Faculty Bibliography

BACKGROUND CONTEXT: The International Spine Study Group (ISSG) and the European Spine Study Group (ESSG) developed an adult spinal deformity (ASD) specific risk calculator based on the largest and most granular, prospective ASD database. The calculators utilize preoperative radiographic, surgical, and patient-specific variables in order to predict patient-reported outcomes and complication rates at 2 years. PURPOSE: Assess the ISSG-ESSG risk calculator usability in a single institution ASD population. STUDY DESIGN/SETTING: Retrospective cohort study- single surgeon institution. PATIENT SAMPLE: ASD pts: A total of 631 patients undergoing surgery for adult spinal deformity. OUTCOME MEASURES: Improvement from BL SRS-22 [Pain, Function, total], major complications, Oswestry Disability Index (ODI).
METHOD(S): ASD pts were isolated in the single-center ASD Database 2013-2020. Frail pts were isolated (Frail[F] 0.3>0.5). Basic demographics were assessed for these F pts via chi-squared and t-tests. Each F patient was inputted into the ESSG risk calculator to identify individual predictive rates for postoperative 2-year HRQL outcomes as well as major complications. These calculated predicted outcomes were analyzed against those identified from the ASD database in order to validate the calculator predictability in a single center institution via Brier scores. Having a score closer to 1 means the EESG calculator is not predictive of that specific outcome. A score closer to 0 meant the EESG calculator was a predictive tool for that factor.
RESULT(S): A total of 631 ASD pts were isolated (55.8;16.8yrs, 26.68kg/m², 0.95+/-1.3CCI). Of these patients, 7.8% were frail. Fifty percent of frail pts received an interbody fusion, 58.3% received a decompression, and 79.2% had an osteotomy. Surgical details: mean operative time 342.9+/-94.3minutes, mean estimated blood loss 2131.82+/-1011mL, and an average length of stay 7.12+/-2.5days. The EESG calculator predicted the likelihood of improvement for the following HRQL's ODI(86%), SRS-22 Mental Health (71.1%), SRS-22 Total (87.6%), major complication (53.4%). The single institution had lower percentages of improvement in ODI (24.6%), SRS-22 Mental Health (21.3%), SRS-22 Total (25.1%), and lower presence of major complication (34.8%). The calculated Brier scores identified the calculator's predictability for each factor: ODI (0.24), SRS-22 Mental Health (0.21), SRS-22 Total (0.25), major complication (0.28).
CONCLUSION(S): The newly developed ESSG-ISSG risk-assessment tool has a wide application in single institutions as it accurately predicts 2-year outcomes for various SRS-22 questionnaires and development of major complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Based on biomechanical studies, the use and type of interbody device at the lumbosacral junction creates variable stress/strain on the lumbopelvic fixation. This variability may lead to differential failure mechanisms and rates within following correction of adult spinal deformity (ASD). PURPOSE: We aimed to evaluate the relationship of lumbosacral interbody presence and type with lumbopelvic fixation failure after ASD correction utilizing iliac (IS) or S2 alar iliac (S2AI) screws. STUDY DESIGN/SETTING: Retrospective review of prospective, multicenter ASD database. PATIENT SAMPLE: A total of 342 patients. OUTCOME MEASURES: Pelvic fixation loosening, IS/S2AI screw fracture, S1 screw fracture, rod fracture (below L4), revision surgery, pseudarthrosis, HRQLs.
METHOD(S): Inclusion criteria consisted of patients with ASD (coronal Cobb >=20degree, sagittal vertical axis (SVA) >=5cm, pelvic tilt >=25degree and/or thoracic kyphosis >60degree) >=18 years old and 2yr f/u who underwent >5 level fusion with pelvic fixation. Patients with prior L5-S1 fusion were excluded. Patients were divided into three groups based on the lumbosacral interbody fusion strategy (none, ALIF, TLIF/PLIF). Univariate testing via one-way ANOVA and chi-square tests, and multivariate logistic regression, accounting for significant confounders, were used to examine the difference between the three groups in regard to pseudarthosis, pelvic fixation loosening, rod fracture and revision surgery. Level of significance=p<0.05.
