Single-level Fusion Research Articles

Long-term (>\u200910\xa0years) clinical outcomes of instrumented posterolateral fusion for spondylolisthesis

PurposeDespite the rapid increase in instrumented spinal fusions for a variety of indications, most studies focus on short-term fusion rates. Long-term clinical outcomes are still scarce and inconclusive. This study investigated clinical outcomes > 10 years after single-level instrumented posterolateral spinal fusion for lumbar degenerative or isthmic spondylolisthesis with neurological symptoms.MethodsCross-sectional long-term follow-up among the Dutch participants of an international multicenter randomized controlled trial comparing osteogenic protein-1 with autograft. Clinical outcomes were assessed using the Oswestry Disability Index (ODI), EQ-5D-3L and visual analogue scale (VAS) for leg and back pain, as well as questions on satisfaction with treatment and additional surgery.ResultsThe follow-up rate was 73% (41 patients). At mean 11.8 (range 10.1–13.7) years after surgery, a non-significant deterioration of clinical outcomes compared to 1-year follow-up was observed. The mean ODI was 20 ± 19, mean EQ-5D-3L index score 0.784 ± 0.251 and mean VAS for leg and back pain, respectively, 34 ± 33 and 31 ± 28. Multiple regression showed that diagnosis (degenerative vs. isthmic spondylolisthesis), graft type (OP-1 vs. autograft) and 1-year fusion status (fusion vs. no fusion) were not predictive for the ODI at long-term follow-up (p = 0.389). Satisfaction with treatment was excellent and over 70% of the patients reported lasting improvement in back and/or leg pain. No revision surgeries for non-union were reported.ConclusionThis study showed favourable clinical outcomes > 10 years after instrumented posterolateral spinal fusion and supports spondylolisthesis with neurological symptoms as indication for fusion surgery.

A Randomized Control Trial Comparing Local Autografts and Allografts in Single Level Anterior Cervical Discectomy and Fusion Using a Stand-Alone Cage.

Study DesignRandomized controlled trial.PurposeTo compare the functional and radiological outcomes of anterior cervical discectomy and fusion (ACDF) using local graft and allograftOverview of LiteratureThe choice of bone grafts for ACDF varies among different types: iliac crest, allograft, and substitutes. Availability, cost, and donor site morbidity are potential disadvantages. Local osteophyte grafts are then advantageous and shows to have good fusion.MethodsWe randomly sampled participants requiring a single level ACDF for degenerative conditions (n=27) between allograft (n=13) and local graft (n=14) groups. Follow-up of patients occurred at 6 weeks, 3 months, 6 months, and 1 year using Numerical Pain Rating Scale (NPRS) scores for arm and neck pain, Neck Disability Index (NDI), 2-item Short Form Health Survey (SF-12), and lateral disk height. We then assessed radiological fusion using computed tomography (CT) scan at 12 months, and graded as F− (no fusion), F (fusion seen through the cage), F+ (fusion seen through the cage, with bridging bone at one lateral edge), and F++ (fusion seen through cage with bridging bone bilaterally).ResultsThere were no significant differences in the age, sex, duration of intervention, blood loss, and hospital stay between the two groups (p>0.05). Both groups showed significant improvements in all functional outcome scores including NPRS for arm and neck pain, NDI, and SF-12 at each visit (p<0.01). We observed a marked improvement in disk height in both groups (p<0.05), but at 1 year of follow-up, there was a significant though slight subsidence (p=0.47). CT at 1 year showed no non-unions. We recorded F, F+, and F++ grades of fusion in 23.2%, 38.4%, and 38.4% in allograft group and 28.6%, 42.8%, and 28.6% in local graft group, respectively, though no significant differences observed (p=0.73).ConclusionsMarginal osteophytes are effective as graft inside cages for ACDF, since they provide similar radiological outcomes, and equivalent improvements in functional outcomes, as compared to allografts.

Congenital Osseous Torticollis that Mimics Congenital Muscular Torticollis: A Retrospective Observational Study.

It may be difficult to diagnose congenital osseous torticollis based on physical examinations or plain X-rays, especially when children have no other accompanying congenital defects. This study reports the children with torticollis caused by the vertebral anomaly with the symptom of abnormal head and neck posture only. We retrospectively reviewed the records of 1015 patients diagnosed with congenital torticollis in a single tertiary hospital (Incheon St. Mary’s Hospital, Korea) who were referred from a primary local clinic. We included those with deficits in passive range of motion (PROM) of neck. Ultrasonography of the sternocleidomastoid (SCM) muscles, ophthalmologic and neurologic examinations, and cervical X-rays were performed for all patients. If bony malalignment was suspected from X-ray, three-dimensional volume-rendered computed tomography (3D-CT) was performed. Ten patients were diagnosed with osseous torticollis with no defect other than bony anomalies. Although X-ray images were acquired for all patients, vertebral anomalies were definitely confirmed in three cases (30.0%) only, and the others (70.0%) were confirmed by CT. The most common type of vertebral anomaly was single-level fusion. Identifying congenital vertebral anomalies is challenging especially when the degree of invasion is only one level. Although abnormal findings on X-rays may be subtle, a careful examination must be performed to avoid misdiagnosis.

