Percutaneous Instrumentation Research Articles

Paraspinal muscle volume and fatty infiltration after circumferential minimally-invasive deformity correction

IntroductionParaspinal muscle robustness is an area of growing interest in spinal deformity that may impact biomechanical integrity and patient quality-of-life after reconstructive surgery. Changes in paraspinal musculature after circumferential minimally-invasive (cMIS) deformity correction have not yet been investigated. MethodsWe identified patients who underwent cMIS deformity correction and had lumbar spine MRIs at baseline and at minimum 1-year postoperatively. Using T2-weighted MRI, we measured total muscular volume of the psoas major, erector spinae, and multifidus muscles. We used the threshold method to determine fatty infiltration as percent fat area (PFA) along the length of these scanned regions, encompassing the final surgical construct. ResultsWe identified 10 patients who met inclusion criteria. On average, patients underwent interbody fusion at 3.8 ± 0.9 disc levels and posterior instrumentation at 4.6 ± 1.7 vertebral levels. All constructs included lateral interbody fusion (average 2.7 ± 0.8 levels); 6 were from a right-sided approach. Postoperative MRIs were obtained at 28 ± 14.2 months.There were no significant changes in pre- and postoperative volumes or PFA in any muscle group. There were no significant differences in left/right psoas volume or PFA in patients when stratified by side of lateral approach, nor did the number of lateral interbody fusion levels correlate with psoas volume or PFA. Change in posterior paraspinal musculature characteristics did not correlate with increasing number of fixated levels, nor significantly differ in patients who underwent posterior decompression. Preoperative muscle volumes were strongly correlated with postoperative volumes. ConclusionsIn this pilot series, paraspinal and psoas muscle volumes were preserved after circumferential MIS deformity correction. Fatty infiltration was not increased in paraspinal muscles after multi-level percutaneous instrumentation, nor in the psoas after multi-level trans-psoas approaches. These findings call for more in-depth investigation in a larger cohort of patients with comparison to open deformity correction patients to determine the impact of muscle volume changes on clinical outcomes.

Percutaneous lumbopelvic fixation is effective in the management of unstable transverse sacral fractures

ObjectivesHistorically, fractures causing lumbopelvic dissociation have been managed with open lumbosacral fusion and instrumentation. Our aim was to evaluate outcomes and complications following surgical management of unstable transverse sacral fractures with percutaneous lumbopelvic fixation. MethodsDesign: Retrospective case series. Setting: Academic Single Center, Level I Trauma Center. Patient Selection Criteria: Patients with lumbopelvic dissociation undergoing surgery. Outcome Measures and Comparisons: Patient demographics, mechanism of injury, ISS, associated injuries, radiographic classification (Roy-Camille), patient-reported outcomes (PROMIS PI, PF, D, and ODI), and complications were collected. Results27 patients were enrolled with an average follow-up of 18.7 ± 17.6 months and age of 54.4 ± 25.1 years. All patients underwent lumbar pedicle screw and iliac screw placement. Sacral laminectomy was performed if the patient had a preoperative neurological deficit. Patients were counseled on instrumentation removal at 6–12 months. 67 % of patients sustained a fall, and 33 % were involved in an MVA. 52 % were Roy-Camille Type 2, and 32 % and 20 % were Types 1 and 3, respectively. The mean EBL was 261 ± 400 ml. 37 % required concurrent sacral laminectomy. There were no intraoperative complications and four postoperative complications, including surgical site infection, rod dislodgment, and deep venous thrombosis. 63 % underwent removal of instrumentation after fracture healing. ODI scores significantly improved from 6 weeks post-op (35.5 ± 4.5) to one-year follow-up (18.3 ± 9.6, p = 0.005), two-year follow-up (20.3 ± 10.0, p = 0.03), and final follow-up (16.4 ± 8.8, p = 0.002). Statistically significant improvements were observed in the PROMIS PI, PF, and D domains (p < 0.05). ConclusionOur study demonstrates that lumbopelvic instrumentation leads to successful management of unstable transverse sacral fractures, with improvement in PRO. The combination of percutaneous instrumentation without arthrodesis did not result in any fracture non-union. Level of evidenceLevel IV

Risk Factors for Surgical Site Infections and the Effects of Betadine Irrigation and Intrawound Vancomycin Powder on Infection Rates in Spine Tumor Surgery.

Background Surgical site infection (SSI) following spine tumor surgery results in delays in radiation therapy and the initiation of systemic treatment.The study aims to assess risk factors for SSI in malignancy-related spinal infections and rates of infection observed in a single center with the use of betadine irrigation (BI) and intrawound vancomycin powder (IVP). Methods Spine tumor patients managed from 11/2012 to 11/2023 were identified using a surgical database (JotLogs, Efficient Surgical Apps, Portland, Maine). Inclusion criteria were patients receiving BI and IVP and alive at 30 days post-op.Exclusion criteria were patients not receiving a combination of BI and IVP due to allergies and mortality within 30 days of surgery. Patient demographics, histology, history of pre-operative and post-operative radiation treatment history, tumor location, procedure type, number of procedures per patient, SSI, wound culture results, and mortality were collected. Results One hundred two patients undergoing 130 procedures had an SSI rate of 3.85% (5/130).There were 18.6% primary and 81.4% metastatic tumors.Demographics were average age 59.5 years old (range 7-92), 60.8% male, 39.2% female, White 88.2%, Black 9.8%, and others 2%.Pre-operative radiation therapy was significantly associated with the risk of SSI (p=0.005). Percutaneous instrumentation did not lead to a significant difference in infection rates (p=0.139).There was no significant difference in infection rates between primary and metastatic tumors (p=0.58). Multivariable regression analysis revealed pre-operative radiation (OR: 18.1; 95%CI: 1.9-172.7; p=0.009) as the statistically significant independent risk factor. Conclusions Pre-operative radiation therapy remains a risk factor for SSI. However, percutaneous instrumentation did not lead to SSI, and there was no significant difference in infection rates between primary and metastatic tumors.SSI rate was3.85%in patients who had a combination of BI and IVPin spine tumor surgery.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion with Percutaneous Instrumentation: A Technical Note

Endoscopic spine surgery (ESS) has gained popularity in recent years due to its effectiveness and minimal invasiveness. In addition to decompression surgery, ESS has been used in lumbar fusion surgery to minimize tissue trauma and improve the fusion rate due to its ability to facilitate better endplate preparation under an endoscope. Biportal endoscopic transforaminal lumbar interbody fusion (BETLIF) has recently been proven to be a safe and efficient method with good clinical outcomes. We have adopted BETLIF to treat patients since 2021 and have experienced satisfactory results. In this article, we introduce our surgical steps and techniques for BETLIF with percutaneous instrumentation.

Percutaneous Screw Distraction for Anatomic Restoration: Case Series.

Percutaneous pedicle screw fixation with distraction reduces morbidity after traumatic thoracolumbar burst fractures; however, there are substantial limitations, particularly for correction of kyphosis. The use of fixed-angle screws may offer improved anatomic restoration, facilitating greater postdistraction vertebral height restoration and spinal canal fragment reduction. We examined the radiographic results of distraction across fixed-angle screws immediately after surgery and in long-term follow-up. Demographic and clinical characteristics were captured for patients with traumatic thoracolumbar fractures undergoing percutaneous pedicle screw fixation by a single surgeon. Radiographic measurements were collected at predistraction, postdistraction, and long-term follow-up time points. Paired t-tests, Student's t-tests, Mann-Whitney U tests, and χ2 tests were used to assess data where appropriate. The case series included 22 patients (77.3% male; mean age 42.0 ± 18.4 years). Hounsfield density consistent with osteopenia was seen in 13.6% of patients at the time of injury. Sporting injuries and motor vehicle accidents were common (both 31.8%). Most injuries occurred at L1 (45.5%). Upon long-term follow-up, the mean injured-level predistraction cross-sectional area improved from 2.1 to 2.9 cm2 (P < .01). Compared with the superadjacent level, the injured-level cross-sectional canal area improved by 28.6% (P < .01). Vertebral body index also improved significantly (18.8° mean change, P < .01). The mean bisegmental Cobb angle improved by 6.2° (P = .01), and injured vertebral body compression decreased by 22.4% (P < .01). Significant improvement in correction was achieved with experience, with final technique yielding superior cross-sectional area (P = .04) and compression ratios (P = .03). Distraction across fixed-angle percutaneous screw instrumentation systems stabilizes traumatic thoracolumbar burst fractures, corrects deformity, and decompresses the spinal canal. Further comparative research is necessary to demonstrate whether outcomes are different between percutaneous instrumentation vs open fusion for thoracolumbar trauma.