RESULT(S): A total of 342 patients met inclusion criteria (L5-S1 interbody groups: none=164, ALIF=87, TLIF=91). The three groups were similar in terms of baseline comorbidities, gender, BMI, pelvic fixation type (iliac screws vs S2AI), and use of BMP2 posteriorly. There were differences in rate of interbody BMP2 use (ALIF 22.9%, TLIF 48.35%, p=0.0001), use of unilateral pelvic fixation (none 7.36%, ALIF 19.8%, TLIF 3.29%, p=0.0001) and age (none 65.41, ALIF 60.47, TLIF 63.81, p=0.0005). Multivariate logistic regression revealed ALIF at L5-S1 was associated with lower odds of pseudarthrosis (OR 0.16, p-0.026) and rod fracture (OR 0.19, p=0.012) compared to no interbody fusion, while TLIF was no different than no interbody. There were no differences between groups in regard to pelvic fixation loosening or revision surgery.
CONCLUSION(S): The use of ALIF at L5-S1 during correction of ASD protects against fixation failure at the lumbopelvic junction compared to the use of TLIF or no interbody. This more protective effect of ALIF at the lumbosacral junction may allow for selective unilateral pelvic fixation for ASD surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Scoliosis is frequently associated with Chiari malformation (CM). More specifically, reports have been made about this association with CM-1 in the absence of syrinx status. There is paucity in literature in the surgical risks associated with concurrent CM types and scoliosis diagnosis. PURPOSE: To identify the risks adolescent patients have when diagnosed with CM and scoliosis. STUDY DESIGN/SETTING: Adolescents in pts in Kids' Inpatient Database (KID) during the years of 2003-2012. PATIENT SAMPLE: A total of 35,073 Chiarim pts. OUTCOME MEASURES: Complications.
METHOD(S): CM and scoliosis pts were isolated in KID from 2003-2012. The patients were stratified into three groups: those with concomitant CM and scoliosis (CmS), those with only CM (OCm), and those with only scoliosis (Scol). Demographics, incidence, comorbidity profiles, surgical strategy, and postoperative complications were assessed. Comorbidity profiles were stratified by body systems (neurological, musculoskeletal, pulmonary, cardiovascular, renal). Groups were compared using t-tests and chi-squared tests for continuous and discrete variables, respectively. Multivariate logistic regressions were used to assess association between surgical characteristics/diagnosis with complication rate.
RESULT(S): Included 90,707 spine pts, 63.3% Scol, 38.7%Ocm, and 2.0%Cms. Scol were older (13.6yrs vs CM: 5.9 vs Both:10.9) and had a higher invasiveness score (2.4 vs OCm: 0.5 vs Both:1.5), while CmS pts were more comorbid (0.9 vs OCm: 0.55 vs Scol: 0.89; all p<0.001). CmS pts had higher rates of surgical decompression (25.4%) and Scol pts had higher rates of fusions (35.3%) and osteotomies (1.2%; all p<0.001). However, CmS pts had the highest surgical rate (37.1% vs Scol: 36.6% vs OCm:10.6%) among the cohort (p<0.001). Controlling for age and invasiveness, Scol pts receiving a fusion (1.8[1.08-3.2] operation were associated with development of postoperative complications as well as OCm osteotomies (2.9[1.4-6.0]) and fusions (1.8[1.2-2.9]), and CmS fusion surgeries (1.8[1.0-3.2]; all p<0.05). Having a complication of acute respiratory distress (2.1[3.4-1.3]) and anemia (0.6[0.85-0.36]) were independently associated with CmS operation (all p<0.05).
CONCLUSION(S): Having concurrent scoliosis and Chiari malformation increases operative risk for when decompressive surgeries are performed. Being independently inflicted with scoliosis or Chiari leads to increased complication rate when paired with fusion surgeries. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Surgical intervention of the cervical spine is a challenging procedure that can present postoperative complications such as dysphagia, swelling, and reoperations. However, the risk of reoperation can possibly be mitigated with the use of biologics to enhance fusion. There is paucity in the literature on long-term incidence of reoperations after application of BMP during ACDF. PURPOSE: To evaluate if bone morphogenetic protein usage during anterior cervical discectomy and fusion will decrease reoperation rates. STUDY DESIGN/SETTING: Retrospective review of the PearlDiver database between 2006-2014. PATIENT SAMPLE: Matched cohort of 35,544 ACDF patients. OUTCOME MEASURES: Reoperations.
