Faculty Bibliography

BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients undergoing surgery risk neurological decline following surgery. However, surgery may be the key in improving outcomes in patients starting with lower extremity motor deficits at baseline (BL). We aim to analyze the improvement in neurological outcomes of ASD patients undergoing spinal reconstruction with BL and 6-week postoperative lower extremity motor scores (LEMS). PURPOSE: The aim of this study is to analyze the improvement in neurological outcomes of adult patients undergoing deformity surgery with baseline abnormal LEMS. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: A total of 205 patients were included in the study. OUTCOME MEASURES: Patient and procedural factors that lead to the improvement in neurological outcomes of adult patients undergoing deformity surgery with baseline abnormalLEMS.
METHOD(S): ASD patients ages = 18 were prospectively studied from 2018-2021. All patients underwent an instrumented PSF with a few also having an ASF of the lumbar spine. Patients were dichotomized based on BL LEMS (NML = 50, ABML < 50). The ABNML group was then dichotomized based on whether LEMS improved overall from BL or experienced no change or declined by first postoperative follow-up (PO) and various factors were analyzed and compared using standard statistical tests.
RESULT(S): Of the 205 patients evaluated, 134 (65.4%) were NML and 71 were ABNML (34.3%) at BL. Among the 71 patients with ABML LEMS at BL, 49% (N=35) improved to NML levels, 21% (N=15) improved from BL levels but not to NML, 20% (N=14) remained the same, and 10% (N=7) declined further at 6week PO. Compared to ABNML patients with no change or a decline in LEMS at first PO, patients who improved overall (70%; N=50) had significantly more decompressions performed (86% vs 57%; p=0.0092), and had more PCOs performed intraoperatively (90% vs 62%, p=0.0074). There were no statistical differences between the groups in age, BL LEMS, BMI, total instrumented vertebrae (TIV), EBL, and OR time. Overall, the number of patients with NML LEMS at 6 weeks PO increased by 7.5% (65.4% to 70.2%; p<.0001).
CONCLUSION(S): Seventy percent of patients with ABML LEMS at BL improved their motor strength by the first PO visit, while 30% stayed the same or declined. ABNML patients who improved from BL had significantly more decompressions performed and, surprisingly, more PCOs performed. Interestingly, patient factors between the two groups demonstrated no statistical differences further highlighting that improvement may be influenced by the differences in surgical techniques. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Several studies have suggested that Hounsfield units (HU) in the spine are associated with increased complications for adult spinal deformity (ASD) patients. PURPOSE: The aim of this study is to assess whether there exists a threshold for HU that is associated with increased blood loss following ASD surgery. We hypothesize that HU below thresholds on spinal CT are predictive of increased blood loss during surgery and implant complications within 90 days after surgery for ASD. STUDY DESIGN/SETTING: Retrospective analysis. PATIENT SAMPLE: ASD patients who had HU measured in the spine were identified from a multicenter database. OUTCOME MEASURES: High Intraoperative blood loss and implant complications within 90 days of surgery.
METHOD(S): HU at L1, upper instrumented vertebrae (UIV) and total averages were assessed. Threshold linear regression with Bayesian information criteria was utilized to identify optimal cut-offs for predicting high blood loss (>2100mL, top 25% by volume) or any implant complications within 90 days. Implant complications included loosening, breakage and dislocation of rods or screws. Multivariable logistic regression was utilized controlling for age, gender, comorbidity, osteotomy and levels fused.
RESULT(S): Of 527 patients included, the mean age was 61+/-14. Mean L1 HU was 154.59+/-87, UIV HU was 175.1+/-304, and total average HU was 165+/-168. There were 59 patients with high blood loss (mean 5,026+/-233ml) and 467 with low blood loss (1,331+/-39.5ml). Threshold regression analysis identified that a cut-off of =140.33 was optimal for predicting high blood loss and =99.75 total average HU was optimal for predicting implant complications within 90 days of surgery. On multivariable analysis, L1 HU less than 140 was associated with 1.57x higher odds of high blood loss (P=0.032). Total average HU less than 100 was associated with a 3.6x higher odds of having an implant related failure within 90 days of surgery (P=0.035).
