Faculty Bibliography

BACKGROUND CONTEXT: Prophylaxis usage has been established in literature as an important component of minimizing the risk of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) development. However, literature is scarce on the effects of prophylaxis in patients who have achieved adequate postoperative alignment and those who maintained poor alignment postoperatively. PURPOSE: To investigate how PJK prophylaxis impacts rates of PJK and PJF with and without ideal alignment and the associated cost/cost-effectiveness. STUDY DESIGN/SETTING: Retrospective cohort study of a prospective adult thoracolumbar deformity database. PATIENT SAMPLE: This study included 1,541 patients. OUTCOME MEASURES: Radiographic alignment, patient-reported outcome measures (ODI), cost per QALY.
METHOD(S): Operative adult spinal deformity patients (scoliosis >20degree, SVA>5cm, PT>25degree, or TK>60degree) with an UIV at L1 or below and available baseline (BL) and 2-year (2Y) radiographic and HRQL data were included. "Matched" and "unmatched" alignment refers to the age-adjusted alignment criteria. PJK prophylaxis was defined by usage of cement, hooks or tethers. PJF was defined as PJK with reoperation. Costs were calculated using the PearlDiver database, accounting for additional costs of prophylaxis when applicable, through estimates from Medicare pay scales for services within a 30-day window, including estimates regarding costs of postoperative complications, outpatient healthcare encounters, revisions and medical related readmissions. QALY was calculated using SF6D.
RESULT(S): A total of 738 ASD patients or below met inclusion criteria (59.9yrs+/-14.0, 79%F, BMI: 27.7 kg/m2 +/-6.0, CCI: 1.8 +/-1.7). Surgically, patients had a mean level fused of 11.1+/-4.4, LOS of 7.9 days+/-4.4, EBL of 1577 mL, operative time of 377 min, with 63% undergoing an osteotomy. Forty percent of patients had PJK prophylaxis. Controlling for age, CCI, BL osteoporosis, levels fused, usage of 3CO, UIV, BL SVA and BL PI-LL, patients who were matched postoperatively in PT, SVA, or PI-LL had lowered PJF rates (OR:.5, 95% CI:.28-.86, p=.01) with prophylaxis. Among those unmatched in either SVA, PILL, or PT by 6W, prophylaxis significantly reduced the rates of PJK and PJF as well (p <0.05). ANCOVA controlling for age, CCI, BL osteoporosis, levels fused, usage of 3CO, UIV, BL SVA and BL PI-LL shows patients with ideal age-adjusted alignment and prophylaxis resulted in a lower cost per QALY by 2Y ($399,948 vs $514,228, p <.001). Similarly, in unmatched patients, prophylaxis resulted in a substantially lower cost per QALY by 2Y ($466,409 vs 672, 024, p <.001), primarily due to decreased costs of reoperation and greater improvements in QALY among prophylaxis cohorts.
CONCLUSION(S): Despite additional surgical cost, optimization of radiographic realignment in conjunction with utilization of proximal junctional failure prophylactic techniques achieves ideal cost utility, predominately due to the minimization of mechanical failure related reoperations. Even among those not achieving optimal alignment, junctional prophylactic measures improved cost utility, emphasizing its critical role of minimization of junctional failures to achieve cost efficiency in adult spinal deformity surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Despite studies reporting the efficacy of BMP to promote surgical spinal fusion, hospital systems and third-party payors continue to deny use of BMP, claiming high cost and lack of long term follow up. PURPOSE: Perform a propensity score matched analysis of complications and cost-effectiveness for surgically treated adult spinal deformity (ASD) patients receiving BMP vs no BMP. STUDY DESIGN/SETTING: Prospective, multicenter, propensity score matched analysis. PATIENT SAMPLE: ASD patients enrolled into a prospective multicenter study. OUTCOME MEASURES: Numeric rating scale (NRS) back and leg pain, Scoliosis Research Society-22r questionnaire (SRS-22r), Short Form-36v2 questionnaire (SF-36), Oswestry Disability Index (ODI), cost of care, cost/QALY, postoperative complications.