METHOD(S): Patients undergoing an anterior cervical discectomy and fusion between the years 2006-2014 were isolated in the PearlDiver database. Patients receiving BMP operatively and a control with no BMP were matched for baseline demographics including age, sex, and comorbidities. A Kaplan Meier Survival analysis assessed five-Year Reoperation-Free Survival between BMP patients and controls. Statistical significance was set to p<0.05.
RESULT(S): A matched cohort of 35,544 ACDF patients was isolated. A total of 17,772 patients received BMP while undergoing cervical fusion and 17,772 did not receive any BMP during surgery. Patients did not differ in age, sex or comorbidities (p>0.05). Kaplan Meier survival analysis showed patients receiving BMP during cervical fusion were significantly more likely to remain reoperation free five years after index surgery (p<0.05). Overall, 91.3% of BMP patients remained reoperation free at five years.
CONCLUSION(S): For patients receiving bone morphogenetic protein during anterior cervical discectomy and fusion, Kaplan-Meier survival analysis following five years post index surgery had showed a 91.3% reoperation-free survivorship. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: AI algorithms have shown substantial promise in medical image analysis. Previous studies of ASD clusters have analyzed alignment metrics - this study sought to complement these efforts by analyzing images of anatomical landmarks. PURPOSE: We hypothesized that a neural-network-based artificial intelligence (AI) algorithm would cluster preoperative lateral radiographs of into groups with distinct morphology. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 915 patients with adult spinal deformity and preoperative lateral radiographs. OUTCOME MEASURES: Schwab modifiers for SVA and PI-LL, three-column osteotomy, upper instrumented vertebrae, baseline Oswestry Disability Index, and 2-year likelihood of reaching MCID in ODI (set at -12.8). Proximal junctional kyphosis and proximal junctional failure were defined using previously published radiographic criteria.
METHOD(S): Vertebral locations for C3-L5, sacral endplate, and femoral heads were measured on lateral radiographs. Pixel locations were used to create a black-and-white overlay to the image, which was subsequently standardized for size and position using the femoral heads and sacral endplate. These images were used to train a self-organizing map (SOM). SOMs are a form of artificial neural network frequently employed in unsupervised classification tasks.
RESULT(S): In total, 915 preoperative lateral radiographs were analyzed. A 2 x 3, toroidal SOM was trained. The mean spine shape was plotted for each cluster. Alignment, surgical characteristics, and outcomes were compared between clusters. Clusters C and D exhibited a particularly high proportion of patients with optimal (ie, modifier 0) values of PI-LL (65.0% and 68.5%) and SVA (72.8% and 53.1%). Conversely, clusters B, E, and F tended to have poor (ie, modifier ++) PI-LL (74.8%, 66.9%, and 74.6%) and SVA (75.5%, 48.6%, and 58.7%). 3-CO was most common among cluster A (26.8%), cluster B (32.6%), and cluster F (32.7%). UIV at T7-T12 was most common among cluster B (51.1%) and cluster F (60.3%). ODI <30 was most prevalent among cluster D (31.4%). There was little difference, however, between groups in likelihood of reaching MCID in ODI at 2-year follow-up. PJK and PJF were particularly prevalent among clusters A (51.2% and 15.5%) and E (50.4% and 18.7%).
