Faculty Bibliography

BACKGROUND CONTEXT: The durability of adult spinal deformity (ASD) surgery is key for cost-effective treatment. Malalignment is one of the main reasons for revision surgery. PURPOSE: To investigate risk factors for loss of correction within the instrumented lumbar spine following ASD surgery. STUDY DESIGN/SETTING: Retrospective cohort study of a prospective database. PATIENT SAMPLE: This study included 321 ASD patients with minimum 3 -year follow-up. OUTCOME MEASURES: L1-S1, L4-S1 and L1-L4 lumbar lordosis.
METHOD(S): A total of 321 patients who underwent fusion of the lumbar spine (=5 levels, LIV S1/ilium) with a revision-free follow-up =3 years were identified. Patients were stratified by the change in PI-LL from 6 weeks to 3 years postop as Maintained vs Loss > 5degree. Those with a loss due to instrumentation failure (broken rod, screw pullout, etc.) were excluded before comparisons. Changes in regional and focal lordosis over time were investigated with repeated measures ANOVA and factor comparison.
RESULT(S): Mean age 64 yrs, BMI 28 kg/m², 80% female. The baseline alignment (PI-LL=21+/-19degree, T1PA=26+/-12degree) was corrected to PI-LL=3+/-13degree, and T1PA=18+/-10degree at 3 yrs (mean 3Y follow-up: 45+/-11m, with 44+/-11 mo between early and late follow-up). Eighty-two patients (25.5%) lost >5degree of PI-LL correction (mean loss 10+/-5degree). After exclusion of patients with instrumentation failure, 52 patients (Loss) with a mean loss of correction of 8.6+/-2.9 were compared to 222 controls with maintained LL correction. Demographics were similar between groups (age: 63 vs 61 p=0.15; Sex: 78.4% F vs 88.5% p=0.10). There were no significant differences in use of osteotomy, 3CO, and IBF between Loss and Maintained LL (all p >0.1). There was no significant difference in number of levels fused (11 vs 12 p=0.39), rod material (CoCr 59.4% vs 58.8% p=0.34), and BMP use (88.7% vs 84.6% p=0.41) but Loss had less supplemental rod use (5.8% vs 23.4% p=0.004). Comparison between Maintained and Loss revealed a similar PI-LL mismatch at pre-op (16.7+/-18.7 vs 20.9+/-18.3 p=0.14) and final postop (1.8+/-12.5 vs 5.1+/-14.5 p=0.11) but a significantly smaller PI-LL for Loss at early postop (0.6+/-12.8 vs -3.5+/-13.7 p=0.41). Distally, Maintained had a significant improvement in L4-S1 lordosis from preop to early postop (p=0.013), with no significant difference from early to final follow-up. In contrast, patients in the Loss group had no difference in L4-S1 from preop to early postop (p=0.14), but showed a significant loss of correction at 3 years (p <0.001). Proximally, significant increase between pre and early postop in L1-L4 (all p <0.001), with Loss and Maintained reaching similar early postop value (p=0.34). However, from early postop to final follow up, Loss showed a significant decrease in proximal lordosis (p <0.001) while Maintained did not (p=0.08), corresponding with a smaller absolute L1-L4 in the Loss cohort at 3 yrs (p=0.002). Screw orientation showed a significant decrease from early to late follow-up between the L1 and S1 screws for Loss (1.3+/-4.1 p=0.031), without any changes across the L4-S1 segment (-0.1+/-2.9 p=0.97).
CONCLUSION(S): Approximately a quarter of patients lose an average of 10degree of their 6-week correction by 3 years. Lordosis is lost proximally through the instrumentation (ie, tulip/shank angle shifts and/or rod bending), but lost distally through bone "settling" through the instrumentation itself. The use of supplemental rods and avoiding sagittal overcorrection may help mitigate this loss. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Advancements in artificial intelligence (AI), machine learning, and minimally-invasive (MIS) technique may offer enhanced preoperative planning, intraoperative robotic or navigational guidance, and prediction of postoperative complications for adult spinal deformity patients. Despite relatively widespread utilization, few studies in the literature assess the clinical and radiographic impact of AI in MIS surgery. PURPOSE: To assess the impact of artificial intelligence on peri- and postoperative course in minimally-invasive adult spinal deformity corrective surgery. STUDY DESIGN/SETTING: Retrospective cohort review. PATIENT SAMPLE: This study included 524 MIS patients. OUTCOME MEASURES: Intra- and postoperative complication rates; reoperation rate; HRQLs METHODS: Operative cervical deformity patients 18 years old with complete pre-(BL) and up to 2-year (2Y) postop radiographic/HRQL data were stratified by primary utilization AI-based patient-specific rod customization and robotic or navigational assistance in pre- and perioperative course (AI+) or not (AI-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Analysis of covariance (ANCOVA) assessed postoperative complications while controlling for BL age and gender.
RESULT(S): A total of 133 MIS patients were included (51.74+/-11.59 years, 41% female, 30.85+/-6.93 kg/m²). Of these patients, 44 (33.1%) were classified as AI+. At baseline, patient groups were comparable in BL age, BMI and CCI (all p>.05), though AI+ patients were more likely to be male (p=.040). Patient groups were comparable in terms of both regional and global radiographic alignment, as well as HRQLs at BL (all p>.05). Surgically, AI+ patients had significantly shorter operative times overall (p=.022) and decreased EBL (p=.001), as well as decreased likelihood of undergoing corpectomy (p=.001). Furthermore, AI+ patients reported significantly lower hospital LOS vs AI- patients (p=.012). At 2 years postoperatively, AI+ patients with custom rods were noted to have significantly improved segmental alignment in terms of decreased pelvic tilt (S1PT) and pelvic incidence (S1PI) (both p <.001). Adjusted complications analysis revealed that AI+ patients were significantly less likely to experience any postoperative complication (p=.003), neurological complications (p=.021) or complication requiring reoperation (p=.003).
CONCLUSION(S): Artificial intelligence and machine learning technologies may provide a substantial benefit to patients undergoing minimally-invasive adult spinal deformity surgery. The findings in this study demonstrate that patients operated on using AI-based robotic or navigational guidance, as well as the utilization of customized instrumentation, may reduce intraoperative invasiveness, shorten hospital length of stay, and decrease complication rates. As such, surgeons should consider utilization of AI-based technology in practice. 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: Surgical correction of cervical deformity is a proven treatment option that provides functional restoration and pain relief. It is unclear whether patient outcomes and costs of the procedure are influenced by the time between initial symptom onset and definitive surgical intervention. This study sought to determine how long nonoperative treatment should be exhausted prior to offering surgery for cervical deformity. PURPOSE: To identify whether delayed procedures influence patients' ability to recover and cervical deforminty corrective surgery cost effectiveness. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: This study included 290 cervical deformity patients. OUTCOME MEASURES: Delayed surgical intervention, recovery kinetics, cost effectiveness.
METHOD(S): Cervical deformity patients with baseline (BL) and two-year (2Y) follow-up data were included. Patients were stratified by time to surgery following the onset of their neck pain: >5 years=Delayed; <5 years=not Delayed. Normalized HRQL scores at BL and follow-up intervals (3M, 6M, 1Y, 2Y) were generated. Normalized HRQLs were plotted and area under the curve was calculated, generating one number describing overall recovery (Integrated Health State [IHS]). Cost was calculated using the PearlDiver database, which represents national average Medicare cost. Cost per Quality-Adjusted Life Year (QALY) at 2Y was calculated. Multivariable regression analysis assessed the impact of Delayed surgery on patient outcomes and cost.
RESULT(S): A total of 123 patients were included (54 Delayed, 69 not Delayed). Demographic and surgical characteristics were similar between groups (p > 0.05). Normalized HRQLs showed that Delayed patients exhibit worse NDI and NRS Neck at 2Y follow-up, both p 0.05. Utility gained at 2Y follow-up was 0.172 for Delayed and 0.2847 for not Delayed. This translated to QALY gained at 2Y of 0.334 for Delayed and 0.553 for not Delayed, p 0.05. Multivariable analysis found Delayed patients were less likely to gain utility (OR 0.125 [CI 0.019-0.840]) and QALYs (OR 0.343 [CI 0.129-0.914]) at 2Y postoperatively, both p< 0.05.
CONCLUSION(S): Patients who had a 5-year or greater delay to surgery from the onset of neck pain had more significant postoperative neck disability. Cost by procedure and cost-effectiveness when stratified by time to surgery following enrollment were comparable. While both patient cohorts had postop improvement, patients without delay had greater utility gained and quality adjusted life years at 2-year follow-up. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients maintain upright posture by compensating through their spine, pelvis and lower extremities. Little data exist quantifying the contribution of lower extremity compensation through the hips, knees, and ankles to maintain upright posture. PURPOSE: Evaluate the effect of the lower limb compensation by numerically unfolding patients. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: A total of 288 patients surgically treated for complex ASD with preoperative full body images. OUTCOME MEASURES: Horizontal distance between vertebra centroid and ankle.
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). Preop full-body images were evaluated and age and PI-adjusted normative values were used to model spine alignment based upon three configurations: COMP (all lower extremity compensatory mechanisms maintained), PARTIAL (removal of ankle dorsiflexion and knee flexion, maintained hip extension), UNCOMP (ankle, knee, and hip compensation eliminated by reset PT to the age and PI norms). The three configurations were compared, and COMP alignment was stratified by TPA percentiles to investigate the offsets from each vertebra to the ankle joint acting as a surrogate of the gravity line in free-standing position.
RESULT(S): A total of 288 patients met inclusion criteria (60+/-15yo, 70.5% female, 27.4+/-5.9 BMI). COMP spine deformity magnitude included PI-LL 15+/-24, TPA 24+/-14, and SVA 65+/-69mm. As the model transitioned from COMP to UNCOMP alignment, the initial posterior translation of the pelvis decreased significantly to an anterior translation vs the ankle (P.Shift 30 to -7.6 mm). This was associated with a decrease in pelvic retroversion (PT 24.1 to 16.1), hip extension (SFA 203 to 200), knee flexion (KA 5.5 to -0.4), and ankle dorsiflexion (AA 5.3 to 3.7). As a result, the anterior malalignment of the trunk significantly increased SVA (65 to 120mm) and G-SVA (C7-Ankle from 36 to 127 mm), leading to a three-fold increase in bending moments sustained by the ankle joint. The stratification of the COMP position by TPA percentiles revealed that as the deformity increases, the vertebrae above T8 translate anteriorly, those below T10 move posteriorly, with the T8-T10 segment remaining ~3cm posterior to the ankle joint independently of the deformity severity.
CONCLUSION(S): Removal of lower limbs' compensation revealed an unsustainable truncal malalignment with a three-fold increase of bending moments at the ankle joints. Combined, lower limb compensations permit "reducing" the SVA by two-fold and the C7-ankle SVA by three-fold. From a mechanical point of view, this compensation permits maintaining the trunk center of mass (T9) at a fixed offset of ~3 cm from the ankle joint. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Operative intervention for adult spinal deformity (ASD) is associated with high rates of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). Multiple attempts have been made to guide realignment for ASD corrective surgery, yet the predominance have been based on functional gains, which may or may not directly impact such junctional malcompensation. PURPOSE: To assess impact of baseline patient deformity and surgical realignment on rates of PJK and PJF. STUDY DESIGN/SETTING: Retrospective study of patients prospectively enrolled in a single center ASD database. PATIENT SAMPLE: A total of 298 ASD patients. OUTCOME MEASURES: Proximal junctional kyphosis (PJK); proximal junctional Failure (PJF).
METHOD(S): ASD patients with 2-year (2Y) data, UIV above L1 and LIV at S1 or pelvis were included. Those with evidence of PJK at 6-weeks postoperatively were excluded. Six-week radiographs were used to assess alignment by 5 published alignment systems: SRS-Schwab, GAP Score, age-adjusted (AA), Roussouly (Rous), and the newly published sagittal age-adjusted score (SAAS). To compare the impact of each alignment system on rates of PJK and PJF by level of baseline deformity, all radiographic measurements used to calculate SRS-Schwab, AA, Rous, GAP and SAAS were re-scaled from 0 to 100 using the min-max of the cohort for each respective angle. Normalized values were then summed to compute a composite "deformity score" for each patient. Patients were ranked by deformity score into 3 groups: mild, moderate, and severe. Means comparison tests were used to assess rates of PJK and PJF (defined as PJK with reoperation) by alignment system in the cohort and by deformity group. Multivariate logistic regressions controlling for covariates such as age, PJK prophylaxis, and osteoporosis were used to generate odds ratios (OR) and identify the alignment systems associated with lower odds of developing PJK and PJF.
RESULT(S): A total of 298 patients met inclusion (62.5yrs, BMI: 27.5kg/m², CCI: 1.5, 76% F). Overall, 33.6% of the cohort developed PJK and 6.7% developed PJF. MVA of the cohort found those aligned to AA had a 55% lower odds of PJK (OR: 0.453, [0.283, 0.727], p=.001) and 60.4% lower odds of PJF (OR: 0.396, [0.169, 0.933], p=.034). Subanalysis of patients presenting with mild deformity scores (N=71) found none of the alignment systems reduced odds of PJK or PJF (all p>.05). Subanalysis of patients presenting with moderate deformity scores (N=108) found those meeting AA had 79% lower odds of PJK (OR: 0.210, [0.072, 0.615], p=.004), yet none of the alignment systems significantly reduced odds of PJF. In those severe deformity scores (N=119), meeting Schwab significantly reduced odds of PJK (OR: 0.492, [0.318, 0.761], p=.001). With regard to PJF, in those with severe deformity scores, alignment to Schwab (OR: 0.235, [0.104, 0.532], p=.001) and AA significantly reduced odds of PJF (OR: 0.352, [0.124, 0.994], p=.049).
