Faculty Bibliography
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604
Identifying Thoracic Compensation and Predicting Reciprocal Thoracic Kyphosis and PJK in Adult Spinal Deformity Surgery
STUDY DESIGN/METHODS:Retrospective analysis. OBJECTIVE: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. METHODS:Patients enrolled in a multicenter ASD registry undergoing fusions to the pelvis with UIV between T9-L1 were included. Patients were divided into those with postoperative reciprocal thoracic kyphosis (RK: change in unfused 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. RESULTS:For RK (n = 117), the mean change in unfused TK was 21.7° vs 6.1° for MT (n = 102) and the mean PJK angle change was 17.6° vs 5.7° for MT (all p < 0.001). RK and MT were similar in age, BMI, gender, and comorbidities. RK had larger preoperative PI-LL mismatch (30.7 vs. 23.6 p = 0.008) and less preoperative TK (22.3 vs. 30.6 p < 0.001), otherwise SVA, PT and TPA were similar. RK patients had more preoperative thoracic compensation (29.9 vs. 20.0, p < 0.001), more PI-LL correction (29.8 vs. 17.3, p < 0.001) and higher rates of PJK (66% vs. 19%, p < 0.001). There were no differences in preoperative HRQOL except RK had worse SRS appearance (2.2 vs. 2.5, p = 0.005). Using a logistic regression model, the only predictor for postoperative reciprocal thoracic kyphosis was more preoperative thoracic compensation. Postoperatively the RK and MT groups were well aligned. Both younger and older (>65y) RK patients had greater thoracic compensation than MT counterparts. The eTK was not significantly different from the postoperative TK for the RK group without PJK (p = 0.566). CONCLUSIONS:The presence of thoracic compensation in adult spinal deformity is the primary determinant of postoperative reciprocal thoracic kyphosis and these patients have higher rates of proximal junctional kyphosis. LEVEL OF EVIDENCE/METHODS:3.
PMID: 30096125
ISSN: 1528-1159
CID: 3236492
Outcomes of Operative Treatment for Adult Cervical Deformity: A Prospective Multicenter Assessment With 1-Year Follow-up
BACKGROUND:Despite the potential for profound impact of adult cervical deformity (ACD) on function and health-related quality of life (HRQOL), there are few high-quality studies that assess outcomes of surgical treatment for these patients. OBJECTIVE:To determine the impact of surgical treatment for ACD on HRQOL. METHODS:We conducted a prospective cohort study of surgically treated ACD patients eligible for 1-yr follow-up. Baseline deformity characteristics, surgical parameters, and 1-yr HRQOL outcomes were assessed. RESULTS:Of 77 ACD patients, 55 (71%) had 1-yr follow-up (64% women, mean age of 62 yr, mean Charlson Comorbidity Index of 0.6, previous cervical surgery in 47%). Diagnoses included cervical sagittal imbalance (56%), cervical kyphosis (55%), proximal junctional kyphosis (7%) and coronal deformity (9%). Posterior fusion was performed in 85% (mean levels = 10), and anterior fusion was performed in 53% (mean levels = 5). Three-column osteotomy was performed in 24% of patients. One year following surgery, ACD patients had significant improvement in Neck Disability Index (50.5 to 38.0, P < .001), neck pain numeric rating scale score (6.9 to 4.3, P < .001), EuroQol 5 dimension (EQ-5D) index (0.51 to 0.66, P < .001), and EQ-5D subscores: mobility (1.9 to 1.7, P = .019), usual activities (2.2 to 1.9, P = .007), pain/discomfort (2.4 to 2.1, P < .001), anxiety/depression (1.8 to 1.5, P = .014). CONCLUSION/CONCLUSIONS:Based on a prospective multicenter series of ACD patients, surgical treatment provided significant improvement in multiple measures of pain and function, including Neck Disability Index, neck pain numeric rating scale score, and EQ-5D. Further follow-up will be necessary to assess the long-term durability of these improved outcomes.
PMID: 29281107
ISSN: 1524-4040
CID: 3369612
Development of a validated computer-based preoperative predictive model for pseudarthrosis with 91% accuracy in 336 adult spinal deformity patients
OBJECTIVEPseudarthrosis 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.METHODSA 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.RESULTSA 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.CONCLUSIONSA 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.
PMID: 30453452
ISSN: 1092-0684
CID: 3562712
Lack of Consensus in Physician Recommendations Regarding Return to Driving After Cervical Spine Surgery
STUDY DESIGN/METHODS:Cross-Sectional Study. OBJECTIVE:The goal of this study is to investigate how surgeons differ in collar and narcotic use, as well as return to driving recommendations following cervical spine surgeries and the associated medico-legal ramifications of these conditions. SUMMARY OF BACKGROUND DATA/BACKGROUND:Restoration of quality of life is one of the main goals of cervical spine surgery. Patients frequently inquire when they may safely resume driving after cervical spine surgery. There is no consensus regarding post-operative driving restrictions. This study addresses how surgeons differ in their recommendations concerning cervical immobilization, narcotic analgesia, and suggested timeline of return to driving following cervical spine surgery. METHODS:Surgeons at the Cervical Spine Research Society annual meeting completed anonymous surveys assessing postoperative patient management following fusion and non-fusion cervical spine surgeries. RESULTS:70% of surgeons returned completed surveys (n = 71). 80.3% were orthopaedic surgeons and 94.2% completed a spine fellowship. Experienced surgeons (>15y in practice) were more likely to let patients return to driving within 2 weeks than less experienced surgeons (47.1% vs 24.3%, p = .013) for multi-level ACDF and laminectomy with fusion procedures. There were no differences between surgeons practicing inside and outside the USA for prescribing collars or return to driving time. Cervical collars were used more for fusions than non-fusions (57.7% vs 31.0%, p = .001). Surgeons reported 75.3% of patients ask when they may resume driving. For cervical fusions, 31.4% of surgeons allowed their patients to resume driving while restricting them with collars for longer durations. Furthermore, 27.5% of surgeons allowed their patients to resume driving while taking narcotics post-operatively. CONCLUSIONS:This survey-based study highlights the lack of consensus regarding patient 'fitness to drive' following cervical spine surgery. The importance of establishing evidence-based guidelines is critical as recommendations for driving in the post-operative period may have significant medical, legal, and financial implications. LEVEL OF EVIDENCE/METHODS:5.
PMID: 29528997
ISSN: 1528-1159
CID: 2992522
Primary Drivers of Adult Cervical Deformity: Prevalence, Variations in Presentation, and Effect of Surgical Treatment Strategies on Early Postoperative Alignment
BACKGROUND: Primary drivers (PDs) of adult cervical deformity (ACD) have not been described in relation to pre- and early postoperative alignment or degree of correction. OBJECTIVE: To define the PDs of ACD to understand the impact of driver region on global postoperative compensatory mechanisms. METHODS: Primary cervical deformity driver/vertebral apex level were determined: CS = cervical; CTJ = cervicothoracic junction; TH = thoracic; SP = spinopelvic. Patients were evaluated if surgery included PD apex, based on the lowest instrumented vertebra (LIV): CS: LIV
PMID: 28950349
ISSN: 1524-4040
CID: 2717642
The value of sitting radiographs: analysis of spine flexibility and its utility in preoperative planning for adult spinal deformity surgery
OBJECTIVE Preoperative planning of thoracolumbar deformity (TLD) surgery has been shown to improve radiographic and clinical outcomes. One of the confounders in attaining optimal postoperative alignment is the reciprocal hyperkyphosis of unfused thoracic segments. Traditional planning utilizes standing radiographs, but the value of sitting radiographs to predict thoracic flexibility has not been investigated. Authors of the present study propose that alignment changes from a sitting to a standing position will predict changes in unfused thoracic segments after TLD correction. METHODS Patients with degenerative spine pathology underwent preoperative sitting and standing full-spine stereotactic radiography. A subset of TLD patients who had undergone corrections with minimum T10-pelvis fusions was analyzed in terms of pre- to postoperative alignment. Radiographic parameters were analyzed, including the T1 pelvic angle (TPA), T1-L1 pelvic angle (TLPA), lumbar pelvic angle (LPA), pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL mismatch), and T2-12 kyphosis (TK). Thoracic compensation was calculated as the expected TK minus actual TK (i.e., [2/3 × PI] - actual TK). Statistical analysis consisted of paired and unpaired t-tests and linear regression analysis. RESULTS The authors retrospectively identified 137 patients with full-body standing and sitting radiographs. The mean age of the patients was 60.9 years old, 60.0% were female, and the mean BMI was 27.8 kg/m2. The patients demonstrated significantly different radiographic alignments in baseline spinopelvic and global parameters from the preoperative sitting versus the standing positions: LL (-34.20° vs -47.87°, p < 0.001), PT (28.31° vs 17.50°, p < 0.001), TPA (27.85° vs 16.89°, p < 0.001), TLPA (10.63° vs 5.17°, p < 0.001), and LPA (15.86° vs 9.67°, p < 0.001). Twenty patients (65.0% female) with a mean age of 65.3 years and mean BMI of 30.2 kg/m2 had TLD and underwent surgical correction (pre- to postoperative standing change in TPA: 33.90° to 24.50°, p = 0.001). Preoperative sitting radiographs demonstrated significant differences in alignment compared to postoperative standing radiographs: larger TPA (39.10° vs 24.50°, p < 0.001), PT (35.40° vs 28.10°, p < 0.001), LL (-11.20° vs -44.80°, p < 0.001), LPA (22.80° vs 14.20°, p < 0.001), and unfused Cobb (T2 to upper instrumented vertebra [UIV] Cobb angle: 19.95° vs 27.50°, p = 0.039). Also in the TLD group, mean thoracic compensation was 6.75°. In the linear regression analysis, the change from sitting to standing predicted pre- to postoperative changes for TK and the unfused thoracic component of TPA (5° change in preoperative sitting to preoperative standing corresponded to a pre- to postoperative change in standing TK of 6.35° and in standing TPA of 7.23°, R2 = 0.30 and 0.38, respectively). CONCLUSIONS Sitting radiographs were useful in demonstrating spine flexibility. Among the TLD surgery group, relaxation of the unfused thoracic spine in the sitting position predicted the postoperative increase in kyphosis of the unfused thoracic segments. Sitting radiographs are a useful tool to anticipate reciprocal changes in thoracic alignment that diminish global corrections.
PMID: 29979136
ISSN: 1547-5646
CID: 3186192
Radiological severity of hip osteoarthritis in patients with adult spinal deformity: the effect on spinopelvic and lower extremity compensatory mechanisms
PURPOSE/OBJECTIVE:Sagittal spinal deformity (SSD) patients utilize pelvic tilt (PT) and their lower extremities in order to compensate for malalignment. This study examines the effect of hip osteoarthritis (OA) on compensatory mechanisms in SSD patients. METHODS:Patients ≥ 18 years with SSD were included for analysis. Spinopelvic, lower extremity, and cervical alignment were assessed on standing full-body stereoradiographs. Hip OA severity was graded by Kellgren-Lawrence scale (0-4). Patients were categorized as limited osteoarthritis (LOA: grade 0-2) and severe osteoarthritis (SOA: grade 3-4). Patients were matched for age and T1-pelvic angle (TPA). Spinopelvic [sagittal vertical axis (SVA), T1-pelvic angle, thoracic kyphosis (TK), pelvic tilt (PT), lumbar lordosis (LL), pelvic incidence minus lumbar lordosis (PI-LL), T1-spinopelvic inclination (T1SPi)] and lower extremity parameters [sacrofemoral angle, knee angle, ankle angle, posterior pelvic shift (P. Shift), global sagittal axis (GSA)] were compared between groups using independent sample t test. RESULTS:136 patients (LOA = 68, SOA = 68) were included in the study. SOA had less pelvic tilt (p = 0.011), thoracic kyphosis (p = 0.007), and higher SVA and T1Spi (p < 0.001) than LOA. SOA had lower sacrofemoral angle (p < 0.001) and ankle angle (p = 0.043), increased P. Shift (p < 0.001) and increased GSA (p < 0.001) compared to LOA. There were no differences in PI-LL, LL, knee angle, or cervical alignment (p > 0.05). CONCLUSIONS:Patients with coexisting spinal malalignment and SOA compensate by pelvic shift and thoracic hypokyphosis rather than PT, likely as a result of limited hip extension secondary to SOA. As a result, SOA had worse global sagittal alignment than their LOA counterparts. These slides can be retrieved under Electronic Supplementary Material.
PMID: 29417324
ISSN: 1432-0932
CID: 2948212
Rod Fracture Following Apparently Solid Radiographic Fusion in Adult Spinal Deformity Patients
PMID: 29929025
ISSN: 1878-8769
CID: 3158312
The Posterior Use of BMP-2 in Cervical Deformity Surgery Does Not Result in Increased Early Complications: A Prospective Multicenter Study
Study Design/UNASSIGNED:Prospective cohort study. Objectives/UNASSIGNED:To describe the rate of short-term complications following the posterior use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in cervical deformity (CD) surgery. Methods/UNASSIGNED:CD patients from 2013 to 2015 were enrolled in a prospective, multicenter database. Patients were divided into those receiving rhBMP-2 (BMP) and no rhBMP-2 (NOBMP). The relationship between BMP use, demographic variables surgical variables, radiographic parameters and complications was evaluated. Results/UNASSIGNED:= 0.09, 0.08, 0.06) between the use of BMP and complications (major or operative). Conclusions/UNASSIGNED:BMP use was not directly associated with an increased incidence of early complications in this prospective cohort of operative adult CD patients. Its use was associated with increased number of levels instrumented and fused.
PMCID:6125935
PMID: 30202717
ISSN: 2192-5682
CID: 3286732
Severity of hip osteoarthritis affects lower extremity compensatory mechanisms in spinopelvic malalignment [Meeting Abstract]
Introduction/objectives: Diagnosis and treatment of patients with coexisting hip and spine pathologies can be challenging. Patients with sagittal spinopelvic deformity utilize pelvic tilt (PT) and their lower extremities in order to compensate for malalignment. In patients with lower extremity osteoarthritis (OA), these compensatory mechanisms can be compromised, leading to further disability. Methods: Patients > 18 years with SSD [SVA > 50mm, PT > 25degree, or TK > 60degree] were included for analysis. Spinopelvic, lower extremity, and cervical alignment were assessed on standing full-body stereoradiographs. Hip OA severity was graded by Kellgren-Lawrence scale (0-4). Propensity score matching was used to control for age and T1 pelvic angle (TPA). Patients were categorized as limited OA (LOA: grade 0-2) and severe OA (SOA: grade 3-4). Results: A total of 997 patients (LOA=929, SOA=68) were identified meeting inclusion criteria. After PSM, 136 patients (SOA: n=68, LOA n=68) were included in the study. SOA had less PT (17.8degree+/-12.6degree vs 22.6degree+/-8.4degree, p=0.011), TK (42.5degree+/-21.2degree vs 52.3degree+/-20.2degree, p=0.007), higher SVA (71.6 mm+/-47.1 vs 40.7 mm+/-43.9, p<0.001) and T1Spi (+2.3degree+/-6.4degree vs -2.6degree+/-5.5degree, p<0.001) than LOA. SOA also had a lower SFA (194.3degree+/-12.4degree vs 202.4degree+/-9.5degree, p<0.001) and AA (5.9degree+/-3.5degree vs 7.2degree+/-3.6degree, p=0.043), increased P.Shift (49.7mm+/-39.5 vs 19.7mm+/-28.4; p<0.001) and increased GSA (7.7degree+/-4.5degree vs 5.0degree+/-4.0degree, p< 0.001) compared to LOA. There was no difference in PI, PI-LL mismatch, LL, KA or cervical alignment (p >0.05). Conclusion: Patients with coexisting spinal malalignment and severe hip OA compensate by pelvic shift and thoracic hypokyphosis rather than pelvic tilt, likely as a result of limited hip extension
EMBASE:624286771
ISSN: 1120-7000
CID: 3370832