Operative Nonunion Rates in Posterolateral Lumbar Fusions: Analysis of a Cohort of 2591 Patients from a National Spine Registry

Radiographic nonunion rates in the literature for posterolateral lumbar fusions with pedicle screws (PLFs) range from 8.1% to 43.3% but may not represent nonunion rates. A few small studies have reported reoperations for symptomatic nonunions (operative nonunions) to range from 3.2% to 13.9%. The objective of this study is to determine operative nonunion rates for 1-level, 2-level, 3-level, and ≥4-level PLFs and to determine the risks for these nonunions. A retrospective cohort study, using data from the Kaiser Permanente Spine Registry, identified adult patients (≥18 years old) who underwent PLFs for degenerative disc disease. Multivariable Cox proportional hazards regression and Kaplan-Meier survival estimates using the log-rank statistic were used to evaluate operative nonunion rates. The cohort consisted of 2591 patients with single-level and multilevel PLFs with mean follow-up of 4.6 years, time to operative nonunion of 1.52 years, and 2-year operative nonunion rate of 1.08%. Compared with single-level fusions, patients with 3-level and ≥4-level fusion had 2.8 and 3.7 times higher risk of operative nonunions. Patients with PLFs involving L5-S1 had 2.5 times the risk of an operative nonunion compared with those without. Our study reports results from one of the largest cohort of patients for the first time with single-level and multilevel instrumented PLFs and found a 2-year operative nonunion rate of 1.08% with increased risk of nonunion for constructs that included L5-S1 and ≥3-level fusions. Operative nonunion combines clinical and radiographic data and provides an alternative measure of fusion rates.

A Novel Local Cancellous Autograft Source for Anterior Cervical Discectomy With Fusion.

Study Design:Case series.Objectives:Successful clinical outcome scores following anterior cervical discectomy and fusion (ACDF) have been correlated with high fusion rate. Published fusion rates using iliac crest bone graft (ICBG) have been shown to be as high as 100% for single-level fusions in some studies; however, there is potential associated morbidity with ICBG harvest. This technical description and preliminary case series assessed the clinical efficacy and results of a novel grafting technique for ACDF.Methods:Twelve patients underwent novel grafting technique for ACDF in which autograft was procured from the cervical vertebra adjacent to the operative disk. Patients were followed for 2 years using visual analogue pain scale (VAS) and radiological assessment of fusion.Results:Patients experienced clinically meaningful reduction of radicular symptoms in the affected arm(s) with an average preoperative VAS score of 5.0 ± 0.8 and an average 2-year postoperative score of 1.108 ± 0.475 (P = .0013). Patients also experienced significant resolution of neck pain with an average preoperative VAS score of 7.1 ± 0.5 and average 2-year postoperative score of 2.708 ± 0.861 (P = .0018). All patients achieved solid fusion by 1 year. There were no major or minor complications noted during follow-up.Conclusions:This procedure allows for both autograft harvest and cervical decompression to be performed through a single incision. In this series, this technique eliminated the morbidity associated with autograft harvest from the iliac crest while achieving high fusion rates and without additional technique-related complications.

One Year Outcomes From a Prospective Multicenter Investigation Device Trial of a Novel Conformal Mesh Interbody Fusion Device.

A prospective multicenter investigational device exempt trial is underway evaluating a novel conformable mesh interbody fusion device in subjects undergoing single-level fusion for degenerative disc disease. Patients meeting inclusion and exclusion criteria were offered enrollment. There is no comparative group in this study. Establish the short and long-term safety and effectiveness of a novel conformable mesh interbody fusion device in subjects undergoing single-level fusion for degenerative disc disease unresponsive to conservative care. Transforaminal lumbar interbody fusion remains a critical procedure for patients with degenerative lumbar disc disease. Increasingly minimally invasive techniques have been proposed to minimize muscle dissection and tissue damage with the goal of minimizing pain and length of stay. One hundred two subjects were enrolled across 10 sites. Ninety nine subjects remained available for follow-up at 12-months. Physical evaluations/imaging were performed serially through 12-months. Validated assessment tools included 100 mm visual analogue scale (VAS) for pain, Oswestry Disability Index (ODI) for function, and computerized tomography scan for fusion. Independent committees were used to identify adverse events and for assessment of radiographic fusion. Reductions in low back pain (LBP)/leg pain and improvements in functional status occur early and are maintained through 12-month follow-up. Mean VAS-LBP change from baseline to 6-weeks post-op (-46 mm) continued to improve through 12 months (-51 mm). Similar trends were observed for leg pain. Mean ODI change from baseline to 6 weeks post-op (-17) was almost doubled by 12 months (-32). Fusion rates at 12-months are high (98%). No device-related serious adverse events have occurred. 12-month outcomes demonstrated excellent patient compliance and positive outcomes for pain, function, fusion, and device safety. Clinical improvements were observed by 6-weeks post-op and appear durable up to 1 year later. A novel mesh interbody device may provide an alternative means of interbody fusion that reduces connective tissue disruption.Level of Evidence: 3.

Disparities in Rates of Fusions in Lumbar Disc Pathologies.

