Economics of less invasive spinal surgery: an analysis of hospital cost differences between open and minimally invasive instrumented spinal fusion procedures during the perioperative period

Long-Term Outcomes of Minimally Invasive vs. Traditional Open Spinal Fusion: A Comparative Analysis

Spinal fusion is a widely performed surgical intervention for managing degenerative spinal conditions, instability, and deformities. Traditionally, open spinal fusion has been the standard approach, offering direct visualization and access to spinal structures. However, advancements in surgical techniques have led to the development of minimally invasive spinal fusion (MISF) as an alternative, aiming to achieve comparable clinical outcomes while reducing surgical trauma, postoperative pain, and recovery time. Despite these advantages, concerns remain regarding the long-term effectiveness of MISF, particularly in terms of fusion rates, complication risks, and adjacent segment disease (ASD). This review critically examines the long-term outcomes of MISF compared to traditional open fusion, focusing on key factors such as perioperative outcomes, pain relief, functional recovery, fusion success rates, and cost-effectiveness. Perioperative data indicate that MISF is associated with reduced blood loss, shorter hospital stays, and lower infection rates but may involve longer surgical times and a steeper learning curve. Long-term clinical outcomes appear comparable between MISF and open fusion, with both techniques achieving high fusion rates and significant improvements in pain and function. However, the impact of MISF on adjacent segment disease remains inconclusive, with conflicting evidence regarding its potential biomechanical advantages. Cost-effectiveness analyses suggest that MISF may offer financial advantages in the long term by reducing hospitalization and rehabilitation expenses, despite higher initial surgical costs. Nonetheless, limitations in current research, including variability in study methodologies, patient selection, and surgeon expertise, necessitate further high-quality, long-term randomized controlled trials. This review synthesizes the current literature on MISF and traditional open fusion, identifies existing research gaps, and outlines future directions for optimizing surgical decision-making and improving patient outcomes.

Modified single-incision MIS-TLIF with expandable tubular assistance for degenerative lumbar spine diseases

Objective

Evaluating the clinical value of the modified single-incision posterior median approach with expandable tubular assistance for lumbar interbody fusion in managing degenerative lumbar spine diseases.

Method

A retrospective analysis was conducted on 121 patients with single-level degenerative lumbar spine disease treated in our spine surgery department from January 2017 to December 2021. Of these, 72 patients underwent a modified single-incision posterior median approach with expandable tubular assistance lumbar interbody fusion (single-incision MIS-TLIF group), while 49 patients received the classic open posterior median incision P-TLIF (open surgery group). We collected basic demographic data including age, gender, BMI, and surgical level. Surgical-related indicators such as operation time, intraoperative blood loss, postoperative drainage, length of hospital stay, hospital costs, and complication rates were compared between the two groups. Laboratory results [whole blood C-reactive protein (CRP), serum creatine kinase (CK)] and clinical outcomes [VAS scores for low back and leg pain, Oswestry Disability Index (ODI), excellent and good rate according to the modified MacNab criteria, and interbody fusion rate according to the Brantigan criteria] were also evaluated.

Result

There were no significant differences in the basic demographics between the two groups. The operation time, postoperative hospital stay, and hospital costs were also similar between the groups. However, significant differences were observed in intraoperative blood loss, postoperative drainage, and complication rates. On postoperative days 1 and 3, whole blood CRP and CK levels showed marked differences between the groups. At 3, 6, and 12 months postoperatively, the single-incision MIS-TLIF group had lower ODI scores and VAS scores for back pain compared to the open surgery group. The excellent and good rate according to the MacNab criteria was higher in the single-incision MIS-TLIF group. There were no significant differences in leg pain VAS scores and interbody fusion rates at 12 months postoperatively between the groups.

Conclusion

The modified single-incision posterior median approach with expandable tubular assistance lumbar interbody fusion is highly effective in treating degenerative lumbar spine diseases. It results in less postoperative pain, faster recovery, and significant improvement in postoperative functional outcomes, making it a valuable treatment option.

Cost-Effectiveness and Clinical Outcomes of Lateral Lumbar Interbody Fusion With Tricalcium Phosphate and Iliac Bone Graft Compared With Posterior Lumbar Interbody Fusion With Local Bone Graft in Single-Level Lumbar Spinal Fusion Surgery in Thailand

BACKGROUND

Nowadays, minimally invasive lateral lumbar interbody fusion (LLIF) is used to treat degenerative lumbar spine disease. Many studies have proven that LLIF results in less soft tissue destruction and rapid recovery compared with open posterior lumbar interbody fusion (PLIF). Our recent cost-utility study demonstrated that LLIF was not cost-effective according to the Thai willingness-to-pay threshold, primarily due to the utilization of an expensive bone substitute: bone morphogenetic protein 2. Therefore, this study was designed to use less expensive tricalcium phosphate combined with iliac bone graft (TCP + IBG) as a bone substitute and compare cost-utility analysis and clinical outcomes of PLIF in Thailand.

METHODS

All clinical and radiographic outcomes of patients who underwent single-level LLIF using TCP + IBG and PLIF were retrospectively collected. Preoperative and 2-year follow-up quality of life from EuroQol-5 Dimensions-5 Levels and health care cost were reviewed. A cost-utility analysis was conducted using a Markov model with a lifetime horizon and a societal perspective.

RESULTS

All enrolled patients were categorized into an LLIF group (n = 30) and a PLIF group (n = 50). All radiographic results (lumbar lordosis, foraminal height, and disc height) were improved at 2 years of follow-up in both groups (P < 0.001); however, the LLIF group had a dramatic significant improvement in all radiographic parameters compared with the PLIF group (P < 0.05). The fusion rate for LLIF (83.3%) and PLIF (84%) was similar and had no statistical significance. All health-related quality of life (Oswestry Disability Index, utility, and EuroQol Visual Analog Scale) significantly improved compared with preoperative scores (P < 0.001), but there were no significant differences between the LLIF and PLIF groups (P > 0.05). The total lifetime cost of LLIF was less than that of PLIF (15,355 vs 16,500 USD). Compared with PLIF, LLIF was cost-effective according to the Thai willingness-to-pay threshold, with a net monetary benefit of 539.76 USD.

CONCLUSION

LLIF with TCP + IBG demonstrated excellent radiographic and comparable clinical health-related outcomes compared with PLIF. In economic evaluation, the total lifetime cost was lower in LLIF with TCP + IBG than in PLIF. Furthermore, LLIF with TCP + IBG was cost-effective compared with PLIF according to the context of Thailand.

CLINICAL RELEVANCE

LLIF with less expensive TCP + IBG as bone graft results in better clinical and radiographic outcomes, less lifetime cost, and cost-effectiveness compared with PLIF. This suggests that LLIF with TCP + IBG could be utilized in lower- and middle-income countries for treating patients with degenerative disc disease.

LEVEL OF EVIDENCE: 3

Bibliometric and trend analysis of the top 100 most-cited articles on lateral interbody fusion (LIF)

PURPOSE

Lateral interbody fusion (LIF) is an increasingly popular minimally-invasive spine procedure. This study identifies notable trends in LIF literature and provides a detailed review of the bibliometric aspects of the top 100 most-cited articles.

METHODS

Articles were queried from the Web of Science database. Inclusion criteria consisted of peer-reviewed articles, full-text availability, and LIF focus. Network analysis including co-authorship mapping and bibliographic coupling were complemented by trend analysis to determine prominent contributors and themes. Analyses were conducted using VOSviewer and Bibliometrix (RStudio).

RESULTS

There has been a rapid increase in LIF publication and citation count since 1998. Leading journals were Spine (n = 24), Journal of Neurosurgery Spine (n = 22), and European Spine Journal (n = 12). NuVasive funded the most publications (n = 17), followed by DePuy Synthes Spine (n = 4). The United States was the most represented country (n = 81); however, trend analysis suggests a steadily growing international contribution. The most prolific author was J.S. Uribe (n = 16), followed by a tie in second place by E. Dakwar and L. Pimenta (n = 8). The most frequent keywords, "complication" (n = 34), "surgery" (n = 30), and "outcomes" (n = 24), demonstrated a patient-centric theme.

CONCLUSIONS

This bibliometric analysis provides in-depth insights into the evolution and trends of LIF over the last two decades. The trends and themes identified demonstrate the innovative, collaborative, and patient-focused characteristics of this subfield. Future researchers can use this as a foundation for understanding the past and present state of LIF research while designing investigations.

An effectiveness and economic analyses of tricalcium phosphate combined with iliac bone graft versus RhBMP-2 in single-level XLIF surgery in Thailand

STUDY DESIGN

Retrospective study.

OBJECTIVES

To perform effectiveness and economic analyses using data from a retrospective study of patients who underwent XLIF surgery using tricalcium phosphate combined with iliac bone graft (TCP + IBG) or BMP-2 in Thailand.

METHODS

Data were collected from retrospective review of the medical charts and the spine registry of Siriraj Hospital, Bangkok, Thailand. The patients were divided into two groups (TCP + IBG group and BMP-2 group). Demographic, perioperative data, radiographic, clinical results, and quality of life related to health were collected and analyzed at 2-year follow-up. All economic data were collected during the perioperative period and presented as total charge, bone graft, implant/instrumentation, operative service, surgical supply, transfusion, medication, anesthesia, laboratory, and physical therapy.

RESULTS

Twenty-five TCP + IBG and 30 BMP-2 patients with spondylolisthesis and spinal stenosis as primary diagnosis were included. There were no significant differences in all demographic parameters (gender, age, underlying disease, diagnosis, and level of spine) between these two groups. During the perioperative period, the TCP + IBG group had more mean blood loss and more postoperative complications compared to the BMP-2 group. At 2 years of follow-up, there were no significant differences between the radiographic and clinical outcomes of the TCP + IBG and BMP-2 groups. The fusion rate for TCP + IBG and BMP-2 at 2 years of follow-up was 80% and 96.7%, respectively, and no statistically significant differences were observed. All clinical outcomes (Utility, Oswestry Disability Index, and EuroQol Visual Analog Scale) at 2-year follow-up improved significantly compared to preoperative outcomes, but there were no significant differences between the TCP + IBG and BMP-2 groups, either at preoperatively or at 2-year follow-up. The total charge of TCP + IBG was statistically significantly lower than that of BMP-2. Furthermore, the charges of TCP + IBG and BMP-2 during the perioperative period in Thailand were up to three times less than those in the United States.

CONCLUSIONS

Using TCP + IBG as a standalone bone substitution for XLIF surgery with additional posterior instrumentation resulted in significantly lower direct medical charge compared to those using BMP-2 in the perioperative period. However, we could not detect a difference in the long-term radiographic and clinical outcomes of patients with TCP + IBG and BMP-2. These suggest that TCP + IBG may be a valuable alterative bone graft, especially in low- and middle-income countries.

Lateral lumbar interbody fusion (LLIF) reduces total lifetime cost compared with posterior lumbar interbody fusion (PLIF) for single-level lumbar spinal fusion surgery: a cost-utility analysis in Thailand

BACKGROUND

Lumbar interbody fusion techniques treat degenerative lumbar diseases effectively. Minimally invasive lateral lumbar interbody fusion (LLIF) decreases soft tissue disruption and accelerates recovery better than standard open posterior lumbar interbody fusion (PLIF). However, the material cost of LLIF is high, especially in Thailand. The cost-effectiveness of LLIF and PLIF in developing countries is unclear. This study compared the cost-utility and clinical outcomes of LLIF and PLIF in Thailand.

