Faculty Bibliography

INTRODUCTION/BACKGROUND:Complex surgery for adult spinal deformity has high rates of complications, reoperations, and readmissions. Preoperative discussions of high-risk operative spine patients at a multidisciplinary conference may contribute to decreased rates of these adverse outcomes through appropriate patient selection and surgical plan optimization. With this goal, we implemented a high-risk case conference involving orthopedic and neurosurgery spine, anesthesia, intraoperative monitoring neurology, and neurological intensive care. METHODS:Included in this retrospective review were patients ≥ 18 years old meeting one of the following high-risk criteria: 8 + levels fused, osteoporosis with 4 + levels fused, three column osteotomy, anterior revision of the same lumbar level, or planned significant correction for severe myelopathy, scoliosis (> 75˚), or kyphosis (> 75˚). Patients were categorized as Before Conference (BC): surgery before 2/19/2019 or After Conference (AC): surgery after 2/19/2019. Outcome measures include intraoperative and postoperative complications, readmissions, and reoperations. RESULTS:263 patients were included (96 AC, 167 BC). AC was older than BC (60.0 vs 54.6, p = 0.025) and had lower BMI (27.1 vs 28.9, p = 0.047), but had similar CCI (3.2 vs 2.9 p = 0.312), and ASA Classification (2.5 vs 2.5, p = 0.790). Surgical characteristics, including levels fused (10.6 vs 10.7, p = 0.839), levels decompressed (1.29 vs 1.25, p = 0.863), 3 column osteotomies (10.4% vs 18.6%, p = 0.080), anterior column release (9.4% vs 12.6%, p = 0.432), and revision cases (53.1% vs 52.4%, p = 0.911) were similar between AC and BC. AC had lower EBL (1.1 vs 1.9L, p < 0.001) and fewer total intraoperative complications (16.7% vs 34.1%, p = 0.002), including fewer dural tears (4.2% vs 12.6%, p = 0.025), delayed extubations (8.3% vs 22.8%%, p = 0.003), and massive blood loss (4.2% vs 13.2%, p = 0.018). Length of stay (LOS) was similar between groups (7.2 vs 8.2 days, 0.251). AC had a lower incidence of deep surgical site infections (SSI, 1.0% vs 6.6%, p = 0.038), but a higher rate of hypotension requiring vasopressor therapy (18.8% vs 4.8%, p < 0.001). Other postoperative complications were similar between groups. AC had lower rates of reoperation at 30 (2.1% vs 8.4%, p = 0.040) and 90 days (3.1 vs 12.0%, p = 0.014) and lower readmission rates at 30 (3.1% vs 10.2%, p = 0.038) and 90 days (6.3 vs 15.0%, p = 0.035). On logistic regression, AC patients had higher odds of hypotension requiring vasopressor therapy and lower odds of delayed extubation, intraoperative RBC, and intraoperative salvage blood. CONCLUSIONS:Following implementation of a multidisciplinary high-risk case conference, 30- and 90-day reoperation and readmission rates, intraoperative complications, and postoperative deep SSIs decreased. Hypotensive events requiring vasopressors increased, but did not result in longer LOS or greater readmissions. These associations suggest a multidisciplinary conference may help improve quality and safety for high-risk spine patients. particularly through minimizing complications and optimizing outcomes in complex spine surgery.

Accurate and reproducible acetabular component positioning is among the most important technical factors affecting outcomes of total hip arthroplasty. Although several studies have investigated the influence of pelvic tilt and obliquity on functional acetabular anteversion, the effect of pelvic axial rotation has not yet been established. We analyzed a generic simulated pelvis created using preoperative full-body standing and sitting radiographs. A virtual acetabulum was placed in 144 different scenarios of acetabular anteversion and abduction angles. In each scenario, the effects of pelvic tilt and pelvic axial rotation on different combinations of acetabular orientations were assessed. The change in acetabular anteversion was 0.75° for each 1° of pelvic tilt and was most linear in abduction angles of 40°±45°. The change in acetabular anteversion was 0.8° for each 1° of pelvic axial rotation. Surgeons may consider adjusting acetabular anteversion in fixed axial pelvic deformities when the degree of deformity affects functional acetabular positioning, assessed from preoperative standing and sitting weight-bearing radiographs. [Orthopedics. 2023;46(1):e27-e30.].

BACKGROUND CONTEXT/BACKGROUND:The advantages of Lateral Single Position surgery (LSPS) in the perioperative period has previously been demonstrated, 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/OBJECTIVE:Evaluate the safety and efficacy of LSPS versus gold-standard FLIP STUDY DESIGN/SETTING: Multi-center retrospective cohort review. PATIENT SAMPLE/METHODS:Four hundred forty- two patients undergoing lumbar fusion via LSPS or FLIP OUTCOME MEASURES: Levels fused, operative time, estimated blood loss, perioperative complications, and reasons for reoperation at 30-days, 90-days, 1-year, and 2-years. Radiographic outcomes included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, and segmental lumbar lordosis. METHODS:Patients were grouped as LSPS 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 under the same anesthetic. 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<.05. RESULTS:Four hundred forty- two pts met inclusion, including 352 LSPS and 90 FLIP pts. Significant differences were noted in age (62.4 vs 56.9; p≤.001) and smoking status (7% vs 16%; p=.023) between the LSPS and FLIP groups. LSPS demonstrated significantly lower Op time (97.7min vs 297.0 min; p<.001), fluoro dose (36.5mGy vs 78.8mGy; p<.001), EBL (88.8mL vs 270.0mL; p<.001), and LOS (1.91 days vs 3.61 days; p<.001) compared to FLIP. LSPS also demonstrated significantly fewer post-op complications than FLIP (21.9%vs 34.4%; p=.013), specifically regarding rates of ileus (0.0% vs 5.6%; p<.001). No differences in reoperation were noted at 30-day (1.7%LSPS vs 4.4%FLIP, p=.125), 90-day (5.1%LSPS vs 5.6%FLIP, p=.795) or 2-year follow-up (9.7%LSPS vs 12.2% FLIP; p=.441). LSPS group had a significantly lower preoperative PI-LL (4.1° LSPS vs 8.6°FLIP, p=.018), and a significantly greater postoperative LL (56.6° vs 51.8°, p = .006). No significant differences were noted in rates of fusion (94.3% LSPS vs 97.8% FLIP; p=.266) or subsidence (6.9% LSPS vs 12.2% FLIP; p=.260). CONCLUSIONS:LSPS and circumferential fusions have similar outcomes at 2-years post-operatively, while reducing perioperative complications, improving perioperative efficiency and safety.

