Faculty Bibliography

BACKGROUND CONTEXT/BACKGROUND:Lateral decubitus single position anterior-posterior (AP) fusion utilizing anterior lumbar interbody fusion and percutaneous posterior fixation is a novel, minimally invasive surgical technique. Single position lumbar surgery (SPLS) with anterior lumbar interbody fusion (ALIF) or lateral lumbar interbody fusion (LLIF) has been shown to be a safe, effective technique. This study directly compares perioperative outcomes of SPLS with lateral ALIF vs. traditional supine ALIF with repositioning (FLIP) for degenerative pathologies. PURPOSE/OBJECTIVE:To determine if SPLS with lateral ALIF improves perioperative outcomes compared to FLIP with supine ALIF. STUDY DESIGN/SETTING/METHODS:Multicenter retrospective cohort study. PATIENT SAMPLE/METHODS:Patients undergoing primary AP fusions with ALIF at 5 institutions from 2015 to 2020. OUTCOME MEASURES/METHODS:Levels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), and PI-LL mismatch. METHODS:Retrospective analysis of primary ALIFs with bilateral percutaneous pedicle screw fixation between L4-S1 over 5 years at 5 institutions. Patients were grouped as FLIP or SPLS. Demographic, procedural, perioperative, and radiographic outcome measures were compared using independent samples t-tests and chi-squared analyses with significance set at p <.05. Cohorts were propensity-matched for demographic or procedural differences. RESULTS:A total of 321 patients were included; 124 SPS and 197 Flip patients. Propensity-matching yielded 248 patients: 124 SPLS and 124 FLIP. The SPLS cohort demonstrated significantly reduced operative time (132.95±77.45 vs. 261.79±91.65 min; p <0.001), EBL (120.44±217.08 vs. 224.29±243.99 mL; p <.001), LOS (2.07±1.26 vs. 3.47±1.40 days; p <.001), and rate of perioperative ileus (0.00% vs. 6.45%; p =.005). Radiation dose (39.79±31.66 vs. 37.54±35.85 mGy; p =.719) and perioperative complications including vascular injury (1.61% vs. 1.61%; p =.000), retrograde ejaculation (0.00% vs. 0.81%, p =.328), abdominal wall (0.81% vs. 2.42%; p =.338), neuropraxia (1.61% vs. 0.81%; p =.532), persistent motor deficit (0.00% vs. 1.61%; p =.166), wound complications (1.61% vs. 1.61%; p =.000), or VTE (0.81% vs. 0.81%; p =.972) were similar. No difference was seen in 90-day return to OR. Similar results were noted in sub-analyses of single-level L4-L5 or L5-S1 fusions. On radiographic analysis, the SPLS cohort had greater changes in LL (4.23±11.14 vs. 0.43±8.07 deg; p =.005) and PI-LL mismatch (-4.78±8.77 vs. -0.39±7.51 deg; p =.002). CONCLUSIONS:Single position lateral ALIF with percutaneous posterior fixation improves operative time, EBL, LOS, rate of ileus, and maintains safety compared to supine ALIF with prone percutaneous pedicle screws between L4-S1.

BACKGROUND:There is controversy as to whether fusions should have the upper instrumented vertebrae (UIV) end in the upper lumbar spine or cross the thoracolumbar junction. This study compares outcomes and reoperation rates for thoracolumbar fusions to the sacrum or pelvis with UIV in the lower thoracic versus lumbar spine to determine if there is an increased reoperation rate depending on UIV selection. METHODS:A retrospective review of prospectively collected data was conducted from a single-center database on adult patients with degeneration and deformity who underwent primary and revision fusions with a caudal level of S1 or ilium between 2012 and 2018. Fusions were classified as anterior, posterior, or combination approach. Revision fusions included patients who had spinal surgery at another institution prior to their revision surgery at the center. Patients were categorized into 1 of 3 groups based on UIV: T9-T11, upper lumbar region (L1-L2), and lower lumbar region (L3-L5). Inclusion criteria were age 18 years or older and at least 1 year of clinical follow-up. Patients were excluded from analysis if they had tumors, infections, or less than 1 year of follow-up after the index procedure. RESULTS:= .002) from the reoperation rates for the same diagnoses in the upper lumbar spine (4.6% and 1%) or lower lumbar spine (6.2% and 0%). A multivariate logistical regression model at 2-year follow up did not show a statistically significant difference between reoperation rates between the thoracic and upper lumbar spine UIV groups. CONCLUSION/CONCLUSIONS:Constructs with UIV in the thoracic spine suffer from higher rates of proximal junctional kyphosis and pseudoarthrosis, whereas those with UIV in the upper lumbar spine have higher rates of adjacent segment disease. Given this tradeoff, there is no certain recommendation on what UIV will result in a lower reoperation rate in thoracolumbar fusion constructs to the sacrum or pelvis. Surgeons must evaluate patient characteristics and risks to make the optimal decision.

AIMS/OBJECTIVE:Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. METHODS:) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at six weeks and a minimum of one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria. RESULTS:increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional cup anteversion. Contralateral hip OA was the only radiological predictor of hypermobility persisting at one year after surgery. The overall reoperation rate was 1.5%. CONCLUSION/CONCLUSIONS: 2021;103-B(12):1766-1773.

Adult spinal deformity is a broad spectrum of disorders that are becoming more prevalent with an ageing population. In those with moderate to severe deformity, surgical correction of spinal alignment is an increasingly common treatment and has demonstrated improvement in patients"™ quality of life. Whilst continued research in risk stratification, advances in surgical techniques, and preoperative optimization has taken place, rates of adverse outcomes following surgery for adult spinal deformity are still frequent. Pain is a common complaint after spinal deformity correction; however, whether this pain is deemed a "˜normal"™ amount, or a "˜pathological"™ pain has not been well characterized in the literature. This paper aims to provide a framework for evaluating pain after spinal deformity correction surgery in order to guide clinical decision making.

Minimally invasive interspinous process devices (IPD), including interspinous distraction devices (IDD) and interspinous stabilizers (ISS), are increasingly utilized for treating symptomatic lumbar canal stenosis (LCS). There is ongoing debate around their efficacy and safety over traditional decompression techniques with and without interbody fusion (IF). This study presents a comprehensive review of IPD and investigates if: (I) minimally invasive IDD can effectively substitute direct neural decompression and (II) ISS are appropriate substitutes for fusion after decompression. Articles published up to 22^nd January 2020 were obtained from PubMed search. Relevant articles published in the English language were selected and critically reviewed. Observational studies across different IPD brands consistently show significant improvements in clinical outcomes and patient satisfaction at short-term follow-up. Compared to non-operative treatment, mini-open IDD was had significantly greater quality of life and clinical outcome improvements at 2-year follow-up. Compared to open decompression, mini-open IDD had similar clinical outcomes, but associated with higher complications, reoperation risks and costs. Compared to open decompression with concurrent IF, ISS had comparable clinical outcomes with reduced operative time, blood loss, length of stay and adjacent segment mobility. Mini-open IDD had better outcomes over non-operative treatment in mild-moderate LCS at 2-year follow-up, but had similar outcomes with higher risk of re-operations than open decompression. ISS with open decompression may be a suitable alternative to decompression and IF for stable grade 1 spondylolisthesis and central stenosis. To further characterize this procedure, future studies should focus on examining enhanced new generation IPD devices, longer-term follow-up and careful patient selection.

BACKGROUND:Up to 70% of multiple myeloma (MM) patients develop vertebral metastasis and subsequent pathological vertebral fractures (PVF). With contemporary systemic therapies, life expectancy of MM patients has improved drastically, and the need to manage pain and associated disability from PVF is increasingly a high priority. The aim of this review is to provide an updated comprehensive synthesis of evidence in the use of vertebral augmentation, including percutaneous vertebroplasty (PV) and balloon kyphoplasty (BKP), to treat MM-related PVF. METHODS:A comprehensive multi-database search in accordance with PRISMA guidelines was performed up to 10 February 2021. Relevant English language articles were selected and critically reviewed. FINDINGS:A total of 23 clinical studies have been included in the review. PV and BKP showed significant pain and functional improvements in terms of analgesia requirements, Cervical Spine Function Score, Eastern Cooperative Oncology Group scale, EQ-5D score, Karnofsky score, Neck Pain Disability Index, Oswestry Disability Index, Short form-36 (SF-36) questionnaire and VAS pain scale. Both procedures also reported promising radiographic outcomes in terms of vertebral height improvement, maintenance and restoration, as well as kyphotic deformity correction. Asymptomatic cement leakage was commonly reported. There was no significant difference between the two procedures. CONCLUSION:PV and BKP are safe and effective procedure that offers pain relief, reduction in pain associated disability and reduction of fracture incidence. Its minimally invasive approach is associated with minimal morbidity risk, making it a viable option in frail patients. LEVEL OF EVIDENCE IV:Narrative review.