CONCLUSION(S): This study developed a self-organizing map that clustered preoperative lateral radiographs of ASD patients into groups with highly distinct overall spinal morphology. These clusters predicted alignment, surgical characteristics, and HRQOL. Further studies of this classification approach will expand to compare pre- and postoperative radiographs. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Many different risk factors for PJK have been identified in those having surgery for ASD. The presence of CF prior to thoracolumbar fusion as a risk factor in this patient population has not been investigated. PURPOSE: To investigate if prior cervical fusion would be a risk factor for PJK when upper thoracic UIV was selected. STUDY DESIGN/SETTING: Retrospective review of prospective multicenter database. PATIENT SAMPLE: Inclusion: age >18 and one of the following inclusion criteria was queried: PI-LL >10, PT >20, Max Cobb>10, SVA > 5 cm. OUTCOME MEASURES: Development of PJK; HRQOL include NRS back and leg, ODI, SRS-22, EQ5D METHODS: Inclusion: age >18 and one of the following inclusion criteria was queried: PI-LL >10, PT >20, Max Cobb>10, SVA > 5 cm. 1023 patients were identified and grouped as CF (prior CF; n=101) and NoCF (n=922). Patients with 5 or fewer levels of CF and those without further cervical spine surgery at final follow-up were included (cASD= 86; ASD= 910). After initial analysis propensity matching was performed controlling for: age, BMI, pre-op alignment (PI, PI-LL, TPA, SVA), change in alignment (PI-LL), and UIV/LIV.
RESULT(S): Among 996 patients the CF group was older (64 v 60; p<0.000), higher BMI (29.7 v 28; p<0.014), with equal gender distribution. PJK at 1 year was 34.9% (n=30) in CF and 34.7% (n=316) in NoCF. All patients included had a minimum of four segments unfused between CF and TL fusion. No differences were found between groups when stratifying by UIV (UT=upper thoracic; LT=Lower thoracic; L=lumbar). Radiographically CF had worse preop deformity (PI-LL 21.3 v 17.2; TPA 27.3 v 23.6; SVA 90.6 v 68.5; p<0.05), with no difference in postop alignment between groups. CF was more likely to have LT UIV (61.6% v 46%; p=0.045) and fusion to the ilium (93% v 81%; p=0.005). After propensity matching 79 patients were included in each group. CF had 68 patients with ACDF, 5 patients with PSF, and 6 patients with A/PSF. There was no difference in the rate of PJK (39.2 v 34.2%), PJK magnitude (13.4 v 13.7) or change in PJK angle (10.1 v 10.4). PJK rate and magnitude are not different by UT or LT as UIV.
CONCLUSION(S): The presence of CF is not associated with the development of PJK or PJK magnitude in this propensity matched cohort. All CF patients had a minimum of four segments unfused between the CF and the TL fusion which may act as a buffer and be protective of PJK. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Complications occur commonly following adult spinal deformity surgery. Length of stay may be influenced by the type of surgical intervention, and/or by postoperative complication and the intervention required to treat that complication. PURPOSE: To understand the impact of complications and their intervention severity on the incremental increase in length of stay. STUDY DESIGN/SETTING: Retrospective cohort study of prospective ASD database. PATIENT SAMPLE: The study included 1418 adult spinal deformity patients. OUTCOME MEASURES: Neurologic complications, HRQL scores.
METHOD(S): ASD patients (>18yrs, scoliosis >=20degree, SVA >=5cm, PT >=25degree and/or TK >60degree). Complications were classified based on complication type, and intervention severity (grade 0, no intervention, Grade 1 minimal intervention (medication change, etc), Grade 2 moderate (cardioversion, chest tube, etc), grade 3 major intervention (return to OR).
RESULT(S): Of the 1418 patients included, 901 had at least one complication event, with 568 with a complication before discharge. Three hundred and six had an event that required a reoperation and 275 were readmitted for their event. When determining LOS, a baseline was established that was influenced by the type of surgery and placed into three groups based on osteotomy (O) and interbody use (I); Group 1 (n408): 0% O, 75% I, LOS=7.9, Group 2 (n374): 100% O, 0% I, LOS=11.9, Group 3 (n595) 100% O and I, LOS=11.2. Having a complication event prior to discharge led to an increase of 1-4 days for each group (p<0.01). This was true for every complication, regardless of type, but was worse for renal and pneumonia. The increase in LOS was most driven by the intervention required. No intervention had an LOS of 6.9, Grade 1 +1.2 days, Grade 2, +1.8 days, Grade 3 +2.5 days. Using the sum of a weighted intervention score (SUM=1*#grade1 + 2*#grade2 + 3*#grade3), we can even more accurately predict the incremental increase in LOS. This occurs until a weighted score of 7 which accurately predicts an increase of 7.5 days.