STUDY DESIGN/METHODS:Retrospective analysis of outcomes in cervical spine and shoulder arthroscopy patients. OBJECTIVE:The objective of this study is to assess differential improvements in health-related quality of life for cervical spine surgery compared with shoulder surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:An understanding of outcome differences between different types of orthopedic surgeries is helpful in counseling patients about expected postoperative recovery. This study compares outcomes in patients undergoing cervical spine surgery with arthroscopic shoulder surgery using computer-adaptive Patient-reported Outcome Information System scores. MATERIALS AND METHODS/METHODS:Patients undergoing cervical spine surgery (1-level or 2-level anterior cervical discectomy and fusion, cervical disc replacement) or arthroscopic shoulder surgery (rotator cuff repair±biceps tenodesis) were grouped. Patient-reported Outcome Information System scores of physical function, pain interference, and pain intensity at baseline and at 3, 6, and 12 months were compared using paired t tests. RESULTS:Cervical spine (n=127) and shoulder (n=91) groups were similar in sex (25.8% vs. 41.8% female, P=0.731) but differed in age (51.6±11.6 vs. 58.60±11.2, P<0.05), operative time (148.3±68.6 vs. 75.9±26.9 min, P<0.05), American Society of Anesthesiologists (ASAs) (2.3±0.6 vs. 2.0±0.5, P=0.001), smoking status (15.7% vs. 4.4%, P=0.008), and length of stay (1.1±1.0 vs. 0.3±0.1, P=0.000). Spine patients had worse physical function (36.9 ±12.6 vs. 49.4±8.6, P<0.05) and greater pain interference (67.0±13.6 vs. 61.7±4.8, P=0.001) at baseline. Significant improvements were seen in all domains by 3 months for both groups, except for physical function after shoulder surgery. Spine patients had greater physical function improvements at all timepoints (3.33 vs. -0.43, P=0.003; 4.81 vs. 0.08, P=0.001; 6.5 vs. -5.24, P=<0.05). Conversely, shoulder surgery patients showed better 6-month improvement in pain intensity over spine patients (-8.86 vs. -4.46, P=0.001), but this difference resolved by 12 months. CONCLUSIONS:Cervical spine patients had greater relative early improvement in physical function compared with shoulder patients, whereas pain interference and intensity did not significantly differ between the 2 groups after surgery. This will help in counseling patients about relative difference in recovery and improvement between the 2 surgery types. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND CONTEXT: Prone LLIF (P-LLIF) is a novel technique allowing for placement of a lateral interbody in the prone position and allowing posterior decompression and revision of posterior instrumentation without repositioning. To date, studies evaluating the P-LLIF have been small single surgeon series. This multicentre retrospective cohort examines perioperative outcomes and complications of single position P-LLIF againsttraditional Lateral LLIF (L-LLIF) technique with patient repositioning in patients undergoing revision lumbar fusion surgery. PURPOSE: To evaluate the feasibility and safety of the single-position P-LLIF technique for revision lumbar fusion surgery. STUDY DESIGN/SETTING: Multicenter retrospective cohort study. PATIENT SAMPLE: A total of 101 patients undergoing revision circumferential fusion with lateral lumbar interbody fusion (LLIF) were included, of which 43 had P-LLIF and 58 had L-LLIF. 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): A multicenter retrospective cohort study was performed from 4 institutions from the USA and Australia of patients undergoing revision anterior-posterior lumbar fusion via either: 1) single-position prone LLIF (P-LLIF); or 2) lateral decubitus LLIF with repositioning to prone (L-LLIF) between January 2015 and November 2021. Patients with greater than 4 levels fused were excluded. Demographics, perioperative outcomes, complications and radiological outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p<0.05.
RESULT(S): A total of 101 patients undergoing revision lateral lumbar interbody fusion surgery were included, of which 43 had P-LLIF and 58 had L-LLIF. Age, BMI and CCI were similar between groups. The number of posterior levels fused (2.21 P-LLIF vs 2.66 L-LLIF, p=0.469) and interbody levels fused (1.23 P-LLIF vs 1.25 L-LLIF, p=0.838) were similar between groups. Levels decompressed, posterior column osteotomy and anterior column release were similar between groups. Operative time was significantly less in the P-LLIF group compared to the L-LLIF group (151 vs 206 min, p=0.004). EBL was similar between groups (150 mL P-LLIF vs 182 mL L-LLIF, p=0.31) and there was a trend toward reduced length of stay (2.7 vs 3.3 days, p=0.09). No significant difference was demonstrated in perioperative or postoperative complications between P-LLIF and L-LLIF groups. Radiographic analysis demonstrated no significant differences in preoperative or postoperative sagittal alignment as measured by lumbar lordosis, PI-LL mismatch, or segmental lumbar lordosis between groups.
CONCLUSION(S): P-LLIF significantly improves operative efficiency and may reduce length of stay when compared to L-LLIF and repositioning for revision lumbar fusion. No increase in complications was demonstrated by P-LLIF or trade-offs in sagittal alignment restoration. 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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OBJECTIVE:To assess whether surgical cervical deformity (CD) patients meet spinopelvic age-adjusted alignment targets, reciprocal, and lower limb compensation changes. STUDY DESIGN/METHODS:Retrospective review. METHODS:CD was defined as C2-C7 lordosis >10°, cervical sagittal vertical angle (cSVA) >4 cm, or T1 slope minus cervical lordosis (TS-CL) >20°. Inclusion criteria were age >18 years and undergoing surgical correction with complete baseline and postoperative imaging. Published formulas were used to create age-adjusted alignment target for pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), sagittal vertical angle (SVA), and lumbar lordosis and thoracic kyphosis (LL-TK). Actual alignment was compared with age-adjusted ideal values. Patients who matched ±10-year thresholds for age-adjusted targets were compared with unmatched cases (under- or overcorrected). RESULTS:= 0.269). CONCLUSIONS:In response to worsening CD postoperatively, patients increased in TK and recruited less lower limb compensation. Almost 75% of CD patients did not meet previously established spinopelvic alignment goals, of whom a subset of patients were actually made worse off in these parameters following surgery. This finding raises the question of whether we should be looking at the entire spine when treating CD. LEVEL OF EVIDENCE: 3/METHODS/:

