Faculty Bibliography

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:Assess changes in outcomes and surgical approaches for adult cervical deformity (ACD) surgery over time. SUMMARY OF BACKGROUND DATA/BACKGROUND:As the population ages and prevalence of cervical deformity increases, corrective surgery has been increasingly seen as a viable treatment. Dramatic surgical advancements and expansion of knowledge on this procedure have transpired over years, but the impact on cervical deformity surgery is unknown. METHODS:ACD patients (≥18 yrs) with complete baseline and up to two-year HRQL and radiographic data were included. Descriptive analysis included demographics, radiographic, and surgical details. Patients were grouped into Early(2013-2014) and Late(2015-2017) by DOS. Univariate and multivariable regression analyses were used to assess differences in surgical, radiographic, and clinical outcomes over time. RESULTS:119 cervical deformity patients met inclusion criteria. Early group consisted of 72 patients, and Late group consisted of 47. Late group had a higher CCI (1.3 vs. 0.72), more cerebrovascular disease (6% vs. 0%, both P<0.05), and no difference in age, frailty, deformity, or cervical rigidity. Controlling for baseline deformity, and age, Late group underwent fewer three-column osteotomies (OR=0.18, 95% CI:0.06-0.76, P=0.014). At last follow-up, Late group had less patients with: a moderate/high Ames horizontal modifier (71.7% vs. 88.2%), and overcorrection in PT (4.3% vs. 18.1%, both P<0.05). Controlling for baseline deformity, age, levels fused, and three-column osteotomies, Late group experienced fewer adverse events (OR =0.15, 95% CI: 0.28-0.8, P=0.03), and neurological complications (OR =0.1, 95% CI:0.012-0.87, P=0.03). CONCLUSION/CONCLUSIONS:Despite a population with greater co-morbidity and associated risk, outcomes remained consistent between early and later time-periods, indicating general improvements in care. The later cohort demonstrated fewer three-column osteotomies, less suboptimal realignments and concomitant reductions in adverse events and neurologic complications. This may suggest greater facility with less invasive techniques.

BACKGROUND:Frailty is influential in determining operative outcomes, including complications, in patients with cervical deformity (CD). OBJECTIVE:To assess whether frailty status limits the highest achievable outcomes of patients with CD. METHODS:Adult patients with CD with 2-year (2Y) data included. Frailty stratification: not frail (NF) <0.2, frail (F) 0.2 to 0.4, and severely frail (SF) >0.4. Analysis of covariance established estimated marginal means based on age, invasiveness, and baseline deformity, for improvement, deterioration, or maintenance in Neck Disability Index (NDI), Modified Japanese Orthopaedic Association (mJOA), and Numerical Rating Scale Neck Pain. RESULTS:One hundred twenty-six patients with CD included 29 NF, 83 F, and 14 SF. The NF group had the highest rates of deterioration and lowest rates of improvement in cervical Sagittal Vertical Axis and horizontal gaze modifiers. Two-year improvements in NDI by frailty: NF: -11.2, F: -16.9, and SF: -14.6 (P = .524). The top quartile of NF patients also had the lowest 1-year (1Y) NDI (7.0) compared with F (11.0) and SF (40.5). Between 1Y and 2Y, 7.9% of patients deteriorated in NDI, 71.1% maintained, and 21.1% improved. Between 1Y and 2Y, SF had the highest rate of improvement (42%), while NF had the highest rate of deterioration (18.5%). CONCLUSION/CONCLUSIONS:Although frail patients improved more often by 1Y, SF patients achieve most of their clinical improvement between 1 and 2Y. Frailty is associated with factors such as osteoporosis, poor alignment, neurological status, sarcopenia, and other medical comorbidities. Similarly, clinical outcomes can be affected by many factors (fusion status, number of pain generators within treated levels, integrity of soft tissues and bone, and deformity correction). Although accounting for such factors will ultimately determine whether frailty alone is an independent risk factor, these preliminary findings may suggest that frailty status affects the clinical outcomes and improvement after CD surgery.

BACKGROUND CONTEXT: The ACS-NSQIP and SpineSage are both easy to use and readily available online perioperative risk calculators The ACS-NSQIP calculator predicts perioperative complications after surgery, but lacks more spine-specific predictors. The SpineSage platform was developed as a tool built for predicting complications in spine surgery. While a limited number of studies have shown it be predictive of both overall and major medical complications in spine surgery, large external validation studies are limited and none have directly compared NSQIP against SpineSage in the same cohort of spine surgery patients. PURPOSE: Assess the ACS-NSQIP Risk Calculator and SpineSage informatics platform for prediction of perioperative complications in spine surgery STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 440 patients undergoing thoracolumbar spine with or without fusion. OUTCOME MEASURES: Any complication, serious complication, pneumonia, cardiac, dural tear, SSI, UTI, VTE, reoperation, death and LOS METHODS: Each patient was entered into the ACS-NSQIP and SpineSage calculators and predicted risk for specific complications were directly compared to actual risks. Paired t-tests compared the differences between calculators and their predictability of complications. Patients were ranked based on risk predicted for each complication and the highest tertile for each was isolated. Multivariate regression controlling for age and gender was used to determine if the highest tertile for each risk calculator had predictability in complications following spine surgery.
RESULT(S): Mean LOS 4.2+3 days, EBL 444+300 mL, operative time 256+240 min, and levels instrumented 2.1+2.3. When assessing the four complications predicted by SpineSage there were significant differences in three of the four variables, as SpineSage underpredicted the risk of all and serious-complications (p.5). Both calculator tertiles were trending towards significance for major medical complications (SpineSage: OR: 2.0, [0.94-4.23], p=.073; ACS-NSQIP: OR: 1.8,[0.96-3.48],p=.067). When examining any medical risk, only ACS NSQIP had significant predictability for any medical complication (OR: 2.1, [1.3-3.3]; p=.003).
CONCLUSION(S): Similar to previous studies, the ACS-NSQIP score underpredicted most complications, with the exception of LOS and death. In contrast to previous studies, our data suggest SpineSage was not predictive of actual rates of complications. As both calculators are highly accessible and provide at least some objective perioperative risk data points, we recommend them as a guiding tool but not as an absolute endpoint for clinical decision making as they may be inaccurate and insensitive. Further, higher powered studies elucidating the findings in this study should be conducted. Additionally, the assessment of these calculators for a specific subset of patients, such as deformity, degenerative or pediatrics, can further help guide clinicians regarding the utility of these calculators for their particular patient populations. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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.
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BACKGROUND CONTEXT: Surgical intervention has been shown to be an effective treatment modality for adult cervical deformity (CD), yet patient-reported outcomes vary even when patients are optimally realigned. While patients with higher baseline disability have more room for improvement, we propose there may be a threshold beyond which greater disability limits health-related quality of life (HRQL) improvement due to elevated risks and a point of no return. PURPOSE: To assess impact of baseline disability on HRQL outcomes. STUDY DESIGN/SETTING: Retrospective study of prospectively enrolled CD patients in a multicenter CD database. PATIENT SAMPLE: A total of 116 CD patients were included. OUTCOME MEASURES: HRQL, neck disability index (NDI), modified Japanese Orthopaedic Association (mJOA), EuroQol-5 Dimension (EQ5D).
METHOD(S): CD patients with baseline (BL) and 2-year follow-up (2Y) were included. The cohort was ranked into quartiles by baseline NDI, from lowest/best score (Q1) to highest/worst score (Q4). Means comparison tests analyzed differences between disability groups. Multivariate Analyses (MVA) assessed differences in outcomes of interest controlling for covariates including BL deformity, HRQLs, surgical details and complications.
RESULT(S): A total of 116 patients met inclusion criteria (age: 60.97+/-10.45 yrs, BMI: 28.73+/-7.59kg/m², CCI: 0.94+/-1.31). The cohort presented with mean BL cSVA was 38.54 +/- 19.43mm, TS-CL: 37.34 +/- 19.73, and mJOA: 13.62 +/- 2.71. Surgically, patients had an average of 8.44 +/- 3.41 levels fused, with 53.5% of patients undergoing decompression and 48.3% undergoing osteotomy. Mean BL NDI and numerical rating scale (NRS) of the cohort were 48.33 +/- 17.99 and 6.74 +/- 2.48 respectively. Mean BL NDI by disability group was as follows: Q1: 25.04 +/- 8.19, Q2: 41.61 +/- 2.77, Q3: 53.31 +/- 4.32, and Q4: 69.52 +/- 8.35. MVA assessing improvement in NRS neck and NRS back, found significant differences between disability groups (both p=.007). Patients in Q2 demonstrated the greatest improvement in NRS neck at 2 years (-3.93), which was greater than those in Q3 (-1.61, p=.032) and Q4 (-1.41, p=.015). Patients in Q2 demonstrated greater improvement in NRS back at 2 years (-1.71), compared to those in Q4 (+0.84, p=.010). Rates of MCID in NRS neck were also significantly different across disability groups (p=.023). Patients in Q2 met MCID at the highest rates (69.9%) of all groups, higher than those in Q4 (30.3%), p=.039. MVA found patients in Q2 demonstrated the greatest improvement in EQ5D at 2 years (+0.082), compared to Q1 (+0.073), Q3 (+0.022), and Q4 (+0.014), p=.034. Finally, patients in Q2 demonstrated the greatest improvement in mJOA score from baseline (+1.517), p=.042.
CONCLUSION(S): Patients in Q2, with mean baseline NDI of 42, consistently demonstrated the greatest improvement in HRQLs whereas those in Q4, with mean baseline NDI of 70, saw the least improvement. Thus, baseline NDI between 39 and 44 may represent a disability "wweet spot," within which operative intervention maximizes patient reported outcomes. Furthermore, delaying intervention until patients are severely disabled, beyond an NDI of 61, limits benefits of surgical correction in cervical deformity patients. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Evidence on long-term surgical recovery in adult spinal deformity (ASD) patients who are both frail and have an invasive procedure is limited. PURPOSE: This study aims to evaluate frail and invasive patients with 5-year recovery kinetics. We hypothesize that patients who are both frail and have invasive surgeries will have adverse postoperative recovery kinetics STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: A total of 133 ASD patients with complete HRQOL data at preoperative, 1-year, 2-year, 5-year follow-up were included. OUTCOME MEASURES: Integrated Health State Scores (IHS) in Oswestry Disability Index (ODI), Short-form 36 (SF-36) physical (PCS) and mental (MCS) component score, and Scoliosis Research Society (SRS)-22r measures METHODS: ASD-FI scores were used to stratify non-frail (0.3) patients. ASD-SR scores were used to stratify low invasive (90) surgeries. Using ASD-FI and ASD-SR, patients were separated into four cohorts: non-frail low invasive (NFLI), frail low invasive (FLI), non-frail high invasive (NFHI), and frail high invasive (FHI). HRQOLs at 1 year, 2 years, and 5 years were normalized against preoperative values. AUC was calculated across time points to generate an integrated health state score (IHS). Multivariable linear regression was used to compare IHS scores of FLI, NFHI, and FHI to NFLI while controlling for age, gender, comorbidity, and radiographic alignment.
RESULT(S): Of 633 eligible ASD patients, 339 had 5-year follow-up. Of those, 125 patients with complete HRQOL data at preoperative, 1-year, 2-year, and 5-year visits were included; 27.2% (34) were NFLI, 20.0% (25) were FLI, 26.4% (33) were NFHI, and 26.4% (33) were FHI. Using NFLI as the referent, FLI and NFHI did not have differences in ODI, MCS, PCS or SRS-22r IHS scores (P >0.05). On multivariable analysis of integrated health scores, FHI had higher MCS (7.6 vs 5.47; P=0.0188), SRS activity (6.97 vs 5.67; P=0.0004), SRS pain (8.49 vs 6.4; P=0.001), SRS appearance (8.97 vs 6.81; P=0.0014), SRS satisfaction (11.71 vs 7.97; P=0.0033), and SRS total (7.49 vs. 6.09; P=0.0002), indicating more improved recovery over a 5-year period. Patients who were FHI had higher rates of complications (P <0.05).
CONCLUSION(S): Despite having more complications, patients who were frail and underwent more invasive surgeries were more likely to have greater overall improvement in activity, pain, and satisfaction over a 5-year period relative to preoperative baseline. Our results suggest that frailty in combination with invasiveness do not hinder long-term postoperative recovery kinetics, in comparison to frailty or invasiveness alone. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: L5 nerve root palsy is a complication that can occur after ALIF indirect decompression. It is thought to occur due to the dimensional change in the L5 foramen that can either compress or cause a stretch neuropraxia of the nerve root. While this complication has been observed, reports and studies highlighting its incidence and risk are lacking. PURPOSE: To determine whether ALIF leads to an increased risk in L5 palsy, we sought to compare the relative risk compared to TLIF. We hypothesize that since foraminotomy is part of the TLIF procedure, it should demonstrate a difference in nerve root palsy compared to ALIF indirect decompression. STUDY DESIGN/SETTING: A single institution retrospective cohort study. PATIENT SAMPLE: A total of 626 patients (262 ALIF, 179 open TLIF, 185 MIS TLIF). The study period was 2017 to 2021. OUTCOME MEASURES: Primary outcomes were postoperative leg pain, sensory deficits, and motor weakness in tibialis anterior (TA), extensor hallucis longus (EHL) and gastrocnemius (GC). Secondary outcomes were infection, return to operating room (OR), and return to emergency center (EC) within 90 days.
METHOD(S): Retrospective comparative cohort study comparing ALIF vs TLIF. Inclusion criteria were all patients who underwent L5-S1 ALIF or L5-S1 TLIF (both open and MIS). Multilevel surgeries were excluded. The rate of postop nerve palsy was compared for the two treatment approaches. Chi-square was performed for all categorical comparisons and ANOVA was performed for continuous statistical comparisons.
RESULT(S): There were subtle differences in baseline characteristics between groups. ALIF patients were younger (p = 0.016), had less BMI (p = 0.026) and less likely to smoke (p = 0.008). There were no differences in gender or diabetes status. Patients undergoing TLIF (open and MIS) were more likely to be operated for lumbar spinal stenosis and radiculopathy (p < 0.001). There was an overall 3% rate of neuro deficits in the study population with a higher rate in those undergoing ALIF (5.3%) compared with open TLIF (0.6%) and MIS TLIF (2.2%) (p = 0.011). There was a rate of 3.1% EHL palsy in the ALIF group which was higher than TLIF (both open and MIS) (p = 0.048). There was a trend towards higher TA and GC nerve deficits in the ALIF group, but the difference was not significant. Additionally, there was a trend towards higher rates of return to OR for nerve deficit in the ALIF group, but this was not significant. However, ALIF patients had higher return to OR in 90 days for any reason (p = 0.01). There were no further differences between the groups. Among the 14 ALIF patients with any nerve deficit, 7 followed up at 3 mos and 5 in 1 year. At 3 mos, 5 of 7 patients had improvement in their nerve deficit and at 1 year, 5 of 5 patients had improved their deficiency.
CONCLUSION(S): This study demonstrates a higher rate of L5 nerve root palsy with ALIF compared to TLIF as evidenced by higher rates of EHL palsy with a rate of 3.1% in our study population. The study, however, is limited by its retrospective nature and subtle differences noted in demographics. Despite these differences, ALIF patient characteristics tended to be more favorable, which are unlikely to confound results of higher postoperative nerve deficits. Further study will be required to understand the mechanisms and radiological risk factors for postoperative L5 palsy after ALIF. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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.
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