CONCLUSION(S): Length of stay following ASD is predicted by the type of surgical intervention, and postoperative complication profile. Additional days are most predicted by the type of complication and by intervention severity. A weighted intervention score can predict the additional LOS and is useful to help understand the impact of complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: While neurological complications are known to occur following cervical fusions, few studies with sufficient power have quantified the difference in neurological outcomes as posterior cervical fusion (PCF) surgical invasiveness increases. PURPOSE: Compare longer vs shorter PCF complication rates. STUDY DESIGN/SETTING: Retrospective review of the New York State Statewide Planning and Research Cooperative System (SPARCS) database. PATIENT SAMPLE: All patients undergoing >=2 level PCF. OUTCOME MEASURES: Ninety-day neurological or medical complications status post short-cervical (SC), long-cervical (LC), or long cervicothoracic (LCT).
METHOD(S): From the NYS Statewide Planning and Research Cooperative System (SPARCS) database, retrospective review of all patients who underwent >=2 level PCF from 2009-13 with <= 90-day follow-up were identified and stratified by levels fused: 2-3 (SC), 4-8 (LC), and >= 9 (LCT). Data on demographics, hospital-related parameters, and 90-day neurological and other complications, readmissions, and revisions were collected. Regression analysis identified independent predictors of neurologic and overall complications.
RESULT(S): A total of 6,981 patients were included (SC, n=2,964, LC, n=3,899, LCT, n=118). LC patients were older than SC and LCT (60.8 vs 58.2 and 56.1), while LCT patients were more often female (59.3% vs LC 42.1% and SC 44%) and had higher total charges ($187,996 vs LC $99,020 and SC $82,239) and LOS (12.4 vs 6.1 and 6.9 days), all p<0.001. LC had the highest C5-C7 nerve palsy and overall neurological complication rates compared to SC and LCT patients (3.3 vs 1.8 and 1.7%, p=0.001; 3.8 vs 2.3 and 2.5%, p<0.001). Adverse events of the phrenic and recurrent laryngeal nerve were comparable. Implant infection (0.2 vs 0.3 vs 3.4%), and total complication rates (20.3 vs 23.7 vs 42.4%) increased with the number levels fused SC, LC, and LCT respectively, p<=0.017. 90-day readmissions and revisions were comparable. Only LC was a predictor of sustaining 90-day neurological complication (OR=1.7), while both LCT and LC predicted 90-day medical (OR=3.5, 1.3) and total complications (OR=2.7, 1.2), respectively, p<=0.008.
CONCLUSION(S): Compared to 2-3 levels, longer PCF had higher C5-C7 nerve palsy rates (3.3%) and 70% increased odds of sustaining >=1 neurological complication. Longer PCF was also associated with increased rates of medical and total complications. This data can improve the ability to counsel patients regarding the risks and expectations of potential adverse outcomes preceding cervical fusion via posterior or combined anterior-posterior approach. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: With the rise of health care costs and a focus on value-based outcomes, hospitals have become more cognizant on cost of revisions and complications. However, literature on the effect of distal junctional kyphosis in driving up health care costs is scarce. PURPOSE: To evaluate the effect of distal junctional kyphosis on the cost effectiveness of corrective cervical deformity surgery. STUDY DESIGN/SETTING: Retrospective review of a single surgeon database. PATIENT SAMPLE: This study included 123 cervical deformity patients. OUTCOME MEASURES: Cost per QALY.
METHOD(S): Cervical deformity patients with minimum 1-year HRQL follow-up were included. Means comparison tests assessed differences in baseline demographic and clinical data. Utility data was calculated using published conversion methods to convert NDI to SF-6D. QALYs utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs was calculated using the PearlDiver database incorporating complications, comorbidities (CC), major complications, and comorbidities (MCC) were assessed according to CMS.gov manual definitions. Reimbursement consisted of a standardized estimate using regression analysis of Medicare pay-scales for all services rendered within a 30-day window, including estimates regarding costs of postoperative complications, outpatient health care encounters, revisions and medical-related readmissions. After accounting for CC, MCC, length of stay (LOS) and death, cost per QALY at 2Y was calculated for revisions due to distal junctional kyphosis.