STUDY DESIGN/METHODS:Retrospective cohort analysis. OBJECTIVE:To compare outcomes of plastic versus spine surgeon wound closure in revision 1 to 4 level thoracolumbar fusions. SUMMARY OF BACKGROUND DATA/BACKGROUND:Plastic surgeons perform layered musculocutaneous flap closures in high-risk spine patients such as revision posterior spinal fusion and complex deformity correction surgeries. Few studies have assessed outcomes of revision fusion performed with plastic surgical closures, particularly in nondeformity thoracolumbar spinal surgery. METHODS:A retrospective review of 1 to 4 level revision thoracolumbar fusion performed by Orthopedic or Neurosurgical spine surgeons. Patient charts were reviewed for demographics and perioperative outcomes. Patients were divided into two cohorts: wound closures performed by spine surgeons and those closed by plastic surgeons. Outcomes were analyzed before and after propensity score match for prior levels fused, iliac fixation, and levels fused at index surgery. Significance was set at P < 0.05. RESULTS:Three hundred fifty-seven (87.3%) spine surgeon (SS) and 52 (12.7%) plastic surgeon (PS) closures were identified. PS group had significantly higher number of levels fused at index (PS 2.7 ± 1.0 vs. SS 1.8 ± 0.9, P < 0.001) and at prior surgeries (PS 1.8 ± 1.2 vs. SS 1.0 ± 0.9, P < 0.001), and rate of iliac instrumentation (PS 17.3% vs. SS 2.8%, P < 0.001). Plastics closure was an independent risk factor for length of stay  > 5 days (odds ratio 2.3) and postoperative seroma formation (odds ratio 7.8). After propensity score match, PS had higher rates of seromas (PS 36.5% vs. SS 3.8%, P < 0.001). There were no differences between PS and SS groups in surgical outcomes, perioperative complication, surgical site infection, seroma requiring aspiration, or return to operating room at all time points until follow-up (P > 0.05 for all). CONCLUSION/CONCLUSIONS:Plastic spinal closure for 1 to 4 level revision posterior thoracolumbar fusions had no advantage in reducing wound complications over spine surgeon closure but increased postoperative seroma formation.Level of Evidence: 4.

BACKGROUND CONTEXT/BACKGROUND:The COVID-19 pandemic caused nationwide suspensions of elective surgeries due to reallocation of resources to the care of COVID-19 patients. Following resumption of elective cases, a significant proportion of patients continued to delay surgery, with many yet to reschedule, potentially prolonging their pain and impairment of function and causing detrimental long-term effects. PURPOSE/OBJECTIVE:The aim of this study was to examine differences between patients who have and have not rescheduled their spine surgery procedures originally cancelled due to the COVID-19 pandemic, and to evaluate the reasons for continued deferment of spine surgeries even after the lifting of the mandated suspension of elective surgeries. STUDY DESIGN/SETTING/METHODS:Retrospective case series at a single institution PATIENT SAMPLE: Included were 133 patients seen at a single institution where spine surgery was canceled due to a state-mandated suspension of elective surgeries from March to June, 2020. OUTCOME MEASURES/METHODS:The measures assessed included preoperative diagnoses and neurological dysfunction, surgical characteristics, reasons for surgery deferment, and PROMIS scores of pain intensity, pain interference, and physical function. METHODS:Patient electronic medical records were reviewed. Patients who had not rescheduled their canceled surgery as of January 31, 2021, and did not have a reason noted in their charts were called to determine the reason for continued surgery deferment. Patients were divided into three groups: early rescheduled (ER), late rescheduled (LR), and not rescheduled (NR). ER patients had a date of surgery (DOS) prior to the city's Phase 4 reopening on July 20, 2020; LR patients had a DOS on or after that date. Statistical analysis of the group findings included analysis of variance with Tukey's honestly significant difference (HSD) post-hoc test, independent samples T-test, and chi-square analysis with significance set at p≤.05. RESULTS:Out of 133 patients, 47.4% (63) were in the ER, 15.8% (21) in the LR, and 36.8% (49) in the NR groups. Demographics and baseline PROMIS scores were similar between groups. LR had more levels fused (3.6) than ER (1.6), p= .018 on Tukey HSD. NR (2.1) did not have different mean levels fused than LR or ER, both p= >.05 on Tukey HSD. LR had more three column osteotomies (14.3%) than ER and (1.6%) and NR (2.0%) p=.022, and fewer lumbar microdiscectomies (0%) compared to ER (20.6%) and NR (10.2%), p=.039. Other surgical characteristics were similar between groups. LR had a longer length of stay than ER (4.2 vs 2.4, p=.036). No patients in ER or LR had a nosocomial COVID-19 infection. Of NR, 2.0% have a future surgery date scheduled and 8.2% (4) are acquiring updated exams before rescheduling. 40.8% (20; 15.0% total cohort) continue to defer surgery over concern for COVID-19 exposure and 16.3% (8) for medical comorbidities. 6.1% (3) permanently canceled for symptom improvement. 8.2% (4) had follow-up recommendations for non-surgical management. 4.1% (2) are since deceased. CONCLUSION/CONCLUSIONS:Over 1/3 of elective spine surgeries canceled due to COVID-19 have not been performed in the 8 months from when elective surgeries resumed in our institution to the end of the study. ER patients had less complex surgeries planned than LR. NR patients continue to defer surgery primarily over concern for COVID-19 exposure. The toll on the health of these patients as a result of the delay in treatment and on their lives due to their inability to return to normal function remains to be seen.

