Lumbar Facet Arthroplasty Versus Fusion for Grade-I Degenerative Spondylolisthesis with Stenosis: A Prospective Randomized Controlled Trial.

BACKGROUND: The comparative effectiveness of decompression plus lumbar facet arthroplasty versus decompression plus instrumented lumbar spinal fusion in patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis is unknown. METHODS: In this randomized, controlled, Food and Drug Administration Investigational Device Exemption trial, we assigned patients who had single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo decompression plus lumbar facet arthroplasty (arthroplasty group) or decompression plus fusion (fusion group). The primary outcome was a predetermined composite clinical success score. Secondary outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS) back and leg pain, Zurich Claudication Questionnaire (ZCQ), Short Form (SF)-12, radiographic parameters, surgical variables, and complications. RESULTS: A total of 321 adult patients were randomized in a 2:1 fashion, with 219 patients assigned to undergo facet arthroplasty and 102 patients assigned to undergo fusion. Of these, 113 patients (51.6%) in the arthroplasty group and 47 (46.1%) in the fusion group who had either reached 24 months of postoperative follow-up or were deemed early clinical failures were included in the primary outcome analysis. The arthroplasty group had a higher proportion of patients who achieved composite clinical success than did the fusion group (73.5% versus 25.5%; p < 0.001), equating to a between-group difference of 47.9% (95% confidence interval, 33.0% to 62.8%). The arthroplasty group outperformed the fusion group in most patient-reported outcome measures (including the ODI, VAS back pain, and all ZCQ component scores) at 24 months postoperatively. There were no significant differences between groups in surgical variables or complications, except that the fusion group had a higher rate of developing symptomatic adjacent segment degeneration. CONCLUSIONS: Among patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, lumbar facet arthroplasty was associated with a higher rate of composite clinical success than fusion was at 24 months postoperatively. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Evolution of the Transforaminal Lumbar Interbody Fusion (TLIF): From Open to Percutaneous to Patient-Specific.

The transforaminal lumbar interbody fusion (TLIF) has seen significant evolution since its early inception, reflecting advancements in surgical techniques, patient safety, and outcomes. Originally described as an improvement over the posterior lumbar interbody fusion (PLIF), the TLIF began as an open surgical procedure, that notably reduced the need for the extensive neural retractation that hindered the PLIF. In line with the broader practice of surgery, trending toward minimally invasive access, the TLIF was followed by the development of the minimally invasive TLIF (MIS-TLIF), a technique that further decreased tissue trauma and postoperative complications. Subsequent advancements, including Trans-Kambin's Triangle TLIF (percLIF) and transfacet LIF, have continued to refine surgical access, minimize surgical footprint, and reduce the risk of injury to the patient. The latest evolution, as we will describe it, the patient-specific TLIF, is a culmination of the aforementioned adaptations and incorporates advanced imaging and segmentation technologies into perioperative planning, allowing surgeons to tailor approaches based on individual patient anatomy and pathology. These developments signify a shift towards more precise methods in spine surgery. The ongoing evolution of the TLIF technique illustrates the dynamic nature of surgery and emphasizes the need for continued adaptation and refinement.

Catheter Tip-Associated Mass With Continuous Infusion of Sufentanil for Persistent Spinal Pain Syndrome Type 2: A Case Report Including Histopathologic Examination and Review of the Associated Basic and Clinical Research.

OBJECTIVES: Intrathecal opioids delivered by implanted pumps are used to treat malignant or nonmalignant chronic pain. In this study, we 1) review a case in which intrathecal infusions of sufentanil along with other adjuvants were used and after an extended period led to an intrathecal mass and 2) compared and contrasted the potential mechanisms for these phenomena. MATERIALS AND METHODS: A woman aged 66 years with a history of scoliosis and multiple spine surgeries was treated with an implantable drug delivery system for treating persistent pain after laminectomy. The patient received intrathecal medication comprising sufentanil, bupivacaine, and clonidine. RESULTS: Intrathecal therapy over approximately ten years served to reduce pain and improve function over the treatment period. After the extended treatment interval, the patient developed an intrathecal mass that was associated with impairment. The mass was surgically removed. Systematic histopathology revealed the space-occupying mass to largely comprise fibroblasts and some inflammatory cells embedded in a collagen mass located proximally to the catheter tip. CONCLUSIONS: To our knowledge, this is the first published case report of sufentanil causing this complication. The science and mechanism of intrathecal catheter tip-associated mass formation and associated clinical research correlates are reviewed in detail, and explanations for this phenomenon are proposed based on histochemical analysis of the patient's pathology findings.

Geriatric Surgery Produces a Hypoactive Molecular Phenotype in the Monocyte Immune Gene Transcriptome.

Surgery is a major challenge for the immune system, but little is known about the immune response of geriatric patients to surgery. We therefore investigated the impact of surgery on the molecular signature of circulating CD14+ monocytes, cells implicated in clinical recovery from surgery, in older patients. We enrolled older patients having elective joint replacement (N = 19) or spine (N = 16) surgery and investigated pre- to postoperative expression changes in 784 immune-related genes in monocytes. Joint replacement altered the expression of 489 genes (adjusted p < 0.05), of which 38 had a |logFC| > 1. Spine surgery changed the expression of 209 genes (adjusted p < 0.05), of which 27 had a |logFC| > 1. In both, the majority of genes with a |logFC| > 1 change were downregulated. In the combined group (N = 35), 471 transcripts were differentially expressed (adjusted p < 0.05) after surgery; 29 had a |logFC| > 1 and 72% of these were downregulated. Notably, 21 transcripts were common across procedures. Thus, elective surgery in older patients produces myriad changes in the immune gene transcriptome of monocytes, with many suggesting development of an immunocompromised/hypoactive phenotype. Because monocytes are strongly implicated in the quality of surgical recovery, this signature provides insight into the cellular and molecular mechanisms of the immune response to surgery and warrants further study as a potential biomarker for predicting poor outcomes in older surgical patients.

Genomic analysis of spinal meningiomas: correlation with histopathological grade.

OBJECTIVE: Spinal meningiomas are one of the most common primary intradural tumors of the adult spine. Spinal meningiomas typically have a benign course with low rates of recurrence. Recent advances in genomic profiling have provided valuable information on meningioma biology and natural history, but these studies have focused primarily on cranial meningiomas. Chromosomal copy number analysis of meningiomas has been shown to be a valuable molecular profiling technique for distinguishing benign from aggressive tumors. The Integrated Grade for Meningioma is a novel grading scheme that uses mitotic index and copy-number profile to identify aggressive tumors at high risk for recurrence. The integrated grade has been shown to be a better predictor of tumor behavior than WHO grade alone. The objective of this study was to evaluate the chromosomal copy-number profile of spinal meningiomas, and to correlate these findings with the assigned WHO grades. METHODS: The authors evaluated 94 spinal meningiomas treated surgically at their institution between 2002 and 2022. The histopathological results including WHO grade, mitotic index, presence of atypical features, and MIB-1 index were recorded. Chromosomal copy number as determined by institutional whole-genome DNA copy-number profiling was available for 57 tumors. RESULTS: The WHO grades of the cohort consisted of 81 (86%) WHO grade 1 tumors and 13 (14%) WHO grade 2 tumors. In tumors for which copy-number profiling was available, 44 (77%) of 57 demonstrated loss of 22q/NF2. Notably absent were frequent high-risk copy number alterations including loss of 1p, 3p, 4p/q, 6p/q, 10p/q, 14q, 18p/q, 19p/q, and focal loss of CDKN2A on 9p. Of the 9 WHO grade 2 tumors for which copy-number profiling was available, 6 tumors were reclassified to a lower risk profile (integrated grade 1). CONCLUSIONS: This analysis suggests that spinal meningiomas exhibit overwhelmingly indolent biology, as supported by their benign integrated grade. These findings have implications in the surgical management of these patients in relation to the need for complete Simpson grade I resection, as well as the potential avoidance of adjuvant therapy following surgery in the setting of otherwise frequently benign pathology.

Two-Year Clinical and Radiographic Outcomes for Percutaneous Lumbar Interbody Fusion With an Expandable Titanium Cage Through Kambin's Triangle Without Facetectomy.

BACKGROUND: There has been heightened interest in performing percutaneous lumbar interbody fusions (percLIFs) through Kambin's triangle, an anatomic corridor allowing entrance into the disc space. However, due to its novelty, there are limited data regarding the long-term benefits of this procedure. Our objective was to determine the long-term efficacy and durability of the percutaneous insertion of an expandable titanium cage through Kambin's triangle without facetectomy. METHODS: A retrospective review of patients undergoing percLIF via Kambin's triangle using an expandable titanium cage was performed. Demographics, visual analog scale (VAS) scores, Oswestry Disability Index (ODI), radiographic measurements, perioperative variables, and complications were recorded. VAS, ODI, and radiographic measurements were compared with baseline using the generalized estimating equations assuming normally distributed data. Fusion was assessed with computed tomography (CT) at 1 and 2 years after the procedure. RESULTS: A total of 49 patients were included. Spondylolisthesis, lumbar lordosis (LL), sacral slope, pelvic tilt, and anterior/posterior disc space height were all significantly improved postoperatively at each time point of 3, 6, 12, and 24 months (P < 0.001). Pelvic incidence-LL mismatch decreased significantly at each follow-up (P < 0.001) with a mean reduction of 4° by 24 months. VAS back scores reduced by >2 points at the 6, 12, and 24 month follow-ups. ODI scores reduced by >15 points at the 12- and 24-month follow-ups. Of the patients who had 1- and 2-year CT images, fusion rates at those time points were 94.4% (17/18) and 87.5% (7/8), respectively. The mean annual rate of surgically significant adjacent segment disease was 2.74% through an average follow-up of 2.74 years. CONCLUSION: These results highlight that percLIF, a procedure done without an endoscope or facetectomy, can be performed using an expandable titanium cage through Kambin's triangle with excellent radiographic and clinical results. CLINICAL RELEVANCE: percLIF via Kambin's triangle is a safe and succesful procedure with long-term improvements in both clinical and radiographic outcomes.

Novel Approach to Percutaneous Lumbar Surgeries via Kambin's Triangle-Radiographic and Surgical Planning Analysis with Nerve Segmentation Technology.

OBJECTIVE: While Kambin's Triangle has become an ever more important anatomic window given its proximity to the exiting nerve root, there have been limited studies examining the effect of disease on the corridor. Our goal was to better understand how pathology can affect Kambin's Triangle, thereby altering the laterality of approach for percutaneous lumbar interbody fusion (percLIF). METHODS: The authors performed a single-center retrospective review of patients evaluated for percLIF. The areas of Kambin's Triangle were measured without and with nerve segmentation. For the latter, the lumbosacral nerve roots on 3-dimensional T2 magnetic resonance imaging were manually segmented. Next, the borders of Kambin's Triangle were delineated, ensuring no overlap between the area and nerve above. RESULTS: Fifteen patients (67.5 ± 9.7 years, 46.7% female) were retrospectively reviewed. We measured 150 Kambin's Triangles. The mean areas from L1-S1 were 50.0 ± 12.3 mm2, 73.8 ± 12.5 mm2, 83.8 ± 12.2 mm2, 88.5 ± 19.0 mm2, and 116 ± 29.3 mm2, respectively. When pathology was present, the areas significantly decreased at L4-L5 (P = 0.046) and L5-S1 (P = 0.049). Higher spondylolisthesis and smaller posterior disk heights were linked with decreased areas via linear regression analysis (P < 0.05). When nerve segmentation was used, the areas were significantly smaller from L1-L5 (P < 0.05). Among 11 patients who underwent surgery, none suffered from postoperative neuropathies. CONCLUSIONS: These results illustrate the feasibility of preoperatively segmenting lumbosacral nerves and measuring Kambin's Triangle to help guide surgical planning and determine the ideal laterality of approach for percLIF.