RESULT(S): A total of 123 cervical deformity patients met inclusion criteria (57.22yrs, 54%F, 29.0kg/m2). At baseline, patients presented radiographically as: PT (16.9+/-9.7), PI (54.7+/-11.4), PI-LL (-2.9+/-12.6), SVA (80.5+/-49.8), cSVA (28.4+/-20.6), TS-CL (26.6+/-14.4). Surgical details: EBL of 708 mL, operative time of 438.6 min, with 29.51% undergoing an anterior approach, 50.82% posterior-only approach, and 19.67% combined approach. Overall, 7.9% of patients developed DJK within two years postoperatively. Average cost of revision surgery due to DJK within 2years of index surgery was $50,736 +/- 31,467. Patients that developed DJK within 2years of index surgery trended toward having a greater baseline NDI (62.8 vs 55.47, p>0.05) and showed less improvement in NDI at 2 years (4 vs 16.6). Overall, cost per QALY was higher for patients developing DJK at 2 years ($28,483 vs $20,989).
CONCLUSION(S): Cervical deformity revisions due to distal junctional kyphosis had a cost per QALY of $28,483. Efforts to limit postoperative DJK after surgical intervention can further limit additional costs associated with revisions and complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: This study evaluates the necessity of a multi-rod construct to help prevent a pseudarthrosis in ASD surgery of lesser magnitude. Regardless of an interbody at L5/S1, a multi-rod construct does not decrease the risk of developing a pseudarthrosis. If a pseudarthrosis develops in patients who undergo an interbody fusion at L5/S1, it is more likely to occur above the L5/S1 level and the number of rods used does not decrease this risk. PURPOSE: To examine the necessity of IBF and multi-rod use to prevent pseudarthrosis in these lesser magnitude ASD surgeries. STUDY DESIGN/SETTING: Retrospective review of a multicenter database. PATIENT SAMPLE: A total of 483 patients met our inclusion criteria of pelvic fixation, > 2 year follow up, >5 levels fused, no 3-column osteotomy (3CO), and no multi-level interbody fusions. OUTCOME MEASURES: Pseudarthrosis rate and location in ASD patients.
METHOD(S): A multi-center database was evaluated to identify patients with pelvic fixation, > 2 year follow up, >5 levels fused, and no 3-column osteotomy (3CO). We define a lesser magnitude ASD surgery as surgeries that do not include 3CO or multi-level interbody fusions. In this cohort, ASD patients with and without an IBF at L5/S1 were assessed to evaluate if the number of rods had an impact on the pseudarthrosis rate. Pseudarthrosis was determined by intraoperative findings or record review. Fisher's exact tests, univariate and multivariate analysis were used to identify predictors of pseudo.
RESULT(S): A total of 483 patients met our inclusion criteria with an average follow-up of 48 months. Of those, 321 (66%) had interbody at L5/S1 (IBF). Twenty-three percent of IBF patients had a MR construct and 77% had a SR construct. In the non-IBF group, 33% had a MR construct. In the IBF group, the MR construct did not impact the pseudarthrosis rate compared to a SR construct, (6.8% vs 5.2% respectively, p=.35). In the IBF group, 29% (4) of MR patients and 75% (6) of SR patients with pseudo received BMP. However, regardless of the rod construct, ASD patients with an interbody at L5/S1 had an increased risk of having a pseudarthrosis above this level (OR.096, p=.045). Also, the MR construct did not decrease the risk of developing a pseudarthrosis in the non-IBF group (0% vs 4.5%, p=.18).
CONCLUSION(S): In ASD surgery of lesser magnitude, a multi-rod construct does not decrease the risk of developing a pseudarthrosis. Patients who have an interbody fusion at L5/S1 are more likely to develop a pseudarthrosis above this level, regardless of the rod construct. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright