Cost-effectiveness of circumferential fusion for lumbar spondylolisthesis: propensity-matched comparison of transforaminal lumbar interbody fusion with anterior-posterior fusion

Staged circumferential lumbar fusions have less intraoperative complications and shorter operative time with no difference in 30-, 90-, and 1-year complications: a propensity-matched cohort analysis of 190 patients

BACKGROUND CONTEXT

Circumferential lumbar fusions (cLFs) are becoming more common with increasing and more minimally invasive anterior access techniques. Staging allows reassessment of indirect decompression and alignment prior to the posterior approach, and optimization of OR time management. Safety of staging has been well documented in deformity surgery but has yet to be delineated in less extensive, degenerative cLFs.

PURPOSE

The purpose of this study is to compare perioperative complications and outcomes between staged versus single-anesthetic circumferential fusions in the lumbar spine.

STUDY DESIGN

Propensity-matched comparative observational cohort.

PATIENT SAMPLE

Patients who underwent cLFs for lumbar degenerative disease.

OUTCOME MEASURES

In-hospital, 30-day, 90-day, and 1-year complications.

METHODS

From 123 patients undergoing single-anesthetic and 154 patients undergoing staged cLF, 95 patients in each group were propensity-matched based on age, sex, BMI, ASA score, smoking, revision, and number of levels. We compared perioperative, 30-day, 90-day, and 1-year complications between the two cohorts.

RESULTS

Mean days between stages was 1.58. Single-anesthetic cLF had longer total surgery time (304 vs 240 minutes, p<.001) but shorter total PACU total time (133 vs 196 minutes, p<.001). However, there was no difference in total anesthesia time (368 vs 374 minutes, p=.661) and total EBL (357 vs 320cc, p=.313). Intraoperative complications were nine incidental durotomies in the single-anesthetic and one iliac vein injury in the staged group (9% vs 1%, p=.018). There was no difference of in-hospital (38 vs 31, p=.291), 30-day (16 vs 23, p=.281), 90-day (10 vs 15, p=.391), 1-year complications (9 vs 12, p=.644), and overall cumulative 1-year complications (54 vs 56, p=.883) between the two cohorts.

CONCLUSIONS

There is a decrease in total surgical time and intraoperative complications during staged compared with single-anesthetic cLF with no difference in in-hospital, 30-day, 90-day, and 1-year complications between approaches.

Anterolateral versus posterior minimally invasive lumbar interbody fusion surgery for spondylolisthesis: comparison of outcomes from a global, multicenter study at 12-months follow-up

BACKGROUND CONTEXT

Several minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches.

PURPOSE

To test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery.

DESIGN

Prospective, multicenter, international, observational cohort study.

PATIENT SAMPLE

Patients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion.

OUTCOME MEASURES

Patient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months.

METHODS

Eligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison.

RESULTS

Participants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390).

CONCLUSIONS

Patients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.

Procedures employing interbody devices and multi-level fusion require target price adjustment to build a sustainable lumbar fusion bundled payment model

BACKGROUND CONTEXT

Bundled payment models require risk adjustment to ensure appropriate targets are set. While this may be standardized for many services, spine fusions demonstrate significant variability in approach, invasiveness, and use of implants, that may require further risk adjustment.

PURPOSE

To evaluate variability in costs of spinal fusion episodes in a private insurer bundle payment program and identify whether current procedural terminology (CPT) code modifications are necessary for sustainable implementation.

STUDY DESIGN/SETTING

Retrospective single-institution cohort study.

PATIENT SAMPLE

A total of 542 lumbar fusion episodes in a private insurer bundled payment program from October 2018 to December 2020.

OUTCOME MEASURES

A total of 120-day episode of care net surplus/deficit, 90-day readmissions, discharge disposition, and length of hospital stay.

METHODS

A review was conducted of all lumbar fusions in a single institution's payer database. Surgical characteristics (approach [posterior lumbar decompression and fusion (PLDF), transforaminal lumbar interbody fusion (TLIF), and circumferential fusion], levels fused, and primary vs revision) were collected from manual chart review. Episode of care cost data were collected as net surplus or deficit with respect to target prices. A multivariate linear regression model was constructed to measure the independent effects of primary versus revision, levels fused, and approach on the net cost savings.

RESULTS

Most procedures were PLDFs (N=312, 57.6%), single-level (N=416, 76.8%) and primary fusions (N=477, 88.0%). Overall, 197 (36.3%) resulted in a deficit, and were more likely to be three levels (7.11% vs 2.03%, p=.005), revisions (18.8% vs 8.12%, p<.001), and TLIF (47.7% vs 35.1%, p<.001) or circumferential fusions (p<.001). One-level PLDFs resulted in the greatest cost savings per episode ($6,883). Across both PLDFs and TLIFs, 3-level procedures resulted in significant deficit of -$23,040 and -$18,887, respectively. For circumferential fusions, 1-level fusions resulted in deficit of -$17,169 per case which rose to -$64,485 and -$49,222 for 2- and 3-level fusions. All 2- and 3-level circumferential spinal fusions resulted in a deficit. On multivariable regression, TLIF and circumferential fusions were independently associated with a deficit of -$7,378 (p=.004) and -$42,185 (p<.001), respectively. Three-level fusions were independently associated with an additional -$26,003 deficit compared to single-level fusions (p<.001).

CONCLUSIONS

Interbody fusions, especially circumferential fusions, and multi-level procedures are not adequately risk adjusted by current bundled payment models. Health systems may not be able to financially support these alternative payment models with improved procedure-specific risk adjustment.

Methodology of economic evaluations in spine surgery: a systematic review and qualitative assessment

OBJECTIVES

The present study is a systematic review conducted as part of a methodological approach to develop evidence-based recommendations for economic evaluations in spine surgery. The aim of this systematic review is to evaluate the methodology and quality of currently available clinical cost-effectiveness studies in spine surgery.

STUDY DESIGN

Systematic literature review.

DATA SOURCES

PubMed, Web of Science, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, EconLit and The National Institute for Health Research Economic Evaluation Database were searched through 8 December 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they met all of the following eligibility criteria: (1) spine surgery, (2) the study cost-effectiveness and (3) clinical study. Model-based studies were excluded.

DATA EXTRACTION AND SYNTHESIS

The following data items were extracted and evaluated: pathology, number of participants, intervention(s), year, country, study design, time horizon, comparator(s), utility measurement, effectivity measurement, costs measured, perspective, main result and study quality.

RESULTS

130 economic evaluations were included. Seventy-four of these studies were retrospective studies. The majority of the studies had a time horizon shorter than 2 years. Utility measures varied between the EuroQol 5 dimensions and variations of the Short-Form Health Survey. Effect measures varied widely between Visual Analogue Scale for pain, Neck Disability Index, Oswestry Disability Index, reoperation rates and adverse events. All studies included direct costs from a healthcare perspective. Indirect costs were included in 47 studies. Total Consensus Health Economic Criteria scores ranged from 2 to 18, with a mean score of 12.0 over all 130 studies.

CONCLUSIONS

The comparability of economic evaluations in spine surgery is extremely low due to different study designs, follow-up duration and outcome measurements such as utility, effectiveness and costs. This illustrates the need for uniformity in conducting and reporting economic evaluations in spine surgery.

Trends in Reimbursement and Approach Selection for Lumbar Arthrodesis

BACKGROUND

Changes in reimbursement policies have been demonstrated to correlate with clinical practice.

OBJECTIVE

To investigate trends in physician reimbursement for anterior, posterior, and combined anterior/posterior (AP) lumbar arthrodesis and relative utilization of AP.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Project registry for anterior, posterior, and AP lumbar arthrodeses during 2010 and 2020. Work relative value units per operative hour (wRVUs/h) were calculated for each procedure. Trends in reimbursement and utilization of the AP approach were assessed with linear regression. Subgroup analyses of age and underlying pathology of AP arthrodesis were also performed.

RESULTS

During 2010 and 2020, AP arthrodesis was associated with significantly higher average wRVUs/h compared with anterior and posterior arthrodesis (AP = 17.4, anterior = 12.4, posterior = 14.5). The AP approach had a significant yearly increase in wRVUs/h (coefficient = 0.48, P = .042), contrary to anterior (coefficient = -0.01, P = .308) and posterior (coefficient = -0.13, P = .006) approaches. Utilization of AP approaches over all arthrodeses increased from 7.5% in 2010 to 15.3% in 2020 (yearly average increase 0.79%, P < .001). AP fusions increased significantly among both degenerative and deformity cases (coefficients 0.88 and 1.43, respectively). The mean age of patients undergoing AP arthrodesis increased by almost 10 years from 2010 to 2020. Rates of major 30-day complications were 2.7%, 3.1%, and 3.5% for AP, anterior, and posterior arthrodesis, respectively.

CONCLUSION

AP lumbar arthrodesis was associated with higher and increasing reimbursement (wRVUs/h) during the period 2010 to 2020. Reimbursement for anterior arthrodesis was relatively stable, while reimbursement for posterior arthrodesis decreased. The utilization of the combined AP approach relative to the other approaches increased significantly during the period of interest.

Lateral decubitus single position anterior posterior surgery improves operative efficiency, improves perioperative outcomes, and maintains radiological outcomes comparable with traditional anterior posterior fusion at minimum 2-year follow-up

BACKGROUND CONTEXT

The advantages of Lateral Single Position surgery (LSPS) in the perioperative period has previously been demonstrated, however 2-year postoperative outcomes of this novel technique have not yet been compared to circumferential anterior-posterior fusion (FLIP) at 2-years postoperatively.

PURPOSE

Evaluate the safety and efficacy of LSPS versus gold-standard FLIP STUDY DESIGN/SETTING: Multi-center retrospective cohort review.

PATIENT SAMPLE

Four hundred forty- two patients undergoing lumbar fusion via LSPS or FLIP OUTCOME MEASURES: Levels fused, operative time, estimated blood loss, perioperative complications, and reasons for reoperation at 30-days, 90-days, 1-year, and 2-years. Radiographic outcomes included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, and segmental lumbar lordosis.

METHODS

Patients were grouped as LSPS if anterior and posterior portions of the procedure were performed in the lateral decubitus position, and FLIP if patients were repositioned from supine or lateral to prone position for the posterior portion of the procedure under the same anesthetic. Groups were compared in terms of demographics, intraoperative, perioperative and radiological outcomes, complications and reoperations up to 2-years follow-up. Measures were compared using independent samples or paired t-tests and chi-squared analyses with significance set at p<.05.

RESULTS

Four hundred forty- two pts met inclusion, including 352 LSPS and 90 FLIP pts. Significant differences were noted in age (62.4 vs 56.9; p≤.001) and smoking status (7% vs 16%; p=.023) between the LSPS and FLIP groups. LSPS demonstrated significantly lower Op time (97.7min vs 297.0 min; p<.001), fluoro dose (36.5mGy vs 78.8mGy; p<.001), EBL (88.8mL vs 270.0mL; p<.001), and LOS (1.91 days vs 3.61 days; p<.001) compared to FLIP. LSPS also demonstrated significantly fewer post-op complications than FLIP (21.9%vs 34.4%; p=.013), specifically regarding rates of ileus (0.0% vs 5.6%; p<.001). No differences in reoperation were noted at 30-day (1.7%LSPS vs 4.4%FLIP, p=.125), 90-day (5.1%LSPS vs 5.6%FLIP, p=.795) or 2-year follow-up (9.7%LSPS vs 12.2% FLIP; p=.441). LSPS group had a significantly lower preoperative PI-LL (4.1° LSPS vs 8.6°FLIP, p=.018), and a significantly greater postoperative LL (56.6° vs 51.8°, p = .006). No significant differences were noted in rates of fusion (94.3% LSPS vs 97.8% FLIP; p=.266) or subsidence (6.9% LSPS vs 12.2% FLIP; p=.260).

CONCLUSIONS

LSPS and circumferential fusions have similar outcomes at 2-years post-operatively, while reducing perioperative complications, improving perioperative efficiency and safety.

Cost-effectiveness of open transforaminal lumbar interbody fusion (OTLIF) versus minimally invasive transforaminal lumbar interbody fusion (MITLIF): a systematic review and meta-analysis

BACKGROUND CONTEXT

The number of performed instrumented lumbar spine surgeries and associated health-care-related costs has increased over the last decades, and will increase further in the future. With the consistent growth of health-care-related costs, cost-effectiveness of surgical techniques is of major relevance. Common indications for instrumented lumbar spine surgery are spondylolisthesis and degenerative disease. A commonly used technique is the open transforaminal lumbar interbody fusion (OTLIF). Nowadays, there is an increasing interest in the minimally invasive variation of this technique (minimally invasive transforaminal lumbar interbody fusion [MITLIF]). Currently available literature describes that MITLIF has comparable or even better clinical results compared to OTLIF. Cost-effectiveness of MITLIF and OTLIF is important considering the growing health-care related costs, although no consensus has been reached regarding the most cost-effective technique. In this systematic review, previous literature concerning costs and cost-effectiveness of OTLIF was compared with MITLIF in patients with lumbar spondylolisthesis or degenerative disease. Furthermore, methodological quality of included studies was assessed.

PURPOSE

This study aims to evaluate the current literature on cost-effectiveness of OTLIF compared MITLIF to in patients with lumbar spondylolisthesis or degenerative disease.

STUDY DESIGN

This study is a systematic literature review and meta-analysis.

STUDY SAMPLE

Clinical studies reporting costs or cost-effectiveness for either OTLIF or MITLIF in patients with spondylolisthesis, lumbar instability, or degenerative disease were included.

OUTCOME MEASURES

The following data items were evaluated: study design, study population, utility measurement tool, gained quality adjusted life years (QALYs), cost sources, health care and societal perspective costs, total costs, costs per QALY (cost-effectiveness) and incremental cost-effectiveness ratio (ICER).

METHODS

A systematic search was conducted using databases PubMed, CINAHL, EMBASE, Cochrane, Clinical Trials, Current Controlled Trials, ClinicalTrials.gov, NHS Centre for Review and Dissemination, Econlit and Web of Science on studies reporting OTLIF or MITLIF, spondylolisthesis or lumbar instability or degenerative disease, and costs. Relevant studies were selected and reviewed independently by two authors. For comparison, all costs were converted to American dollars with the reference year 2018.

RESULTS

After duplicate removal, a total of 892 studies were identified. Eventually, 32 studies were included. Nine studies compared OTLIF and MITLIF directly. All studies mentioned health care perspective costs. Seven studies mentioned societal perspective costs. Cost-effectiveness of OTLIF was mentioned in five studies, ranging from $47,303/QALY to $218,766/QALY. Cost-effectiveness of MITLIF was mentioned in one study, $121,105/QALY. Meta-analysis of hospital perspective costs showed a significant overall effect in favor of MITLIF, with a mean difference of $2,650. There was great heterogeneity in health care and societal perspective costs due to different in-, and exclusion factors, baseline characteristics, and calculation methods. Overall quality of studies was low.

CONCLUSIONS

OTLIF and MITLIF appear to be expensive interventions when using a threshold of $50,000/QALY. Results of this study and previous literature suggest that MITLIF is more cost-effective compared to OTLIF. Considering the increase in health care costs of instrumented spine surgery, cost-effectiveness could be one of the factors in surgical decision-making. Prospective randomized studies directly comparing cost-effectiveness of OTLIF and MITLIF from both hospital and societal perspectives are needed to obtain higher level of evidence.

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.

Systematic Review of Cost-Effectiveness Analyses in U.S. Spine Surgery

BACKGROUND

Increasing costs put the value of spine surgery under scrutiny. In health economics, cost-effectiveness analyses (CEA) are used to compare the value of competing procedures. However, inconsistent methodology prevents standardization and implementation of recommendations. The goal of this study is to perform a systematic review of all U.S. CEAs in spine surgery reported to date, highlight their strengths and weaknesses, and define metrics essential for high-quality CEAs.

METHODS

We followed AMSTAR systematic review methods, identifying all U.S. spine surgery CEAs reported to March 2019 with a structured, reproducible search of PubMed, Embase, and the Tufts CEA Registry.

RESULTS

We identified 40 CEA studies. Twelve (30%) used outcome data from a randomized controlled trial. To calculate costs, 22 (55%) used allowed charges but costing methods were often unclear or imprecise. Studies applying discounting had mean follow-up of 5.92 years compared with 3.00 years for studies without. Eleven of 15 (73%) cervical studies compared cervical disc arthroplasty with anterior cervical discectomy and fusion, finding cervical disc arthroplasty to be cost-effective (<$100,000/quality-adjusted life year) for 1-level and 2-level procedures. Eleven of 25 lumbar studies (44%) compared operative with nonoperative interventions for intervertebral disc herniation, lumbar stenosis, and lumbar spondylolisthesis. Lumbar studies comparing surgical with nonoperative intervention found surgery at least cost-effective for intervertebral disc herniation and lumbar stenosis, but cost-effective only for lumbar spondylolisthesis at 4 years follow-up. Most studies (70%) lacked appropriate sensitivity analyses.

CONCLUSIONS

Costing methodology remains obscure and inconsistent and incremental cost-effectiveness ratio results incomparable. The language of costing methodology must be standardized and sensitivity analyses of outcome and cost inputs mandatory for publication.

Effect of bone graft granule volume on postoperative fusion after lumber spinal internal fixation: A retrospective analysis of 82 cases

Objective:

To investigate the effect of bone graft volume on postoperative fusion and symptom improvement in lumbar posterior lumbar fusion and internal fixation.

Methods:

A total of 82 patients receiving pedicle screw rod system internal fixation with Cage bone graft fusion in the First Hospital of Baoding City, Hebei Province were selected and randomly divided into three groups. The excised autologous laminar bones were bitten into different sizes of bone fragments. And different sizes of bone grafts were implanted during the operation. Group-A (n=28) was implanted by bone graft granule with the average volume of 0.2 cm³, Group-B (n=27) was implanted by bone graft granule with the average volume of 0.1 cm³, and Group-C (n=27) was implanted by bone graft granule with the average volume of 0.05 cm³. The bone graft granule volume, clinical effect, bone graft fusion rate and intervertebral space height were compared.

Results:

The three groups had significantly different bone graft granule volumes (P<0.05), but similar intervertebral bone graft total volumes and Cage heights (P>0.05). In the final follow-up, VAS and ODI of low back pain and two lower limbs pain significantly reduced compared with those before surgery (P<0.05), but the three groups had similar results (P>0.05). The bone graft fusions of Group-B one and two years after surgery were significantly higher than those of Group-A and Group-C, and the values of Group-A exceeded those of Group-C (P<0.05). In the final follow-up, the intervertebral space height change of Group-B was significantly smaller than those of Group-A and Group-C (P<0.05).

Conclusion:

Size of bone graft granule has no significant effect on postoperative symptoms. However, middle-sized volume bone graft granule (0.1 cm³/granule) showed increased postoperative intervertebral fusion rate and reduced intervertebral space height loss in our study.