Prospective, randomized controlled multicenter study of posterior lumbar facet arthroplasty for the treatment of spondylolisthesis.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of a posterior facet replacement device, the Total Posterior Spine (TOPS) System, for the treatment of one-level symptomatic lumbar stenosis with grade I degenerative spondylolisthesis. Posterior lumbar arthroplasty with facet replacement is a motion-preserving alternative to lumbar decompression and fusion. The authors report the preliminary results from the TOPS FDA investigational device exemption (IDE) trial. METHODS: The study was a prospective, randomized controlled FDA IDE trial comparing the investigational TOPS device with transforaminal lumbar interbody fusion (TLIF) and pedicle screw fixation. The minimum follow-up duration was 24 months. Validated patient-reported outcome measures included the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. The primary outcome was a composite measure of clinical success: 1) no reoperations, 2) no device breakage, 3) ODI reduction of ≥ 15 points, and 4) no new or worsening neurological deficit. Patients were considered a clinical success only if they met all four measures. Radiographic assessments were made by an independent core laboratory. RESULTS: A total of 249 patients were evaluated (n = 170 in the TOPS group and n = 79 in the TLIF group). There were no statistically significant differences between implanted levels (L4-5: TOPS, 95% and TLIF, 95%) or blood loss. The overall composite measure for clinical success was statistically significantly higher in the TOPS group (85%) compared with the TLIF group (64%) (p = 0.0138). The percentage of patients reporting a minimum 15-point improvement in ODI showed a statistically significant difference (p = 0.037) favoring TOPS (93%) over TLIF (81%). There was no statistically significant difference between groups in the percentage of patients reporting a minimum 20-point improvement on VAS back pain (TOPS, 87%; TLIF, 64%) and leg pain (TOPS, 90%; TLIF, 88%) scores. The rate of surgical reintervention for facet replacement in the TOPS group (5.9%) was lower than the TLIF group (8.8%). The TOPS cohort demonstrated maintenance of flexion/extension range of motion from preoperatively (3.85°) to 24 months (3.86°). CONCLUSIONS: This study demonstrates that posterior lumbar decompression and dynamic stabilization with the TOPS device is safe and efficacious in the treatment of lumbar stenosis with degenerative spondylolisthesis. Additionally, decompression and dynamic stabilization with the TOPS device maintains segmental motion.

Spinal osteomyelitis and epidural abscess caused by ureterovertebral fistula: A case report.

Background: Ureteral fistulas are abnormal connections between the ureters and other organs. Maintaining a high index of suspicion is important because they can precipitate dangerous complications such as sepsis and renal failure. Connections to a vertebral body have only been documented in the setting of trauma. Here, we present a 67-year-old female with a ureterovertebral fistula extending into the L3 vertebral body. Case Description: A 67-year-old female with a history of endometrial adenocarcinoma underwent surgery and radiation therapy complicated by a right ureteral obstruction requiring stent placement. Five months later, she developed back pain and MR-documented L2-L4 level osteomyelitis/discitis with a psoas phlegmon/abscess, which required drainage. A fistula was later identified between the right ureter and the psoas phlegmon. Despite percutaneous nephrostomy placement and aggressive IV antibiotic treatment, she was readmitted for persistent signs of infection over the next few months during which time she was repeatedly and unsuccessfully treated with multiple antibiotics. Sixteen months following her original stent placement, she developed right leg weakness and urinary incontinence attributed to the MR-documented ureteropsoas fistula extending into the L3 vertebral body. Following a nephrectomy with ureteral ligation, an L3 anterior corpectomy with interbody fusion for discitis at both L2-L3 and L3-L4, and an L1-L5 posterolateral fusion, she was discharged to a rehabilitation center. Conclusion: In patients with recurrent sepsis, osteomyelitis/discitis, or psoas abscess of unknown origin or who have a significant history (e.g., pelvic malignancy, radiation, and instrumentation), it is important to consider urodynamic testing to look for a ureteral leak or fistula.

A Novel Mobile Device-Based Navigation System for Placement of Posterior Spinal Fixation.

BACKGROUND: Spinal navigation technology has revolutionized the field of spine surgery. However, adoption has not been universal. Reasons include cost, interruption in surgical workflow, increased OR time, and potential implant incompatibility, among others. A technology that maintains performance but alleviates these drawbacks would be valuable. A mobile device-based navigation system has been developed which relies on the iOS platform and the gyroscopic-on-chip technology, therein to guide accurate placement of pedicle screws. This system maintains a minimal footprint and resolves difficulty with line-of-sight interruption and attention shift. OBJECTIVE: To evaluate the accuracy and reliability of this device in a preclinical setting. METHODS: A cadaver study was performed involving 13 surgeons placing 26 pedicle screws using the novel assistive technology. CT scans were then performed, and accuracy was assessed by designating each screw a Gertzbein-Robbins score. In addition, bench top table testing was performed. This consisted of 360 tests of both the accuracy of the device's pitch and roll, corresponding to the rotation about the device's x-axis and y-axis, respectively. RESULTS: The mean Gertzbein-Robbins score of the 26 screws placed in the cadaver study was 1.29. The mean deviation from centerline pedicle placement was 0.66 mm, with a standard deviation of 1.52 mm. The bench top study results included a mean pitch error of 0.17° + 0.09° and a mean roll error of 0.29 + 0.21. CONCLUSION: The novel mobile device-based navigation system for placement of pedicle screws presented here demonstrates high levels of accuracy and reliability in the preclinical setting.

Multicentric Chordoma With Initial Resection by Bilateral Transcondylar Approach: 2-Dimensional Operative Video.

Chordoma is a rare skull base tumor with malignant behavior.1-3 It invades locally with high recurrences, metastasizes distally, and seeds after interventions.1-4 Chordoma exemplifies the malignant progression doctrine as it accumulated genetic mutations. The natural history of untreated disease is 2.4 yr on average survival.5 Best tumor control is achieved by radical resection, followed by high doses radiation. Multicentric chordoma is an ill-defined challenging entity extremely rare in the literature. However, chordoma is known for distal metastasis, particularly to the lungs, iatrogenic cerebrospinal fluid (CSF) dissemination with drop metastasis, or surgical implantation. A subset of patients present with synchronous or metachronous regional or distal neuraxial lesions associated with the initial chordoma. Patients presenting with multicentric bony axial lesions and no extra-axial metastases point toward the multicentric chordoma concept rather than local, hematogenous, or CSF spread.6-12 Biopsy of these multicentric lesions can show a spectrum of abnormalities ranging from benign notochordal tumor to chordomas confirming the multicentric hypothesis.9 We present a patient who underwent a bilateral transcondylar approach for giant craniovertebral junction chordoma and then treated with radiation and a second lesion at the C6 transverse foramen. Six years later, she presented with a chordoma at the petrous apex. The patient consented to surgery and to the publications of her image. The participants and any identifiable individuals consented to publication of his/her image. Image at 1:39 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.

Predictors of thoracic and lumbar spine injuries in patients with TBI: A nationwide analysis.

OBJECTIVE: Cervical spine injury screening is common practice for traumatic brain injury (TBI) patients. However, risk factors for concomitant thoracolumbar trauma remain unknown. We characterized epidemiology and clinical risk for concomitant thoracolumbar trauma in TBI. METHODS: We conducted a multi-center, retrospective cohort analysis of TBI patients in the National Trauma Data Bank from 2011-2014 using multivariable logistic regression. RESULTS: Out of 768,718 TBIs, 46,654 (6.1%) and 42,810 (5.6%) patients were diagnosed with thoracic and lumbar spine fractures, respectively. Only 11% of thoracic and 7% of lumbar spine fracture patients had an accompanying spinal cord injury at any level. The most common mechanism of injury was motor vehicle accident (67% of thoracic and 71% and lumbar fractures). Predictors for both thoracic and lumbar fractures included moderate (thoracic: OR 1.26, 95%CI 1.21-1.31; lumbar: OR 1.13, 95%CI 1.08-1.18) and severe Glasgow Coma Scale (GCS) score (OR 1.71, 95%CI 1.67-1.75; OR 1.17, 95%CI 1.13-1.20) compared to mild; epidural hematoma (OR 1.36, 95%CI 1.28-1.44; OR 1.1, 95%CI 1.04-1.19); lower extremity injury (OR 1.38, 95%CI 1.35-1.41; OR 2.50, 95%CI 2.45-2.55); upper extremity injury (OR 2.19, 95%CI 2.14-2.23; OR 1.15, 95%CI 1.13-1.18); smoking (OR 1.09, 95%CI 1.06-1.12; OR 1.12, 95%CI 1.09-1.15); and obesity (OR 1.39, 95%CI 1.34-1.45; OR 1.29, 95%CI 1.24-1.35). Thoracic injuries (OR 4.45; 95% CI 4.35-4.55) predicted lumbar fractures, while abdominal injuries (OR 2.02; 95% CI 1.97-2.07) predicted thoracic fractures. CONCLUSIONS: We identified GCS, smoking, upper and lower extremity injuries, and obesity as common risk factors for thoracic and lumbar spinal fractures in TBI.

Expandable Versus Static Cages in Minimally Invasive Lumbar Interbody Fusion: A Systematic Review and Meta-Analysis.

BACKGROUND: Expandable cages for interbody fusion allow for in situ expansion optimizing fit while mitigating endplate damage. Studies comparing outcomes after using expandable or static cages have been conflicting. METHODS: This was a meta-analysis A systematic search was performed in accordance with the Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines identifying studies reporting outcomes among patients who underwent minimally invasive lumbar interbody fusion (MIS-LIF). RESULTS: Fourteen articles with 1129 patients met inclusion criteria. Compared with MIS-LIFs performed with static cages, those with expandable cages had a significantly lower incidence of graft subsidence (expandable: incidence 0.03, I2 22.50%; static: incidence 0.27, I2 51.03%, P interaction <0.001), length of hospital stay (expandable: mean difference [MD] 3.55 days, I2 97%; static: MD 7.1 days, I2 97%, P interaction <0.01), and a greater increase in disc height (expandable: MD -4.41 mm, I2 99.56%; static: MD -0.79 mm, I2 99.17%, P interaction = 0.02). There was no statistically significant difference among Oswestry Disability Index (expandable: MD -22.75, I2 98.17%; static: MD -17.11, I2 95.26%, P interaction = 0.15), fusion rate (expandable: incidence 0.94, I2 0%; static incidence 0.92, I2 0%, P interaction = 0.44), overall change in lumbar lordosis (expandable: MD 3.48 degrees, I2 59.29%; static: MD 3.67 degrees, I2 0.00%, P interaction 0.88), blood loss (expandable: MD 228.9 mL, I2 100%; static: MD 261.1 mL, I2 94%, P interaction = 0.69) and operative time (expandable: MD 184 minutes, I2 95.32%; static: MD 150.4 minutes, I2 91%, P interaction = 0.56). CONCLUSIONS: Expandable interbody cages in MIS-LIF were associated with a decrease in subsidence rate, operative time and greater in increase in disc height.

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

STUDY DESIGN: 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. OBJECTIVE: 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. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Prospective validation of a clinical prediction score for survival in patients with spinal metastases: the New England Spinal Metastasis Score.

BACKGROUND CONTEXT: The New England Spinal Metastasis Score (NESMS) was proposed as an intuitive and accessible prognostic tool for predicting survival in patients with spinal metastases. We designed an appropriately powered, prospective, longitudinal investigation to validate the NESMS. PURPOSE: To prospectively validate the NESMS. STUDY DESIGN: Prospective longitudinal observational cohort study. PATIENT SAMPLE: Patients, aged 18 and older, presenting for treatment with spinal metastatic disease. OUTCOME MEASURES: One-year mortality (primary); 6-month mortality and mortality at any time point following enrollment (secondary). METHODS: The date of enrollment was set as time zero for all patients. The NESMS was assigned based on data collected at the time of enrollment. Patients were prospectively followed to one of two predetermined end-points: death, or survival at 365 days following enrollment. Survival was visually assessed with Kaplan-Meier curves and then analyzed using multivariable logistic regression, followed by Bayesian regression to assess for robustness of point estimates and 95% confidence intervals (CI). RESULTS: This study included 180 patients enrolled between 2017 and 2018. Mortality within 1-year occurred in 56% of the cohort. Using NESMS 3 as the referent, those with a score of 2 had significantly greater odds of mortality (odds ratio 7.04; 95% CI 2.47, 20.08), as did those with a score of 1 (odds ratio 31.30; 95% CI 8.82, 111.04). A NESMS score of 0 was associated with perfect prediction, as 100% of individuals with this score were deceased at 1-year. Similar determinations were encountered for mortality at 6-months and overall. CONCLUSIONS: This study validates the NESMS and demonstrates its utility in prognosticating survival for patients with spinal metastatic disease, irrespective of selected treatment strategy. This is the first study to prospectively validate a prognostic utility for patients with spinal metastases. The NESMS can be directly applied to patient care, hospital-based practice and health-care policy.

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

BACKGROUND: Interbody fusion is a widely utilized and accepted procedure to treat advanced debilitating lumbar degenerative disc disease (DDD). Increasingly, surgeons are seeking interbody devices that are large for stability and grafting purposes but can be inserted with less invasive techniques. To achieve these contrary objectives a novel, conformable mesh interbody fusion device was designed to be placed in the disc space through a small portal and filled with bone graft in situ to a large size. This design can reduce the risk of trauma to surrounding structures while creating a large graft footprint that intimately contours to the patient's own anatomy. The purpose of this Investigational Device Exempt (IDE) trial was to evaluate the perioperative and long-term results of this novel conformable mesh interbody fusion device. METHODS: This investigation is a prospective, multicenter, single-arm, Food and Drug Administration and Institutional Review Board-approved IDE, performance goal trial. A total of 102 adults presenting with DDD at a single level between L2 and S1 and unresponsive to 6 months conservative care had instrumented lumbar interbody fusion. Validated assessment tools include 100 mm visual analog scale for pain, Oswestry Disability Index (ODI) for function, single question survey for patient satisfaction, and computed tomography (CT) scan for fusion. Patients were enrolled across 10 geographically distributed sites. Pain/ODI surveys, physical evaluations, and imaging were performed serially through 24 months. Specifically, CT was performed at 12 and, if not fused, 24 months. Independent radiologists assessed CTs for fusion. An independent committee adjudicated adverse events. Patients with complete data at 24 months were included in the analysis. RESULTS: Ninety-six (96, 94% follow-up rate) patients (57.0 ± 12.0 years, 50.0% female, Body Mass Index 30.6 ± 4.9) reported average decreased low back pain 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 patients 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, and length of stay were 2.6 ± 0.9 hours, 137 ± 217 mL, and 2.3 ± 1.2 days, respectively. No device-related serious adverse events have occurred. CONCLUSIONS: Clinically significant outcomes for pain, function, fusion, and device safety were demonstrated in this population. Substantial clinical improvements occur by 6 weeks postoperative 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. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: This reports substantiates that the preliminary 1-year findings published earlier for this investigation are confirmed and the fusion rates and that patient improvements reported are sustained through 2 years.

Percutaneous Lumbar Interbody Fusion With an Expandable Titanium Cage Through Kambin's Triangle: A Case Series With Initial Clinical and Radiographic Results.

BACKGROUND: There has been an increased interest in lumbar interbody fusions through Kambin's triangle. In this study, we describe percutaneous access to the lumbar disc and insertion of an expandable titanium cage through Kambin's triangle without facetectomy. The objective of this study is to determine the feasibility as well as clinical and radiographical outcomes of completely percutaneous lumbar interbody fusion (percLIF) using an expandable titanium cage through Kambin's triangle. METHODS: A retrospective review of patients undergoing single-level percLIF for grade 1 lumbar spondylolisthesis via Kambin's triangle using an expandable titanium cage was performed. Demographic information, Oswestry Disability Index (ODI), preoperative and postoperative radiographic factors, perioperative data, and complications were recorded. Fusion was assessed with 1-year postoperative computed tomography scan or lumbar spine x-ray and defined as bridging disc or posterolateral fusion without evidence of hardware fracture or perihardware lucency. RESULTS: A total of 16 patients (3 males) were included in this study. Spondylolisthesis, anterior disc height, and posterior disc height were significantly improved at 6 weeks, 6 months, and 12 months, postoperatively (P < 0.05). ODI was significantly improved by 24.4% at 12 months postoperatively (P = 0.0036). One patient was readmitted within 30 days for pain control but otherwise there were no complications including permanent neurological injury, infection, deep vein thrombosis, pulmonary embolism, or cardiac events. Fifteen (93.8%) patients had radiographic fusion at their 1-year postoperative imaging. CONCLUSION: Our initial experiences have shown that percLIF can be performed using an expandable titanium cage through Kambin's triangle with excellent radiographic and clinical results. In this series, percLIF is a safe and clinically efficacious procedure for reducing grade 1 lumbar spondylolisthesis and improving radiculopathy. This procedure is completed percutaneously without the use of an endoscope. CLINICAL RELEVANCE: This study highlights improvements in outcomes of minimally invasive surgery. LEVEL OF EVIDENCE: IV.