METHODS

Data from patients with lumbar spondylosis who underwent single-level LLIF and PLIF between 2014 and 2020 were retrospectively reviewed. Preoperative and 1-year follow-up EuroQol-5D-5L and healthcare costs were collected. A cost-utility analysis with a lifetime time horizon was performed using a societal perspective. Outcomes are reported as the incremental cost-effectiveness ratio (ICER) and quality-adjusted life-year (QALY) gained. A Thai willingness-to-pay threshold of 5003 US dollars (USD) per QALY gained was used.

RESULTS

The 136 enrolled patients had a mean age of 62.26 ± 11.66 years. Fifty-nine patients underwent LLIF, while 77 underwent PLIF. The PLIF group experienced greater estimated blood loss (458.96 vs 167.03 ml; P < 0.001), but the LLIF group had a longer operative time (222.80 vs 194.62 min; P = 0.007). One year postoperatively, the groups' Oswestry Disability Index and EuroQol-Visual Analog Scale scores were improved without statistical significance. The PLIF group had a significantly better utility score than the LLIF group (0.89 vs 0.84; P = 0.023). LLIF's total lifetime cost was less than that of PLIF (30,124 and 33,003 USD). Relative to PLIF, LLIF was not cost-effective according to the Thai willingness-to-pay threshold, with an ICER of 19,359 USD per QALY gained.

CONCLUSIONS

LLIF demonstrated lower total lifetime cost from a societal perspective. Regard to our data, at the 1-year follow-up, the improvement in patient quality of life was less with LLIF than with PLIF. Additionally, economic evaluation modeling based on the context of Thailand showed that LLIF was not cost-effective compared with PLIF. A strategy that facilitates the selection of patients for LLIF is required to optimize patient benefits.

Systematic Review of Cost-Effectiveness Analyses Comparing Open and Minimally Invasive Lumbar Spinal Surgery

BACKGROUND

Minimally invasive surgery (MIS) has benefits over open surgery for lumbar decompression and/or fusion. Published literature on its cost-effectiveness vs open techniques is mixed.

OBJECTIVE

Systematically review the cost-effectiveness of minimally invasive vs open lumbar spinal surgical decompression, fusion, or discectomy using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

A systematic electronic search of databases (MEDLINE, Embase, and Cochrane Library) and a manual search from the cost-effectiveness analysis (CEA) database and National Health Service economic evaluation database was conducted. Studies that included adult populations undergoing surgery for degenerative changes in the lumbar spine (stenosis, radiculopathy, and spondylolisthesis) and reported outcomes of costing analysis, CEA, or incremental cost-effectiveness ratio were included.

RESULTS

A total of 17 studies were included. Three studies assessed outcomes of MIS vs open discectomy. All 3 reported statistically significant lower total costs in the MIS, compared with the open group, with similar reported gains in quality-adjusted life years (QALYs). Two studies reported cost differences in MIS vs open laminectomy, with significantly lower total costs attributed to the MIS group. Twelve studies reported findings on the relative direct costs of MIS vs open lumbar fusion. Among those, 3 of the 4 studies comparing single-level MIS-transforaminal lumbar interbody fusion (TLIF) and open TLIF reported lower total costs associated with MIS procedures. Six studies reported cost evaluation of single- and 2-level TLIF procedures. Lower total costs were found in the MIS group compared with the open fusion group in all studies except for the subgroup analysis of 2-level fusions in a single study. Three of these 6 studies reported cost-effectiveness (cost/QALY). MIS fusion was found to be more cost-effective than open fusion in all 3 studies.

CONCLUSION

The studies reviewed were of poor to moderate methodological quality. Generally, studies reported a reduced cost associated with MIS vs open surgery and suggested better cost-effectiveness, particularly in MIS vs open single- and 2-level TLIF procedure. Most studies had a high risk of bias. Therefore, this review was unable to conclusively recommend MIS over open surgery from a cost-effectiveness perspective.

CLINICAL RELEVANCE

The incidence of spinal decompressive and fusion surgey and financial constraints on healthcare services continue to increase. This study aims to identify the cost and clinical effectiveness of common approaches to spinal surgery.

LEVEL OF EVIDENCE

3a.

Comparison of Operative Time and Blood Loss With the FFX® Device Versus Pedicle Screw Fixation During Surgery for Lumbar Spinal Stenosis: A Retrospective Cohort Study

Background Pedicle screw (PS) placement can be associated with soft tissue damage and blood loss. The study objective was to evaluate differences in operative time and blood loss between PS fixation and an implantable facet fusion device in patients undergoing lumbar fusion surgery. Materials and methods A retrospective analysis was performed on patients undergoing lumbar fusion surgery with PS fixation or the lumbar Facet FiXation (FFX) device. Procedures were performed by the same surgeon at a single institution. The PS group included patients from 2016 and the FFX group included patients from 2018. Variables including age, sex, levels operated on, operative time, and operative blood loss were collected. Results A total of 70 patients were included in the study. Twenty-eight in the PS arm and 42 in the FFX arm. The PS group had a mean age of 67.5 ± 9.3 years compared to 70.4 ± 11.5 years for the FFX group. The PS group had a higher percentage of females (57.1%) versus the FFX group (31.0%); p = 0.025. Mean number of levels operated on were similar between the PS and FFX groups (2.3 ± 1 .1 vs. 2.2 ± 1.0, respectively; p = 0.89). Mean operative time was significantly longer for the PS group versus the FFX group (152.5 ± 39.4 vs. 99.4 ± 44.0 minutes; p < 0.001). Mean operative blood loss was significantly greater for the PS group versus the FFX group (446.5 ± 272.0 vs. 251.0 ± 315.9 mL; p < 0.01). Differences were independent of the number of levels operated on. Conclusion Placement of the FFX device is associated with a significant reduction in operative time and blood loss compared to PS fixation in patients undergoing spinal fusion surgery.

Overview of Robotic Technology in Spine Surgery

As robotics in spine surgery has progressed over the past 2 decades, studies have shown mixed results on its clinical outcomes and economic impact. In this review, we highlight the evolution of robotic technology over the past 30 years, discussing early limitations and failures. We provide an overview of the history and evolution of currently available spinal robotic platforms and compare and contrast the available features of each. We conclude by summarizing the literature on robotic instrumentation accuracy in pedicle screw placement and clinical outcomes such as complication rates and briefly discuss the future of robotic spine surgery.

A Prospective Randomized Study of the Safety and Efficacy of Transforaminal Lumbar Interbody Fusion Versus Posterior Lumbar Interbody Fusion in the Treatment of Lumbar Spondylolisthesis: A Cost utility from a Lower-middle-income Country Perspective and Review of Literature

BACKGROUND: The safety and efficacy of transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) in lumbar spondylolisthesis have not been validated in many prospective randomized trials. AIM: We aimed to validate the safety and efficacy of TLIF and PLIF surgery in lumbar spondylolisthesis using the clinical, radiographic, and cost-utility outcomes. METHODS: The data of surgically treated single-level spondylolisthesis patients were randomized prospectively into two groups. The groups were compared regarding demographics, perioperative complications, hospital stay, total expenditure, fusion rate, and clinical outcomes (visual analog scale, Oswestry disability index, Zurich claudication scale, and Odom’s criteria). A review of literature was done to compare the outcomes with the ones from higher-income nations. RESULTS: Thirty-three patients underwent prospective randomization. The improvement in the clinical outcomes at 12-month follow-up showed improvement in the TLIF group more than the PLIF group but with no significant difference. The mean operative time was significantly longer in the PLIF (p < 0.05), also, the blood loss was significantly less in the TLIF (p < 0.001). The complications frequency did not show any statistical significance between both groups and no significant difference in the patient’s post-operative patient satisfaction (p = 0.6). The mean hospital stay was non-significantly longer in the PLIF (p = 0.7). At 12-month follow-up, 93.3% of the TLIF patients were fused versus 86.7% of the PLIF (p = 0.5). The total cost of the TLIF was significantly less (p < 0.001). CONCLUSION: Both PLIF and TLIF could achieve similar fusion rates and clinical satisfaction in the management of lumbar spondylolisthesis. The TLIF group was significantly better in terms of financial burden, operative time, and blood loss.

Cost-Effectiveness of Adult Spinal Deformity Surgery

STUDY DESIGN

Review article.

OBJECTIVE

A review of the literature evaluating the cost-effectiveness of undergoing adult spinal deformity surgery and potential avenues for reducing costs.

METHODS

A review of the current literature and synthesis of data to provide an update on the cost effectiveness of undergoing adult spinal deformity surgery.

RESULTS

Compared with nonoperative management, operative management for adult spinal deformity is associated with improved patient-reported outcomes and quality of life; however, it is associated with significant financial and resource use.

CONCLUSION

Operative management for adult spinal deformity has been shown to be effective but is associated with significant cost and resource utilization. The optimal operative treatment is highly dependent on the patients' symptomatology and is surgeon dependent. Maximizing preoperative surgical health and minimizing postoperative complications are key measures in reducing the cost and resource utilization of adult spinal deformity surgery. Future studies are needed to evaluate how to optimize the cost-effectiveness.

Psoas Major Muscle Volume Does Not Affect the Postoperative Thigh Symptoms in XLIF Surgery

Background: Extreme lateral interbody fusion (XLIF) is a minimally invasive surgery that accesses the lumbar spine through the psoas muscle. This study aimed to evaluate the correlation between the psoas major muscle volume and anterior thigh symptoms after XLIF. Methods: Eighty-one patients (mean age 63 years) with degenerative spine diseases underwent XLIF (total = 94 levels). Thirty-eight patients were female (46.9%), and 24 patients (29.6%) had a history of lumbar surgery. Supplemental pedicle screws were used in 48 patients, and lateral plates were used in 28 patients. Neuromonitoring devices were used in all cases. The patients were classified into two groups (presence of thigh symptoms and no thigh symptoms after the surgery). The psoas major volumes were measured and calculated by CT (computed tomography) scan and compared between the two patient groups. Results: In the first 24 h after surgery, 32 patients (39.5%) had thigh symptoms (20 reported pain, 9 reported numbness, and 18 reported weakness). At one year postoperatively, only 3 of 32 patients (9.4%) had persistent symptoms. Conclusions: As a final observation, no statistically significant difference in the mean psoas major volume was found between the group of patients with new postoperative anterior thigh symptoms and those with no thigh symptoms. Preoperative psoas major muscle volume seems not to correlate with postoperative anterior thigh symptoms after XLIF.