BACKGROUND:Persistent pelvic compensation following adult spinal deformity (ASD) corrective surgery may impair quality of life and result in persistent pathologic lower extremity compensation. Ideal age-specific alignment targets have been proposed to improve surgical outcomes, though it is unclear whether reaching these ideal targets reduces rates of pelvic nonresponse following surgery. Our aim was to assess the relationship between pelvic nonresponse, age-specific alignment, and lower-limb compensation following surgery for ASD. METHODS:Single-center retrospective cohort study. ASD patients were grouped: those who did not improve in Scoliosis Research Society-Schwab pelvic tilt (PT) modifier (pelvic nonresponders [PNR]), and those who improved (pelvic responders [PR]). Groups were propensity score matched for preoperative PT and assessed for differences in spinal and lower extremity alignment. Rates of pelvic nonresponse were compared across patient groups who were undercorrected, overcorrected, or matched age-specific postoperative alignment targets. RESULTS:< 0.05). CONCLUSIONS:For patients with moderate to severe baseline truncal inclination, more aggressive surgical correction relative to ideal age-specific PI-LL was associated with lower rates of pelvic nonresponse. Postoperative alignment targets may need to be adjusted to optimize alignment outcomes for patients with substantial preoperative sagittal deformity. CLINICAL RELEVANCE/CONCLUSIONS:These findings increase our understanding of the poor outcomes that occur despite ideal realignment. Surgical correction of severe global sagittal deformity should be prioritized to mitigate these occurrences. LEVEL OF EVIDENCE: 3/METHODS/:

STUDY DESIGN/METHODS:A retrospective review of operative patients at a single institution. OBJECTIVE:To validate a novel method of detecting pseudarthrosis on dynamic radiographs. SUMMARY OF BACKGROUND DATA/BACKGROUND:A common complication after anterior cervical discectomy and fusion is pseudarthrosis. A previously published method for detecting pseudarthrosis identifies a 1 mm difference in interspinous motion (ISM), which requires calibration of images and relies on anatomic landmarks difficult to visualize. An alternative is to use angles between spinous processes, which does not require calibration and relies on more visible landmarks. METHODS:ISM was measured on dynamic radiographs using the previously published linear method and new angular method. Angles were defined by lines from screw heads to dorsal points of spinous processes. Angular cutoff for fusion was calculated using a regression equation correlating linear and angular measures, based on the 1 mm linear cutoff. Pseudarthrosis was assessed with both cutoffs. Sensitivity, specificity, inter- and intra-reliability of angular and linear measures used post-operative CT as the reference. RESULTS:242 fused levels (81 allograft, 84 PEEK, 40 titanium, 37 standalone cages) were measured in 143 patients (mean age 52.0±11.5, 42%F). 36 patients (66 levels) had 1-year postoperative CTs; 13 patients (13 levels) had confirmed pseudarthrosis. Linear and angular measurements closely correlated (R=0.872), with 2.3° corresponding to 1 mm linear ISM. Potential pseudarthroses was found in 28.0% and 18.5% levels using linear and angular cutoffs, respectively. Linear cutoff had 85% sensitivity, 87% specificity; angular cutoff had 85% sensitivity, 96% specificity for detecting CT-validated pseudarthrosis. Interclass correlation coefficients were 0.974 and 0.986 (both P<0.001); intra-rater reliability averaged 0.953 and 0.974 (P<0.001 for all) for linear and angular methods, respectively. CONCLUSIONS:The angular measure for assessing potential pseudarthrosis is as sensitive as and more specific than published linear methods, has high inter-observer reliability, and can be used without image calibration.

BACKGROUND:More sophisticated surgical techniques for correcting adult spinal deformity (ASD) have increased operative times, adding to physiologic stress on patients and increased complication incidence. This study aims to determine factors associated with operative time using a statistical learning algorithm. METHODS:Retrospective review of a prospective multicenter database containing 837 patients undergoing long spinal fusions for ASD. Conditional inference decision trees identified factors associated with skin-to-skin operative time and cutoff points at which factors have a global effect. A conditional variable-importance table was constructed based on a nonreplacement sampling set of 2000 conditional inference trees. Means comparison for the top 15 variables at their respective significant cutoffs indicated effect sizes. RESULTS:66 minutes of increased operative time. Increased operative time also correlated with increased hospital length of stay (LOS), increased estimated intraoperative blood loss (EBL), and inferior 2-year Oswestry Disability Index (ODI) scores. CONCLUSIONS:Procedure location and specific surgeon are the most important factors determining operative time, accounting for operative time increases <2 hours. Surgical approach and number of levels fused were also associated with longer operative times, respectively. Extended operative time correlated with longer LOS, higher EBL, and inferior 2-y ODI outcomes. CLINICAL RELEVANCE/CONCLUSIONS:We further identified the poor outcomes associated with extended operative time during surgical correction of ASD, and attributed the useful predictors of time spent in the operating room, including site, surgeon, surgical approach, and the number of levels fused. LEVEL OF EVIDENCE: 3/METHODS/: