Posterior Percutaneous Instrumentation Research Articles

Facet joint violation after open and percutaneous posterior instrumentation: a comparative study

PurposePosterior instrumentation is the state-of-the-art surgical treatment for fractures of the thoracic and lumbar spine. Options for pedicle screw placement comprise open or minimally invasive techniques. Open instrumentation causes large approach related muscle detachment, which minimally invasive techniques aim to reduce. However, concerns of accurate pedicle screw placement are still a matter of debate. Beside neurological complications due to pedicle screw malplacement, also affection of the facet joints and thus motion dependent pain is known as a complication. The aim of this study was to assess accuracy of pedicle screw placement concerning facet joint violation (FJV) after open- and minimally invasive posterior instrumentation.MethodsA retrospective data analysis of postoperative computer tomographic scans of 219 patients (1124 pedicle screws) was conducted. A total of 116 patients underwent open screw insertion (634 screws) and 103 patients underwent minimally invasive, percutaneous screw insertion (490 screws). ResultsIn the lumbar spine (segments L3, L4, L5), there were significantly more and higher grade (open = 0.55 vs. percutaneous = 1.2; p = 0.001) FJV’s after percutaneously compared to openly inserted screws. In the thoracic spine, no significant difference concerning rate and grade of FJV was found (p > 0.56).ConclusionFJV is more likely to occur in percutaneously placed pedicle screws. Additionally, higher grade FJV’s occur after percutaneous instrumentation. However, in the thoracic spine we didn’t find a significant difference between open and percutaneous technique. Our results suggest a precise consideration concerning surgical technique according to the fractured vertebrae in the light of the individual anatomic structures in the preop CT.

Surgeon Learning Curve and Clinical Outcomes of Minimally Invasive Anterior Lumbar Interbody Fusion With Posterior Percutaneous Instrumentation.

This study reports the learning phase of the minimally invasive anterior lumbar interbody fusion (mini-ALIF) approach with a vascular and orthopaedic spine surgeon team. Adult patients who underwent primary mini-ALIF at the lowest two segments of the lumbar spine (i.e., L4/5, L5/S1) between January 2010 and December 2018 were analyzed. One hundred twenty-seven patients were included. There was no notable change in total surgical time over the study period. Estimated blood loss markedly decreased until stabilizing at case 30 and slowly declined thereafter. The mean estimated blood loss was 184 mL for L5/S1, 232 mL for L4/L5, and 458 mL for two-level mini-ALIF. There were 20 vascular issues requiring primary repair or packing. Vascular issues declined over time, with a rate of 32% in the first 25 cases and 0% in the last 25. The postoperative complication rate was highest in the first 25 cases (7 of 21 total complications). The odds ratio of vascular injury with body mass index (BMI) > 35 was 4.09 (1.4 to 11.7 confidence interval, P ≤ 0.008). Total surgical time and postoperative complications increased with increasing BMI. Performance of the mini-ALIF approach is associated with a learning curve of 25 to 30 cases before complications begin to decline. BMI > 35 is associated with increased surgical time and complications.

Treatment for Pyogenic Spondylodiscitis and Spinal Epidural Abscess

Spontaneous spinal infections, such as pyogenic spondylodiscitis(PSD)and spinal epidural abscess(SEA), are relatively rare, but the number of patients is increasing because of the increase in the older population with chronic comorbidities. Magnetic resonance imaging is the most useful tool for identifying PSD or SEA, with high sensitivity and specificity. Effective antibiotic medication is essential to treat the infection, and selection of antibiotics should be based on not only sensitivity to the causative bacteria, but also ability to penetrate bone tissues. Medication should be continued for at least 6 weeks while monitoring C-reactive protein levels. Surgical treatment is indicated when neurological symptoms or severe spinal instability cannot be managed conservatively. Percutaneous endoscopic surgery enables simultaneous tissue sampling for diagnosis and curative debridement without injury to the spinal supporting tissues. Anterior debridement and interbody fusion(ADIF)with autologous bone grafts have been frequently used for PSD. ADIF can be applied more easily to the lumbar spine using techniques and devices for lateral interbody fusion. Posterior decompression is frequently performed in patients with SEA without severe spinal instability. Percutaneous posterior instrumentation, with or without posterior decompression, is a useful option for PSD, especially in the thoracic spine.