CONCLUSION(S): In this prospective multi-center study, Those with L1 HU=140 had a 1.52x higher odds of high blood loss. Patients with an average HUof =100 have 3.6x higher odds of implant related complication within 90 days of surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Previous orthopedic literature has shown that patients with diabetes mellitus (DM) are more likely to develop complications in the postoperative period. To date, however, no study has assessed the specific pre- and postoperative risk factors that may contribute to this association for diabetic patients undergoing adult spinal deformity surgery. PURPOSE: Establish relevant risk factors for postoperative complications in a cohort of diabetic patients undergoing spinal deformity surgery. STUDY DESIGN/SETTING: Single-center retrospective cohort study. PATIENT SAMPLE: A total of 138 patients with DM who underwent spinal deformity surgery at a single academic hospital from 2012-2019. OUTCOME MEASURES: Primary outcomes were the development of any post-operative complications. These complications included the development of neurologic complications, urinary complications, cardiac complications, pulmonary complications, venous thromboembolism (VTE) and surgical site infections (SSI).
METHOD(S): This study is a retrospective cohort review of diabetic patients undergoing spinal deformity surgery, with 5 levels fused at a single academic medical center. Patients' age, BMI, levels fused, pre- and postoperative hemoglobin (Hgb), hematocrit (HCT) and preoperative HbA1C were collected. T-test and chi-square analyses were used to compare relevant outcomes. Significance was set to p<0.05.
RESULT(S): A total of 138 patients with DM met the inclusion criteria and were included in the analysis. Of these, 50.7% of the total cohort developed a postoperative complication within 90 days of the index surgery. Patients who developed postoperative complications were noted to have significantly lower postoperative Hgb (9.82+/-1.46 g/dL vs 10.72+/-1.76 g/dL, p=0.002) postoperative HCT (28.8+/-3.92% vs 32.60+/-4.61%, p<0.001) and significantly greater number of levels fused (9.49+/-3.74 vs 7.47+/-3.16, p=0.001). Diabetic patients who developed cardiac complications had significantly lower postoperative Hgb (9.47+/-1.50 g/dL vs 10.40+/-1.66 g/dL, p=0.021) and HCT (27.87+/-3.16% vs 31.15+/-4.72%, p=0.003) compared with those who did not. Diabetic patients who developed urinary complications were noted to be older on average (72.56+/-8.20 vs 64.43+/-11.70 years, p=0.043), while patients who developed VTE and pulmonary complications were noted to have significantly higher numbers of levels fused (VTE: 14.00+/-3.61 vs 8.37+/-3.51, p=0.007; PC: 10.82+/-4.14 vs 8.29+/-3.49, p=0.025)Finally, diabetic patients who developed a surgical site infection had significantly lower postoperative HCT (26.74+/-3.27% vs 30.86+/-4.64%, p=0.022) than those who did not. Multivariate logistic regression analysis showed that postoperative HCT (OR: 0.765 [0.613-1.098], p=0.001) and number of levels fused (OR: 1.243 [1.084-1.425], p=0.002) were predictive of development of any postoperative complication, when controlled for BMI, age, and and postoperative Hgb. Postoperative HCT was an independent predictor of the development of cardiac complications (OR: 0.827 [0.692-0.989], p=0.037) and SSI (OR: 0.709 [0.528-0.952], p=0.022).
CONCLUSION(S): Postoperative HCT is predictive of the development of postoperative complications in general, and more specifically the development of cardiac complications and surgical site infections. Along with blood-glucose and HbA1C, it should be closely monitored perioperatively in diabetic patients undergoing spinal deformity surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Thoracic decompensation (TD) represents a distinct radiographic complexity from proximal junctional kyphosis (PJK). Few studies exist on the occurrence of TD following adult spinal deformity (ASD) corrective surgery. PURPOSE: To assess the incidence of TD following ASD-corrective surgery in comparison with the occurrence of PJK. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: ASD, TD, PJK, thoracic compensation.
METHOD(S): ASD patients with complete baseline (BL) and two-year (2Y) followup were included. Patients were divided into groups: those who developed TD: T4-T12 >54.2degree and those who developed PJK. Further analysis assessed outcomes among patients with both TD and PJK (TDPJK). Thoracic compensation was defined as expected thoracic kyphosis minus BL thoracic kyphosis. Means comparison tests and multivariable logistic regression analysis assessed differences between patient groups.