Study Design:Retrospective cohort study.Objective:To identify disparities in surgical decision making for lumbar disc pathologies based on patient demographics, hospital characteristics, and temporal characteristics of admission.Methods:A retrospective analysis of patients admitted for surgical intervention of disc herniation or degeneration was performed to observe the effect of demographic, hospital, and admission-related factors on the decision to perform an isolated decompression or decompression with single level fusion using the National Inpatient Sample.Results:Of 84 953 patients with lumbar disc pathologies, 69 975 patients were treated electively, and 14 978 patients were treated nonelectively. Hispanic and Asian/Pacific Islander patients were less likely to receive a fusion for elective cases compared with White patients (odds ratio [OR] 0.88, P = .004; OR 0.70, P < .001, respectively). In elective cases, privately insured and self-paying patients were less likely to receive a fusion compared with Medicare patients (OR 0.83, P < .001; OR 0.66, P < .001, respectively), while this effect was limited to self-pay patients in nonelective cases (OR 0.44, P < .001). Urban teaching and nonteaching hospitals were less likely to perform fusions compared with rural hospitals in nonelective cases (OR 0.47, P < .001; OR 0.58, P < .001, respectively). Private for-profit hospitals were associated with higher rates of fusion in both elective and nonelective cases (OR 1.16, P = .003; OR 1.94, P < .001).Conclusion:This study illustrates disparities in the modality of surgical intervention for lumbar disc pathologies in terms of demographics, hospital characteristics, and temporal characteristics of admission. The development of more evidence-based guidelines is warranted to reduce variability seen in treatment regimens for these conditions.

Single-level controlled comparison of OLIF51 and percutaneous screw in lateral position versus MIS-TLIF for lumbosacral degenerative disorders: Clinical and radiologic study

BackgroundWe have performed minimally invasive Oblique Lateral Interbody Fusion at L5/S1 (OLIF51) and simultaneous posterior screwing in lateral position for lumbosacral disorders. This study compared the clinical and radiologic results between OLIF51 versus Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) in single-level fusion for lumbosacral degenerative disorders. MethodsA total of 71 patients underwent either OLIF51 (33 cases) or MIS-TLIF (38 cases) at L5/S1 spinal segment. The average age was 64 yrs (27–88). The disorders were L5 isthmic or degenerative spondylolisthesis, foraminal stenosis, pseudarthrosis and adjacent segment degeneration, and others. Using 35 mm oblique incision, OLIF51 was performed followed by posterior percutaneous fixation in same lateral position. MIS-TLIF was performed with midline 40 mm incision and modified cortical bone trajectory (CBT) screws. The operation time, estimated blood loss, JOABPEQ effectiveness rate (%), Visual Analogue Scale (VAS), fusion rate, radiologic alignment, and complications were evaluated. ResultsAverage follow-up period was 25 and 31 months (12–45) in OLIF51 and MIS-TLIF, respectively. The average operation time and estimated blood loss were 165min, 62 ml and 163 min and 68 ml, respectively. The JOABPEQ effectiveness rate in OLIF51 demonstrated higher value in low back function (44% vs 17%, P < 0.02). The fusion rate was 97% and 92% in OLIF51 and MIS-TLIF, respectively. The segmental lordosis was significantly larger in OLIF51 (17 vs 11 deg, P < 0.01). There were no vascular or neural complications. ConclusionsAlthough two groups demonstrated the equivalent surgical invasiveness, there was the significant superiority of OLIF51 in terms of low back function over MIS-TLIF. The segmental lordosis creation was also better in OLIF51. Even in the single-level lumbosacral fusion, OLIF51 serves as the safe and viable surgical procedure with use of lateral position surgery, minimizing the residual low back dysfunction.

P49. Physical activity measures in lumbar laminectomy patients: a prospective comparison of fitness tracker measures versus patient-reported outcome measures