P138. Preoperative multifidus muscle quality is associated with patient-reported outcomes after lateral lumbar interbody fusion

<h3>BACKGROUND CONTEXT</h3> Lateral lumbar interbody fusion (LLIF) is a commonly performed spinal surgery which involves a transpsoas approach. Despite the association between LLIF and postoperative iliopsoas weakness and iatrogenic neuropraxia of the lumbar plexus, no study has yet examined the effect of psoas or multifidus muscle quality on patient-reported outcomes (PROs). <h3>PURPOSE</h3> This study sought to investigate the effect of psoas and multifidus muscle quality on postoperative subjective patient-reported outcomes following LLIF. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort. <h3>PATIENT SAMPLE</h3> Patients who underwent LLIF with one of two senior surgeons at a single institution with 1-year minimum followup. <h3>OUTCOME MEASURES</h3> PROs evaluated included the Short Form 12-Item Health Survey (SF12), Veterans RAND 12-Item Health Survey (VR12), Oswestry Disability Index (ODI), and Visual Analog Scales (VAS) for Back and Leg pain. <h3>METHODS</h3> Preoperative psoas and multifidus muscle qualities were graded on magnetic resonance imaging (MRI) using two validated classification systems for muscle atrophy (Kader [KCS] and Goutallier [GCS]). Average psoas and multifidus muscle quality was calculated as the mean score from all levels (L1-2 through L5-S1). Univariate and multivariate statistics were utilized to investigate the relationship between psoas/multifidus muscle quality and preoperative, 6 weeks postoperative, and 1 year postoperative PROs. The variables adjusted for in the multivariate analysis included age, sex, BMI, smoking history, diabetes, concomitant posterior percutaneous instrumentation and history of prior open posterior lumbar surgery. <h3>RESULTS</h3> Seventy-four patients (110 levels) with a mean follow-up time of 18.71±8.02 months were included for analysis. Univariate analysis demonstrated that increased psoas atrophy was significantly associated with worse ODI scores (KCS: p=.018; GCS: p=.017). This became non-significant on multivariate analysis. Greater multifidus atrophy was associated with less improvement on ODI (KCS: p=.033; GCS: p=.019), SF12 (KCS: p=.005; GCS: p=.003) and VR12 (KCS: p=.003; GCS: p=.004) on univariate analysis. On multivariate analysis, a higher degree of multifidus atrophy independently predicted less improvement on SF12 (KCS, p=.023; GCS, p=.032) and VR12 (KCS, p=.016; GCS, p=.045). Patients with a history of prior lumbar surgery reported significantly worse pain and disability at all time points (p<.05), as well as less improvement in ODI (p=.043) and VAS Back (p=.028) from preoperatively to 1-year postoperatively. <h3>CONCLUSIONS</h3> Despite the direct manipulation of the psoas muscle inherent to LLIF, preoperative psoas muscle quality did not affect postoperative outcomes. Rather, the extent of preoperative multifidus fatty infiltration and atrophy was more likely to predict postoperative pain and disability. These findings suggest that multifidus atrophy may be more pertinent than psoas atrophy in its association with patient-reported outcome measures after LLIF. Our results also indicate that a history of prior lumbar surgery is associated with significantly less improvement in PROs after LLIF. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Adult Isthmic Spondylolisthesis: A Radiographic and Outcomes Analysis Comparing Circumferential Fusions Versus TLIF Procedures.

This was a retrospective cohort study. The objective of this study was to compare radiographic and patient-reported outcome measures (PROMs) between circumferential fusions and transforaminal lumbar interbody fusion (TLIF) for adult isthmic spondylolisthesis (IS). Definitive management of adult IS typically requires decompression and fusion. Multiple fusion techniques have been described, but literature is sparse in identifying the optimal technique. Patients with IS undergoing single-level or 2-level circumferential fusion or TLIF with a minimum 1-year follow-up were included. Patient demographics, surgical characteristics, and PROMs were extracted from patients' electronic medical records. Descriptive statistics and multivariate regression analysis compared outcomes with significance set at P -value &lt;0.05. A total of 78 circumferential fusions (48 open decompression and fusions and 30 circumferential fusions utilizing posterior percutaneous instrumentation) and 50 TLIF procedures were included. Length of stay was significantly longer when comparing circumferential procedures (3.56±0.96 d) versus TLIFs (2.88±1.14 d) ( P =0.002). The circumferential fusion group resulted in greater postoperative improvement in segmental lordosis [anterior/posterior (A/P): 6.45, TLIF: -1.99, P &lt;0.001], posterior disk height (A/P: 12.6 mm, TLIF: 8.9 mm, P &lt;0.001), and ∆disk height (A/P: 7.7 mm, TLIF: 3.6 mm, P &lt;0.001). Both groups significantly improved in all PROMs ( P &lt;0.001). While the circumferential fusion group had a significantly higher rate of perioperative surgical complications (12.82% vs. 2.00%, P =0.049), there was no difference in the rate of 30-day readmissions ( P =0.520) or revision surgeries between techniques ( P =0.057). Circumferential fusions are associated with improvements in radiographic outcomes compared with TLIFs, but this is at the expense of longer hospital length of stay and increased risk for perioperative complications. The surgical technique did not result in superior postoperative PROMs or differences in readmissions or revisions.

Supine and Dynamic Extension Radiographs as the Strongest Predictors of Post-operative Alignment in Minimally Invasive Lumbar Spine Surgery.

Institutional review board-approved retrospective cohort study. Failure to achieve alignment goals may result in accelerated adjacent segment degeneration and poorer outcomes. In "open" spine surgery, intraoperative tools can fine tune alignment; minimally invasive spine surgery techniques may not allow for this type of intraoperative adjustment. The aim of this study was to identify pre-operative radiographic parameters that accurately predict post-operative alignment after minimally invasive lumbar spine surgery. We hypothesized that pre-operative supine and extension sagittal alignment would predict post-operative standing alignment. 50 consecutive patients underwent lateral or anterior lumbar interbody fusion with or without percutaneous posterior instrumentation by a single-surgeon. Sagittal alignment parameters were evaluated on pre-operative standing scoliosis radiographs, dynamic radiographs, supine CT scout, and 6-week post-operative standing radiographs. Demographic and perioperative data were analyzed. The mean age was 67.8years. The mean BMI was 29.7. On average, 3 levels were instrumented (range, 2-6). Surgical time was 4.5 ± 1.8hours. Following surgery, global lordosis increased from 44.7 ± 17° to 48.6 ± 16° (P = .001). However, there was no significant difference between the pre-operative supine (48.5 ± 15°), pre-operative extension (49.2 ± 18°), or 6-week post-operative standing radiographs (48.6 ± 16°). There were strong correlations between post-operative alignment and pre-operative supine (r = .825) and extension (r = .851) alignment. Our results suggest that pre-operative supine and extension radiographs could be a gold standard for minimally invasive lumbar spine surgery alignment correction as they predict post-operative alignment. The extension alignment was the strongest predictor of post-operative alignment.

10-Year Clinical, Functional, and X-ray Follow-Up Evaluation of a Novel Posterior Percutaneous Screw-Rod Instrumentation Technique for Single-Level Pyogenic Spondylodiscitis.

Medical treatment with antibiotic therapy remains the mainstay of treatment for pyogenic spondylodiscitis (PS). Nevertheless, orthopaedic treatment is also very important in relieving pain, preventing neurological damage, and avoiding development of spinal deformities (e.g., scoliosis, kyphosis) due to spinal instability. Rigid thoracolumbosacral orthosis (TLSO) bracing is often needed in patients with PS, and average duration of treatment of 3 to 4 months. However, TLSO bracing can be poorly tolerated and limit ability of the patient to go back to a normal life. In 2004 our group developed an alternative surgical treatment to TLSO bracing by percutaneous posterior screw-rod bridge instrumentation of the infected level. This treatment allows early and free mobilization of the patients and is associated with faster recovery, lower pain scores and improved quality of life as previously reported. Herein, we report the clinical outcome of the first 3 patients who have completed the 10 years follow-up mark after the procedure. A case report is also described and details of the procedure are provided.

P146. MIS TLIF procedures had lower postoperative opioid consumption compared to single position and traditional percutaneous lumbar spinal fusion approaches

<h3>BACKGROUND CONTEXT</h3> One of the reported advantages of MIS spine surgery is less postoperative pain and less postoperative opioid consumption. Traditional lumbar approaches (open TLIF, percutaneous ALIF with flip, and percutaneous LLIF with flip) were compared to minimally invasive (MIS TLIF) and single position (lateral decubitus) anterior posterior surgery (SPS ALIF, SPS LLIF) to evaluate for differences in postoperative opioid consumption. <h3>PURPOSE</h3> To evaluate inpatient MME administration for different lumbar spinal fusion surgeries. <h3>STUDY DESIGN/SETTING</h3> Single-center retrospective cohort study. <h3>PATIENT SAMPLE</h3> A total of 447 single level lumbar spinal fusion procedures from 2013 to 2020: 125 open TLIF, 110 MIS TLIF, 122 Traditional Percutaneous (TP) ALIF/LLIF, and 45 SPS ALIF/LLIF. <h3>OUTCOME MEASURES</h3> Patient demographics, surgical procedure and approach, perioperative clinical characteristics, incidence of ileus and inpatient MME. <h3>METHODS</h3> Patients ≥ 18 years of age who underwent one level TLIF or one level ALIF or LLIF with percutaneous posterior instrumentation between L2-S1. All groups included patients with a diagnosis of Grade I spondylolisthesis, stenosis, degenerative disc disease or pars defect. Statistical analysis included independent samples t-tests and chi-square analyses. Propensity score matching (PSM) was used when comparing SPS ALIF/LLIF vs TP ALIF/LLIF to control for age. MME was calculated as per the Centers for Medicare & Medicaid Services. To adjust for differences in length of stay (LOS), inpatient MME was quantified as a rate per hour. Significance set at p<0.05. <h3>RESULTS</h3> There were no differences in demographics except the MIS TLIF group was older (55.9±12.5 vs 51.6±13.1, p=0.011) than TP ALIF/LLIF. After a PSM for age, SPS ALIF/LLIF had shorter op times (202.3±71.0 vs 271.8±77.7 min, p=0.000) and showed no differences in total MME (322.4 ± 397.8 vs 342.5 ± 243.7, p=0.463) or rates of ileus (both 0%) compared to TP ALIF/LLIF. MIS TLIF had a shorter LOS compared to open TLIF (2.6±1.4 vs 3±1.7 days, p=0.000), lower total MME administration (214.1±235.4 vs 310.3±373.4, p=0.021) but no difference in total MME per hour (3.2±2.4 vs 3.7±2.8, p=0.198). MIS TLIF had shorter op time (212.1±66.4 vs 271.8 ±77.7 min, p=0.000), LOS (2.6±1.4 vs 3.5±1.6 days, p=0.000) and total MME (214.1±235.3 vs 342.5±243.7, p=0.000) than TP ALIF/LLIF. MIS TLIF also had shorter LOS (2.6±1.4 vs 3.3±2.1days, p=0.017), lower total MME (214.1±235.4 vs 322.4±397.8, p=0.037) and similar rates of ileus (0.9% vs 0.0%, p=0.521) compared to SPS ALIF/LLIF. <h3>CONCLUSIONS</h3> Patients undergoing MIS TLIF had lower inpatient opioid intake compared to open TLIF, single level TP ALIF/LLIF, and single level SPS. When propensity score matching for age, there was no difference in opioid administration post operatively in patients undergoing TP ALIF/LLIF or SPS ALIF/LLIF. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Managing Incomplete and Complete Thoracolumbar Burst Fractures (AO Spine A3 and A4). Results from a Prospective Single-Center Study Comparing Posterior Percutaneous Instrumentation plus Mini-Open Anterolateral Fusion versus Single-Stage Posterior Instrumented Fusion

The treatment strategy for thoracolumbar burst fractures is still debated. The aim of this study is to evaluate clinical and radiologic outcomes of a 2-stage strategy with immediate posterior percutaneous instrumentation and delayed anterolateral fusion (group A) versus a single-stage open posterior instrumented fusion (group B). Demographics and clinical and surgical data of patients operated for AO Spine A3 and A4 fractures were prospectively collected. Vertebral height and deformity were evaluated before and after surgery. Visual analog scale score for back pain, Oswestry Disability Index, and 12-Item Short Form Health Survey results for quality-of-life assessment were collected during follow-up. Among the 110 patients enrolled, 66 were allocated to group A and 44 to group B; the most common fractured level was T12 (34%). Postoperative complications were higher in group B, especially the wound infection rate (18% vs. 3%), and pseudomeningocele (14% vs. 0%). The 2-stage approach allowed an average long-term gain of 15.8° at the local kyphosis of fractured vertebra and 5.8° at the regional level (Cobb angle), versus 15.4° and 5.5° in group B. At 2 years follow-up, both groups showed significant functional improvements; however, the visual analog scale and Oswestry Disability Index metrics seemed more favorable for group A patients (P < 0.0001 vs. P < 0.003). A complete fusion rate was obtained in 100% of group A vs. 65% of group B. Our study indicates that percutaneous instrumentation and anterior fusion or an expandable cage lead to excellent long-term clinical and radiologic outcomes with a lower complication rate and higher fusion rate than those of open posterior approaches.

Kyphoplasty versus percutaneous posterior instrumentation for osteoporotic vertebral fractures with posterior wall injury: a propensity score matched cohort study.

Osteoporotic vertebral fractures (OVFs) that present with posterior wall cortical injury pose a higher risk for instability. Surgical management includes standard cement augmentation techniques like balloon kyphoplasty (BKP) or percutaneous posterior instrumentation with pedicle screws (PS) or both. Neither treatment has yet demonstrated superiority, and posterior cement leakage is of special concern in these fractures. At a single tertiary care center, 25 patients with 32 OVFs with posterior wall injury treated with percutaneous instrumentation and cement augmentation (PS group) were retrospectively included and matched (1:1) using propensity scores to 25 patients with 29 OVFs with posterior wall injury treated with standalone BKP (BKP group) from 2010 to 2018. Our primary study aim identified 30-day morbidity rates using a 4-point grading system by comparing BKP with and without percutaneous instrumentation with PS for the treatment of OVFs with posterior wall injury. Our secondary aims evaluated cement leakage, radiographic results, surgical time, length of stay (LOS), pain relief, and subsequent fractures. Overall 30-day morbidity was 34% and did not differ between groups (24% BKP vs. 44% PS groups, P=0.136). Most complications were mild (82.4%), requiring no interventions beyond drug treatment. In the PS group, a trend towards more mild complications was observed (16% vs. 40%, P=0.059). Moderate and severe complications affected 17.6% of all morbidity cases and were comparable between groups. Asymptomatic cement leakage into the spinal canal was noted in 2 (8%) BKP patients and symptomatic pulmonary cement embolism in 1 (4.8%) PS patient. Compared with baseline, all radiographic parameters significantly improved in both groups. In the BKP group, mean surgical times (52±32.9 vs. 164.9±48.4 minutes, P<0.001) and LOS (4.3±2.5 vs. 7±2.9 days, P<0.001) were significantly shorter, and use of opioids at discharge was significantly lower (52% vs. 84%, P=0.015). At 3-month follow-up, no differences between groups were seen in back pain, use of opioids, and occurrence of subsequent OVFs. Follow-up averaged 8.4 months. Standalone BKP may be a viable option for the treatment of OVFs even in the presence of posterior wall cortical injury.

Pyogenic Dorsal and Lumbar Spondylodiscitis treated with Minimally Invasive Endoscopic Procedure and Posterior Percutaneous Instrumentation

Introduction: Spondylodiscitis is a rare infection of the intervertebral disc and nearby bone structures, which incidence has been increasing in the past decades. Conservative treatment is the gold standard, but sometimes surgery is needed to relief the symptoms and eradicate the infection, preserve the neurological function, and restore structural alignment and stability.

Retrospective radiographic analysis of anterior lumbar fusion for high grade lumbar spondylolisthesis.

High-grade spondylolisthesis (>50% slippage) is infrequently encountered in adults and frequently requires surgical treatment. The optimal surgical treatment is controversial with limited literature guidance as to optimal approach to treatment. An observational study to examine the technique and radiographic outcomes of adult patients treated with anterior lumbar interbody fusion (ALIF) and posterior percutaneous instrumentation for high-grade spondylolisthesis. ALIF was performed in 5 consecutive patients (3/5 female, 2/5 male) aged 29-67 years old who presented with low back pain and L5 radiculopathy. All patients failed conservative treatment and were treated with L4-5 and L5-S1 ALIF followed by posterior percutaneous L4-S1 pedicle screw and rod fixation. Pre- and postoperative clinical data was collected including L5-S1 posterior disk height in millimeters, millimeters of spondylolisthesis at L5-S1, degrees of segmental lordosis (L4-S1), lumbar lordosis (L1-S1), and lumbar lordosis pelvic incidence (LL-PI) mismatch. Six weeks following surgery, no patient reported residual L5 radicular symptoms. At last follow up, patient satisfaction, according to Modified Macnab Criteria, was excellent in 4/5 patients and good in 1/5 patient. In the 4 patients with greater than 1 year radiographic follow up, fusion rate was 100% on computed tomography (CT). Mean increase in posterior disk height was 12.5 mm (range, 11.4-13.5 mm). Mean reduction in spondylolisthesis was 58.7% (range, 20.2-100%). Mean segmental (L4-S1) and overall (L1-S1) lumbar lordosis increased by 23.6% (range, 6.5-41.7%) and 16.6% (2.5-31.5%), respectively. Following surgery, LL-PI mismatch decreased from a mean of 16.4 to 10.2 degrees. ALIF with posterior percutaneous instrumentation is a safe and effective treatment for high-grade lumbosacral spondylolisthesis in properly selected adults. This technique improves lumbar sagittal parameters and reduces spondylolisthesis. The indirect neural decompression from simultaneous disk height restoration and spondylolisthesis reduction may be associated with lower neurological injury rate compared to posterior-only. Future prospective study is needed to validate this hypothesis.

112. Degenerative disc disease and isthmic spondylolisthesis have similar outcomes after L5-S1 ALIF

BACKGROUND CONTEXT Anterior lumbar interbody fusion (ALIF) is a well-accepted surgical technique for lumbar spondylolisthesis and has been shown to have excellent radiographic and clinical outcomes. ALIF as a treatment for lumbar degenerative disc disease (DDD) is more controversial, with some authors reporting less reliable clinical improvement compared to other pathology. PURPOSE The purpose of this study is to compare the clinical outcomes of L5-S1 ALIF with posterior instrumentation in the setting of isthmic spondylolisthesis (IS) with L5-S1 ALIF for DDD. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE The study included 93 consecutive patients who underwent L5-S1 ALIF without direct posterior decompression for either IS (n=37) or DDD (n=56) identified. All patients who underwent ALIF for IS underwent percutaneous posterior instrumentation, while DDD patients had a stand-alone construct. OUTCOME MEASURES Baseline characteristics including age, sex, body mass index (BMI), and American Society of Anesthesiologists (ASA) physical status classification were reviewed and compared between groups. Preoperative/baseline clinical outcome measures, including visual analog scale (VAS), Short Form 12 (SF-12), Oswestry Disability index (ODI), and Veterans RAND 12 (VR-12), were collected and compared to postoperative measures at a minimum of 6 months. METHODS Changes in outcome measures from preoperative to final postoperative visit were calculated and compared between IS and DDD groups. Proportions of patients who reached minimum clinically important differences (MCID) in VAS and ODI were compared between IS and DDD groups. Bivariate and multivariate logistic regression were used to control for baseline differences in patient characteristics. RESULTS There were no significant differences between IS and DDD groups in terms of age, sex, and ASA score (p>0.05). There was a small, but statistically significant, difference in BMI between IS and DDD groups (27.32 vs 29.99, respectively, p=0.012). There were no significant differences in preoperative VAS-back, VAS-leg, and ODI between IS and DDD groups (p>0.05, Table 2). DDD patients had a lower preoperative SF-12 and VR-12 compared to IS patients (p=0.011 and p=0.01, respectively). At final follow-up, IS patients had better VAS-back, ODI, SF-12, and VR-12 scores compared to DDD patients, with no significant difference in VAS-leg scores. When comparing change from preoperative scores to final follow-up, there were no significant differences in improvement in terms of VAS, ODI, SF-12, and VR-12 between IS and DDD groups. IS and DDD groups had similar proportions of patients who achieved MCID in terms of VAS-back, VAS-leg, and ODI. CONCLUSIONS Although DDD patients have worse preoperative and postoperative clinical measures compared to IS patients, patients with DDD achieve similar levels of clinical improvement after ALIF compared to patients with IS. Additionally, DDD patients were just as likely as IS patients to achieve MCID at final follow-up after ALIF. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Scoliosis surgery in adulthood: what challenges for what outcome?

Adolescent idiopathic scoliosis that has progressed over time, de novo scoliosis, and degenerative scoliosis represent different types of adult spinal deformity (ASD). Functional impairment and muscular fatigue are due to sagittal and coronal imbalance of the trunk. Surgical treatment can provide a significant improvement of three-dimensional (3D) thoracolumbar alignment, function, and health-related quality of life (QoL). A patient-specific benefit-risk assessment, including clinical expectations, comorbidities, and the spinal deformity itself, has to be done preoperatively since the risk for mechanical complications is relatively high. Minimal invasive techniques combine posterior percutaneous instrumentation and lateral interbody fusion cages which enables vertebral realignment and indirect foraminal stenosis decompression. This strategy seems appropriate in mild and moderate ASD with a limited number of degenerated segments in the lumbar spine and remaining curve flexibility. Severe ASD needs to be addressed by open surgery, which combines posterior instrumentation, interbody fusion, and osteotomies in stiff deformities. Longer posterior instrumentation of the thoracolumbar spine, the sacrum, and the pelvis carries a risk for mechanical complications such as non-union and proximal junctional kyphosis (PJK). Modern surgical techniques including circumferential lumbosacral fusion and double rods might lower the risk for non-union. Accurate sagittal alignment planning, setting the lumbar sagittal apex according to pelvic incidence, and segmental lordosis distribution, are mandatory for minimizing the risk of PJK.

The Feasibility of Long-Segment Fluoroscopy-guided Percutaneous Thoracic Spine Pedicle Screw Fixation, and the Outcome at Two-year Follow-up.

Introduction: Posterior percutaneous instrumentation may represent a challenge when multiple levels need to be instrumentated, especially when including the upper thoracic spine. The aim of the present study was to evaluate the technical feasibility and the long-term outcome of such long constructs in different surgical conditions.Materials and Methods: This investigation was a retrospective cohort study which included patients who underwent thoraco-lumbar percutaneous fixations. We collected clinical, surgical and radiological data, with a minimum follow-up of 24 months. Health-related quality-of-life, residual pain, instrumentation placement, and complications were studied.Results: A total of 18 procedures were enrolled, in which 182 screws were implanted, (170 positioned in thoracic and 12 in lumbar pedicles, respectively). No surgical complications or hardware failure occurred in our series, 6 out of 182 (3,2%) screws had a partial pedicle breach, without neurological impairment or need for surgical revision.Conclusion: According to our results, a fully posterior percutaneous approach for long thoraco-lumbar spine instrumentation can be considered safe and reproducible, although an adequate training is strictly required.

Oblique Lumbar Interbody Fusion Combined with Minimally Invasive Percutaneous Posterior Instrumentation for Adult Spinal Deformity

Minimally invasive surgery(MIS)for adult spinal deformity(ASD)is aimed at minimizing perioperative and postoperative complications. However, MIS techniques have been reported to result in suboptimal sagittal plane correction or pseudoarthrosis when used for severe deformities. The authors present their early experience with circumferential MIS(cMIS), which involves oblique lumbar interbody fusion(OLIF)with percutaneous pedicle screw(PPS)fixation using a rod cantilever technique to enhance lumbar lordosis(LL)for ASD. Twenty-one thoracolumbar ASD cases in which surgical correction was performed from the lower thoracic spine corresponded to class IIIa in the modified minimally invasive spinal deformity surgery(MISDEF)algorithm. Patients with a rigid curve and prior fusion were excluded. Surgery was performed in 2 stages. During the first stage, OLIF was performed from L1/2 or Th12/L1 to L4/5. After 4 to 7 days, the patients were re-imaged with standing radiography, and the second-stage surgery was performed with L5/S1 posterior lumbar interbody fusion(PLIF)and percutaneous instrumentation from the lower thoracic spine to the pelvis. Radiological deformity correction at 4 weeks and perioperative complications were evaluated. Scatter plots were created for comparison of preoperative and postoperative sagittal spinopelvic parameters. The patients' mean age was 75 years. The mean operative time was 488 min, and the blood loss was 901 mL. Significant improvement in the spinopelvic parameters were found on the preoperative images of the sagittal vertical axis(SVA)(108mm to 33.5 mm), lumbar lordosis(LL)(18° to 48°), pelvic tilt(PT)(31.8° to 19.2°), and Cobb angle(CA)(21.1° to 11.9°). The change from the preoperative to the postoperative sagittal spinopelvic parameters(SVA, PI-LL, and PT)strongly correlated with preoperative values. As cMIS resulted in improvement in spinopelvic parameters and no major complications, this technique could provide a safe and effective strategy to manage ASD even with severe sagittal imbalance.

A Less Invasive Technique for Correction of Thoracolumbar Sagittal Deformity in Ankylosing Spondylitis

Background Data: Ankylosing spondylitis (AS) is a chronic inflammatory disease that can severely alter the normal spinal sagittal balance resulting in functional and social disability. Although the traditional open corrective techniques have provided a great radiographic improvement, they are associated with relatively high morbidity and mortality in an already vulnerable patient with several medical comorbidities. Therefore, a new less invasive technique has been developed in an attempt to achieve both radiographic and clinical improvement while minimizing the possible surgical risks of conventional open approaches.Purpose: To present an innovative less invasive technique for management of thoracic and/or lumbar sagittal imbalance in AS and to evaluate the morbidity, clinical results and radiographic correction following the use of this technique.Study design: Retrospective analysis of prospectively collected data.Methods: Between September 2008 and September 2013, 51 patients (43 males and 8 females) with thoracic and/or lumbar sagittal imbalance due to AS were operated upon. Those patients underwent minimally invasive dorso-ventral osteotomy and reconstruction plus posterior percutaneous instrumentation in the same prone position. Sagittal vertical axis (SVA), T1 pelvic angle (TPA), angle of fusion levels (AFL) and chin-brow vertical angle (CBVA) were used to evaluate radiographic outcomes and degree of correction. Clinical outcomes were assessed by Oswestry Disability Index (ODI) and visual analogue scale (VAS).Results: The mean age at operation was 49.02 years. The mean operative time was 419.31 min with a mean blood loss of 698.24 ml. One third of the patients underwent more than one single dorso-ventral osteotomy. All clinical and radiographic parameters (except for PI) showed a statistically significant improvement after surgery (P 30% improvement from the baseline ODI. Moreover, the changes in ODI were significantly related to the changes in SVA, TPA, AFL and CBVA. Dural tear and transient radiculopathy were the most common complications.onclusion: This technique has obvious advantages in reducing blood loss, optimizing correction and reconstruction, facilitating the postoperative course, and providing satisfactory clinical outcomes. We believe that this novel technique, although technically demanding, offers a safe and effective alternative for traditional open surgery in managing thoracic and/or lumbar sagittal imbalance due to AS. (2018ESJ159)

Thoracoscopically Assisted Vertebral Reconstruction Simultaneously with Percutaneous Pedicle Screws Fixation for Management of Thoracic and Thoracolumbar Spinal Fractures.

Background Data: Thoracic and thoracolumbar fractures are commonly provoked by axial compression which disrupts the anterior column. In this setting, posterior stabilization using pedicle screws alone may lead to delayed kyphosis and hardware failure due to inadequate anterior column support. Application of thoracoscopic anterior column reconstruction while patient in prone position for posterior percutaneous instrumentation is a minimally invasive combined technique.Purpose: To evaluate the outcome of percutaneous pedicle screw instrumentation in combination with thoracoscopically assisted vertebral reconstruction using expandable titanium cage.Study Design: Prospective clinical case study.Patients and Methods: Eighteen patients with acute thoracolumbar fractures with different preoperative neurological status were recruited for this study. Patients were treated using a short segment percutaneous screw fixation construct combined with thoracoscopic corpectomy and insertion of expandable cage. Patients were followed for at least 6 months. Visual analogue scale (VAS), Oswestry disability index (ODI) and local kyphotic angle were recorded prospectively and compared to preoperative parameters. Intraoperative data including operative time, blood loss and perioperative complication was documented.Results: Patients were operated within 7 days after trauma using combined anterior and posterior stabilization technique. Mean operative time was 213±42 min (Range, 170-300). The mean blood loss was 225±79 ml (Range, 100-350). The mean VAS score improved significantly after surgery. The mean of ODI preoperatively was 74±6.9 preoperatively and improved after 6 months to become 17.5±14.6. The mean regional kyphotic angle was 22.6±6.82ᴼ preoperatively, improved to 6.9±4.1ᴼ postoperatively and at final follow-up it became 8.67±4.8ᴼ. No patient had neurological deterioration or hardware failure during ≥6 months of follow up.Conclusion: our data suggest that thoracoscopic anterior reconstruction and decompression augmented with posterior percutaneous in prone position yield good clinical and radiological results with minimal complications in thoracolumbar trauma. (2018ESJ158)

Minimally invasive reduction and percutaneous posterior fixation of one-level traumatic thoraco-lumbar and lumbar spine fractures

Although open procedures are the gold standard, the alternative approach of minimal invasive reduction using percutaneous screws for thoracic and lumbar spine fractures is under discussion. Aim of this study was to investigate the results of reduction and the accuracy of screw placement in minimally invasive percutaneous posterior instrumentation for these fractures. One hundred and twenty-seven patients with thoraco-lumbar and lumbar burst fractures and minimal invasive dorsal instrumentation were analyzed retrospectively in terms of the accuracy of pedicle screw placement and results of fracture reduction. In total, 542 screws were placed. Thirty-four (6.3%) screws of 22 patients (17.3%) were misplaced, but misplacement was minimal, replacement of any screw position due to instability was not necessary, and no new neurological deficit occurred. In thoraco-lumbar fractures (82/64.5%), reduction succeeded from 2.5 ± 6° kyphosis to 5.6 ± 5.7° lordosis (p < 0.001) and in lumbar spine fractures from 6.9° ± 10.3° lordosis to 14.5° ± 8.8° lordosis (p < 0.001). Minimal invasive percutaneous dorsal instrumentation of burst fractures of the thoraco-lumbar and lumbar spine provides adequate reduction and reliable regular screw placement. Level IV (retrospective series).

Short-term outcomes of lateral lumbar interbody fusion without decompression for the treatment of symptomatic degenerative spondylolisthesis at L4-5.

OBJECTIVE Recently, authors have called into question the utility and complication index of the lateral lumbar interbody fusion procedure at the L4-5 level. Furthermore, the need for direct decompression has also been debated. Here, the authors report the clinical and radiographic outcomes of transpsoas lumbar interbody fusion, relying only on indirect decompression to treat patients with neurogenic claudication secondary to Grade 1 and 2 spondylolisthesis at the L4-5 level. METHODS The authors conducted a retrospective evaluation of 18 consecutive patients with Grade 1 or 2 spondylolisthesis from a prospectively maintained database. All patients underwent a transpsoas approach, followed by posterior percutaneous instrumentation without decompression. The Oswestry Disability Index (ODI) and SF-12 were administered during the clinical evaluations. Radiographic evaluation was also performed. The mean follow-up was 6.2 months. RESULTS Fifteen patients with Grade 1 and 3 patients with Grade 2 spondylolisthesis were identified and underwent fusion at a total of 20 levels. The mean operative time was 165 minutes for the combined anterior and posterior phases of the operation. The estimated blood loss was 113 ml. The most common cage width in the anteroposterior dimension was 22 mm (78%). Anterior thigh dysesthesia was identified on detailed sensory evaluation in 6 of 18 patients (33%); all patients experienced resolution within 6 months postoperatively. No patient had lasting sensory loss or motor deficit. The average ODI score improved 26 points by the 6-month follow-up. At the 6-month follow-up, the SF-12 mean Physical and Mental Component Summary scores improved by 11.9% and 9.6%, respectively. No patient required additional decompression postoperatively. CONCLUSIONS This study offers clinical results to establish lateral lumbar interbody fusion as an effective technique for the treatment of Grade 1 or 2 degenerative spondylolisthesis at L4-5. The use of this surgical approach provides a minimally invasive solution that offers excellent arthrodesis rates as well as favorable clinical and radiological outcomes, with low rates of postoperative complications. However, adhering to the techniques of transpsoas lateral surgery, such as minimal table break, an initial look-and-see approach to the psoas, clear identification of the plexus, minimal cranial caudal expansion of the retractor, mobilization of any traversing sensory nerves, and total psoas dilation times less than 20 minutes, ensures the lowest possible complication profile for both visceral and neural injuries even in the narrow safe zones when accessing the L4-5 disc space in patients with degenerative spondylolisthesis.