Evaluating a cutting-edge augmented reality-supported navigation system for spinal instrumentation

ObjectiveDorsal instrumentation using pedicle screws is a standard treatment for multiple spinal pathologies, such as trauma, infection, or degenerative indications. Intraoperative three-dimensional (3D) imaging and navigated pedicle screw placement are used at multiple centers. For the present study, we evaluated a new navigation system enabling augmented reality (AR)-supported pedicle screw placement while integrating navigation cameras into the reference array and drill guide. The present study aimed to evaluate its clinical application regarding safety, efficacy, and accuracy.MethodsA total of 20 patients were operated on between 06/2021 and 01/2022 using the new technique for intraoperative navigation. Intraoperative data with a focus on accuracy and patient safety, including patient outcome, were analyzed. The accuracy of pedicle screw placement was evaluated by intraoperative CT imaging.ResultsA median of 8 (4–18) pedicle screws were placed in each case. Percutaneous instrumentation was performed in 14 patients (70%). The duration of pedicle screw placement (duration scan–scan) was 56 ± 26 (30–107) min. Intraoperative screw revision was necessary for 3 of 180 pedicle screws (1.7%). Intraoperatively, no major complications occurred—one case of delay due to software issues and one case of difficult screw placement were reported.ConclusionThe current study's results could confirm the use of the present AR-supported system for navigated pedicle screw placement for dorsal instrumentation in clinical routine. It provides a reliable and safe tool for 3D imaging-based pedicle screw placement, only requires a minimal intraoperative setup, and provides new opportunities by integrating AR.

Minimally Invasive Fixation in Osteoporotic Vertebral Fractures: A Review Article

here are several surgical strategies which have been proposed to treat the osteoporotic patient with vertebral fracture, ranging from vertebral body cement augmentation, percutaneous/mini-open short segment pedicle screw fixation, and cortical bone trajectory screw to kyphotic deformity correction surgery. Minimally invasive spine surgery has the potential benefits of faster recovery, reduced blood loss, less postoperative wound pain, lower infection risk, and shorter length of hospital stay. Novel surgical techniques such as percutaneous instrumentation fixation, cortical bone trajectory technique, screw cement augmentation, and vertebral body augmentation are developed. However, various complications have been reported, including pedicle fracture, instrumentation loosening, adjacent-level disc degeneration with herniation, and progressive junctional kyphosis. The purpose of this review was to outline various advancements in minimally invasive spinal surgery for patients with osteoporosis. Minimally invasive surgical techniques for fixation including percutaneous instrumentation, cortical bone trajectory technique, screw cement augmentation, and vertebral body augmentation have benefited patient with osteoporosis. Studies and discussions about short-segment pedicle screw fixation (one level above and below the fracture level) have shown that it provides enough stability for thoracolumbar burst fractures. There are also complications, including cement embolism, adjacent vertebral fracture, neuraxial anesthesia, and infection, which have been observed with the above technique. With the advancement of instrument and technique, the complication rate decreased in recent studies. Minimally invasive fixation still has many advantages for patients with osteoporosis. Many of these studies and strategies only have evidence from biomechanical and cadaveric studies and require further clinical trials to establish their clinical efficacy.

The one-stop-shop approach: Navigating lumbar 360-degree instrumentation in a single position.

Treatment strategies of patients suffering from pyogenic spondylodiscitis are a controverse topic. Percutaneous dorsal instrumentation followed by surgical debridement and fusion of the infectious vertebral disc spaces is a common approach for surgical treatment. Technical advances enable spinal navigation for dorsal and lateral instrumentation. This report investigates combined navigated dorsal and lateral instrumentation in a single surgery and positioning for lumbar spondylodiscitis in a pilot series. Patients diagnosed with 1- or 2-level discitis were prospectively enrolled. To enable posterior navigated pedicle screw placement and lateral interbody fusion (LLIF) patients were positioned semi-prone in 45-degree fashion. For spinal referencing, a registration array was attached to the pelvic or spinal process. 3D scans were acquired intraoperatively for registration and implant control. 27 patients suffering from 1- or 2-level spondylodiscitis with a median ASA of 3 (1-4) and a mean BMI of 27.9 ± 4.9 kg/m2 were included. Mean duration of surgery was 146 ± 49 min. Mean blood loss was 367 ± 307 ml. A median of 4 (4-8) pedicle screws were placed for dorsal percutaneous instrumentation with an intraoperative revision rate of 4.0%. LLIF was performed on 31 levels with an intraoperative cage revision rate of 9.7%. Navigated lumbar dorsal and lateral instrumentation in a single operation and positioning is feasible and safe. It enables rapid 360-degree instrumentation in these critically ill patients and potentially reduces overall intraoperative radiation exposure for patient and staff. Compared to purely dorsal approaches it allows for optimal discectomy and fusion while overall incisions and wound size are minimized. Compared to prone LLIF procedures, semi-prone in 45-degree positioning allows for a steep learning curve due to minor changes of familiar anatomy.

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.

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.

Use of Minimally Invasive Spine Surgery in the Management of High-grade Thoracolumbar Spine Injuries

Objective: Spinal fractures often have devastating sequelae. Thoracolumbar fractures are classified using the Thoracolumbar Injury Classification and Severity score (TLICS) to determine the severity of injury and to guide treatment. Recently advancements in minimally invasive spine surgery (MISS) have led to new approaches to high-severity fractures. Studies have suggested that MISS may yield similar outcomes to conventional, more invasive procedures while producing several benefits.Methods: This retrospective study involves 46 patients treated from 2005 through 2020 for high grade thoracolumbar trauma from T2 to L5 with a minimum follow-up of 6-months treated with MISS techniques using percutaneous instrumentation. Results: Average TLICS was 7.5. Patient derived outcome measures with average length of follow-up of 602 days included Oswestry Disability Index 28.9, Patient Satisfaction Index 4.2, Short Form-12 Mental Component Score 51.9, and Short Form-12 Physical Component Score 37.7. Average estimated blood loss was 119.2 mL.Conclusion: The TLICS is a validated tool used to guide surgical intervention in high grade trauma. The utilization of MISS techniques for the treatment and stabilization of thoracolumbar trauma is efficacious and a viable alternative to traditional open approaches.

Percutaneous screw fixation versus open fusion for the treatment of traumatic thoracolumbar fractures: A retrospective case series of 185 Patients with a single-level spinal column injury

Study designRetrospective Single-Center Review of Data at a Level 1 Trauma Center. ObjectiveCompare deformity correction and surgical outcomes of percutaneous instrumentation and open fusion in traumatic thoracolumbar fractures. MethodsIn our retrospective study, all patients undergoing elective spine surgery for TL fractures at a Level 1 trauma center between 2000 and 2017 were reviewed. Patients who underwent percutaneous fixation were given the option of hardware removal after the fracture had healed. ResultsA total of 185 patients were included in the study, with 109 treated with an open fusion, and 76 with percutaneous fixation. Twenty-five patients in the latter group had the instrumentation removed after the fracture had healed. None of them required reoperation. In the open fusion group 54.1% of patients required a decompressive laminectomy. Percutaneous fixation patients had a shorter operative time (98.3 min vs 214 min, p < 0.0001), shorter length of stay (9.8 days vs 13.5 days, p = 0.04), and less blood loss (68.4 cc vs 691 cc, p < 0.001). They also had a better correction of their traumatic kyphosis after surgery (p = 0.005). ConclusionPercutaneous fixation is a valuable option for the treatment of TL fractures in cases without evidence of neural compression. It is still unclear whether hardware removal helps prevent adjacent segment degeneration. Percutaneous fixation could allow for better reduction of the fracture with improvement of postoperative alignment.

Incidence and risk factors associated with superior-segmented facet joint violation during minimal invasive lumbar interbody fusion

BACKGROUND CONTEXTThe trend of minimally invasive lumbar interbody fusion is increasing, and adjacent segmental degeneration (ASD) is one of the complications of the procedures in which facet joint violation (FJV) is a cause. FJVs can occur during percutaneous instrumentation. This study aimed to identify the risk factors that affect FJV during minimally invasive lumbar interbody fusion. PURPOSETo identify the risk factors for FJVs and the factors that have a strong impact on the violation. STUDY DESIGNRetrospective study. PATIENT SAMPLEPatients who underwent minimally invasive lumbar interbody fusion with percutaneous screw fixation between June 2018 and December 2019. OUTCOME MEASURESPrevalence of the FJV was reviewed by CT scans which obtained within 6 months after surgery, and the axial, coronal, and sagittal cuts of the scans were evaluated. The FJV was defined as the screw being visible in the facet joint in at least one plane of the CT scan. Radiographic parameters were measured using CT scans including diameters of the facet joints in the axial, coronal, and sagittal planes defined by the facet diameter. The facet angle (FA), the pedicle angle (PA), the screw-facet angle (SFA), the screw-endplate angle (SEA), and the superior margin of the facet joint in the sagittal plane (SD) differed from the head of the screw. At Last, the depth of back muscle was measured in the axial cut of the MRI. METHODSThis study analyzed 119 patients who underwent minimally invasive lumbar interbody fusion between June 2018 and December 2019. Facet joint violation at the uppermost level was examined using CT in all dimensions. Radiographic parameters (facet diameter, facet angle, pedicle angle, screw-facet angle, screw-endplate angle, and distance between the head of the screws and the facet) were measured. BMI, age, diagnosis, and navigation assistance were included in the study. Risk factors were analyzed to determine which factors had an effect on FJV, and the cut-off was calculated for each parameter. RESULTSThis study included 119 patients, with a mean age of 63 years. FJV occurred in 13/119 (10.9%) patients and 15/238 (6.3%) joints, respectively. No FJV occurred in 120 joints operated with navigation-assistance and 15/178 (8.4%) joints operated without navigation (p=.01). We found an increasing proportion of violations at more caudal levels: no violations occurred in eight patients with lumbar at L1 or L2, and 1/40 (2.5%), 7/158 (4.4%), and 7/32 (21.9%) of violations occurred at L3, L4, and L5, respectively (p=.01). The diameter of the facet in the axial cut, facet angle, screw facet angle, and distance between the head of the screw and facet were statistically significant in determining the increasing rate of FJV after multivariate analysis was performed (AROC=0.9486, p≤.05). The cutoff point for each radiographic parameter were diameter of facet in the axial ≥17.5 mm, diameter of facet in coronal plane ≥19.5 mm, facet angle ≥41.5o, screw-facet angle ≥39o, and distance between facet and the screw ≥-2.6 mm. The estimated probability of FJV was 96.9% when every parameter was greater than the cut-off point. CONCLUSIONSAn increase in the facet diameter in the axial plane, coronal plane, facet angle, screw facet angle, and the distance between the dome of the screw and facet are risk factors for FJV. Surgeons can avoid violations when radiographic considerations are done. Careful screw placement and good entry points for instrumentation may decrease the rate of facet violation.

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.

An updated management algorithm for incorporating minimally invasive techniques to treat thoracolumbar trauma.

Minimally invasive surgery (MIS) techniques can effectively stabilize and decompress many thoracolumbar injuries with decreased morbidity and tissue destruction compared with open approaches. Nonetheless, there is limited direction regarding the breadth and limitations of MIS techniques for thoracolumbar injuries. Consequently, the objectives of this study were to 1) identify the range of current practice patterns for thoracolumbar trauma and 2) integrate expert opinion and literature review to develop an updated treatment algorithm. A survey describing 10 clinical cases with a range of thoracolumbar injuries was sent to 12 surgeons with expertise in spine trauma. The survey results were summarized using descriptive statistics, along with the Fleiss kappa statistic of interrater agreement. To develop an updated treatment algorithm, the authors used a modified Delphi technique that incorporated a literature review, the survey results, and iterative feedback from a group of 14 spine trauma experts. The final algorithm represented the consensus opinion of that expert group. Eleven of 12 surgeons contacted completed the case survey, including 8 (73%) neurosurgeons and 3 (27%) orthopedic surgeons. For the 4 cases involving patients with neurological deficits, nearly all respondents recommended decompression and fusion, and the proportion recommending open surgery ranged from 55% to 100% by case. Recommendations for the remaining cases were heterogeneous. Among the neurologically intact patients, MIS techniques were typically recommended more often than open techniques. The overall interrater agreement in recommendations was 0.23, indicating fair agreement. Considering both literature review and expert opinion, the updated algorithm indicated that MIS techniques could be used to treat most thoracolumbar injuries. Among neurologically intact patients, percutaneous instrumentation without arthrodesis was recommended for those with AO Spine Thoracolumbar Classification System subtype A3/A4 (Thoracolumbar Injury Classification and Severity Score [TLICS] 4) injuries, but MIS posterior arthrodesis was recommended for most patients with AO Spine subtype B2/B3 (TLICS > 4) injuries. Depending on vertebral body integrity, anterolateral corpectomy or mini-open decompression could be used for patients with neurological deficits. Spine trauma experts endorsed a range of strategies for treating thoracolumbar injuries but felt that MIS techniques were an option for most patients. The updated treatment algorithm may provide a foundation for surgeons interested in safe approaches for using MIS techniques to treat thoracolumbar trauma.

Thoracolumbar Instrumentation Surgery in Patients with Parkinson's Disease: A Case-Control Study.