BACKGROUND CONTEXT Assessing spine surgery patients' disability and mobility levels allows clinicians to evaluate the efficacy of surgical procedures and track postoperative recovery. While the current standard, patient-reported outcome measures (PROMs), provides a cross-sectional subjective assessment of functional levels, wearable fitness trackers can continuously and objectively track physical activity even outside of the clinic. PURPOSE The present study aims to assess how a wearable fitness tracker and two PROMs compare in tracking patients' recoveries from lumbar laminectomy. STUDY DESIGN/SETTING This is a prospective observational clinical study conducted within an urban academic health system. PATIENT SAMPLE The sample is composed of patients with lumbar stenosis who have undergone non-revision lumbar laminectomy with or without single level fusion. Patients who have had spine surgery within the past 5 years or have medical conditions that significantly inhibit mobility (including cardiovascular conditions and other orthopedic conditions) were excluded. OUTCOME MEASURES Patient median steps taken per day were continuously collected using the Fitbit Flex 2 fitness tracker. The Oswestry Disability Index (ODI) and Physical and Mental Components of the 12-Item Short Form Health Survey (SF-12 PCS/MCS) PROMs were assessed using standardized questionnaires throughout the study period. METHODS Each patient was provided with a fitness tracker at least 2 weeks prior to surgery until 6 months postoperatively to record median steps taken per day during the preoperative (baseline) and 2 week, 1, 3, and 6 month postoperative intervals. ODI and SF-12 PCS/MCS scores were calculated at enrollment and at the end of each interval. Two-tailed Student's t-tests were used to evaluate changes from baseline. Associations between the change in median steps per day and PROMs throughout the study were evaluated using Pearson's correlation coefficient. RESULTS Twelve of 18 enrolled subjects have thus far completed the study. Average compliance for wearing the fitness tracker, which was defined as the percentage of days the device was worn relative to the number of days the subject was enrolled in the study, was 91%. Average median steps per day and PROM scores normalized to preoperative levels decline immediately after surgery but recover after 1-3 months. Median steps per day were not significantly different from baseline at 6 months postoperatively (2.45% increase; p = 0.60). Average SF-12 PCS and ODI scores surpassed baseline scores by 1 month postoperatively and improved from baseline by 38% and 45% respectively at 6 months postoperatively (p = 0.004 and 0.05). No significant correlations were found between the change in median steps per day and corresponding change in PROM scores at any study time points. CONCLUSIONS Though enrollment is still ongoing, we can conclude that lumbar laminectomy patients had significantly improved SF-12 PCS and ODI scores by 6 months postoperatively while median steps per day only returned to baseline. Patients therefore perceive that their conditions have improved after lumbar laminectomy more quickly than their mobilities objectively increase. The lack of significant correlations between the change in median steps per day and corresponding change in PROM scores throughout the study also suggests that these outcome measurements describe distinct patient experiences. Though patients' self-reported pain-free mobility increases, lifestyle and other factors may be important in explaining the lack of difference between preoperative and 6-month postoperative median steps taken per day. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

P123. 24-month outcomes of a prospective investigation of a novel mesh interbody spacer in single level fusions

BACKGROUND CONTEXT Interbody fusions are widely accepted as a successful method to treat lumbar degenerative disc disease (DDD). Increasingly, surgeons are seeking interbody devices that are larger for stability and grafting purposes, but can still be inserted through less-invasive techniques. An investigational device exempt (IDE) trial of such a device is complete to 24 months. This novel, conformable mesh interbody fusion device when placed in the disc space through a small portal and filled with bone graft in situ may reduce the risk of trauma to surrounding structures while creating a large graft footprint that intimately contours to the patient's own anatomy. PURPOSE The purpose of this study is to evaluate the long-term results of a novel conformable mesh interbody fusion device. STUDY DESIGN/SETTING This investigation is a prospective, multi-center, single-arm, FDA and IRB approved IDE, performance goal trial. PATIENT SAMPLE A total of 102 adult subjects presenting with degenerative disc disease at a single level between L2 and S1 and unresponsive to six-months conservative care had instrumented lumbar interbody fusion. OUTCOME MEASURES Validated assessment tools include 100mm VAS for pain, Oswestry Disability Index (ODI) for function, single question survey for patient satisfaction, and computerized tomography (CT) scan for fusion. METHODS Subjects were enrolled across 10 geographically distributed sites. Pain/ODI surveys, physical evaluations, and imaging were performed serially through 24 months. Specifically, CT scans were done at 12 and, if not fused, 24 months. Independent radiologists assessed CTs for fusion. An independent committee adjudicated adverse events. Subjects with complete data at 24-months were included in the analysis. RESULTS Ninety-six (96, 94% follow up rate) subjects (57.0±12.0 y, 50.0% Female, Body Mass Index 30.6±4.9) reported average decreased low back pain (LBP) from baseline of 45.0± 26.6 at 6-weeks and 51.4±26.2 at 24-months. Right/left leg pain reduced by 28.9±36.7/37.8±32.4 at 6-weeks and 30.5±33.0/40.3±34.6 at 24-months. Mean ODI improved 17.1±18.7 from baseline to 6 weeks and 32.0±18.5 by 24-months. At 24 months, 91.7% of subjects rated their procedure as excellent/good. Fusion rates were 97.9% (94/96) at 12-months, and 99% (95/96) at 24 months. Mean operative time, estimated blood loss (EBL), length of stay (LOS) were 2.6±0.9 h, 137±217 mL, and 2.3±1.2 d, respectively. No device-related serious adverse events have occurred. CONCLUSIONS Clinically significant outcomes for pain, function, fusion and device safety are demonstrated in this population. Substantial clinical improvements occur by 6 weeks postop and continue to improve to 24-months. The successful outcomes observed in this trial support use of this novel device in an instrumented lumbar interbody fusion. FDA DEVICE/DRUG STATUS OptiMesh (Not approved for this indication)

73. Sex-based difference in response to recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rat posterolateral fusion model

BACKGROUND CONTEXT Despite the known influence of hormones on bone metabolism and osteogenic differentiation, the few clinical studies evaluating outcomes after spine surgery have come to contradictory conclusions as to a sex-based differential response. This study aimed to quantify and compare the bone regenerative response to rhBMP-2 in males vs females in a preclinical setting of spine fusion. PURPOSE The purpose of this study was to determine whether sex influences fusion success, bone regenerative capacity, and bone quality after rhBMP-2-mediated spine fusion. STUDY DESIGN/SETTING Preclinical animal study. PATIENT SAMPLE Male and female Sprague-Dawley rats, ages 12-16 weeks. OUTCOME MEASURES Radiography, fusion scoring, microCT imaging, biomechanics testing. METHODS Twenty-four male and 24 female Sprague Dawley rats underwent L4-L5 posterolateral spine fusion with bilateral placement of an absorbable collagen sponge loaded with 5 μg of rhBMP-2 each (Infuse™; 10 μg/animal). Fusion was evaluated at 8 weeks postoperatively via blinded manual palpation on 14 rats/treatment group using an established scoring system wherein 0=no fusion, 1=unilateral fusion, 2=bilateral fusion, 3=bilateral fusion adjacent to a unilateral fusion, and 4=two adjacent bilateral fusion. A fusion score of 1 or greater (unilateral, single level fusion) was considered successfully fused. Specimens then underwent microCT imaging to evaluate and quantify new bone formation. Biomechanical testing was performed on the remaining 10 rats/group to quantify segmental flexion-extension range of motion and stiffness. RESULTS Both male and female rats achieved 100% fusion rates (with 1-level unilateral bridging considered fused), as assessed by blinded manual palpation. However, fusion scores were greater in male rats when compared with females (female: 2.4 vs males 3.1; p CONCLUSIONS Although a smaller amount of new bone was formed in females treated with Infuse™ relative to their male counterparts, that new bone was denser, with twice the number of trabeculae. Interestingly, female spines exhibited on average a greater segmental flexion-extension range-of-motion, suggesting that biomechanical stabilization may be more dependent upon fusion mass volume than density of the newly formed bone. These results are strongly suggestive of sex-dependent differences in the bone regenerative response to rhBMP-2, and they underscore the need for further study of this phenomenon and the underlying mechanisms involved. FDA DEVICE/DRUG STATUS rhBMP-2: Investigational.

P105. The influence of standalone cage versus plate-augmented single-level ACDF on global and local cervical sagittal alignment

BACKGROUND CONTEXT Prior studies have demonstrated that the postoperative sagittal alignment parameters of the cervical spine influence clinical outcomes and patient-reported outcome scores. For example, increased C2-C7 sagittal vertical axis (SVA) has been shown to decease neck disability index (NDI) scores. One recent study characterized the influence that different implant choices (particularly standalone versus plate-augmented constructs) had on cervical alignment parameters for 2-level ACDFs, and found that plate-augmented devices were better at restoring cervical lordosis. PURPOSE There is a paucity of literature investigating sagittal alignment parameters for single level constructs, and thus we sought to compare the ACDF-plate and ACDF-cage constructs in terms of their influence on sagittal parameters for single level fusions. STUDY DESIGN/SETTING This is a retrospective cohort study comparing patients who underwent ACDF with a plate-augmented construct to those who underwent ACDF with a standalone interbody device. PATIENT SAMPLE We identified 43 patients who underwent ACDF during the period studied. Of those, 17 underwent ACDF with a standalone device, whereas 26 underwent plate-augmented ACDF. OUTCOME MEASURES Demographic and perioperative factors were collected. Radiographic parameters of C2-C7 SVA, C2-C7 lordosis, segmental cobb angle, T1 slope, and T1 slope minus C2-C7 lordosis were measured on preoperative and postoperative images. METHODS We retrospectively analyzed the preoperative and most recent postoperative radiographs from patients who underwent a single-level ACDF for degenerative cervical spondylosis at our institution between May 2014 and July 2019. The average follow-up time was 10.5 months. Patients were separated into groups based on the construct used (ACDF-cage and ACDF-plate). Demographic and perioperative factors were collected. Radiographic parameters of C2-C7 SVA, C2-C7 lordosis, segmental cobb angle, T1 slope, and T1 slope minus C2-C7 lordosis were measured on preoperative and postoperative images. Patient demographic, perioperative and radiographic factors were compared using Pearson's chi-square test for categorical and independent samples t-test for continuous variables. RESULTS We identified 43 patients who underwent ACDF during the period studied. Of those, 17 underwent ACDF with a standalone device, whereas 26 underwent plate-augmented ACDF. There was no significant difference between groups in terms of age (52.0 vs 48.8, p = >0.05) or which levels were fused (p = 0.615). We did not find a significant difference between groups in the final postoperative sagittal alignment parameters (SVA 28.6 vs 33.7, cervical lordosis 10.2 vs 12.4, segmental angle 4.9 vs 4.3, T1 slope 25.8 vs 27.7, T1 slope minus cervical lordosis 0.83 vs 4.03, p>0.05). We also compared the change from preoperative to postoperative alignment between groups, and again found no significant difference when comparing ACDF-plate to ACDF-cage constructs. CONCLUSIONS Our data has failed to demonstrate a difference in radiologic alignment outcomes between plate-augmented and standalone single-level ACDF constructs. This is not consistent with a prior study comparing these constructs in patients with 2-level ACDFs, which found better postoperative cervical alignment with the use of an ACDF with an anterior plate. However, a recent meta-analysis comparing single-level ACDF-plate to ACDF-cage constructs also found no difference between groups in terms of C2-C7 lordosis or segmental cobb angle, but that study did not examine other parameters such as C2-C7 SVA. Thus, our data, taken in tandem with the existing literature, seem to support the conclusion that the effects of construct on cervical alignment are significant for fusions of at least two levels, but may not reach significance for single level fusions. However, the power of our study to detect small but significant differences between groups is limited due to the number of cases analyzed, and thus further study is still needed to make definitive conclusions regarding ACDF construct choice. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Radiographic Analysis Comparison of Cervical Alignment After Variable Level of Anterior Cervical Discectomy and Fusion (ACDF)