METHOD(S): Surgically treated ASD patients prospectively enrolled into a multicenter study from 2009-2018 were assessed for receiving BMP or NOBMP (iliac crest bone graft and allograft only) at the time of surgery. BMP and NOBMP cohorts were propensity score matched (PSM) for age, BMI, frailty, total levels fused, fusion to the pelvis, osteotomies, interbody fusion and supplemental rod use. Postoperative alignment, complications, rod fractures, patient-reported outcomes (PROMs), cost of care (based on DRG reimbursements adjusted to 2021 US dollars), were evaluated at minimum 3-year follow-up, and cost/QALY calculated at 1-,2-, and minimum 3-year follow-up.
RESULT(S): Of 888 patients, 483 (mean 4.2 years follow-up, range 2.9 to 8.8) were evaluated. Mean BMP dosage was 27.6 mg total (range 1 to 200), 2.2 mg/level posterior (range 0 to 25) and 1.7 mg/level interbody (range 0 to 18). BMP (n=407) had similar demographics, osteotomies, total and interbody levels fused, preop PROMs, follow-up duration, and pre- and postoperative spinal alignment as NOBMP (n=76; p>0.05). BMP had fewer implant failures (0.17/patient vs 0.33/patient; p 0.05). At last follow-up, BMP had better SF-36 social function (46.7 vs 43.9) and SF-36 mental component scores (51.5. vs 47.8) than NOBMP (p <0.05, respectively). BMP had lower mean total cost of care/patient ($78,679.61 vs $103,388.78) and lower cost/QALY ($22,455.48 vs $32,947.68) at last follow-up vs NOBMP, respectively (p < 0.05). Revision surgery rates were similar for BMP vs NOBMP (0.32 vs 0.42/patient, p=0.11); however, costs of revision surgery were less for BMP ($11,114.33) vs NOBMP ($22,912.53, p <0.05).
CONCLUSION(S): Propensity score matched analysis demonstrated BMP use in ASD surgery at mean 4-year follow-up was associated with decreased implant fracture rates, lower treatment costs and better cost/QALY than NOBMP. Hospital systems, administrators and third-party payors should consider that the initial cost of BMP use at index surgery may be offset by decreased total cost of care and improve cost/QALY for ASD patients. FDA DEVICE/DRUG STATUS: Bone morphogenetic protein: Investigational.
Copyright

BACKGROUND CONTEXT: As adult spinal deformity (ASD) prevalence increases in our ever-aging population there is a concomitant increase in poor bone quality. ASD surgery is expensive and carries a high complication profile. It is important to optimize modifiable preoperative risk factors, such as osteopenia or osteoporosis. Additional diagnostic modalities such as a DEXA can add cost, delay diagnosis, and can be an additional insurance hurdle. Some studies suggest HU's can be utilized as a proxy for frailty, but it is unclear if this is useful in risk stratification. PURPOSE: Our goal was to evaluate the relationship between bone health as measured by HU's and PJK and identify a HU threshold in which PJK risk is increased. We hypothesize that HU will correlate with occurrence of PJK after ASD surgery. STUDY DESIGN/SETTING: Retrospective review of a prospective, multicenter ASD database. PATIENT SAMPLE: Of 1,330 pts eligible, 997 (74.9%) had complete 2Y follow-up. Of these, 605 meet inclusion criteria with 110 (18.18%) patients having a PJK. OUTCOME MEASURES: Development of PJK within 2 years of surgery.
METHOD(S): Operative ASD patients (scoliosis >20, SVA>5cm, PT>25, or TK>60) with available baseline (BL) and 2-year (2Y) radiographic and HRQL data were included if they had a preop CT. HU were measured from axial views within the cancellous body (x3) at both L1 and UIV with the mean value calculated for each. Threshold linear regression with Bayesian information criteria was utilized to identify optimal cut-offs of risk factors for PJK. Multivariable analysis (MVA) controlled for PJK prophylaxis and surgeon. Additionally, risk factors identified were controlled against each other.
RESULT(S): Threshold regression identified that cut-offs of <125 HU for UIV, >63 years for age, >0.31 for ASD-FI, and >47degree for preoperative T4-12 thoracic kyphosis, and <10 levels fused were predictive of PJK on bivariate analysis (P<0.05 for all). On MVA, age > 63 years old (OR 4.7; P = 0.003), female gender (OR 3.33; P=0.035), HU at UIV vertebrae <125 (2.83; P=0.008), ASD-FI >0.31 (OR 4.02; P=0.011), TK > 46degree (OR 3.75; P=0.003), and < 10 levels fused (OR 3.31; P=0.0310) were associated with increased odds of PJK.
CONCLUSION(S): Bone health as measured by HU appears to be an independent predictor of PJK after ASD surgery, specifically values <125 at the UIV. It also parallels frailty in prediction of PJK and can potentially be used as a proxy for frailty assessment. This can be easily measured and could help with risk stratification in the future. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Adult spinal deformity (ASD) and cervical deformity (CD) surgery has seen great improvements in increasing perioperative patient safety and decreasing patient mortality. Previous studies have also demonstrated relatively higher risk of death in cervical deformity surgeries, yet there remains a paucity of literature comparing and contrasting the comorbidities and predictive factors associated with death in ASD versus CD surgery. PURPOSE: To assess morbidity and mortality rates and potential correlations with frailty in ASD vs CD patients. STUDY DESIGN/SETTING: Retrospective review of prospective cervical deformity (CD) and adult spinal deformity (ASD) databases. PATIENT SAMPLE: There were 689 ASD patients, 290 CD patients: 979 total. OUTCOME MEASURES: Demographic factors; baseline comorbidities; intra/postoperative complications; mortality.
METHOD(S): Operative CD patients 18yrs with pre-(BL) and up to 5-year (5Y) postoperative radiographic/HRQL data were assessed. Differences in demographics, radiographic alignment, and complication rates were assessed via means comparison analyses. Conditional backstep binary logistic regression analysis identified predictive factors for mortality. Kaplan-Meier curves assessed survivorship of expired patients. Cox regression assessed survivability adjusting for BL frailty status. Logrank analysis determined differences in the survival distribution between ASD and CD patients.
RESULT(S): A total of 625 patients met inclusion criteria (417 ASD, 208 CD). Within 5Y, 12 ASD patients (2.88% of ASD cohort) and 16 CD patients (7.69% of CD cohort) expired (p=.004). At baseline, ASD and CD patients differed significantly in BL Frailty score (0.29 vs 0.41, p.05). No significant differences were noted in BL disability per EQ5D-VAS (p>.05). In terms of baseline self-reported comorbidities in expired patients, the three most common for ASD patients were: arthritis (46%), hypertension (31%) and anemia (23%). In CD patients, the three most common comorbid conditions were: osteoporosis (50%), previous myocardial infarction (17%) and any cancer (17%). Complications analysis revealed no significant differences in major, minor or intraoperative complications between ASD or CD patients, nor between expired vs living patients (all p>.05). Similarly, there were no significant differences in mortality overall within 30 days, between 30 and 90 days, nor >90 days after surgery between ASD or CD patient cohorts (all p>.05). Regression analysis revealed that when accounting for age, BMI and gender, only frailty status remained a significant predictor of death overall (p=.047). Mean survival time for ASD was 84.11 weeks versus 65.17 in CD patients(chi2(1)=.748, p=.387).
