Steinmetz, Michael P.

OBJECTIVE The optimal surgical treatment for lumbar spinal stenosis (LSS) with degenerative spondylolisthesis (DS) remains controversial. Posterior lumbar facet arthroplasty preserves motion after decompression and may address some of the limitations of fusion techniques. The Total Posterior Spine System (TOPS) investigational device exemption trial compared decompression with facet arthroplasty to decompression plus fusion (open with interbody). This study reports the 3-year outcomes from this trial. METHODS This randomized, controlled, multicenter trial enrolled 321 patients with LSS and grade I DS across 37 sites (2:1 randomization of arthroplasty to fusion). Eligible patients were 35–80 years old, had failed ≥ 6 months of nonsurgical treatment, and met thresholds for disability and leg pain. The primary endpoint was a composite clinical success score at 36 months, defined by four criteria: 1) no reoperation or lumbar injection, 2) no major device adverse events, 3) ≥ 15-point improvement in the Oswestry Disability Index (ODI), and 4) no new/progressive neurological deficit. Secondary outcomes included the ODI score, visual analog scale (VAS) scores for back and leg pain, the Zurich Claudication Questionnaire (ZCQ), device-related adverse events, and reoperations. RESULTS One hundred seventy-nine patients in the arthroplasty (TOPS) group and 74 in the fusion group were eligible for the 36-month analysis. The composite clinical success achievement rate was significantly higher in the arthroplasty group (76.0%) than in the fusion group (56.8%; p = 0.0038). The rate of reoperation or lumbar injection was significantly lower for the arthroplasty group (14.0%) compared to the fusion group (25.3%; p = 0.0222). Arthroplasty was associated with a significantly higher minimal clinically important difference (MCID) achievement rate for VAS back pain score compared with fusion (85.2% vs 72.2%; p = 0.041). Although there was no significant difference in ODI score, VAS leg pain score, or ZCQ component scores between groups, the arthroplasty group trended toward higher MCID achievement rates across all patient-reported outcome measures. There was no significant difference in reoperation failure rates between groups (5.8% for arthroplasty vs 9.5% for fusion; p = 0.329). CONCLUSIONS Decompression and dynamic stabilization with lumbar facet arthroplasty was associated with statistically significantly superior clinical outcomes and lower rates of secondary invasive procedures, including reoperations and injections, compared with decompression and fusion. Long-term follow-up is critical in defining the role of lumbar facet arthroplasty for the treatment of DS.

BACKGROUND Bertolotti syndrome is an underrecognized cause of chronic low back pain. Back pain generated from Bertolotti syndrome is believed to result from altered weight dissipation mechanics and/or instability of the pseudoarticulation, while local nerve root compression may result in radiculopathy. Here, the authors describe the findings of a patient with treatment-refractory low back pain found to have a cystic lesion arising from a Bertolotti joint causing L5 nerve root compression. To their knowledge, this has not been previously described in the literature. OBSERVATIONS Despite early recognition of Bertolotti syndrome, the patient’s back pain remained resistant to many years of both conservative and surgical management. The novel finding of a cyst arising from the pseudoarticulation complicated the management. The patient is scheduled to undergo further surgery this year. LESSONS This case highlights a pseudocyst associated with a Bertolotti joint. The cyst introduced additional clinical uncertainty to what is already an uncommon and difficult to treat condition. Resection of the Bertolotti joint failed to improve the patient’s symptoms. Postoperatively, a complex hemorrhagic pseudocyst was seen on imaging, possibly due to the pseudoarticulation with persistent motion. Ongoing efforts to characterize Bertolotti syndrome and its associated imaging findings are necessary to better optimize management strategies in these patients. https://thejns.org/doi/10.3171/CASE25948

The integration of mobile health (mHealth) technologies is transforming neurosurgery. Despite its potential, many uses remain unrealized due to the unique challenges and complexity of developing mHealth technology. While neurosurgeons bring invaluable clinical expertise and an understanding of patient needs, the technical intricacies of application development often require collaboration with developers and computer scientists, a process that can feel unfamiliar and difficult to navigate. The aim of this article was to demystify mHealth development by providing a guide for neurosurgeons seeking to develop disease-specific mHealth applications. We outline this process using the development of SynapTrack, an mHealth tool designed to provide objective assessments of degenerative cervical myelopathy, a chronic condition caused by symptomatic compression of the cervical spinal cord. This article offers neurosurgeons concrete guidance on navigating key considerations such as design decisions, algorithm integration, database architecture, and data security. By grounding these insights with SynapTrack, this guide offers a transparent view into the development process and provides a practical framework that can be adapted to the development of other mHealth tools. The aim of this work was to foster interdisciplinary collaboration and enable neurosurgeons to develop mHealth applications tailored to the specific needs of their specialty.

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.

OBJECTIVE The American Spine Registry (ASR) is a collaborative effort between the American Academy of Orthopaedic Surgeons and the American Association of Neurological Surgeons. The goal of this study was to evaluate how representative the ASR is of the national practice with spinal procedures, as recorded in the National Inpatient Sample (NIS). METHODS The authors queried the NIS and the ASR for cervical and lumbar arthrodesis cases performed during 2017–2019. International Classification of Diseases, 10th Revision and Current Procedural Terminology codes were used to identify patients undergoing cervical and lumbar procedures. The two groups were compared for the overall proportion of cervical and lumbar procedures, age distribution, sex, surgical approach features, race, and hospital volume. Outcomes available in the ASR, such as patient-reported outcomes and reoperations, were not analyzed due to nonavailability in the NIS. The representativeness of the ASR compared to the NIS was assessed via Cohen’s d effect sizes, and absolute standardized mean differences (SMDs) of < 0.2 were considered trivial, whereas > 0.5 were considered moderately large. RESULTS A total of 24,800 arthrodesis procedures were identified in the ASR for the period between January 1, 2017, and December 31, 2019. During the same time period, 1,305,360 cases were recorded in the NIS. Cervical fusions comprised 35.9% of the ASR cohort (8911 cases) and 36.0% of the NIS cohort (469,287 cases). The two databases presented trivial differences in terms of patient age and sex for all years of interest across both cervical and lumbar arthrodeses (SMD < 0.2). Trivial differences were also noted in the distribution of open versus percutaneous procedures of the cervical and lumbar spine (SMD < 0.2). Among lumbar cases, anterior approaches were more common in the ASR than in the NIS (32.1% vs 22.3%, SMD = 0.22), but the discrepancy among cervical cases in the two databases was trivial (SMD = 0.03). Small differences were illustrated in terms of race, with SMDs < 0.5, and a more significant discrepancy was identified in the geographic distribution of participating sites (SMDs of 0.7 and 0.74 for cervical and lumbar cases, respectively). For both of these measures, SMDs in 2019 were smaller than those in 2018 and 2017. CONCLUSIONS The ASR and NIS databases presented a very high similarity in proportions of cervical and lumbar spine surgeries, as well as similar distributions of age and sex, and distribution of open versus endoscopic approach. Slight discrepancies in anterior versus posterior approach among lumbar cases and patient race, and more significant discrepancies in geographic representation were also identified, yet decreasing trends in differences suggested the improving representativeness of the ASR over the course of time and its progressive growth. These conclusions are important to underline the external validity of quality investigations and research conclusions to be drawn from analyses in which the ASR is used.

Mobile health (mHealth) technology has assumed a pervasive role in healthcare and society. By capturing real-time features related to spine health, mHealth assessments have the potential to transform multiple aspects of spine care. Yet mHealth applications may not be familiar to many spine surgeons and other spine clinicians. Consequently, the objective of this narrative review is to provide an overview of the technology, analytical considerations, and applications of mHealth tools for evaluating spine surgery patients. Reflecting their near-ubiquitous role in society, smartphones are the most commonly available form of mHealth technology and can provide measures related to activity, sleep, and even social interaction. By comparison, wearable devices can provide more detailed mobility and physiological measures, although capabilities vary substantially by device. To date, mHealth evaluations in spine surgery patients have focused on the use of activity measures, particularly step counts, in an attempt to objectively quantify spine health. However, the correlation between step counts and patient-reported disease severity is inconsistent, and further work is needed to define the mobility metrics most relevant to spine surgery patients. mHealth assessments may also support a variety of other applications that have been studied less frequently, including those that prevent postoperative complications, predict surgical outcomes, and serve as motivational aids to patients. These areas represent key opportunities for future investigations. To maximize the potential of mHealth evaluations, several barriers must be overcome, including technical challenges, privacy and regulatory concerns, and questions related to reimbursement. Despite those obstacles, mHealth technology has the potential to transform many aspects of spine surgery research and practice, and its applications will only continue to grow in the years ahead.

Study Design: Prospective randomized Food and Drug Administration investigational device exemption clinical trial. Objective: The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device. Summary of Background Data: Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty. Methods: Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient. Results: At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points (P>0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening. Conclusions: Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate.

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.

Study Design: Narrative review. Objectives: Artificial intelligence (AI) and machine learning (ML) have emerged as disruptive technologies with the potential to drastically affect clinical decision making in spine surgery. AI can enhance the delivery of spine care in several arenas: (1) preoperative patient workup, patient selection, and outcome prediction; (2) quality and reproducibility of spine research; (3) perioperative surgical assistance and data tracking optimization; and (4) intraoperative surgical performance. The purpose of this narrative review is to concisely assemble, analyze, and discuss current trends and applications of AI and ML in conventional and robotic-assisted spine surgery. Methods: We conducted a comprehensive PubMed search of peer-reviewed articles that were published between 2006 and 2019 examining AI, ML, and robotics in spine surgery. Key findings were then compiled and summarized in this review. Results: The majority of the published AI literature in spine surgery has focused on predictive analytics and supervised image recognition for radiographic diagnosis. Several investigators have studied the use of AI/ML in the perioperative setting in small patient cohorts; pivotal trials are still pending. Conclusions: Artificial intelligence has tremendous potential in revolutionizing comprehensive spine care. Evidence-based, predictive analytics can help surgeons improve preoperative patient selection, surgical indications, and individualized postoperative care. Robotic-assisted surgery, while still in early stages of development, has the potential to reduce surgeon fatigue and improve technical precision.

Study Design: Systematic review. Objectives: Spinal epidural abscesses (SEAs) are rare, but when missed or when diagnosis is delayed, SEA can lead to permanent neurological impairment or death. Limited information exists on the optimal treatment modalities for SEA, especially in the lumbar spine. We synthesize the current literature to identify the clinical features, diagnosis, management, and outcomes of lumbar SEA. Methods: Queries in 4 databases—EMBASE, MEDLINE, Scopus, and Web of Science—were performed using comprehensive search terms to locate published literature on lumbar SEA. Results: Ten articles reporting results for 600 cases of lumbar SEA were included, published between 2000 and 2017. Negative prognostic factors included diabetes, older age, methicillin-resistant Staphylococcus aureus, immune compromise, and more severe disease at presentation. Early first-line surgically treated patients responded better, specifically in terms of motor recovery, than those undergoing medical management or failing medical treatment, despite generally worse initial presentation. Elevated C-reactive protein, leukocytosis, and positive blood cultures predicted medical management failure. Conclusions: This systematic review provides guidance to neurological and orthopedic spine surgeons seeking the best treatment for lumbar-localized SEA. This study is limited by a dearth of high-quality publications to support evidenced-based management recommendations. Surgical treatment appears to provide better outcomes than medical treatment alone, especially in those who present with a motor deficit. Further investigation is needed to confirm this finding. What is clear is that early recognition and treatment remains crucial to minimizing morbidity and mortality of SEA.