RESULT(S): A total of 373 patients met inclusion criteria. Patient breakdown by radiographic outcome was: TD (N=31), PJK (N=223) and TDPJK (N=119). Age, gender, and ASD-mFI were similar between TD and PJK patients. TD patients were more likely to be osteoporotic than PJK patients, p < 0.05. Procedures on TD patients were less invasive and utilized a shorter construct (9.3 vs 11.5 levels; both p < 0.05). TD patients had significantly greater cervical lordosis, thoracic kyphosis, and lumbar lordosis than PJK patients at BL and 2Y follow-up, all p < 0.05. Thoracic compensation was significantly associated with TD (OR 1.07 [CI 1.04-1.09], p < 0.001) controlling for age, ASD-mFI, and invasiveness. TDPJK had the highest complication rate (84.9%), significantly greater than PJK patients (70.9%), and TD patients (61.3%), both p < 0.05. PJK patients were 78.7% less likely to develop PJF than TDPJK patients (OR 0.213 [CI 0.101-0.453], p < 0.001).
CONCLUSION(S): Patients who developed thoracic decompensation were more likely to present with osteoporosis, but had less invasive procedures and levels fused than patients with proximal junctional kyphosis. The tradeoff between fusing too much resulting in proximal junctional kyphosis and fusing too little predisposing to thoracic decompensation can serve as the basis of future studies to determine optimal construct length to balance these two risks. Thoracic compensation was predictive of postoperative thoracic decompensation in adult spinal deformity-correction. Patients who developed TDPJK had the highest rate of complications and greater odds of junctional failure. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Prior studies assessed the association between underlying neurological condition and worse outcomes following spinal surgery with recent emphasis of self-reported loss of balance (Imbalance) by Uribe et al. PURPOSE: To investigate if patients with self-reported loss of balance have poorer outcomes following adult spinal deformity (ASD) surgery. STUDY DESIGN/SETTING: Retrospective review of prospectively collected database. PATIENT SAMPLE: ASD patients with baseline and 2-year radiographic and patient-reported outcome measure (PROM) data were included. OUTCOME MEASURES: Demographics, radiographic outcomes, complications, and PROM were compared from baseline to 2-year follow up.
METHOD(S): Patients undergoing a long spinal fusion with no prior history of spine surgery were retained. Patients were grouped according to imbalance and unsteady gait. The groups were propensity matched by age, PI-LL, and surgical invasiveness score. Demographics, radiographic, complications and PROM were compared from baseline to 2-year post-op.
RESULT(S): A total of 212 patients were reported (106 patients in each group). The mean age (64 vs 63 years), BMI (27.2 vs 27.0 kg/m2), and gender (76% vs 87% female) were not significantly different for patients with imbalance and without imbalance respectively (all p >0.05). Patients in the imbalance group had a higher Frailty Index Score compared to patients without imbalance (3.74 vs 2.33, p <0.001). At baseline, the sagittal profile for both groups were comparable with regard to PT, PI-LL, and SVA. Patients with loss of balance had a significantly lower thoracic Cobb angle (25.27degree vs 37.45degree, p <0.001) and lumbar Cobb angle (37.03degree vs 45.53degree, p=0.004), although the global coronal alignment was similar (imbalance:41.51 mm vs 34.25 mm, p=0.155). Patients with imbalance had worse PROM measures, including ODI (45.15 vs 36.62), SF-36 Mental Component Score (44.04 vs 51.76), SF-36 Physical Component Score (30.17 vs 35.10), and SRS-22 Mental domain score (3.28 vs 3.80) (p <0.001 for all). Postoperatively, patients with imbalance had less PT correction (-1.45degree vs -3.60degree, p=0.039) for a comparable correction in their PI-LL (-11.93degree vs-15.08degree, p=0.144) by 2-year follow-up. Both groups demonstrated similar improvements in their coronal plane deformity. Imbalance patients had higher rates of radiographic PJK at 2-year follow-up (26.4% vs 14.2%, p=0.026). Furthermore, patients with reported imbalance have significantly higher rate of implant related complications (47.2% vs 34.0%, p=0.05). After controlling for age, baseline sagittal parameters, PI-LL correction and Charlson Comorbidity Index, patients with imbalance had 2.2 times increased odds of sustaining PJK by 2 years.
CONCLUSION(S): Patients with a self-reported loss of balance and unsteady gait have significantly worse baseline frailty and PROMs, represented by poorer mental health and physical function. Although those patients had higher rates of PJK and implant-related complications, surgical intervention significantly improved their quality of life. Despite the improvement, they remained with lower PROMs by 2-year follow-up. Therefore, in the clinic setting and with limited institutional access to Frailty scores, asking patients if they have loss of balance or unsteady gait is a simple yet powerful question which may trigger their preoperative risk stratification and optimization. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Previous literature has demonstrated the advantages of lateral single position surgery (L-SPS) in the perioperative period; however, 2-year postoperative outcomes of this novel technique have not yet been compared to circumferential anterior-posterior fusion (FLIP) at 2-years postoperatively. PURPOSE: Evaluate the feasibility and safety of L-SPS technique against the conventional FLIP. STUDY DESIGN/SETTING: Multi-center retrospective cohort study. PATIENT SAMPLE: Patients undergoing primary AP (ALIF or LLIF) fusions with bilateral percutaneous pedicle screw fixation between L2-S1 with minimum 2-year followup at three institutions. OUTCOME MEASURES: Outcome measures included levels fused, operative time, estimated blood loss and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch and segmental lumbar lordosis.
METHOD(S): Patients were grouped as L-SPS if anterior and posterior portions of the procedure were performed in the lateral decubitus position, and FLIP if patients were repositioned from supine or lateral to prone position for the posterior portion of the procedure. Groups were compared in terms of demographics, intraoperative, perioperative and radiological outcomes, complications and reoperations up to 2 years follow-up. Measures were compared using independent samples or paired t-tests and chi-squared analyses with significance set at p<0.05.
RESULT(S): A total of 442 pts met inclusion, including 352 L-SPS and 90 FLIP pts. Significant differences were noted in age (62.4 vs. 56.9; p= < 0.001) and smoking status (7% vs. 16%; p=0.023) between the L-SPS and FLIP groups. No differences between L-SPS and FLIP were noted in gender (57.4% female vs 57.8% female, p=1.000), BMI (30.0kg/m2 vs 29.3kg/m2; p=0.318). No differences were noted in number of levels fused between L-SPS and FLIP (1.45vs 1.50; p=0.533), proportion including ALIF (38% vs 39%; p=0.809), or the proportion of surgeries including L5-S1 (38%vs 31%; p=0.222). Perioperative outcomes: L-SPS demonstrated significantly lower Op time (97.7min vs 297.0 min; p < 0.001), fluoro dose (36.5mGy vs 78.8mGy; p < 0.001), EBL (88.8mL vs 270.0mL; p < 0.001), and LOS (1.91 days vs. 3.61 days; p < 0.001) compared to FLIP. L-SPS also demonstrated significantly fewer post-op complications than FLIP (21.9% vs 34.4%; p=0.013), specifically regarding rates of ileus (0.0% vs 5.6%; p < 0.001). There was no difference in remaining surgical site, neurological, or medical complications between groups. Reoperation: N=no differences in reoperation were noted at 30-day (1.7%L-SPS vs 4.4%FLIP, p=0.125), 90-day (5.1%L-SPS vs 5.6%FLIP, p=0.795) or 2-year follow-up (9.7%L-SPS vs 12.2%FLIP; p=0.441). The most common reason for return to OR was Adjacent Segment Disease, (L-SPS 3.1% vs. FLIP 7.8%; p=0.067). Pseudarthrosis rates were similar between groups (0.0%L-SPS vs. 1.1%FLIP; p=0.204). Radiological Outcomes: no significant differences were noted in rates of radiological fusion (94.3% L-SPS vs 97.8%FLIP; p=0.266) or subsidence (6.9%L-SPS vs 12.2%FLIP; p=0.260). There were no differences noted between L-SPS and FLIP in change in LL from Baseline to 1-year (3.5 vs 2.8; p=0.466) and post-op to 1yr (-0.18 vs -0.51; p=0.777), or in PI-LL from Baseline to 1-year (-3.5 vs -3.2; p=0.835) and from post-op to 1-year (0.71 vs 0.71; 0.998).
CONCLUSION(S): L-SPS improves safety, improves operative efficiency and reduces complications in the perioperative period while maintaining similar efficacy of AP fusion at 2-year followup in treating degenerative lumbar spinal conditions. 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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BACKGROUND CONTEXT: Malalignment following adult spinal deformity (ASD) surgery can negatively impact clinical outcomes and increase risk of mechanical complications. Despite improved definition of ideal alignment for ASD surgery and increasingly sophisticated preoperative alignment planning tools, it remains unclear whether the preoperative goals for alignment are actually achieved with surgery. PURPOSE: The objective of this study was to assess whether preoperative goals for sagittal alignment following ASD surgery are consistently achieved. STUDY DESIGN/SETTING: Multicenter, prospective cohort study. PATIENT SAMPLE: Operatively treatedASD patients. OUTCOME MEASURES: Sagittal vertical axis (SVA), pelvic incidence to lumbar lordosis mismatch (PI-LL), T4-T12 thoracic kyphosis (TK).
METHOD(S): From 2018-2021, ASD patients were enrolled into a prospective ASD study based on three criteria: deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR), and/or patient age (>65 and >7 levels fused). The operating surgeon documented sagittal alignment goals prior to surgery, including SVA, PI-LL mismatch and TK. Alignment goals were compared with achieved alignment at 6 weeks postop and the overall mean and SD were calculated for the offset (achieved minus goal) for each measure. Goal alignment was considered attained if the offset was within +/-1 SD of the goal. Demographic, surgical and baseline radiographic measures demonstrating significant association with achieving alignment goal on univariate analysis were used for multivariate regression analysis.
RESULT(S): The 266 enrolled patients had a mean age of 61.0 yrs (SD=14.6 yrs) and 68% were women. Mean number of instrumented levels was 13.6 (SD=3.8) and 24% had a 3-column osteotomy (3CO). Mean (SD) offsets were: SVA=-8.5 mm (45.6 mm), PI-LL=-4.6degree (14.6degree), TK=7.2degree (14.7degree), reflecting a tendency to undercorrect SVA and PI-LL relative to goal and to increase TK relative to goal. Surgeons achieved goal alignment (within 1 SD) for SVA, PI-LL, and TK in 74.4%, 71.4%, and 68.8% of cases, respectively. On regression analysis: goal SVA was more likely to be achieved with lower baseline SVA (OR=0.993, 95%CI=0.988-0.997, p=0.001) and greater baseline TK (OR=1.016, 95%CI=1.002-1.031, p=0.029); goal PI-LL was more likely to be achieved with greater patient age (OR=1.021, 95%CI=1.002-1.039, p=0.026) and history of previous TL spine surgery (OR=2.028, 95% CI=1.136-3.621, p=0.017); and goal TK was more likely to be achieved with lower baseline SVA (OR=0.995, 95%CI=0.991-0.999; p=0.014). The proportions of patients with achieved alignment within 1 SD of goal were not significantly different for patients with a UIV above T7 vs those with a UIV at or below T7 for SVA (p=0.20), PI-LL (p=0.49) or TK (p=0.06). Notably, patient-specific rods were used in 21 patients and were not associated with greater achievement of goal alignment for any parameter (p>0.8), with similar tendencies to undercorrect SVA and PI-LL and increase TK (p>0.6).
CONCLUSION(S): Surgeons failed to achieve goal alignment of each sagittal parameter in ~25% of patients operated for ASD, with a tendency to undercorrect SVA and PI-LL and increase TK. Patients at greatest risk tended to be those with more severe baseline deformity. Further advancements are needed to enable more consistent translation of preoperative alignment planning to the operating room. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Numerous studies have reported the interplay between spinal deformity and pelvis compensatory mechanisms, but little data exist evaluating the contribution of lower extremity compensation (LE) to maintain upright posture. We hypothesis that hip, knee and ankle compensation is proportional to the severity of the spinal deformity and varies by demographics. PURPOSE: Evaluate the association between spinal alignment and lower limbs compensation. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: This study included 288 patients treated for complex adult spinal deformity (ASD) with full body images available. OUTCOME MEASURES: Pelvic retroversion (PT), hip extension (SFA), knee flexion (KA), ankle dorsiflexion (AA), pelvic translation (P.Shift) and patient reported outcomes (ODI, PROMIS and SRS-22).