Comparison of (Partial) economic evaluations of transforaminal lumbar interbody fusion (TLIF) versus Posterior lumbar interbody fusion (PLIF) in adults with lumbar spondylolisthesis: A systematic review

Introduction

The demand for spinal fusion surgery has increased over the last decades. Health care providers should take costs and cost-effectiveness of these surgeries into account. Open transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) are two widely used techniques for spinal fusion. Earlier research revealed that TLIF is associated with less blood loss, shorter surgical time and sometimes shorter length of hospital stay, while effectiveness of both techniques on back and/or leg pain are equal. Therefore, TLIF could result in lower costs and be more cost-effective than PLIF. This is the first systematic review comparing direct and indirect (partial) economic evaluations of TLIF with PLIF in adults with lumbar spondylolisthesis. Furthermore, methodological quality of included studies was assessed.

Methods

Searches were conducted in eight databases for reporting on eligibility criteria; TLIF or PLIF, lumbar spondylolisthesis or lumbar instability, and cost. Costs were converted to United States Dollars with reference year 2020. Study quality was assessed using the bias assessment tool of the Cochrane Handbook for Systematic Reviews of Interventions, the Level of Evidence guidelines of the Oxford Centre for Evidence-based Medicine and the Consensus Health Economic Criteria (CHEC) list.

Results

Of a total of 693 studies, 16 studies were included. Comparison of TLIF and PLIF could only be made indirectly, since no study compared TLIF and PLIF directly. There was a large heterogeneity in health care and societal perspective costs due to different in-, and exclusion criteria, baseline characteristics and the use of costs or charges in calculations. Health care perspective costs, calculated with hospital costs, ranged from $15,867-$43,217 in TLIF-studies and $32,662 in one PLIF-study. Calculated with hospital charges, it ranged from $8,964-$51,469 in TLIF-studies and $21,838-$93,609 in two PLIF-studies. Societal perspective costs and cost-effectiveness, only mentioned in TLIF-studies, ranged from $5,702/QALY-$48,538/QALY and $50,092/QALY-$90,977/QALY, respectively. Overall quality of studies was low.

Conclusions

This systematic review shows that TLIF and PLIF are expensive techniques. Moreover, firm conclusions about the preferable technique, based on (partial) economic evaluations, cannot be drawn due to limited studies and heterogeneity. Randomized prospective trials and full economical evaluations with direct TLIF and PLIF comparison are needed to obtain high levels of evidence. Furthermore, development of guidelines to perform adequate economic evaluations, specified for the field of interest, will be useful to minimize heterogeneity and maximize transferability of results.

Trial registration

Prospero-database registration number: CRD42020196869.

Classifying Complications: Assessing Adult Spinal Deformity 2-Year Surgical Outcomes

STUDY DESIGN

Retrospective review of prospective database.

OBJECTIVE

Complication rates for adult spinal deformity (ASD) surgery vary widely because there is no accepted system for categorization. Our objective was to identify the impact of complication occurrence, minor-major complication, and Clavien-Dindo complication classification (Cc) on clinical variables and patient-reported outcomes.

METHODS

Complications in surgical ASD patients with complete baseline and 2-year data were considered intraoperatively, perioperatively (<6 weeks), and postoperatively (>6 weeks). Primary outcome measures were complication timing and severity according to 3 scales: complication presence (yes/no), minor-major, and Cc score. Secondary outcomes were surgical outcomes (estimated blood loss [EBL], length of stay [LOS], reoperation) and health-related quality of life (HRQL) scores. Univariate analyses determined complication presence, type, and Cc grade impact on operative variables and on HRQL scores.

RESULTS

Of 167 patients, 30.5% (n = 51) had intraoperative, 48.5% (n = 81) had perioperative, and 58.7% (n = 98) had postoperative complications. Major intraoperative complications were associated with increased EBL (P < .001) and LOS (P = .0092). Postoperative complication presence and major postoperative complication were associated with reoperation (P < .001). At 2 years, major perioperative complications were associated with worse ODI, SF-36, and SRS activity and appearance scores (P < .02). Increasing perioperative Cc score and postoperative complication presence were the best predictors of worse HRQL outcomes (P < .05).

CONCLUSION

The Cc Scale was most useful in predicting changes in patient outcomes; at 2 years, patients with raised perioperative Cc scores and postoperative complications saw reduced HRQL improvement. Intraoperative and perioperative complications were associated with worse short-term surgical and inpatient outcomes.

Minimally invasive lateral approaches for the treatment of spinal tumors: single-position surgery without the "flip"

Although primary tumors of the spine and neural elements are rare, metastatic disease to the spine is quite common. Traditionally, surgical treatment for spinal tumor patients involves open decompression with or without stabilization. The single-position minimally invasive (MIS) lateral approach, which has been recently described over the recent decade, allows simultaneous access to the anterior and posterior columns with the patient positioned in the lateral decubitus position. Herein, we review the application of single-position MIS lateral surgery for the treatment of spinal neoplasm. The aim was to review the evolution, operative technique, outcomes, and complications associated with MIS lateral approaches for spinal tumors. The history of spinal tumor diagnosis and management are reviewed and discussed as well as the author's experience and literature regarding spinal tumor treatment outcome and surgical complications, with particular attention to single-position, MIS lateral approaches. In addition, the author's surgical technique is outlined in detail for thoracic, thoracolumbar and lumbar tumors. Furthermore, there are specific indications and complications associated with the surgical treatment of spinal tumors, and the MIS, single-position lateral approach, when applied appropriately, allows for concurrent access to the anterior and posterior column while mitigating the complications associated with traditional, open posterior-based approaches. In the treatment of spinal neoplasms, the goals of surgery are dictated by a number of tumor-specific and patient-specific factors. Therefore, operative treatment of tumors in the future may be a consolidation of historical surgical techniques and MIS, single-position lateral approaches. Regardless, multidisciplinary management is imperative for the individualized treatment of the patient and optimization of outcome.

Novel Titanium Cages for Minimally Invasive Lateral Lumbar Interbody Fusion: First Assessment of Subsidence

Introduction

Implant subsidence is a potential complication of spinal interbody fusion and may negatively affect patients subjected to procedures relying on indirect decompression such as minimally invasive transpsoas lateral lumbar interbody fusion (LLIF). The porous architecture of a recently developed titanium intervertebral cage maximizes bone-to-implant contact and minimizes stress shielding in laboratory experiments; however, its subsidence rate in patients has not yet been evaluated. The goal of this current study was to evaluate implant subsidence in patients subjected to LLIF.

Methods

Our institutional review board-approved single-center experience included 29 patients who underwent 30 minimally invasive LLIF from July 2017 to September 2018 utilizing the novel 3D-printed porous titanium implants. Radiographs, obtained during routine postoperative follow-up visits, were reviewed for signs of implant subsidence, defined as any appreciable compromise of the vertebral endplates.

Results

Radiographic subsidence occurred in 2 cases (6.7%), involving 2 out of 59 porous titanium interbody cages (3.4%). Both cases of subsidence occurred in four-level stand-alone constructs. The patients remained asymptomatic and did not require surgical revision. Ten surgeries were stand-alone constructs, and 20 surgeries included supplemental posterior fixation.

Conclusions

In our patient cohort, subsidence of the porous titanium intervertebral cage occurred in 6.7% of all cases and in 3.4% of all lumbar levels. This subsidence rate is lower compared to previously reported subsidence rates in patients subjected to LLIF using polyetheretherketone implants.

Three-Dimensional Printing in Minimally Invasive Spine Surgery

PURPOSE OF REVIEW

To summarize the recent advances in 3D printing technology as it relates to spine surgery and how it can be applied to minimally invasive spine surgery.

RECENT FINDINGS

Most early literature about 3D printing in spine surgery was focused on reconstructing biomodels based on patient imaging. These biomodels were used to simulate complex pathology preoperatively. The focus has shifted to guides, templates, and implants that can be used during surgery and are specific to patient anatomy. However, there continues to be a lack of long-term outcomes or cost-effectiveness analyses. 3D printing also has the potential to revolutionize tissue engineering applications in the search for the optimal scaffold material and structure to improve bone regeneration without the use of other grafting materials. 3D printing has many potential applications to minimally invasive spine surgery requiring more data for widespread adoption.

Economic Value in Minimally Invasive Spine Surgery

PURPOSE OF REVIEW

The field of spine surgery remains a unique target in the transition to value-based care. While spine surgery has benefited from new medical technologies, including minimally invasive surgery (MIS), these technologies may be a key driver in rising US healthcare costs. As such, MIS needs to clear an economic value threshold through a rigorous evaluation of the outcomes they provide and costs they incur. In this article, we review recent MIS surgery literature from the perspective of economic value.

RECENT FINDINGS

Many studies report modest all-in cost savings and direct procedural cost equivalence for minimally invasive approaches relative to open surgeries. In terms of quality, studies found lower blood loss, length of stay, and infectious complications with MIS surgery but evidence on QALYs was mixed. In the past 5 years, there has been increasing research interest in defining economic value in MIS surgery. However, a significant amount of heterogeneity in research quality and methodology persists. Therefore, MIS surgery has the potential to be of high economic value, though this is not yet definitive. Future research should continue to focus on high-quality cost-effectiveness studies with clear methodologies to further elucidate economic value in MIS surgery.

Lumbar Interbody Fusions for Degenerative Spondylolisthesis: Review of Techniques, Indications, and Outcomes

STUDY DESIGN

Broad narrative review.

OBJECTIVES

To review and summarize the current literature on the outcomes, techniques, and indications of lumbar interbody fusion in degenerative spondylolisthesis.

METHODS

A thorough review of peer-reviewed literature was performed on the outcomes, techniques, and indications of lumbar interbody fusions in degenerative spondylolisthesis.

RESULTS

A number of studies have found similar results between interbody fusions and posterolateral fusion in the setting of degenerative spondylolisthesis. There is some evidence that suggests that interbody fusion may be a useful adjunct in the setting of unstable degenerative spondylolisthesis. The number of options for interbody fusions has quickly expanded. Initially, interbody fusions were accomplished via an anterior approach. Posterior and transforaminal interbody fusions are 2 options that accomplish an interbody fusion without the morbidity of an anterior approach. Over the past decade, minimally invasive options including extreme lateral, oblique, and minimally invasive transforaminal interbody fusions have gained popularity.

CONCLUSIONS

Lumbar interbody fusion can be a useful tool in the setting of unstable degenerative spondylolisthesis. A number of technique options, both open and minimally invasive, are available to accomplish an interbody fusion. The literature to this date does not support a clear benefit of one technique over others in the setting of degenerative spondylolisthesis.

Evidence Based Medicine Review of Posterior Thoracolumbar Minimally Invasive Technology

Background

Evaluate the current evidence in meta-analyses on posterior thoracolumbar minimally invasive surgery techniques and outcomes for degenerative conditions.

Methods

A systematic review of the literature from 1950 to 2015.

Results

The review of the literature yielded 34 meta-analysis studies evaluating posterior thoracolumbar minimally invasive techniques and outcomes for degenerative conditions. There were 11 studies included which investigated minimally invasive surgery (MIS) versus open posterior lumbar decompressions. There were 14 studies included which investigated MIS versus open posterior lumbar interbody fusions. Finally, there were 9 studies focused on navigation techniques and radiation safety within MIS procedures.

Conclusions

There are 34 meta-analysis studies evaluating minimally invasive to open thoracolumbar surgery for degenerative disease. The studies show a trend toward decreased estimated blood loss, decreased length of stay, decreased complications, similar fusion rates, improved accuracy, and decreased radiation when minimally invasive techniques are used.

Does the Addition of Either a Lateral or Posterior Interbody Device to Posterior Instrumented Lumbar Fusion Decrease Cost Over a 6-Year Period?

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

Few studies have compared the costs of single-level (1) posterior instrumented fusion alone (PSF), (2) posterior interbody fusion with PSF (PLIF), and (3) lateral interbody fusion with PSF (circumferential LLIF). The purpose of this study was to compare costs associated with these procedures.

METHODS

Charts were reviewed and patients followed-up with a telephone questionnaire. Medicare reimbursement data was used for cost estimation from the payer's perspective. Multivariate survival analysis was performed to assess time to elevated resource use (greater than 90% of study patients or $68 672).

RESULTS

A total of 337 patients (PSF, 45; PLIF, 222; circumferential LLIF, 70) were included (63% follow-up at 6 years). PSF and circumferential LLIF patients were 3 times more likely to reach the cutoff value compared with PLIF patients (P = .017).

CONCLUSIONS

Circumferential LLIF and PSF patients were more likely to have higher resource use than PLIF patients and thus incur greater costs at 6-year follow-up.

Detection of miR‑29a in plasma of patients with lumbar spinal stenosis and the clinical significance

The present study aimed to detect miR-29a expression in the plasma of patients with lumbar spinal stenosis (LSS) and to investigate the clinical significance. A total of 30 patients with LSS, 27 patients with lumbar intervertebral disc herniation (LDH), 27 healthy people and 7 patients that had succumbed to mortality were involved in the present study for specimen collection. Expression levels of miR-29a in plasma and intervertebral disc tissue were detected by reverse transcription-quantitative polymerase chain reaction analysis. Plasma expression levels of matrix metalloproteinase 9 (MMP9) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) were detected ELISA. The expression levels of MMP9 and ADAMTS5 protein were detected by western blotting. Pearson correlation analysis was used to analyze the correlations between the expression levels of microRNA (miR)-29a, MMP9 and ADAMTS5. Receiver operating characteristic curve analysis was used to analyze the possibility of the use of miR-29a as a biomarker of LSS. The expression levels of miR-29a in plasma and intervertebral disc tissue of patients with LSS were significantly lower in patients with LSS compared with in patients with LDH, as well as healthy controls. Conversely, the protein expression levels of MMP9 and ADAMTS5 were significantly higher in patients with LSS compared with patients with LDH, as well as healthy controls. The expression levels of miR-29a was negatively correlated with the expression levels of MMP9 and ADAMTS5. In addition, miR-29a demonstrated low temperature sensitivity and high freeze-thaw stability, and may be used to accurately diagnose LSS. Therefore, miR-29a may be considered to be a potential biomarker of LSS.

Choice of Approach Does Not Affect Clinical and Radiologic Outcomes: A Comparative Cohort of Patients Having Anterior Lumbar Interbody Fusion and Patients Having Lateral Lumbar Interbody Fusion at 24 Months

STUDY DESIGN

Retrospective analysis of prospectively collected registry data.

OBJECTIVE

This study aimed to compare the clinical and radiologic outcomes between comparative cohorts of patients having anterior lumbar interbody fusion (ALIF) and patients having lateral lumbar interbody fusion (LLIF).

METHODS

Ninety consecutive patients were treated by a single surgeon with either ALIF (n = 50) or LLIF (n = 40). Inclusion criteria were patients age 45 to 70 years with degenerative disk disease or grade 1 to 2 spondylolisthesis and single-level pathology from L1 to S1. Patient-reported outcome measures included pain (visual analog scale), disability (Oswestry Disability Index [ODI]), and quality of life (Short Form 36 physical component score [PCS] and mental component scores [MCS]). Assessment of fusion and measurement of lordosis and posterior disk height were performed on computed tomography scans.

RESULTS

At 24 months, patients having ALIF had significant improvements in back (64%) and leg (65%) pain and ODI (60%), PCS (44%), and MCS (26%; p < 0.05) scores. Patients having LLIF had significant improvements in back (56%) and leg (57%) pain and ODI (52%), PCS (48%), and MCS (12%; p < 0.05) scores. Fourteen complications occurred in the ALIF group, and in the LLIF group, there were 17 complications (p > 0.05). The fusion rate was 100% for ALIF and 95% for LLIF (p = 0.1948). ALIF added ∼6 degrees of lordosis and 3 mm of height, primarily measured at L5-S1, and LLIF added ∼3 degrees of lordosis and 2 mm of height between L1 to L5. Mean follow-up was 34.1 months.

CONCLUSIONS

In comparative cohorts of patients having ALIF and patients having LLIF at 24 months postoperatively, there were no significant differences in clinical outcomes, complication rates, or fusion rates.

Minimally invasive versus open transforaminal lumbar fusion: a systematic review of complications

PURPOSE

The aim of this study is to compare mTLIF vs. oTLIF with regard to peri-operative complications, operative time, estimated blood loss, fluoroscopic time, and the length of hospital stay.

METHODS

The PubMed and EMBASE databases were searched for relevant articles reporting patients undergoing TLIF, and a comparison between mTILF and oTLIF was performed. The database included patient demographic information, complications, operative time, fluoroscopic time, and the length of hospital stay.

RESULTS

Fourteen studies were included in this systematic review. The total number of subjects included was 901, of which 455 underwent mTLIF (50 %) and 446 underwent oTLIF (50 %). The operating time for the mTLIF was ranged from 116 to 390 minutes, compared with 102 to 365 minutes for oTLIF, the operating time tended to be longer in the mTLIF group than the oTLIF group. The estimated blood loss was lower in the mTLIF group, ranging from 51 to 578 ml in mTLIF and 225 to 961 ml in oTLIF, respectively. Length of hospital stay was short for the mTLIF with a 2.3 to 10.6 days hospitalization compared to 2.9 to 14.6 days for oTLIF. However the fluoroscopic time was consistently higher in the mTLIF group with a 49 to 106 seconds of fluoroscopy compared to 16.4 to 44 seconds for oTLIF. The complications divided into technical complications and infection complications. The main technical and infection complications included dural tears, screw malposition, and wound infection. Systemic complications included pneumonia, urinary tract infection, and DVT. The numbers of patients with complication was 54 out of 455 (11.87 %) in the mTLIF, and 64 out of 446 (14.35 %) in the oTLIF.

CONCLUSION

The review shows mTLIF offers several potential advantages in reducing blood loss and the length of hospital stay, especially lowering the complication rates for patients compared with oTLIF. However, it required much more operative time and radiation exposure. Class I evidence and high-quality randomized controlled trials are needed for further study.

Cost-utility of minimally invasive versus open transforaminal lumbar interbody fusion: systematic review and economic evaluation

PURPOSE

To assess the cost-utility and perioperative costs of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) versus open-TLIF for degenerative lumbar pathologies.

METHODS

Relevant articles were identified from six electronic databases. Predefined end points were extracted and meta-analysis conducted from the identified studies.

RESULTS

For each study, the direct hospital cost for MI-TLIF was found to be less than that of open-TLIF. When these outcomes were pooled, direct hospital costs were found to be significantly lower in the MI-TLIF group [weighted mean difference (WMD), -$2820; I (2) = 61 %; P < 0.00001]. MI-TLIF was also associated with shorter hospitalization (WMD, 0.99; 95 % CI -1.81, -0.17; I (2) = 96 %; P = 0.02), trend toward reduced complications (relative risk 0.53; 95 % CI 0.23, 1.06; I (2) = 0 %; P = 0.07), and reduced blood loss (WMD, -246.40 mL; I (2) = 98 %; P = 0.003), but was not associated with a significant difference in operation time (WMD, -67.05; 95 % CI -169.44, 35.35; I (2) = 100 %; P = 0.20).

CONCLUSIONS

From the limited evidence, the available data suggest a trend of significantly reduced perioperative costs, length of stay, and blood loss for minimally invasive compared with open surgical approaches for TLIF. MI-TLIF may represent an opportunity for optimal utilization and allocation of health-care resources from both a hospital and societal perspective.

Relationship between psoas muscle dimensions and post operative thigh pain. A possible preoperative evaluation factor

INTRODUCTION

Advanced intraoperative neuromonitoring (IONM) is used to attenuate postoperative complications and side effects of extreme lateral interbody fusion (XLIF). Specific factors relate to the presence of postoperative injury are not well understood. This study aims to identify intraoperative variables with correlations to new postoperative anterior thigh/groin sensory changes.

METHODS

Twenty-nine patients with various degenerative lumbar conditions were treated with XLIF at a single institution. Mean age was 59 years, 69% were female, and 21% had undergone previous lumbar surgery. A total of 47 levels (mean 1.6, range 1-3) were treated with XLIF. Supplemental pedicle screw and rod fixation was used in 24 patients (83%). Dynamically-evoked electromyography was used in all cases. Analysis of baseline demographic and treatment variables were performed at a per patient basis (n = 29), whereas analysis of intraoperative variables were performed at a per levels treated basis (n = 47).

RESULTS

Within 24 hours postoperative, 10 (34%) patients experienced anterior thigh/groin sensory changes (4 reported pain only, 5 reported pain plus other sensory changes, and 1 paresthesia without pain). Symptom resolution occurred at 1 month postoperative for 4 patients, at 3 months postoperative for 2 patients. At 3 months postoperative, 6 patients had complete symptom resolution, 3 patients had symptom improvements, and 1 patient had no change in perioperative symptoms. Psoas dimension in the lateral-latero direction were significantly smaller for patients with postoperative sensory changes (p = 0.025), and similarly, patients with postoperative sensory changes had a significantly higher ratio of psoas muscle in the anterior-posterior to lateral-latero directions (p = 0.026).

CONCLUSIONS

In addition to IONM, MRI evaluation of psoas shape, position, and dimension may be of help in preoperative planning of a safe XLIF access and eventually, predict those cases with higher risk of approach-related post-operative events.

The Influence of Exercise on Perceived Pain and Disability in Patients With Lumbar Spinal Stenosis: A Systematic Review of Randomized Controlled Trials

Lumbar spinal stenosis (LSS) is an increasingly prevalent condition that has major health and economic implications. While there are many options for the treatment of LSS, exercise is widely considered a first-line intervention as it is associated with reduced complications and cost as compared to more invasive options. Currently, it is not clear if exercise is an effective approach to managing pain and perceived disability in patients with symptomatic LSS. Therefore, the purpose of this systematic review is to evaluate the published literature that has investigated exercise as a primary intervention for LSS. A search was conducted in electronic databases including PubMed, PEDro, SPORTDiscus, CINAHL, and AMED using the key words lumbar spinal stenosis, exercise, physical therapy, rehabilitation, and conservative treatment. Inclusion criteria consisted of published randomized controlled trials written in English that included exercise as the primary treatment in at least one of the groups, and had reported measures of pain and disability clearly stated. The search identified 310 studies of which 5 met all the inclusion parameters. Exercise appears to be an efficacious intervention for pain, disability, analgesic intake, depression, anger, and mood disturbance among patients with LSS. Further research is needed to determine which type of exercise is the most effective in managing symptoms associated with lumbar spinal stenosis.