Background: To compare the radiographic cervical lordosis alignment between pre-operative and post-operative surgery after variable level of anterior cervical discectomy and fusion (ACDF) .In the current review, the standard surgical treatment of cervical spondylotic myelopathy is ACDF the restoration and maintenance of cervical lordosis alignment is an important clinical parameter after single level or multilevel anterior cervical discectomy and fusion. The increase or decrease cervical lordosis alignment is affected by the sagittal vertical axis and balance. Methods: This study was performed a retrospective radiographic analysis of 147 patients who underwent single to multilevel ACDF (Total N= 147; 1-level (N=36), 2-level (N=60), 3-level (N=42) and 4-level (N=9)) by orthopedic spine surgeons and neurosurgeons between 2016 and 2018. The authors measured the cervical lordosis alignment of the cervical spine using the Cobb method (Inferior endplate of C2 to inferior endplate of C7) at pre-operative and post-operative surgery. Radiographs were measured by three orthopedic doctor viewers. Statistical analysis were performed using R software. Results: The radiographic analysis comparison of cervical alignment after ACDF was showed the results that cervical lordosis alignment had no significantly change of decreased cervical lordosis alignment at pre-op mean 14.88°(± 8.66) and initial post-op mean 13.01°(±7.65) in all level of ACDF. Conclusions: The radiographic analysis of variable level anterior cervical discectomy and fusion in single to multilevel (1-level, 2-level, 3-level and 4-level) has no significantly change in cervical lordosis alignment after initial postop surgery.

Ambulation on Postoperative Day #0 Is Associated With Decreased Morbidity and Adverse Events After Elective Lumbar Spine Surgery: Analysis From the Michigan Spine Surgery Improvement Collaborative (MSSIC).

While consistently recommended, the significance of early ambulation after surgery has not been definitively studied. To identify the relationship between ambulation on the day of surgery (postoperative day (POD)#0) and 90-d adverse events after lumbar surgery. The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a prospective multicenter registry of spine surgery patients. As part of routine postoperative care, patients either ambulated on POD#0 or did not. The 90-d adverse events of length of stay (LOS), urinary retention (UR), urinary tract infection (UTI), ileus, readmission, surgical site infection (SSI), pulmonary embolism/deep vein thrombosis (PE/DVT), and disposition to a rehab facility were measured. A total of 23 295 lumbar surgery patients were analyzed. POD#0 ambulation was associated with decreased LOS (relative LOS 0.83, P<.001), rehab discharge (odds ratio [OR] 0.52, P<.001), 30-d (OR 0.85, P=.044) and 90-d (OR 0.86, P=.014) readmission, UR (OR 0.73, P=10), UTI (OR 73, P=.001), and ileus (OR 0.52, P<.001) for all patients. Significant improvements in LOS, rehab discharge, readmission, UR, UTI, and ileus were observed in subset analysis of single-level decompressions (4698 pts), multilevel decompressions (4079 pts), single-level fusions (4846 pts), and multilevel fusions (4413 pts). No change in rate of SSI or DVT/PE was observed for patients who ambulated POD#0. POD#0 ambulation is associated with a significantly decreased risk for several key adverse events after lumbar spine surgery. Decreasing the incidence of these outcomes would be associated with significant cost savings. As ambulation POD#0 is a modifiable factor in any patient's postoperative care following most spine surgery, it should be encouraged and incorporated into spine-related, enhanced-recovery-after-surgery programs.

Lumbar decompression and lumbar interbody fusion in the treatment of lumbar spinal stenosis: A systematic review and meta-analysis.

Background:The goal of this study was to review relevant randomized controlled trials in order to determine the efficacy of decompression and lumbar interbody fusion in the treatment of lumbar spinal stenosis.Method:Using appropriate keywords, we identified relevant studies in PubMed, the Cochrane library, and Embase. Key pertinent sources in the literature were also reviewed, and all articles published through July 2019 were considered for inclusion. For each study, we assessed odds ratios, mean difference, and 95% confidence interval to assess and synthesize outcomes.Result:Twenty-one randomized controlled trials were eligible for this meta-analysis with a total of 3636 patients. Compared with decompression, decompression and fusion significantly increased length of hospital stay, operative time and estimated blood loss. Compared with fusion, decompression significantly decreased operative time, estimated blood loss and overall visual analogue scale (VAS) scores. Compared with endoscopic decompression, microscopic decompression significantly increased length of hospital stay, and operative time. Compared with traditional surgery, endoscopic discectomy significantly decreased length of hospital stay, operative time, estimated blood loss, and overall VAS scores and increased Japanese Orthopeadic Association score. Compared with TLIF, MIS-TLIF significantly decreased length of hospital stay, and increased operative time and SF-36 physical component summary score. Compared with multi-level decompression and single level fusion, multi-level decompression and multi-level fusion significantly increased operative time, estimated blood loss and SF-36 mental component summary score and decreased Oswestry disability index score. Compared with decompression, decompression with interlaminar stabilization significantly decreased operative time and the score of Zurich claudication questionnaire symptom severity, and increased VAS score.Conclusion:Considering the limited number of included studies, we still need larger-sample, high-quality, long-term studies to explore the optimal therapy for lumbar spinal stenosis.