CONCLUSION(S): Total 5-year all-cause mortality in adult spinal deformity and cervical deformity patients remains below 3% despite high rates of comorbidities, suggesting rigorous patient selection criteria plays an important role in maintaining the safety of such surgeries. This study demonstrates that while cervical deformity patients demonstrate greater incidence of death postoperatively, significantly increased baseline frailty status may be the principle cause of such results and should be considered when assessing surgical risks versus benefits. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Correction and maintenance of lordosis can be considered one of the most important aspects of achieving ideal surgical outcomes in ASD. Lumbar interbody fusions have been shown to be a beneficial tool in restoring lordosis, while supplemental rod constructs have been shown to increase durability and strength of the construct. However, there is a paucity of literature on whether multiple lumbar interbody fusions or supplemental rod constructs achieve superior maintenance of lordosis and/or superior surgical outcomes. PURPOSE: To investigate the outcomes and effect on maintenance of correction between multiple lumbar interbody fusions and supplemental rod constructs. STUDY DESIGN/SETTING: Retrospective cohort study of a prospective adult thoracolumbar deformity database. PATIENT SAMPLE: A total of 381 ASD Patients. OUTCOME MEASURES: Radiographic alignment, complications.
METHOD(S): Operative ASD patients (scoliosis >20, SVA>5cm, PT>25, or TK>60) with fusion UIV at or above L1 and fusion to pelvis with available baseline (BL) and 2-year (2Y) radiographic and HRQL data were included. Patients were divided into 2 groups, 1) those who had a supplemental rod construct (SUP) crossing at least 4 levels of the lumbar spine with no lumbar interbody fusion (LIBF), and 2) greater than or equal to 4 LIBF with no SUP. High loss of lumbar lordosis (HL) was defined as 1STD above the mean change in lordosis from post-op to 2Y.
RESULT(S): Out of 381 ASD patients who met inclusion criteria, 53 were analyzed: 24 with LIBF, and 29 with SUPs. At BL patients with a SUP had a greater SVA (9.3cm vs 7cm), p.05). No differences in age, gender, BMI, CCI, frailty or BL HRQLs. ANCOVA adjusting for BL deformity, 3CO, and revision status found SUP patients had a lower operative time (341min vs 663min, p.05. LIBF patients had a comparable degree of LL correction (18 vs 22) and greater HL (19% vs 4%). LIBF patients had higher rates of implant failure (42% vs 14%), rod breakage (21% vs 4%), rod dislocation (13% vs 0%) and overall mechanical complications (71% vs 35%, all p<.05). Rates of PJF trended higher (25% vs 10%). At 2Y, SUP patients had comparable HRQLs and trended higher for 6W GAP Proportionality (35% vs 21%).
CONCLUSION(S): The use of supplemental rods relative to the performance of multiple lumbar interbodies appear to better maintain alignment and substantially lower rates of rod breakage, implant failure, and overall mechanical complications by 2 years and beyond. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Tranexamic acid (TXA) is commonly used to lower blood loss in ASD surgery. Despite widespread use of TXA in ASD surgery, there is a lack of consensus regarding the optimal dosing intraoperatively. PURPOSE: This study aims to assess differences in blood loss and complications between high-dose, medium-dose, and low-dose TXA regimens. Complex ASD patients who receive high-dose TXA will have decreased blood loss compared to those who receive low-dose TXA. STUDY DESIGN/SETTING: Retrospective Review. PATIENT SAMPLE: A total of 265 ASD patients in a multi-center prospective study were retrospectively analyzed. OUTCOME MEASURES: Blood loss (ml), Major Blood Loss (>90th percentile ml), units transfused intraoperatively, units transfused perioperatively.
METHOD(S): Patients were separated into three cohorts by TXA regimen: 1) low-dose patients had =20mg/kg loading dose with =2mg/kg/hr maintenance dose 2) medium-dose patients had 20-50 mg/kg loading dose with 2-5 mg/kg/hr maintenance dose. 3) high-dose patients had =50mg/kg loading dose with =5mg/kg/hr maintenance dose. Major or minor blood loss was defined as above or below the 90th percentile of our cohort respectively. Multivariable analysis controlled for levels fused, BMI, platelets, Hgb, OR time, 3CO, and radiographic alignment.
RESULT(S): Fifty-four (20%) patients received low-dose regimen, 133 (50%) received medium-dose and 80 (30%) received high dose. Mean blood loss was 1,551+/-1,295 ml, intraoperative units RBCs 1.52+/-2, and perioperative units RBCs 2.3+/-2.3. Mean major blood loss was 4,566+/-1,516ml and minor blood loss 1,236+/-755ml. Compared to the low-dose group, patients in the high-dose group had 77.8% decreased odds of major blood loss (OR 0.222; P=0.007), decreased blood loss (Coef. -540.92ml; P=0.019), units transfused intraoperatively (Coef. -.739 units; P < 0.001), and units transfused perioperatively (Coef. -0.328 units; P=0.025). Compared to medium-dose group, the high-dose group had less units transfused intraoperatively (Coef. -.59 units; P < 0.001) and perioperatively (Coef. -.42 units; P < 0.001) with no difference in blood loss. There was no difference between the medium and low dose groups in blood loss or units transfused. There was no association between high-dose TXA regimen and increased rates of DVT, PE, or any medical complication before six weeks. No patients had a seizure.
CONCLUSION(S): In this multicenter prospectively collected database, ASD patients receiving high-dose intraoperative TXA have decreased odds of major blood loss, less RBC transfusions intraoperatively and 540ml less blood loss compared to low dose TXA, without additional risk of seizure or thromboembolic complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The impact of neuromuscular disorders such as multiple sclerosis (MS) on outcomes following long segment (4+ level) fusion is underreported. PURPOSE: To identify the impact of MS on two-year (2Y) postoperative complications and revisions following 4 level fusion for ASD. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: Patients undergoing 4+ level fusion for ASD were identified from the New York State Statewide Planning and Research Cooperative System. OUTCOME MEASURES: Two-year postoperative complications and reoperations.
METHOD(S): Patients undergoing 4-level fusion for ASD were identified from the New York Statewide Planning and Research Cooperative System. Patients with a baseline diagnosis of MS were also identified. Patients with infectious/traumatic/neoplastic indications were excluded. Subjects were 1:1 propensity score-matched (MS to no-MS) by age, sex, and race and compared for rates of 2-year postoperative complications and reoperations. Logistic regression models were utilized to determine risk factors for adverse outcomes at 2 years.
RESULT(S): A total of 86 patients were included (n=43 per group). Age (50.1 vs 50.1 years, p=0.225), sex and race were comparable between groups. MS pts incurred higher charges for their surgical visit ($125,906 vs $84,006, p=0.007) with similar LOS (8.1 vs 5.3 days, p>0.05). MS patients experienced comparable rates of overall medical complications (30.1% vs 25.6%) and surgical complications (34.9% vs 30.2%) all p>0.05. MS pts had similar rates of 2-year revisions (16.3% vs 9.3%, p=0.333). MS was not associated with medical, surgical or overall complications or revisions at minimum 2-year follow-up.
CONCLUSION(S): Patients with MS experienced similar postoperative course compared to those without MS following 4-level fusion for ASD. This data supports the findings of multiple previously published case series' that long segment fusions for ASD can be performed relatively safely in patients with MS. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Adult spinal deformity is associated with severe pain and disability. Recent literature has shown that surgical intervention can significantly improve patient's quality of life and lessen disease burden. As many patients requiring spine surgery are elderly and often frail, restoration of alignment targets may differ. There is paucity in literature on whether different frailty and deformity states may warrant a different level of surgical invasiveness. PURPOSE: To investigate the effect of frailty and deformity severity on appropriate surgical invasiveness. STUDY DESIGN/SETTING: Retrospective cohort study from multicenter database. PATIENT SAMPLE: This study included 381 adult spinal deformity (ASD) patients. OUTCOME MEASURES: Complications; health-related quality of life (HRQL); Oswestry Disability Index (ODI).
METHOD(S): Operative ASD patients (scoliosis >20, SVA>5cm, PT>25, or TK>60) with available baseline (BL) and 2-year (2Y) radiographic and HRQL data were included. The ASD-FI was used to stratify patients into 2 categories: Not Frail (NF): 20. Four groups were formed by frailty and deformity severity: NF Low, F Low, NF Sev, F Sev. ANCOVA determined differences in Surgical Invasiveness (SI) among F/D groups. Logistic regression determined significant association between SI and reaching Ideal Clinical outcome (ICO), defined as: no major complications, no reoperations, and reaching MCID for ODI. Surgical Invasiveness (SI) was normalized to a scale of 0-100 using the SI range. Thresholds for invasiveness and achieving ICO were found through conditional inference tree (CIT) analysis.
RESULT(S): A total of 381 ASD patients (59.3+/-15yrs, 26.9+/- kg/m2, CCI: 1.52+/-1.6, FI: 3.09+/-1.6) were included and underwent surgery (11.6+/-4 lvls fused, EBL: 1522+/-1275 mL, op time: 337+/-124 min, LOS: 7.3+/-3.9 days), with 62.2% having a posterior-only approach, 36.5% combined approach, 46% having a decompression and 65% an osteotomy. By deformity severity: 60% Low-Mod, 40% Severe, while frailty assessment was 49% NF, and 51% F. This categorized the patients into deformity/frailty groups as follows: 35% NF Low, 13% NF Sev, 22% F Low, 25% F Sev. Patients had a significantly different degree of SI: 35 NF Low/Mod, 38 F Low/mod, 48 NF Sev, 50 F Sev (p<0.001). CIT analysis found NF Sev patients had a higher likelihood of reaching ICO with an SI below 40 (OR: 3.6, 95% CI: 1.1-12.1, p=.037), and F Sev with a SI below 30 (OR: 4.6, 95% CI: 1.7-12.6, p=.003). Low/mod groups revealed no significant association between invasiveness and achieving ICO.
CONCLUSION(S): Analysis of increasing surgical invasiveness in patients stratified by frailty and baseline deformity showed frail severely deformed patients, compared with non-frail severely deformed patients, had a lower invasiveness threshold above which there was a higher risk of major complications, reoperations and failure to reach clinically important improvement in ODI. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The relationship of sagittal malalignment to outcomes has been emphasized in adult spinal deformity (ASD) surgery and it is known that sagittal parameters have some correlation to HRQOL measures overall. However, the specific relationship of HRQOL to postop sagittal alignment and changes in the strength of the relationship from preop to postop for deformity surgery has not been well defined. PURPOSE: To determine how postop health-related quality of life (HRQOL) correlates to sagittal alignment. STUDY DESIGN/SETTING: Retrospective analysis of a large prospective multicenter ASD database. PATIENT SAMPLE: This study included 925 ASD patients. OUTCOME MEASURES: HRQOL: Oswestry Disability Index (ODI), Short-Form-36 (SF-36), and Scoliosis Research Society-22r (SRS-22r). Radiographic sagittal alignment thresholds for C7-S1 sagittal vertical axis (SVA), pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL).
METHOD(S): Adult (=18yrs), Cobb angle =20degree, SVA=5cm, PT=25degree, and/or thoracic kyphosis=60degree, 2-yr follow up. Pts were grouped by having met 2/3 of the sagittal alignment thresholds (SVA,PT, and/or PI-LL) at 2 years postop for either the SRS-Schwab values (+SS0) or age-adjusted values (+AGE). The age-adjusted values were calculated within +/-10 years of their actual age. The groups -SS0 and -AGE were patients who didn't meet 2/3 of the SRS-Schwab or the age-adjusted values, respectively. Baseline/2-year HRQOL were evaluated via linear regression for all groups based on 2-year correction.
RESULT(S): Total 925 pts, mean age 60.1+/-14.2yrs, 602(65.1%)+SS0, 323(35.9%)-SS0, 199(21.5%)+AGE, and 283(30.6%)-AGE pts. The remaining age-adjusted pts were either overcorrected or did not have 2/3 sagittal values matched (n=443). All pts had significant improvement in all HRQOL at 2 years and for each of the subgroups (p <0.001 for all). The overall baseline R2 values for all pts for SVA, PI-LL and PT with ODI were (0.110, 0.072, 0.043, respectively) and at 2 years they were lower (0.049, 0.016, 0.008, respectively). Of the pts with pelvic fixation (n=635,68.6%), the same 2-year R2 values increased slightly but were still very weak (0.058, 0.028, 0.021, respectively). Of the pts who developed PJK, the 2-year R2 values were (PJK: 0.007, 0.024, 0.004, noPJK: 0.057, 0.017, 0.006, respectively). This same trend of low values was observed in +/-SS0 and +/-AGE pts. However, the R2 for 2-year ODI vs MCS, SRS appearance, and SRS mental, increased postop (0.19, 0.43, 0.22, respectively) compared with preop (0.17, 0.25, 0.17, respectively).
CONCLUSION(S): Sagittal alignment correlates weakly with preop HRQOL and postop HRQOL is improved. Preop SVA explains only 11% of preop ODI scores based on the R2 value and this decreases postop to 5%. After alignment correction, other patient factors become increasingly important such as the relationship between ODI and SRS appearance, SRS mental, and MCS. More work is necessary to better understand the postop HRQOL relationships including the possibility of a better measurement tool for surgical success. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: As surgical techniques for deformity correction evolve towards minimizing tissue trauma, further clarity is warranted to define differences in complication profiles between cMIS and open surgeries. PURPOSE: To compare cMIS and open surgery reoperation rates and identify contributing etiologies to reoperation in each cohort. STUDY DESIGN/SETTING: Prospective multicenter observational series. PATIENT SAMPLE: Database enrollment required age =18 years, adult spinal deformity and circumferential minimally invasive spine surgery. OUTCOME MEASURES: Reoperation rate, patient reported outcomes (PROMS), spinopelvic parameters, mechanical failures (defined as rod breakage/dislocation, screw breakage/loosening, set screw loosening, proximal/distal junctional kyphosis, pseudoarthrosis) and other factors contributing to re-operation such as wound infection, medial breach, nerve impingement by screw, vertebral body fracture, sagittal/coronal imbalance, and wound infection.
METHOD(S): A total of 85 patients (pts) with cMIS for ASD with 2-year follow-up (2YFU) were identified and propensity matched to 85 patients in open cohort. Propensity matching was performed based on pre-operative PT, PI-LL, BMI, and SVA. Patient demographic variables, reoperation rate, and complications contributing to reoperation were compared with uni- and multi-variate analysis at any time in each cohort (33 open, 17 cMIS). PROMS at 2YFU were compared in the reoperated cohorts.
RESULT(S): Total of 33 reoperation in the open cohort vs 17 in cMIS were identified. The reoperation rate was significantly higher in the open cohort at 39% (33/85) compared to 20% (17/85) in the cMIS cohort (P= 0.012). The reoperation rate in open cohort related to mechanical failure was 52% (17/33) compared to 35% (6/17) in cMIS cohort (P= 0.43). No significant difference was found in rates of specific etiologies contributing to complications in the cMIS vs open reoperation cohorts under uni- and multivariate analysis. The change in spinopelvic parameters among the two reoperation cohorts at 2YFU were statistically not significant (deltaCVA, deltaSVA, deltaPI-LL, deltaPT, deltaLL CA, deltaTL CA). Under univariate analysis, the following PROMS were similar: ODI, NRS Leg and Back Pain, EQ5D, EQ5D-VAS, SF-36 PCS,SF-36 MCS. However, SRS-22 in open cohort was significantly higher at 2YFU (3.55 +/- 0.73 open vs. 3,10 +/- 0.56 MIS, p = 0.029).
CONCLUSION(S): Findings in our ongoing study show that cMIS procedures were associated with a significantly lower reoperation rate compared to open surgical approaches. PROMS and the change in spinopelvic parameters were similar at 2YFU in both reoperated cohorts (except for SRS-22 favored open cohort). FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright