Faculty Bibliography

STUDY DESIGN: Retrospective review of prospective multicenter database. OBJECTIVE: Identify factors influencing readmission, reoperation, and the impact on health related quality of life outcomes (HRQoL's) in adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA: Many ASD patients experience complications requiring readmission. It is important to identify baseline/operative factors leading to rehospitalizations and reoperation, which may impact outcomes. METHODS: Inclusion criteria: ASD surgical patients (age > 18years, major coronal Cobb>/=20 degrees , SVA>/=5 cm, PT>/=25 degrees and/or TK > 60 degrees ) with complete baseline, 1-, and 2-year follow-up. Patients were grouped on the basis of readmission occurrence (yes/no) and type (medical [no reoperation] vs. surgical [revision surgery]). Readmissions caused by infections requiring surgical treatment (e.g. deep infections) were considered reoperations. Univariate and multivariate analyses determined readmission and reoperation predictors. Repeated measures mixed models evaluated readmission impact on HRQoL's at 1- and 2-years. RESULTS: 334 patients were included: 76 (22.8%) readmissions, involving 65 (85.5% of 76) reoperations (surgical readmission) and 11 (14.5% of 76) medical readmissions. The most common surgical readmission indication (n = 65) was implant complications (36.9%; rod breakage n = 13); the most common medical readmission indication was infection (36.4%, n = 4), treated with antibiotics. Non-infectious medical readmission (n = 7) included: pleural effusion, DTV, intra-operative blood loss, neurologic, and unspecified. Readmission predictors: increased number of major peri-operative complications (OR 5.13, p = 0.014), infection presence (OR 25.02, p = 0.001), implant complications (OR 6.12, p < 0.001), and radiographic complications (DJK, PJK, pseudoarthrosis, sagittal/coronal imbalance) (OR 16.94, p < 0.001). HRQoL analysis revealed overall improvement of the full cohort (p < 0.01), though the 76 readmitted improved less overall and at each time point p < 0.001) except in 6-week MCS (p = 0.14). CONCLUSIONS: Major peri-operative, implant, radiographic, and infection complications during index were associated with increased readmission odds. Implant complications most frequently caused surgical readmissions. Readmitted patients improved in outcome scores, although less compared to the non-readmitted cohort, yet displayed reduced 6-week SF-36 MCS. LEVEL OF EVIDENCE: 3.

Prolonged length of stay (PLOS) has been associated with increased hospital resource utilization and worsened patient outcomes in multiple studies. In this study, we defined and identified factors associated with PLOS after posterior surgery for cervical spondylotic myelopathy in patients over the age of 65. PLOS was defined as length of stay beyond the "prolongation point" (that is, the day after which discharge rates begin to decline). Using the United States Nationwide Inpatient Sample database, 2742 patients met inclusion criteria, out of whom 16.5% experienced PLOS (stay beyond 6days). After multivariate analysis, increasing age was independently associated with PLOS (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02-1.06). Multiple comorbid conditions were associated with PLOS, including alcohol abuse (OR 3.85, 95% CI 1.87-7.94), congestive heart failure (OR 1.72, 95% CI 1.11-2.64), obesity (OR 1.70, 95% CI 1.14-2.55), and deficiency anemia (OR 1.44, 95% CI 1.01-2.05); the strongest associated operative parameter was blood transfusion (OR 2.39, 95% CI 1.75-3.28). Major complications independently associated with PLOS were deep vein thrombosis (OR 18.32, 95% CI 6.50-51.61), myocardial infarction (OR 8.98, 95% CI 2.92-27.56), pneumonia (OR 6.67, 95% CI 3.17-14.05), acute respiratory failure (OR 6.27, 95% CI 3.43-11.45), hemorrhage/hematoma (OR 5.04, 95% CI 2.69-9.44), and implant-related complications (OR 2.49, 95% CI 1.24-4.98). Average total hospital charges for patients who experienced PLOS were $122,965 US dollars, compared to $76,870 for the control group (p<0.001). Mortality for patients who experienced PLOS was 2.7% versus 0.5% for patients who did not epxerience PLOS (p<0.001). In conclusion, patients over the age of 65 who underwent posterior surgery for cervical myelopathy and stayed over 6days in hospital were defined as having PLOS. Hospital charges and mortality rates were significantly higher for patients who experienced PLOS. Potentially modifiable and/or preventable risk factors were also identified.

BACKGROUND: Few reports have focused on treatment of adult cervical deformity (ACD). OBJECTIVE: To present early complication rates associated with ACD surgery. METHODS: A prospective multicenter database of consecutive operative ACD patients was reviewed for early (10 degrees, cervical scoliosis >10 degrees, C2-7 sagittal vertical axis >4 cm, or chin-brow vertical angle >25 degrees. RESULTS: Seventy-eight patients underwent surgical treatment for ACD (mean age, 60.8 years). Surgical approaches included anterior-only (14%), posterior-only (49%), anterior-posterior (35%), and posterior-anterior-posterior (3%). Mean numbers of fused anterior and posterior vertebral levels were 4.7 and 9.4, respectively. A total of 52 early complications were reported, including 26 minor and 26 major. Twenty-two (28.2%) patients had at least 1 minor complication, and 19 (24.4%) had at least 1 major complication. Overall, 34 (43.6%) patients had at least 1 complication. The most common complications included dysphagia (11.5%), deep wound infection (6.4%), new C5 motor deficit (6.4%), and respiratory failure (5.1%). One (1.3%) mortality occurred. Early complication rates differed significantly by surgical approach: anterior-only (27.3%), posterior-only (68.4%), and anterior-posterior/posterior-anterior-posterior (79.3%) (P = .007). CONCLUSION: This report provides benchmark rates for overall and specific ACD surgery complications. Although the surgical approach(es) used were likely driven by the type and complexity of deformity, there were significantly higher complication rates associated with combined and posterior-only approaches compared with anterior-only approaches. These findings may prove useful in treatment planning, patient counseling, and ongoing efforts to improve safety of care. ABBREVIATIONS: 3CO, 3-column osteotomiesACD, adult cervical deformityEBL, estimated blood lossISSG, International Spine Study groupSVA, sagittal vertical axis.

BACKGROUND: Few reports have focused on treatment of adult cervical deformity (ACD). OBJECTIVE: To present early complication rates associated with ACD surgery. METHODS: A prospective multicenter database of consecutive operative ACD patients was reviewed for early (<=30 days from surgery) complications. Enrollment required at least 1 of the following: cervical kyphosis >10 degrees, cervical scoliosis >10 degrees, C2-7 sagittal vertical axis >4 cm, or chin-brow vertical angle >25 degrees. RESULTS: Seventy-eight patients underwent surgical treatment for ACD (mean age, 60.8 years). Surgical approaches included anterior-only (14%), posterior-only (49%), anterior-posterior (35%), and posterior-anterior-posterior (3%). Mean numbers of fused anterior and posterior vertebral levels were 4.7 and 9.4, respectively. A total of 52 early complications were reported, including 26 minor and 26 major. Twenty-two (28.2%) patients had at least 1 minor complication, and 19 (24.4%) had at least 1 major complication. Overall, 34 (43.6%) patients had at least 1 complication. The most common complications included dysphagia (11.5%), deep wound infection (6.4%), new C5 motor deficit (6.4%), and respiratory failure (5.1%). One (1.3%) mortality occurred. Early complication rates differed significantly by surgical approach: anterior-only (27.3%), posterior-only (68.4%), and anterior-posterior/posterior-anterior- posterior (79.3%) (P = .007). CONCLUSION: This report provides benchmark rates for overall and specific ACD surgery complications. Although the surgical approach(es) used were likely driven by the type and complexity of deformity, there were significantly higher complication rates associated with combined and posterior-only approaches compared with anterior-only approaches. These findings may prove useful in treatment planning, patient counseling, and ongoing efforts to improve safety of care.

PURPOSE: Characteristics specific to cervical deformity (CD) concomitant with adult thoracolumbar deformity (TLD) remains uncertain, particularly regarding treatment. This study identifies cervical malalignment prevalence following surgical and conservative TLD treatment through 2 years. METHODS: Retrospective analysis of a prospective, multicenter adult spinal deformity (ASD) database. CD was defined in operative and non-operative ASD patients according to the following criteria: T1 Slope minus Cervical Lordosis (T1S-CL) >/=20 degrees , C2-C7 Cervical Sagittal Vertical Axis (cSVA) >/=40 mm, C2-C7 kyphosis >10 degrees . Differences in rates, demographics, health-related quality of life (HRQoL) scores for Oswestry Disability Index (ODI) and Scoliosis Research Society Questionnaire (SRS-22r), and radiographic variables were assessed between treatment groups (Op vs. Non-Op) and follow-up periods (baseline, 1-year, 2-year). RESULTS: Three hundred and nineteen (200 Op, 199 Non-Op) ASD patients were analyzed. Op patients' CD rates at 1 and 2 years were 78.9, and 63.0 %, respectively. Non-Op CD rates were 21.1 and 37.0 % at 1 and 2 years, respectively. T1S-CL mismatch and cSVA malalignment characterized Op CD at 1 and 2 years (p < 0.05). Op and Non-Op CD groups had similar cervical/global alignment at 1 year (p > 0.05 for all), but at 2 years, Op CD patients had worse thoracic kyphosis (TK), T1S-CL, CL, cSVA, C2-T3 SVA, and global SVA compared to Non-Ops (p < 0.05). Op CD patients had worse ODI, and SRS Activity at 1 and 2 years post-operative (p < 0.05), but had greater 2-year SRS Satisfaction scores (p = 0.019). CONCLUSIONS: In the first study to compare cervical malalignment at extended follow-up between ASD treatments, CD rates rose overall through 2 years. TLD surgery, resulting in higher CD rates characterized by T1S-CL and cSVA malalignment, produced poorer HRQoL. This information can aid in treatment method decision-making when cervical deformity is present concomitant with TLD.

INTRODUCTION: Minimally invasive surgical (MIS) techniques are gaining popularity in the treatment of adult spinal deformity (ASD). The premise is that MIS techniques will lead to equivalent outcomes and a reduction in perioperative complications when compared with open techniques. Potential issues with MIS techniques are a limited capacity to correct lumbar lordosis, unknown long-term efficacy, and the potential need for revision surgery. This study compares reoperation rates and reasons for reoperation following MIS, hybrid, and open surgery for ASD through multicenter database analysis. METHODS: We retrospectively analyzed a prospective multicenter ASD database comparing open and MIS correction techniques. Inclusion criteria were: age > 18 years with minimum 20 degrees coronal lumbar Cobb angle, a minimum of three levels fused, and minimum 2-year follow-up. Patients were propensity matched for preoperative sagittal vertebral axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), and number of levels fused. We included 189 patients from three propensity-matched subgroups of 63 patients each: (1) MIS: lateral or transforaminal lumbar interbody fusion (LIF) and percutaneous pedicle instrumentation, (2) Hybrid: MIS LIF with open posterior segmental fixation (PSF), and (3) OPEN: open posterior fixation +/- osteotomies. RESULTS: With propensity matching, there were significant differences between groups in pre-op SVA or PI-LL (p > 0.05). The MIS group had significantly fewer levels fused (5.4) (0-14) than the OPEN group (7.4) (p = 0.002) (0-17). The rate of revision surgery was significantly different between the groups with a higher rate of revision (27 %) amongst the HYB group versus MIS = 11.1 %, and OPEN = 12.0 %. The most common reason for reoperation in the OPEN and HYB groups was a postoperative neurological deficit (7.9 and 11.1 %), respectively. The most common reason for reoperation in the MIS group was pseudoarthrosis (7.9 %). CONCLUSIONS: Reoperation rates were not statistically different among the MIS, and OPEN surgical groups, but differed significantly on multivariate analysis with HYB group. The incidence of reoperations was twice as high in the Hybrid group compared to OPEN and MIS.

PURPOSE: The resection point of a lumbar three-column osteotomy (3CO) creates separation of the spino-pelvic complex. This study investigates the impact of patients' baseline deformity and level of 3CO resection on the distribution of correction between the trunk and the pelvis following osteotomy closure. METHODS: Patients who underwent single lumbar 3CO, upper instrumented vertebra (UIV) T1-T10, and 6 month follow-up were included. The truncal and pelvic closures were calculated based on the vertebrae adjacent to the osteotomy level and the impact of radiographic parameters and level of 3CO on the closures were analyzed. RESULTS: 113 patients were included. Patients who experienced more pelvic correction had significantly higher Pelvic Tilt and lower Sagittal Vertical Axis at baseline. Patients who underwent more caudal osteotomies with higher pelvic compensation with modest SVA sustained more pelvic correction. CONCLUSIONS: The osteotomy closure is driven by patient's specific deformity. More caudal osteotomy level leads to greater pelvic tilt improvement. LEVEL OF EVIDENCE: III.

STUDY DESIGN: A retrospective review of a prospective multicenter database. OBJECTIVE: The aim of this study was to identify variables associated with extended length of stay (ExtLOS) and this impact on health-related quality of life (HRQoL) scores in adult spinal deformity (ASD) patients. SUMMARY OF BACKGROUND DATA: ASD surgery is complex and associated with complications including extLOS. Although variables contributing to extLOS have been considered, specific complications and pre-disposing factors among ASD surgical patients remain to be investigated. METHODS: INCLUSION CRITERIA: ASD surgical patients (age >18 years, scoliosis >/=20 degrees , sagittal vertical axis >/=5 cm, pelvic tilt >/=25 degrees , and/or thoracic kyphosis >60 degrees ) with complete demographic, radiographic, and HRQoL data at baseline, 6 weeks, and 2 years postoperative. ExtLOS was based on 75th percentile (>/=9 days). Univariate and multivariate analyses identified predictors and evaluated effects on outcomes. Repeated-measures mixed models analyzed impact of ExtLOS on HRQoL [Oswestry Disability Index; Short Form-36 physical component summary/mental component summary; SRS22r Activity (AC), Pain (P), Appearance (AP), Satisfaction (S), Mental (M) and Total (T)]. RESULTS: Three hundred eighty patients met inclusion criteria: 105 (27.6%) had extLOS (>/=9 days) and 275 (72.4%) did not. Average LOS was 8 days (range: 1-30 days). Age [odds ratio (OR) 1.04], no. of levels fused (OR 1.12), no. of infections (OR 2.29), no. of neurologic complications (OR 2.51), Charlson Comorbidity Index Score (CCI) predicted ExtLOS (OR 3.92), and no. of intraop complications predicted ExtLOS (OR 3.56). ExtLOS patients had more intracardiopulmonary (pleural effusion: 1.9% vs. 0%) and operative complications (dural tear: 13.3% vs. 5.1%; excessive blood loss: 18% vs. 5.8%) (P < 0.022). At 2 years, both groups of patients experienced an overall improvement in all HRQoL scores (P < 0.001). ExtLOS patients had significantly less overall improvement in all HRQoLs (P < 0.01) except for MCS (P = 0.17) and SRS M (P = 0.08). CONCLUSION: Extended LOS of ASD patients is affected by comorbidities (higher CCI) and number of intraoperative, but not peri-operative, complications. All patients improved overall in HRQoL scores, but extended LOS patients improved less overall at 2 years in comparison. LEVEL OF EVIDENCE: 3.

OBJECTIVE The goal of this study was to compare inpatient morbidity and mortality after adult spinal deformity (ASD) surgery in teaching versus nonteaching hospitals in the US. METHODS The Nationwide Inpatient Sample was used to identify surgical patients with ASD between 2002 and 2011. Only patients > 21 years old and elective cases were included. Patient characteristics, inpatient morbidity, and inpatient mortality were compared between teaching and nonteaching hospitals. A multivariable logistic regression analysis was performed to examine the effect of hospital teaching status on surgical outcomes. RESULTS A total of 7603 patients were identified, with 61.2% (n = 4650) in the teaching hospital group and 38.8% (n = 2953) in the nonteaching hospital group. The proportion of patients undergoing revision procedures was significantly different between groups (5.2% in teaching hospitals vs 3.9% in nonteaching hospitals, p = 0.008). Likewise, complex procedures (defined as fusion of 8 or more segments and/or osteotomy) were more common in teaching hospitals (27.3% vs 21.7%, p < 0.001). Crude overall complication rates were similar in teaching hospitals (47.9%) compared with nonteaching hospitals (49.8%, p = 0.114). After controlling for patient characteristics, case complexity, and revision status, patients treated at teaching hospitals were significantly less likely to develop a complication when compared with patients treated at a nonteaching hospital (OR 0.89; 95% CI 0.82-0.98). The mortality rate was 0.4% in teaching hospitals and < 0.4% in nonteaching hospitals (p = 0.210). CONCLUSIONS Patients who undergo surgery for ASD at a teaching hospital may have significantly lower odds of complication development compared with patients treated at a nonteaching hospital.

OBJECTIVE: Although previous reports suggest that surgery can improve the pain and disability of cervical spinal deformity (CSD), techniques are not standardized. Our objective was to assess for consensus on recommended surgical plans for CSD treatment. METHODS: 18 CSD cases were assembled, including a clinical vignette, cervical imaging (x-rays, CT/MRI), and full-length standing x-rays. Fourteen deformity surgeons (10 orthopedic, 4 neurosurgery) were queried regarding recommended surgical plan. RESULTS: There was marked variation in treatment plans across all deformity types. Even for the least complex deformities (moderate mid-cervical apex kyphosis), there was lack of agreement on approach (50% combined anterior-posterior, 25%, anterior-only, 25% posterior-only), number of anterior (range: 2-6) and posterior (range: 4-16) fusion levels, and types of osteotomies. As the kyphosis apex moved caudally (cervical-thoracic junction/upper thoracic spine) and for cases with chin-on-chest kyphosis, >80% of surgeons agreed on a posterior-only approach and >70% recommended a pedicle subtraction osteotomy (PSO) or vertebral column resection (VCR), but the range in number of anterior (4-8) and posterior (4-27) fusion levels was exceptionally broad. Cases of cervical/cervical-thoracic scoliosis had the least agreement for approach (48% posterior-only, 33% combined anterior-posterior, 17% anterior-posterior-anterior or posterior-anterior-posterior, 2% anterior-only) and had broad variation in number of anterior (2-5) and posterior (6-19) fusion levels, and recommended osteotomies (41% PSO/VCR). CONCLUSIONS: Among a panel of deformity surgeons, there was marked lack of consensus on recommended surgical approach, osteotomies and fusion levels for CSD. Further study is warranted to assess whether specific surgical treatment approaches are associated with better outcomes.