With increasing prevalence of Parkinson's disease (PD), instrumentation surgery of the thoracolumbar spine of PD patients grows in importance. Poor operative results with high rates of revision surgery have been reported. The goal of this study was to compare the biomechanical complications of thoracolumbar instrumentation surgery of patients with and without PD. In a retrospective case-control study, we compared 16 PD patients with a matched cohort of 104 control patients regarding the following postinstrumentation complications: (1) adjacent joint disease, (2) material failure, and (3) material loosening. Also, we compared the spinal bone density, which is the main prognostic criteria for failed instrumentation surgery, between the groups. We found the rate of material revision to be significantly higher in PD patients (43.8 vs. 13.5%, p = 0.008, odds ratio (OR) = 5.0). Furthermore, the indications for revision surgery differed between the groups, with more hardware failures in the PD group and more adjacent segment degeneration in the control group. PD patients profited from modern operation techniques (percutaneous instrumentation and CT-navigated screw implantation). Hospitalization was significantly longer for PD patients (20.2 ± 15.1 vs. 14.1 ± 8.9 days, p = 0.03). PD patients exhibit challenging biomechanical demands on instrumenting the spine. Besides osteoporosis, especially sagittal imbalance, gait disturbance, and altered muscle tone may be contributive. PD patients may particularly profit from navigated and less invasive surgical techniques.

Full-endoscopic debridement and drainage combined with percutaneous instrumentation for spondylodiscitis: Technical note

Full-endoscopic debridement and drainage combined with percutaneous instrumentation for spondylodiscitis: Technical note

The Role of Minimally Invasive Percutaneous Pedicle Screw Fixation for the Management of Spinal Metastatic Disease

Optimal surgical management of spinal metastatic disease remains controversial. Skip and diffuse spinal lesions, patient frailty, and the need for timely adjuvant chemoradiation complicate surgical decision-making. Minimally invasive percutaneous pedicle screw fixation (MIPSF) is an attractive concept that can confer stability and allow early postoperative mobilization. To date, outcomes of the MIPSF technique remain under-investigated. A single-center retrospective review of patients undergoing percutaneous instrumentation for multilevel spinal metastatic disease between January 2012 and October 2020 was performed. Twenty-four patients were identified, and their primary tumor diagnoses, modified Tokuhashi scores, Spine Instability Neoplastic Scores, neurologic functions, pain scores, and procedure types were noted. Of these patients, 17 underwent fixation of 6 or more levels (L-MIPSF), whereas 7 underwent fixation of <6 levels (S-MIPSF). All patients had screw-and-rod constructs placed percutaneously using bi-planar fluoroscopy guidance. Patients undergoing corpectomy, multilevel laminectomies, or open posterior instrumentation were excluded. Improvement in pain and neurological function was noted in nearly all patients who underwent MIPSF. Average skin incision-to-closing time was 130 minutes, and standard deviation of 55 minutes. Likewise, the average estimated operative blood loss was 402 mL, and standard deviation of 388 mL. Only one patient required hardware revision due to proximal loss of fixation. Two patients required mini-open decompression procedures due to tumor recurrence at different levels than the index pathology. Multilevel minimally invasive spinal fixation is feasible in patients with diffuse spinal metastasis. The percutaneous nature of the technique minimizes dissection, blood loss, and operative times. Early outcomes of MIPSF are promising and demonstrate utility in avoiding multiple subsequent procedures in a cohort of deconditioned patients.

PERCUTANEOUS INSTRUMENTATION WITHOUT ARTHRODESIS FOR THORACOLUMBAR BURST FRACTURES (A3/A4, B): A RETROSPECTIVE STUDY

ABSTRACT Objective: There is still no consensus as to the treatment options for thoracolumbar burst fractures, although these fractures are widely described in the literature. The aim of this study was to evaluate the clinical and radiological outcomes of percutaneous instrumentation without arthrodesis as a method of fixation of these lesions. Methods: This retrospective, cross-sectional study evaluated 16 patients by measuring regional kyphosis using the Cobb method and the scores for quality of life and return to work (Oswestry Disability Index, VAS, SF-36 and Denis). Results: Six months after surgical treatment, 62.5% of all patients showed minimal disability according to the Oswestry Disability Index, maintenance of regional kyphosis correction and no synthesis failure. Conclusions: The clinical and radiological outcomes of the study suggest that minimally invasive fixation is indicated for the treatment of thoracolumbar burst fractures. Level of evidence IV; Observational study: retrospective cohort.