BACKGROUND CONTEXT: Robot-guided lumbar instrumented fusion (RGLF) for accurate pedicle screw placement is increasingly popular. Learning curve (LC) has been reported to be short, but simple comparison of a set number of early to later cases may oversimplify the LC. This study offers an analysis of a single institution LC for RGLF as it relates to increasing case complexity as determined by Spine Surgical Invasive Index (SII) as described by Mirza, and advanced techniques. PURPOSE: To determine if RGLF is related to SII and is more dynamic than previously described. STUDY DESIGN/SETTING: Single-center retrospective cohort study. PATIENT SAMPLE: A total of 346 patients undergoing RGLF at a single institution from 2018 to 2021. OUTCOME MEASURES: Case complexity indicators (levels fused, SII, iliac fixation, single position surgery), radiation dose, procedure/operative time (PTime/OpTime), EBL, LOS, failed registration, robotic mechanical failures, perioperative complications and OR returns.
METHOD(S): All RGLFs at a single institution were included. Outcome measures indicating case complexity (levels fused, SII, iliac fixation, single position surgery) underwent regression analysis to determine risk factors for robot-related complications. Peaks in these characteristics over the course of 346 cases were identified. Outcomes including radiation dose, procedure/operative time (PTime/OpTime), EBL, LOS, failed registration, robotic mechanical failures, perioperative complications, and returns to OR were analyzed in stepwise fashion by each consecutive case using independent samples t-tests and chi-squared analyses as appropriate.
RESULT(S): A total of 346 RGLFs included. No significant changes in demographics over time. SII was an independent risk factor for robot registration and intraoperative mechanical failures on multivariate regression analysis (p<0.001). SII had significant peaks between 10 to 20 cases and 165 to 330 cases. The following outcomes were overcome during a first LC corresponding to an early SII peak: PTime (401.2+/-135.6 vs 361.4+/-99.7 min; p= 0.047), OpTime (326.0+/-129.4 vs 279.4+/-91.9 min; p= 0.034), robot mechanical failures (26.7% vs 10.1%; p=0.046), all postop complications (60.0% vs 29.2%; p=0.037), ileus (9.0% vs 3.3%; p=0.046), urinary complications (6.4% vs 1.9%; p=0.043). A later LC corresponding to a second SII peak saw significant changes in PTime per level (291.1+/-84.7 vs 259.5+/-108.5 min; p=0.017), OpTime per level (223.6+/-70.4 vs 200.9+/-90.7 min; p= 0.038), EBL (316.7+/-264.0 vs 247.4+/-204.6 mL; p=0.035), LOS (3.8+/-2.2 vs 2.7+/-1.1 days; p=0.001), all intraoperative complications (23.8% vs 13.2%; p=0.036), surgical site infections (2.54% vs 10.34%; p=0.022), robot registration failures (8.3% vs 2.1%; p=0.039), new neurological deficits (5.2% vs 0.0%; p=0.050), instrumentation failures (1.7% vs 3.7%; p =0.043), and returns to OR for pedicle screw revision (1.2% vs 8.9%; p=0.046) or for neurological deficit (3.9% vs 0.0%; p=0.050).
CONCLUSION(S): Two learning curves were observed that mirrored significant peaks in SII. The second, more significant, wave of complications was observed with increased surgical complexity. This suggests a longer, more dynamic learning curve than has been previously described. Avoiding surgeries with high SII at the beginning of RGLF experience may prevent early complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The inter-relationship between the hip and spine has been increasingly studied in recent years, particularly as it pertains to the effect of spinal deformity and hip osteoarthritis (OA). Changing from standing (ST) to seated (SE) requires rotation of the femur from an almost vertical plane to the horizontal. OA of the hip significantly limits hip extension, resulting in less ability to recruit pelvic tilt (PT) in ST, and requiring increased PT in SE to compensate for loss of hip flexion. To date, the effect of total hip arthroplasty (THA) in altering spinopelvic SE and ST mechanics has not been reported. PURPOSE: To investigate the change in spinopelvic alignment parameters between seated and standing positions in pre and post THA patients. STUDY DESIGN/SETTING: Retrospective review at a single academic institution. PATIENT SAMPLE: Adult patients undergoing THA with full body sitting and standing radiographs pre- and post-THA. OUTCOME MEASURES: Spinopelvic alignment measures including pelvic incidence (PI), pelvic tilt (PT), T1 pelvic angle (TPA), sacral slope (SS), sagittal vertical axis (SVA), pelvic incidence and lumbar lordosis mismatch (PI-LL), and lumbar lordosis (LL).
METHOD(S): Patients >=18yo undergoing THA for hip OA with full spine SE and ST radiographs pre and post THA were included. Spinopelvic alignment was analyzed pre-THA and post-THA in both ST and SE positions in a relaxed posture with the fingers on the clavicles. Paired t-test analysis was performed to compare Pre-and Post-THA groups. The effect of TL deformity (SVA>50, TPA>20, PI-LL>10) on these changes was also analyzed. Statistical significance set at p<0.05.
RESULT(S): There were 192 patients assessed. 179 patients had thoracolumbar (TL) deformity; TPA>20 (N=46), PI-LL>10 (N=55), and SVA>50 (N=78). In standing position, patients have a significant reduction in SVA post THA vs pre THA (34.09+/-42.69 vs 45.03+/-46.87, p=0.001) as a result of an increase in PT (15.7+/-9.74 o vs 14.6+/-9.88o,p=0.028), without significant changes in spinal alignment parameters including lumbar lordosis (-51.26+/-14.59 vs -50.26+/-14.87, p=0.092), thoracic kyphosis (35.98+/-12.72 vs 35.40+/-13.16, p=0.180), sacral slope (38.15+/-10.77 vs 38.83+/-11.31, p=0.205), T1 pelvic angle (14.22+/-9.94 vs 14.51+/-10.13, p=0.053) and PI-LL mismatch (2.59+/-14.61 vs 3.35+/-14.92, p=0.183). This change in ST_SVA was larger in patients with TL deformity, specifically in those with SVA>50 (61.29+/-45.69 vs 89.48+/-35.91, p=0.001), in PI-LL > 10 (59.08+/-45.49 vs 73.36+/-48.50, p=0.001) and in TPA>20 subsets (62.14+/-49.94 vs 82.28+/-49.55, p=0.001). When moving from ST to SE, the DELTAPT was reduced post THA (16.70+/-15.27o vs 20.85+/-17.27o, p=0.001) in addition to a smaller SE_PT vs pre-THA (32.41+/-14.47 vs 35.46+/-14.20, p=0.006).
CONCLUSION(S): Post Total Hip Arthroplasty (THA), patients demonstrated an increased recruitment of pelvic retroversion to achieve a better global balance by reduction in standing SVA. This compensation was achieved solely by greater mobility of their hip and pelvis, and without a significant change in spinal alignment. ST_SVA reduction was more pronounced in patients with thoracolumbar (TL) spinal deformity (SVA>50, TPA>20, PI-LL>10). On the converse, PT was reduced in sitting (SE) post-THA compared to pre-THA, and the compensatory change in PT was also reduced between ST and SE as a result of restoration of hip flexion. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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