METHOD(S): Surgical ASD patients were enrolled into a prospective study based on three criteria: deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR) and/or age (>65 and >7 levels fused). Associations between lower extremity compensation (hip extension, knee flexion, and ankle dorsiflexion) and the magnitude of spinal deformity, patient demographics, patient frailty, and patient-reported outcomes (ODI, SRS, PROMIS-CAT) were assessed via regressions and partial correlations.
RESULT(S): A total of 288/329 patients met inclusion criteria (60+/-15yo, 70.5% female), had moderate to severe spinal deformity (PI-LL:15+/-24, TPA:24+/-14, SVA:65+/-69mm, lumbar Cobb:34+/-24), and reported high pain (PROMIS pain interference; PI=62.7+/-7.8) and reduced physical function (PROMIS physical function; PF=35.6+/-7.6). Lower extremity compensation included pelvic retroversion (PT:24.1+/- 11.8), hip extension (SFA: 203+/-10.5), knee flexion (KA:5.5+/- 9.6), ankle dorsiflexion (AA: 5.3+/-4.5), and posterior pelvic translation (P.Shift: 30+/-51mm). Overall, lower extremity compensation increased with age (all p <0.001), BMI and frailty (all p <0.001, except SFA). For a similar PT, women had greater hip extension than men (SFA: 206 vs 200, p <0.001), with less KA (3.6 vs. 10.1, p <0.001), AA, and P.Shift. Lower extremity compensation increased with PI (r=0.2-0.45, p <0.001), TPA (r=0.5-0.9, p <0.001) and correlated with PROMS (ODI:0.26 - 0.37, PROMIS PF: -0.28 - -0.39, SRS Acti.: -0.20 - -0.33). When controlling for deformity severity and PI, most associations between lower limbs compensation and PROMS were lost. However, P.Shift and SFA remained weakly correlated with physical scores (ODI and PROMIS PF).
CONCLUSION(S): The recruitment of LE compensation is overall proportional to the severity of adult spinal deformity, with different patterns observed between men and women. Patients achieved similar PT by recruiting different patterns of LE compensation. Hip extension and posterior pelvic translation are independently associated with impairment in patient-reported outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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OBJECTIVE:Revision surgery is often necessary for adult spinal deformity (ASD) patients. Satisfaction with management is an important component of health-related quality of life. The authors hypothesized that patients who underwent multiple revision surgeries following ASD correction would exhibit lower self-reported satisfaction scores. METHODS:This was a retrospective cohort study of 668 patients who underwent ASD surgery and were eligible for a minimum 2-year follow-up. Visits were stratified by occurrence prior to the index surgery (period 0), after the index surgery only (period 1), after the first revision only (period 2), and after the second revision only (period 3). Patients were further stratified by prior spine surgery before their index surgery. Scoliosis Research Society-22 (SRS-22r) health-related quality-of-life satisfaction subscore and total satisfaction scores were evaluated at all periods using multiple linear regression and adjustment for age, sex, and Charlson Comorbidity Index. RESULTS:In total, 46.6% of the study patients had undergone prior spine surgery before their index surgery. The overall revision rate was 21.3%. Among patients with no spine surgery prior to the index surgery, SRS-22r satisfaction scores increased from period 0 to 1 (from 2.8 to 4.3, p < 0.0001), decreased after one revision from period 1 to 2 (4.3 to 3.9, p = 0.0004), and decreased further after a second revision from period 2 to 3 (3.9 to 3.3, p = 0.0437). Among patients with spine surgery prior to the index procedure, SRS-22r satisfaction increased from period 0 to 1 (2.8 to 4.2, p < 0.0001) and decreased from period 1 to 2 (4.2 to 3.8, p = 0.0011). No differences in follow-up time from last surgery were observed (all p > 0.3). Among patients with multiple revisions, 40% experienced rod fracture, 40% proximal junctional kyphosis, and 33% pseudarthrosis. CONCLUSIONS:Among patients undergoing ASD surgery, revision surgery is associated with decreased satisfaction, and multiple revisions are associated with additive detriment to satisfaction among patients initially undergoing primary surgery. These findings have direct implications for preoperative patient counseling and establishment of postoperative expectations.