Factors Impacting Outcomes and Health Care Utilization in Osteoporotic Patients Undergoing Lumbar Spine Fusions: A MarketScan Database Analysis

To identify factors impacting long-term complications, reoperations, readmission rates, and health care utilization in patients with osteoporosis (OP) following lumbar fusions. We used International Classification of Disease, Ninth Revision, International Classification of Disease, Tenth Revision , and Current Procedural Terminology codes to extract data from MarketScan (2000-2016). Patients undergoing lumbar spine fusion were divided into 2 groups based on preoperative diagnosis: OP or non-OP. We used multivariable generalized linear regression models to analyze outcomes of interest (reoperation rates, readmissions, complications, health care utilization) at 1, 6, 12, and 24 months after discharge. MarketScan identified 116,749 patients who underwent lumbar fusion with ≥24 months of follow-up; 6% had OP. OP patients had a higher incidence of complications (14% vs. 9%); were less likely to be discharged home (77% vs. 86%, P < 0.05); had more new fusions or refusions at 6 months (2.9% vs. 2.1%), 12 months (5% vs. 3.8%), and 24 months (8.5% vs. 7.4%); incurred more outpatient services at 12 months (80 vs. 61) and 24 months (148 vs. 115); and incurred higher overall costs at 12 months ($22,932 vs. $17,017) and 24 months ($48,379 vs. $35,888). Elderly OP patients (>65 years old) who underwent multilevel lumbar fusions had longer hospitalization, had higher complication rates, and incurred lower costs at 6, 12, and 24 months compared with young non-OP patients who underwent single-level lumbar fusion. Patients of all ages with OP had higher complication rates and required revision surgeries at 6, 12, and 24 months compared with non-OP patients. Elderly OP patients having multilevel lumbar fusions were twice as likely to have complications and lower health care utilization compared with younger non-OP patients who underwent single-level fusion.

Impact of L4/5 Posterior Interbody Fusion With or Without Decompression on Spinopelvic Alignment and Health-related Quality-of-Life Outcomes.

This was a retrospective case control study. The objective was to determine the impact of single-level interbody fusion at L4/5 with or without concomitant decompression on various spinopelvic parameters and health-related quality-of-life (HRQOL) outcomes. Recently, focus has swayed from a regional concern to a global sagittal alignment, more comprehensive approach in multilevel, corrective fusion for adult spinal deformity. However, only a few comprehensive studies have investigated the relationships between the various related spinopelvic parameters and HRQOL outcomes using single-level interbody fusion. In total, 119 patients with lumbar degenerative disorders (mean age, 68 y; 38 males and 81 females) who underwent L4/5 single-level posterior interbody fusion with a minimum 2-year follow-up were included. Participants were divided into 2 groups according to preoperative sagittal modifiers of the SRS-Schwab adult spinal deformity classification. The correlation between spinopelvic parameters and HRQOL outcomes was investigated. Negative or positive values indicated lordosis. HRQOL outcomes were assessed using visual analog scale scores, Japanese Orthopedic Association Back Pain Evaluation Questionnaires (JOABPEQ), and short form-36 (SF-36). L4/5 local lordosis increased from 6.4±4.4 degrees preoperatively to 11.3±4.5 degrees at 2 years postoperatively (P<0.0001). Further analysis of the results also showed a correlation between change in L4/5 local lordosis and change in lumbar lordosis (LL) (rs=0.229, P=0.0143). The high pelvic incidence-LL (≥20 degrees, n=28) and high sagittal vertical axis groups (≥5 cm, n=29) had lower scores in walking ability, social life domains of JOABPEQ, and physical component summary scores of SF-36 preoperatively, and 2 years postoperatively. Fusion status did not affect the HRQOL outcomes, except that concomitant decompression at the adjacent disk level yielded lower SF-36 physical component summary scores 2 years postoperatively. Improvement in L4/5 local lordosis possibly triggers a simultaneous sequence of change in total LL after posterior single-level fusion. HRQOL outcomes were negatively affected by both preoperative and postoperative pelvic incidence-LL mismatch and global sagittal malalignment. Level III.

Does zero-profile anchored cage accompanied by a higher postoperative subsidence compared with cage-plate construct? A meta-analysis

BackgroundThe zero-profile anchored cage (ZP) has been widely used for its lower occurrence of dysphagia. However, it is still controversial whether it has the same stability as the cage-plate construct (CP) and increases the incidence of postoperative subsidence. We compared the rate of subsidence after anterior cervical discectomy and fusion (ACDF) with ZP and CP to determine whether the zero-profile device had a higher subsidence rate.MethodsWe performed a meta-analysis of studies that compared the subsidence rates of ZP and CP. An extensive and systematic search covered the PubMed and Embase databases according to the PRISMA guidelines and identified ten articles that satisfied our inclusion criteria. Relevant clinical and radiological data were extracted and analyzed by the RevMan 5.3 software.ResultsTen trials involving 626 patients were included in this meta-analysis. The incidence of postoperative subsidence in the ZP group was significantly higher than that in the CP group [15.1% (89/588) versus 8.8% (51/581), OR = 1.97 (1.34, 2.89), P = 0.0005]. In the subgroup analysis, we found that the definition of subsidence did not affect the higher subsidence rate in the ZP group. Considering the quantity of operative segments, there was no significant difference in the incidence of subsidence between the two groups after single-level fusion (OR 1.43, 95% CI 0.61–3.37, P = 0.41). However, the subsidence rate of the ZP group was significantly higher than that of the CP group (OR 2.61, 95% CI 1.55–4.40, P = 0.0003) after multilevel (≥ 2-level) procedures. There were no significant differences in intraoperative blood loss, JOA score, NDI score, fusion rate, or cervical alignment in the final follow-up between the two groups. In addition, the CP group had a longer operation time and a higher incidence of dysphagia than the ZP group at each follow-up time.ConclusionBased on the limited evidence, we suggest that ZP has a higher risk of postoperative subsidence than CP, although with elevated swallowing discomfort. A high-quality, multicenter randomized controlled trial is required to validate our results in the future.

Half of Unplanned Readmissions Following One or Two-Level Anterior Cervical Decompression and Fusion Are Unrelated to Surgical Site.

Retrospective review of a national database. In this study we analyze rates of readmission, and the timing and reasons for readmission after one to two level anterior cervical decompression and fusion (ACDF). The safety profile of ACDF has been previously described with readmission rates typically between 2% and 4%. However no studies have investigated the primary diagnoses driving readmission, and whether these diagnoses are related to the surgical site. Demographics, comorbidities, and procedural characteristics were collected for all patients undergoing one or two-level ACDF for degenerative indications identified by Current Procedural Terminology (CPT) coding in the National Surgical Quality Improvement Program (NSQIP) database. The incidence of 30-day complications and readmissions was calculated, and the reasons for readmission as well as the timing of readmission were reviewed. Multivariate logistic regression analyses were performed to identify risk factors associated with complications or readmissions within 30 days of surgery. Eighteen thousand eight hundred thirty three patients underwent ACDF (15,464 single-level and 3369 two-level, mean age 53.7 yrs, standard deviation [SD]: 11.6; 50% male). Postoperative complication rate of was 4.3% in two-level fusions and 3.5% in single-level fusion (P = 0.027). Five hundred sixty nine unplanned readmissions were identified (3.0%), of which 39.5% were related to the surgical site and 49.7% were unrelated to the surgical site (10.5% unknown cause of readmission). The most frequent reason for 30-day readmission was pneumonia (9.3%, mean time to readmission of 11.3 d) followed by dysphagia (7.4%, 6.3 d), and acute postoperative pain (7.2%, 11.4 d). In this nationwide analysis of 18,833 ACDF cases, 3.0% of patients were readmitted within 30 days, of which at least 49.7% were for reasons unrelated to the surgical site. 3.

Perioperative adverse events after different fusion approaches for single-level lumbar spondylosis

BackgroundLow back pain from lumbar spondylosis affects a large proportion of the population. In select cases, lumbar fusion may be considered. However, cohort studies have not shown clear differences in long-term outcomes between PSF, TLIF, ALIF, and AP fusion. Thus, differences in perioperative complications might affect choice between these procedures for the given diagnosis. The current study seeks to compare perioperative adverse events for patients with lumbar spondylosis treated with single-level: posterior spinal fusion (PSF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), or combined anterior and posterior lumbar fusion (AP fusion). MethodsPatients with a diagnosis of lumbar spondylosis who underwent single-level lumbar fusion without decompression were identified in the 2010-2016 National Quality Improvement Program (NSQIP) database. Patients were categorized based on their procedure (PSF, TLIF, ALIF, or AP fusion). Unadjusted Fisher's exact and Pearson's chi-squared tests were used to compare demographics and comorbid factors. Analysis was secondarily done with propensity score matching to address potential differences in patient selection between the study cohorts. ResultsIn total, 1816 patients were identified: PSF n=322, TLIF n=800, ALIF n=460, AP fusion n=234. The procedures did not have different thirty-day individual or aggregated (any, serious, minor, or infection) adverse events. Further, propensity score matched analysis also revealed no differences in individual or aggregated thirty-day perioperative events. ConclusionThe current study demonstrates a lack of difference in thirty-day perioperative adverse events for different fusion procedures performed for lumbar spondylosis, consistent with prior longer-term outcome studies. These findings suggest that patient/surgeon preference and other factors not captured here should be considered to determine the best surgical technique for the select patients with the given diagnosis who are considered for lumbar fusion. Summary SentenceUsing the NSQIP 2010-2016 databases, this study showed that perioperative adverse events were similar for different surgical approaches of single-level fusion for single-level lumbar spondylosis.