CONCLUSION(S): This study aimed to assess impact of realignment to published systems on rates of PJK and PJF in surgical correction of adult spinal deformity. Overally, those meeting age-adjusted alignment had lowest rates of PJK and PJF. Morover, further analysis revealed that moderately and severely deformed patients beneit benefit from realignment to age adjusted criteria. However, none of the alignment systems were associated with lower odds of PJK or PJF in those presenting with mild deformity. This may indicate a certain level of PJK and PJF is not preventable by optimal realignment alone. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: A previous study by Pellise et al identified strong preoperative and surgical predictors of major complications. It is unknown which of these risk factors has the most significant impact on cost-effectiveness. PURPOSE: To assess the impact of previously established risk factors on the cost effectiveness of ASD surgery. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: Quality adjusted life years (QALYs), utility gained, ODI, total cost.
METHOD(S): ASD patients with baseline (BL) and 2-year postoperative (2Y) data were included. Frailty score, sagittal deformity measures (SVA, PI-LL, T1 Sagittal Tilt), blood loss and surgical time were divided into tertiles, with the highest tertile being classified as high risk. Since some patients have multiple risk factors, they may be included in multiple groups. Descriptive analysis identified demographics, radiographic parameters and surgical factors. Published methods for cost was calculated using the PearlDiver database and CMS.gov definitions. Cost per QALY at 2Y was calculated for each risk factor.
RESULT(S): There were 422 patients included. Of the 381 patients with a risk factor, 77% were fused to the pelvis, 44% were highly frail, 56% had a high deformity, 34% had high EBL and 34% had high operative time. When analyzing BL scores, highly frail patients had the highest mean ODI and EQ-5D. After undergoing surgery, patients with a high EBL had the highest rate of SICU admissions, rate of any complications and rate of major complications. This translated to patients with high EBL having the lowest utility gained at 2Y. Interestingly, patients with high frailty had the highest rates of implant complications and pseudarthrosis resulting in the second highest major complication rates and total estimated cost. Despite this high estimated cost, however, patients with high frailty also achieved the highest utility gained at 2Y resulting in the best cost-utility at two years.
CONCLUSION(S): Despite having higher rates of implant failures, pseudarthrosis, and major complications, highly frail patients managed to generate the highest utility gained and best cost-effectiveness, while higher blood loss had higher rates of complications as well, but demonstrated the lowest utility gained and cost-utility. Therefore, spine surgeons should limit intraoperative risk factors, such as blood loss and operative time, which would minimize postoperative complications and improve overall cost-effectiveness during correction of adult spinal deformity. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Previous studies have demonstrated that preoperative rehabilitation (prehab) may be beneficial in adult cervical deformity surgery. Though protocols vary widely, general overlap exists in terms of inclusion of mental and physical modalities in order to optimize patient outcomes. However, there remains a paucity of literature in regards to assessing outcomes in a controlled setting. PURPOSE: To assess the effects of prehabilitation on peri- and postoperative outcomes in adult cervical deformity surgery. STUDY DESIGN/SETTING: Retrospective review of prospective CD database. PATIENT SAMPLE: A total of 290 CD patients. OUTCOME MEASURES: Peri- and postoperative complication rates; medication usage; HRQLs.
METHOD(S): Operative CD patients 18yrs with complete pre-(BL) and 2-year(2Y) postop radiographic/HRQL data were stratified by enrollment in prehabilitation protocols beginning in 2019, consisting of physical therapy, nutritional counseling and/or psychological counseling. Patients were stratified as having underwent prehabilitation (Prehab+), versus those who did not (Prehab-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay-scales. QALY was calculated via NDI mapped to SF6D using validated methods.
RESULT(S): A total of 115 patients were included (56.37+/-8.90 years, 38% female, 29.84+/-6.19 kg/m2). Of these patients, 57 (49.6%) were classified as Prehab+. At baseline, groups were comparable in age, gender, BMI, CCI and frailty. In terms of BL HRQLs, Prehab+ significantly lower mJOA scores (p=.047), though were equivalent in NDI and EQ5D scores (both p>.05). Baseline opioid usage was comparable prior to prehab enrollment (p=.093). Surgically, Prehab+ were able to undergo longer procedures (p=.017) with equivalent EBL (p=.627), and shorter SICU stay (p.05) and QALYs gained by 2Y (.43 vs.40, p>.05).
