with improvement at 1-year in mJOA scores were assessed by whether or not the patient met the minimum clinically important difference (MCID) as well as whether or not they improved by one or more categories (i.e., change from moderate to mild). Odds ratios reported with 95% c...
Spine, 2018
Retrospective analysis. To define thoracic compensation and investigate its association with post... more Retrospective analysis. To define thoracic compensation and investigate its association with postoperative reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) SUMMARY OF BACKGROUND DATA.: Adult spinal deformity (ASD) patients recruit compensatory mechanisms like pelvic retroversion and knee flexion. However, thoracic hypokyphosis is a less recognized compensatory mechanism. Patients enrolled in a multicenter ASD registry undergoing fusions to the pelvis with upper instrumented vertebra (UIV) between T9 and L1 were included. Patients were divided into those with postoperative reciprocal thoracic kyphosis (reciprocal kyphosis [RK]: change in unfused thoracic kyphosis [TK] ≥15°) with and without PJK and those who maintained thoracic alignment (MT). Thoracic compensation was defined as expected thoracic kyphosis (eTK) minus preoperative TK. For RK (n = 117), the mean change in unfused TK was 21.7° versus 6.1° for MT (n = 102) and the mean PJK angle change was 17.6° versu...
The spine journal : official journal of the North American Spine Society, Jan 14, 2018
Scoli-RISK-1 is a multicenter prospective cohort designed to study neurologic outcomes following ... more Scoli-RISK-1 is a multicenter prospective cohort designed to study neurologic outcomes following complex adult spinal deformity (ASD). The effect of unilateral versus bilateral postoperative motor deficits on the likelihood of long term recovery has not been previously studied in this population. Evaluate if bilateral postoperative neurologic deficits have a worse recovery than unilateral deficits. Secondary analysis of a prospective, multicenter, international cohort study. In a cohort of 272 patients neurologic decline was defined as deterioration of the American Spinal Injury Association Lower Extremity Motor Scores (LEMS) following surgery. Patients with lower extremity neurologic decline were grouped into unilateral and bilateral cohorts. Differences in demographics, surgical variables, and patient outcome measures between the two cohorts were analyzed. 265 patients had LEMS completed at discharge. Unilateral decline was seen in 32 patients (12%), while 29 (11%) had bilateral s...
World neurosurgery, Jan 11, 2018
The aims of this retrospective cohort study were to: 1) identify new alignment risk factors for p... more The aims of this retrospective cohort study were to: 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV); and 2) determine the effect of junctional tethers on PJK and UIV alignment. We analyzed consecutive ASD patients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly-anchored junctional tethers were utilized more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper vs. lower segmental lumbar lordosis (ULL, LLL) and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Uni- and multivariable analyses were performed. The study cohort comprised 120 ASD patients (mean age 67 years) with minimum 1-year follow-up. P...
Neurosurgery, Jan 28, 2018
Limited data are available to objectively define what constitutes a "good" versus a &qu... more Limited data are available to objectively define what constitutes a "good" versus a "bad" recovery for operative cervical deformity (CD) patients. Furthermore, the recovery patterns of primary versus revision procedures for CD is poorly understood. To define and compare the recovery profiles of CD patients undergoing primary or revision procedures, utilizing a novel area-under-the-curve normalization methodology. CD patients undergoing primary or revision surgery with baseline to 1-yr health-related quality of life (HRQL) scores were included. Clinical symptoms and HRQL were compared among groups (primary/revision). Normalized HRQL scores at baseline and follow-up intervals (3M, 6M, 1Y) were generated. Normalized HRQLs were plotted and area under the curve was calculated, generating one number describing overall recovery (Integrated Health State). Subanalysis identified recovery patterns through 2-yr follow-up. Eighty-three patients were included (45 primary, 38 ...
International journal of spine surgery, 2018
Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal def... more Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal deformity (CSD). Reciprocal changes in these parameters have been demonstrated in thoracolumbar deformity correction. The purpose of this study was to investigate the development of CSD, using T1 slope minus cervical lordosis (TS-CL) to define CSD and to correlate TS-CL and a novel global sagittal parameter, cervical-thoracic pelvic angle (CTPA), with CPL. A multicenter, retrospective analysis of patients with thoracolumbar deformity undergoing three-column osteotomy was performed. Preoperative and postoperative cervical parameters were investigated. Linear regression for postoperative values resulted in a CPL of 4 cm corresponding to a TS-CL threshold of 17°. Patients were classified based on postoperative TS-CL into uncompensated (TS-CL > 17°) or compensated cohorts (TS-CL < 17°); the two were compared using an unpaired test. Logistic regression modeling was used to determine predic...
European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, Jan 16, 2018
Accurate information regarding the expected complications of complex adult spinal deformity (ASD)... more Accurate information regarding the expected complications of complex adult spinal deformity (ASD) is important for shared decision making and informed consent. The purpose of the present study was to investigate the rate and types of non-neurologic adverse events after complex ASD surgeries, and to identify risk factors that affect their occurrence. The details and occurrence of all non-neurologic adverse events were reviewed in a prospective cohort of 272 patients after complex ASD surgical correction in a mulitcentre database of the Scoli-RISK-1 study with a planned follow-up of 2 years. Logistic regression analyses were used to identify potential risk factors for non-neurologic adverse events. Of the 272 patients, 184 experienced a total of 515 non-neurologic adverse events for an incidence of 67.6%. 121 (44.5%) patients suffered from more than one adverse event. The most frequent non-neurologic adverse events were surgically related (27.6%), of which implant failure and dural te...
Operative neurosurgery (Hagerstown, Md.), Jan 16, 2018
Pedicle subtraction osteotomy (PSO) is an effective technique to correct fixed sagittal malalignm... more Pedicle subtraction osteotomy (PSO) is an effective technique to correct fixed sagittal malalignment. A variation of this technique, the "trans-discal" or "extended" PSO (Schwab grade IV osteotomy), involves extending the posterior wedge resection of the index vertebra to include the superior adjacent disc for radical discectomy. The posterior wedge may be resected in asymmetric fashion to correct concurrent global coronal malalignment.This video illustrates the technical nuances of an extended asymmetrical lumbar PSO for adult spinal deformity. A 62-yr-old female with multiple prior lumbar fusions presented with worsening back pain and posture. Preoperative scoliosis X-rays demonstrated severe global sagittal and coronal malalignment (sagittal vertical axis [SVA, C7-plumbline] of 13.5 cm, pelvic incidence [PI] of 60°, lumbar lordosis [LL] of 14° [in kyphosis], pelvic tilt [PT] of 61°, thoracic kyphosis [TK] of 18°, and rightward coronal shift of 9.3 cm). The pat...
Operative neurosurgery (Hagerstown, Md.), Jan 5, 2018
Proximal junctional kyphosis (PJK) is a common problem after multilevel spine instrumentation for... more Proximal junctional kyphosis (PJK) is a common problem after multilevel spine instrumentation for adult spinal deformity. Various anti-PJK techniques such as junctional tethers for ligamentous augmentation have been proposed. We present an operative video demonstrating technical nuances of junctional tether "weave" application. A 70-yr-old male with prior L2-S1 instrumented fusion presented with worsening back pain and posture. Imaging demonstrated pathological loss of lumbar lordosis (flat back deformity), proximal junctional failure, and pseudarthrosis. The patient had severe global and segmental sagittal malalignment, with sagittal vertical axis (SVA, C7-plumbline) measuring 22.3 cm, pelvic incidence (PI) 55°, lumbar lordosis (LL) 8° in kyphosis, pelvic tilt (PT) 30°, and thoracic kyphosis (TK) 6°. The patient gave informed consent for surgery and use of imaging for medical publication. Briefly, surgery first involved re-instrumentation with bilateral pedicle screws fro...
Spine deformity
Retrospective review of prospective multicenter adult spinal deformity (ASD) database. To create ... more Retrospective review of prospective multicenter adult spinal deformity (ASD) database. To create a model based on baseline demographic, radiographic, health-related quality of life (HRQOL), and surgical factors that can predict patients meeting the Oswestry Disability Index (ODI) minimal clinically important difference (MCID) at the two-year postoperative follow-up. Surgical correction of ASD can result in significant improvement in disability as measured by ODI, with the goal of reaching at least one MCID. However, a predictive model for reaching MCID following ASD correction does not exist. ASD patients ≥18 years and baseline ODI ≥ 30 were included. Initial training of the model comprised forty-three variables including demographic data, comorbidities, modifiable surgical variables, baseline HRQOL, and coronal/sagittal radiographic parameters. Patients were grouped by whether or not they reached at least one ODI MCID at two-year follow-up. Decision trees were constructed using the...
Spine, Jan 12, 2018
Retrospective review OBJECTIVE.: Develop a simplified frailty index for CD patients SUMMARY OF BA... more Retrospective review OBJECTIVE.: Develop a simplified frailty index for CD patients SUMMARY OF BACKGROUND DATA.: To improve preoperative risk stratification for surgical cervical deformity (CD) patients, a CD frailty index (CD-FI) incorporating 40 health deficits was developed. While novel, the CD-FI is clinically impractical due to the large number of factors needed for its calculation. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary. CD patients (C2-C7 Cobb>10°, CL>10°, cSVA>4 cm, or CBVA>25°) >18yr with preoperative CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. Top deficits contributing to CD-FI score were included in multiple stepwise regression models. Deficits from model with largest R were dichotomized, and the mean score of all deficits calculated, resulting in mCD-FI score from 0 to 1. Patients were stratified by mCD-FI: Not Frail (NF...
Neurosurgical Focus
S ome prior reports have suggested that the use of recombinant human bone morphogenetic protein-2... more S ome prior reports have suggested that the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusion (ACF) may be beneficial in select patients with risk factors for developing pseudarthrosis. 1 However, other reports have provided evidence to suggest that there is potential for high complication rates (e.g., hematoma/seroma, cervical swelling, dysphagia) when using rhBMP-2 for ACF. 2 As such, there are currently no clear guidelines or definitive recommendations regarding the usage of rhBMP-2 in patients undergoing ACF. The explanation for some of the discrepancies from prior rhBMP-2/ACF reports is likely multifactorial but could potentially be attributed to nonstandardized dosing and delivery of rhBMP-2. 1-4 To address this important topic, Mendenhall et al. performed a retrospective study to evaluate the safety and efficacy of low-dose rhBMP-2 for use in patients undergoing ACF (both anterior cervical discectomy and corpectomy). 5 The authors hypothesized that the higher doses of rhBMP-2 used in prior ACF studies may have led to the higher complication rates observed. In this study, Mendenhall and colleagues included a total of 198 patients (62 [31%] were smokers) who underwent stand-alone ACF (median of 2 levels fused; mean rhBMP-2 dose 0.50 ± 0.09 mg/level; both contained and noncontained delivery devices were used). The authors reported associated complications and fusion rates with a minimum of 1 year of radiographic follow-up. Briefly, 22 (11%) patients experienced dysphagia, 11 (6%) patients experienced cervical swelling, 2 (1%) patients underwent washout for hematoma, 1 (0.5%) patient had washout for seroma, 2 (1%) patients had pseudarthrosis requiring posterior cervical fusion, and 3 (2%) patients experienced a new postoperative neurological deficit (which was reported to have recovered by the last follow-up). Regarding rates of arthrodesis, study results demonstrated that 190 (96%) patients had solid arthrodesis over an average of 15 months of follow-up (with no statistically significant difference in fusion rates between smokers and nonsmokers). After carefully analyzing these study results, the authors
Neurosurgery
BACKGROUND Lateral (ie, coronal) vertebral listhesis may contribute to disability in adult scolio... more BACKGROUND Lateral (ie, coronal) vertebral listhesis may contribute to disability in adult scoliosis patients. OBJECTIVE To assess for a correlation between lateral listhesis and disability among patients with adult scoliosis. METHODS This was a retrospective multi-center analysis of prospectively collected data. Patients eligible for a minimum of 2-yr follow-up and with coronal plane deformity (defined as maximum Cobb angle ≥20º) were included (n = 724). Outcome measures were Oswestry Disability Index (ODI) and leg pain numeric scale rating. Lateral thoracolumbar listhesis was measured as the maximum vertebral listhesis as a percent of the superior endplate across T1-L5 levels. Linear and logistic regression was utilized, as appropriate. Multivariable analyses adjusted for demographics, comorbidities, surgical invasiveness, maximum Cobb angle, and T1-PA. Minimally clinically important difference (MCID) in ODI was defined as 12.8. RESULTS In total, 724 adult patients were assessed. ...
Spine Deformity
Informed decision making for operative treatment of the skeletally mature adolescent idiopathic s... more Informed decision making for operative treatment of the skeletally mature adolescent idiopathic scoliosis (AIS) patient meeting surgical indications requires a discussion of differences in operative morbidity in adult scoliosis versus AIS. This study evaluated differences in operative data and outcomes between AIS and adult scoliosis patients based on an estimated natural history of curve progression. Twenty-eight adult scoliosis patients (43.7 ± 15.8 years; 93% F) were 1:2 matched with 56 (Risser 4/5) AIS patients (15.7 ± 2.1 years) based on gender and curve type as vetted by 5 surgeons' consensus in committee. Curve progression of 0.3°/year for the first 10 years following skeletal maturity and a 0.5°/year thereafter was assumed to estimate curve progression from AIS to adulthood for the adult counterpart. Operative data, complications, and quality of life (Scoliosis Research Society [SRS-22r] questionnaire) measures were evaluated, with a minimum 2-year follow-up. Postoperative major Cobb and percentage correction were similar between adult versus AIS, whereas operative time, percentage estimated blood loss (EBL; % total blood volume), length of hospital stay (LOS), and total spine levels fused were greater for adult patients (p < .05). No difference was found in EBL, operative time, or LOS when normalized by levels fused. Ten (36%) adult scoliosis patients were fused to the pelvis compared with none in AIS (p < .0001). Major complication rate was higher for adult versus AIS (25% vs. 5.4%; p < .05). Preoperative SRS-22r scores were worse for adult patients; however, they demonstrated greater improvement in SRS-22r than the AIS cohort at final follow-up. A higher percentage of adult patients reached the MCID in self-image domain than the AIS patients (92.3% vs. 61.8%; p = .0040). Treatment of the adult scoliosis patient who has undergone an estimated natural history of progression is characterized by greater levels fused, operative time, and higher complication rates than the AIS counterpart. Longer-term follow-up of AIS is needed to define the benefits of early intervention of relatively asymptomatic adolescent patients versus late treatment of symptomatic disease in the adult.
SPINE
Retrospective review of prospective multicenter database. To identify an optimal set of factors p... more Retrospective review of prospective multicenter database. To identify an optimal set of factors predicting the risk of PJF while taking the time dependency of PJF and those factors into account. Surgical correction of adult spinal deformity (ASD) can be complex and therefore, may come with high revision rates due to proximal junctional failure (PJF). 763 operative ASD patients with a minimum of 1-year follow-up were included. PJF was defined as any type of proximal junctional kyphosis (PJK) requiring revision surgery. Time-dependent ROC curves were estimated with corresponding Cox proportional hazard models. The predictive abilities of demographic, surgical, radiographic parameters and their possible combinations were assessed sequentially. The area under the curve (AUC) was used to evaluate models' performance. PJF occurred in 42 patients (6%), with a median time to revision of approximately one year. Larger preoperative pelvic tilt (PT) (Hazard ratio [HR]=1.044, p = 0.034) significantly increased the risk of PJF. With respect to changes in the radiographic parameters at 6-week post-surgery, larger differences in pelvic incidence-lumbar lordosis (PI-LL) mismatch (HR = 0.924, p = 0.002) decreased risk of PJF. The combination of demographic, surgical and radiographic parameters has the best predictive ability for the occurrence of PJF (AUC = 0.863), followed by demographic along with radiographic parameters (AUC = 0.859). Both models' predictive ability was preserved over time. Over correction increased the risk of PJF. Radiographic along with demographic parameters have shown the approximately equivalent predictive ability for PJF over time as with the addition of surgical parameters. Radiographic rather than surgical factors may of particular importance in predicting the development of PJF over time. These results set the groundwork for risk stratification and corresponding prophylactic interventions for patients undergoing ASD surgery. 4.
SPINE
This study retrospectively analyzes prospectively collected data. Here we aim to determine the in... more This study retrospectively analyzes prospectively collected data. Here we aim to determine the influence of preoperative and 12-month mJOA on satisfaction; and understand the change in mJOA severity classification after surgical management of DCM. Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease resulting from cervical cord compression. The natural progression of DCM is variable; some patients experience periods of stability, while others rapidly deteriorate following disease onset. The modified Japanese Orthopedic Association (mJOA) is commonly used to grade and categorize myelopathy symptoms, but its association with post-operative satisfaction has not been previously explored. The QOD (Quality and Outcomes Database) was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥ 14), moderate (9 to 13), or severe (< 9) categories on the mJOA scores. A McNemar-Bowker test was used to assess whether a significant proportion of patients changed mJOA category between preoperative and 12 months postoperative. A multivariable proportional odds ordinal logistic regression model was fitted with 12-month satisfaction as the outcome of interest. We identified 1963 patients who underwent elective surgery for DCM and completed 12-months follow-ups. Comparing mJOA severity level preoperatively and at 12 months revealed that 55% remained in the same category, 37% improved, and 7% moved to a worse category. After adjusting for baseline and surgery-specific variables, the 12-month mJOA category had the highest impact on patient satisfaction (p < .001). Patient satisfaction is an indispensable tool for measuring quality of care following spine surgery. In this sample, 12-month mJOA category, regardless of preop mJOA, was significantly correlated with satisfaction. Given these findings, it is important to advise patients of the probability that surgery will change their mJOA severity classification and the changes required to achieve post-operative satisfaction. 3.
Journal of neurosurgery. Spine, Jan 10, 2018
OBJECTIVE Achieving appropriate spinopelvic alignment in deformity surgery has been correlated wi... more OBJECTIVE Achieving appropriate spinopelvic alignment in deformity surgery has been correlated with improvement in pain and disability. Minimally invasive surgery (MIS) techniques have been used to treat adult spinal deformity (ASD); however, there is concern for inadequate sagittal plane correction. Because age can influence the degree of sagittal correction required, the purpose of this study was to analyze whether obtaining optimal spinopelvic alignment is required in the elderly to obtain clinical improvement. METHODS A multicenter database of ASD patients was queried. Inclusion criteria were age ≥ 18 years; an MIS component as part of the index procedure; at least one of the following: pelvic tilt (PT) > 20°, sagittal vertical axis (SVA) > 50 mm, pelvic incidence to lumbar lordosis (PI-LL) mismatch > 10°, or coronal curve > 20°; and minimum follow-up of 2 years. Patients were stratified into younger (< 65 years) and older (≥ 65 years) cohorts. Within each cohort,...
World Neurosurgery
Adult spinal deformity (ASD) operations are complex and often require a multi-surgeon team. Simul... more Adult spinal deformity (ASD) operations are complex and often require a multi-surgeon team. Simultaneously, it is the responsibility of academic spine surgeons to train future complex spine surgeons. Our objective was to assess the impact of resident/fellow involvement (RFI) on ASD surgery in four areas: 1) perioperative outcomes, 2) length of stay (LOS), 3) discharge status, and 4) complications. Adults undergoing thoracolumbar spinal deformity correction between 2008 and 2014 were identified in the National Surgical Quality Improvement Program (NSQIP) database. Cases were divided into those with RFI compared to attending(s) only. The outcomes were: operative time, transfusions, LOS, discharge status, and complications. Univariate and multivariable regression modeling was used. Covariates included preoperative comorbidities, specialty, and levels instrumented. A total of 1,471 patients underwent ASD surgery with RFI in 784 (53%) operations. After multivariable regression modeling, RFI was independently associated with longer operations (β=66.01 minutes, 95%CI 35.82-96.19, p<0.001), increased odds of transfusion (OR 2.80, 95%CI 1.81-4.32, p<0.001), longer hospital stay (β=1.76 days, 95% CI 0.18-3.34, p=0.030), and discharge to inpatient rehab or skilled nursing facility (OR 2.02, 95% CI 1.34-3.05, p<0.001). However, RFI was not associated with any increase in major or minor complications. RFI in ASD surgery was associated with increased operative time, additional transfusions, longer LOS, and non-home discharge; however, no increase in major, minor, or severe complications was seen. These data support the continued training of future deformity and complex spine surgeons without fear of worsening complications, yet areas of improvement exist.
Journal of spine surgery (Hong Kong), 2018
Current health-related quality of life (HRQL) metrics used to assess patient outcomes following s... more Current health-related quality of life (HRQL) metrics used to assess patient outcomes following surgical correction of cervical deformity (CD) are not deformity-specific and thus cannot capture all aspects of a patient's deformity and outcomes. The purpose of this study is to evaluate the sensitivity of different HRQL outcome measures in assessing CD patients' outcomes 1-year post-operatively. Retrospective review of prospective multi-center database. Inclusion criteria: CD patients ≥18 yrs with pre- and 1-year post-operative radiographs and HRQLs [modified Japanese Orthopaedic Association (mJOA), EuroQol five-dimensions (EQ-5D), neck disability index (NDI)]. Associations between changes in EQ5D and NDI with improvement at 1-year in mJOA scores were assessed by whether or not the patient met the minimum clinically important difference (MCID) as well as whether or not they improved by one or more categories (i.e., change from moderate to mild). Odds ratios reported with 95% c...
Spine, 2018
Retrospective analysis. To define thoracic compensation and investigate its association with post... more Retrospective analysis. To define thoracic compensation and investigate its association with postoperative reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) SUMMARY OF BACKGROUND DATA.: Adult spinal deformity (ASD) patients recruit compensatory mechanisms like pelvic retroversion and knee flexion. However, thoracic hypokyphosis is a less recognized compensatory mechanism. Patients enrolled in a multicenter ASD registry undergoing fusions to the pelvis with upper instrumented vertebra (UIV) between T9 and L1 were included. Patients were divided into those with postoperative reciprocal thoracic kyphosis (reciprocal kyphosis [RK]: change in unfused thoracic kyphosis [TK] ≥15°) with and without PJK and those who maintained thoracic alignment (MT). Thoracic compensation was defined as expected thoracic kyphosis (eTK) minus preoperative TK. For RK (n = 117), the mean change in unfused TK was 21.7° versus 6.1° for MT (n = 102) and the mean PJK angle change was 17.6° versu...
The spine journal : official journal of the North American Spine Society, Jan 14, 2018
Scoli-RISK-1 is a multicenter prospective cohort designed to study neurologic outcomes following ... more Scoli-RISK-1 is a multicenter prospective cohort designed to study neurologic outcomes following complex adult spinal deformity (ASD). The effect of unilateral versus bilateral postoperative motor deficits on the likelihood of long term recovery has not been previously studied in this population. Evaluate if bilateral postoperative neurologic deficits have a worse recovery than unilateral deficits. Secondary analysis of a prospective, multicenter, international cohort study. In a cohort of 272 patients neurologic decline was defined as deterioration of the American Spinal Injury Association Lower Extremity Motor Scores (LEMS) following surgery. Patients with lower extremity neurologic decline were grouped into unilateral and bilateral cohorts. Differences in demographics, surgical variables, and patient outcome measures between the two cohorts were analyzed. 265 patients had LEMS completed at discharge. Unilateral decline was seen in 32 patients (12%), while 29 (11%) had bilateral s...
World neurosurgery, Jan 11, 2018
The aims of this retrospective cohort study were to: 1) identify new alignment risk factors for p... more The aims of this retrospective cohort study were to: 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV); and 2) determine the effect of junctional tethers on PJK and UIV alignment. We analyzed consecutive ASD patients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly-anchored junctional tethers were utilized more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper vs. lower segmental lumbar lordosis (ULL, LLL) and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Uni- and multivariable analyses were performed. The study cohort comprised 120 ASD patients (mean age 67 years) with minimum 1-year follow-up. P...
Neurosurgery, Jan 28, 2018
Limited data are available to objectively define what constitutes a "good" versus a &qu... more Limited data are available to objectively define what constitutes a "good" versus a "bad" recovery for operative cervical deformity (CD) patients. Furthermore, the recovery patterns of primary versus revision procedures for CD is poorly understood. To define and compare the recovery profiles of CD patients undergoing primary or revision procedures, utilizing a novel area-under-the-curve normalization methodology. CD patients undergoing primary or revision surgery with baseline to 1-yr health-related quality of life (HRQL) scores were included. Clinical symptoms and HRQL were compared among groups (primary/revision). Normalized HRQL scores at baseline and follow-up intervals (3M, 6M, 1Y) were generated. Normalized HRQLs were plotted and area under the curve was calculated, generating one number describing overall recovery (Integrated Health State). Subanalysis identified recovery patterns through 2-yr follow-up. Eighty-three patients were included (45 primary, 38 ...
International journal of spine surgery, 2018
Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal def... more Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal deformity (CSD). Reciprocal changes in these parameters have been demonstrated in thoracolumbar deformity correction. The purpose of this study was to investigate the development of CSD, using T1 slope minus cervical lordosis (TS-CL) to define CSD and to correlate TS-CL and a novel global sagittal parameter, cervical-thoracic pelvic angle (CTPA), with CPL. A multicenter, retrospective analysis of patients with thoracolumbar deformity undergoing three-column osteotomy was performed. Preoperative and postoperative cervical parameters were investigated. Linear regression for postoperative values resulted in a CPL of 4 cm corresponding to a TS-CL threshold of 17°. Patients were classified based on postoperative TS-CL into uncompensated (TS-CL > 17°) or compensated cohorts (TS-CL < 17°); the two were compared using an unpaired test. Logistic regression modeling was used to determine predic...
European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, Jan 16, 2018
Accurate information regarding the expected complications of complex adult spinal deformity (ASD)... more Accurate information regarding the expected complications of complex adult spinal deformity (ASD) is important for shared decision making and informed consent. The purpose of the present study was to investigate the rate and types of non-neurologic adverse events after complex ASD surgeries, and to identify risk factors that affect their occurrence. The details and occurrence of all non-neurologic adverse events were reviewed in a prospective cohort of 272 patients after complex ASD surgical correction in a mulitcentre database of the Scoli-RISK-1 study with a planned follow-up of 2 years. Logistic regression analyses were used to identify potential risk factors for non-neurologic adverse events. Of the 272 patients, 184 experienced a total of 515 non-neurologic adverse events for an incidence of 67.6%. 121 (44.5%) patients suffered from more than one adverse event. The most frequent non-neurologic adverse events were surgically related (27.6%), of which implant failure and dural te...
Operative neurosurgery (Hagerstown, Md.), Jan 16, 2018
Pedicle subtraction osteotomy (PSO) is an effective technique to correct fixed sagittal malalignm... more Pedicle subtraction osteotomy (PSO) is an effective technique to correct fixed sagittal malalignment. A variation of this technique, the "trans-discal" or "extended" PSO (Schwab grade IV osteotomy), involves extending the posterior wedge resection of the index vertebra to include the superior adjacent disc for radical discectomy. The posterior wedge may be resected in asymmetric fashion to correct concurrent global coronal malalignment.This video illustrates the technical nuances of an extended asymmetrical lumbar PSO for adult spinal deformity. A 62-yr-old female with multiple prior lumbar fusions presented with worsening back pain and posture. Preoperative scoliosis X-rays demonstrated severe global sagittal and coronal malalignment (sagittal vertical axis [SVA, C7-plumbline] of 13.5 cm, pelvic incidence [PI] of 60°, lumbar lordosis [LL] of 14° [in kyphosis], pelvic tilt [PT] of 61°, thoracic kyphosis [TK] of 18°, and rightward coronal shift of 9.3 cm). The pat...
Operative neurosurgery (Hagerstown, Md.), Jan 5, 2018
Proximal junctional kyphosis (PJK) is a common problem after multilevel spine instrumentation for... more Proximal junctional kyphosis (PJK) is a common problem after multilevel spine instrumentation for adult spinal deformity. Various anti-PJK techniques such as junctional tethers for ligamentous augmentation have been proposed. We present an operative video demonstrating technical nuances of junctional tether "weave" application. A 70-yr-old male with prior L2-S1 instrumented fusion presented with worsening back pain and posture. Imaging demonstrated pathological loss of lumbar lordosis (flat back deformity), proximal junctional failure, and pseudarthrosis. The patient had severe global and segmental sagittal malalignment, with sagittal vertical axis (SVA, C7-plumbline) measuring 22.3 cm, pelvic incidence (PI) 55°, lumbar lordosis (LL) 8° in kyphosis, pelvic tilt (PT) 30°, and thoracic kyphosis (TK) 6°. The patient gave informed consent for surgery and use of imaging for medical publication. Briefly, surgery first involved re-instrumentation with bilateral pedicle screws fro...
Spine deformity
Retrospective review of prospective multicenter adult spinal deformity (ASD) database. To create ... more Retrospective review of prospective multicenter adult spinal deformity (ASD) database. To create a model based on baseline demographic, radiographic, health-related quality of life (HRQOL), and surgical factors that can predict patients meeting the Oswestry Disability Index (ODI) minimal clinically important difference (MCID) at the two-year postoperative follow-up. Surgical correction of ASD can result in significant improvement in disability as measured by ODI, with the goal of reaching at least one MCID. However, a predictive model for reaching MCID following ASD correction does not exist. ASD patients ≥18 years and baseline ODI ≥ 30 were included. Initial training of the model comprised forty-three variables including demographic data, comorbidities, modifiable surgical variables, baseline HRQOL, and coronal/sagittal radiographic parameters. Patients were grouped by whether or not they reached at least one ODI MCID at two-year follow-up. Decision trees were constructed using the...
Spine, Jan 12, 2018
Retrospective review OBJECTIVE.: Develop a simplified frailty index for CD patients SUMMARY OF BA... more Retrospective review OBJECTIVE.: Develop a simplified frailty index for CD patients SUMMARY OF BACKGROUND DATA.: To improve preoperative risk stratification for surgical cervical deformity (CD) patients, a CD frailty index (CD-FI) incorporating 40 health deficits was developed. While novel, the CD-FI is clinically impractical due to the large number of factors needed for its calculation. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary. CD patients (C2-C7 Cobb>10°, CL>10°, cSVA>4 cm, or CBVA>25°) >18yr with preoperative CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. Top deficits contributing to CD-FI score were included in multiple stepwise regression models. Deficits from model with largest R were dichotomized, and the mean score of all deficits calculated, resulting in mCD-FI score from 0 to 1. Patients were stratified by mCD-FI: Not Frail (NF...