CONCLUSION(S): This study demonstrates that introducing prehabilitation protocols in adult cervical deformity surgery may aid in improving patient physiological status, enabling them to undergo longer surgeries with lessened risk of peri- and postoperative complications. Though cost-effectiveness of such programs should be further assessed, prehabilitation should be considered for eligible patients to assist in optimizing recovery and reducing complications or reoperations. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

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.
Copyright

BACKGROUND CONTEXT: Versatility in patient positioning during spine surgery has recently gained popularity. This includes single-position circumferential minimally invasive surgery, staged and same-day procedure. Overall analysis of outcomes between these approaches is lacking in the literature. PURPOSE: To investigate the perioperative and postoperative outcomes of single-position, staged or same-day patients. STUDY DESIGN/SETTING: Retrospective review of a single-center database. PATIENT SAMPLE: This study included 580 spine fusion patients. OUTCOME MEASURES: Complications, health-related quality of life (HRQL) alignment.
METHOD(S): Operative spine patients with available baseline (BL) and up to 2-year (2Y) radiographic and HRQL data were included. Patients were stratified into three different categories based on surgical approach: single-position (SP), staged (ST), and same-day (SD). ANCOVA analysis was used to assess differences in demographic, radiographic, clinical, surgical factors and outcomes.
RESULT(S): A total of 133 patients were included (age 57.8+/-11.4, BMI 30.6+/-7, 42% female, ASA 2.36+/-.57). Patients had an average of 2.42+/-1.3 levels fused, operative time was 293+/-141 minutes, EBL was 326+/-325, most common UIV was L3, and LIV was L5. Mean LOS was 5+/-4 days. Fifty-six patients were SP, 30 patients ST, and 47 were SD. SP patients were older on average (SP: 62, ST: 56, and SD: 55, <.05), had a lower BMI (SP: 29, S: 32, SD 32, p <.05) and lower mean ASA (SP: 2.2, ST: 2.5, SD: 2.5 p=.094). ST patients had a greater baseline T1PA (SP: 17.7, ST: 23.3, SD: 18.6, p=.11), with lower PI-LL (SP: 3.5, ST:.5, SD: 9.5, p=.06), PT (SP: 20.7, ST: 15.3, SD: 19.4, p=.03), and LL (SP: 55, ST: 56, SD: 48, p=.06). Prior fusion was more common among ST (SP: 29%, ST: 47%, SD 19% p=.033). ST patients had a lower number of levels fused (SP: 2.1, ST: 2.6, SD: 2.7, p=.037). ST patients had a greater amount of interbody fusions (SP: 1.53, ST: 2.3, SD: 1.9, p=.012). SD patients had a greater amount of osteotomies (SP: 14%, ST: 7%, SD: 74%, p <.001), corpectomies (SP: 2%, ST: 7%, SD: 41%, p <.001), and decompressions (SP: 57%, ST: 66%, SD: 100%, p <.001). SP patients had a lower operative time (SP: 386 min, ST: 652, SD: 498, p=.059), lower EBL (SP: 296 ml, ST: 498 ml, SD: 418 ml, p <0.001), and shorter LOS (SP: 4.53, ST: 8.15, SD: 5.71, p=.022). SD approach resulted in more patients going to rehab postoperatively (SP:7%, ST: 8%, SD: 29%, p=.030). SP patients had a lower NRS back score (SP: 3.2, ST: 4, SD: 6, p=.011), and lower NRS leg score (SP: 2.6, ST: 3.5, SD: 4.7, p=.118). Patients had a comparable postoperative T1PA, PI-LL, PT, and LL, with a comparable degree of correction. SP patients had a lower amount of pulmonary, GI/renal complications, and underwent fewer reoperations compared to ST and SD patients.
CONCLUSION(S): Although the SP alternative for circumferential lumbar reconstruction surgery has demonstrated good patient outcomes in the degenerative lumbar spondylosis population, few studies exist comparing outcomes of single position to those of more traditional dual positioning approaches. This study demonstrates that SP is associated with significant improvements in perioperative outcomes, reoperation rates, and pain scores when compared to both the staged and same-day manner of dual positioning with comparable degrees of correction. SP may prove to be a superior approach for certain degenerative spondylosis patients and warrants further studies to determine ideal patient candidacy and elucidate long-term outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright