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Comparative Effectiveness and Economic Evaluations of Open Versus Minimally Invasive Posterior or Transforaminal Lumbar Interbody Fusion: A Systematic Review

Goldstein, Christina L., MD, FRCSC; Phillips, Frank M., MD; Rampersaud, Y. Raja, MD, FRCSC

doi: 10.1097/BRS.0000000000001462
LITERATURE REVIEW
Free

Study Design. Systematic review of randomized and nonrandomized comparative studies.

Objective. To summarize the literature examining comparative effectiveness and economic evaluation of minimally invasive versus open transforaminal/posterior lumbar interbody fusion (T/PLIF).

Summary of Background Data. Minimally invasive approaches to lumbar fusion have been proposed as an alternative to open surgery to decrease patient morbidity and improve clinical and patient-reported outcomes, with the possibility of secondary cost-savings. The comparative clinical and economic effectiveness of minimally invasive versus open T/PLIF remains largely undetermined.

Methods. A systematic review of Medline, EMBASE, Web of Science, and Cochrane from database inception to September 2015 inclusive was performed. Reference lists were manually searched. Studies comparing MIS to open T/PLIF for degenerative lumbar conditions, including at least 10 patients in each arm and reporting at least one clinical, perioperative, radiographic, adverse event, or economic outcome, were included.

Results. Between database inception and October 2015, 45 studies meeting inclusion criteria were identified with 3472 subjects undergoing MIS fusion and 5925 having an open procedure. There were no significant differences in operative time between the two groups, whereas patients undergoing MIS fusion consistently demonstrated less blood loss (16.1–88.7%) and shorter hospital stays (15.0–64.0% shorter). There was no difference in variably reported VAS, ODI, SF-36, SF-12, or EQ-5D scores between the two techniques at intermediate to long-term follow-up (12–60 months). Complication rates and fusion rates were also equivalent between the two groups. Economic studies demonstrate cost-savings in favor of MIS fusion ranging from 2.5 to 49.3%.

Conclusion. Limited quality comparative observational cohort and randomized controlled studies of MIS versus open T/PLIF consistently demonstrate improved perioperative outcomes including operative time, estimated blood loss, and length of stay with no significant difference in patient-reported outcomes or complication rates between the two groups at final follow-up. Increasing economic data suggest both direct and indirect cost-savings in favor of MIS fusion.

Level of Evidence: N/A

*Department of Orthopaedic Surgery, Missouri Orthopaedic Institute, University of Missouri, Columbia, MO

Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL

Division of Orthopaedic Surgery, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada.

Address correspondence and reprint requests to Y. Raja Rampersaud, MD, FRCSC, Associate Professor, Department of Surgery, Division of Orthopaedics, University of Toronto, Medical Director, Back and Neck Program, Altum Health, Krembil Neuroscience—Spine Program, University Health Network, Toronto Western Hospital, 399 Bathurst Street, EW 1-441, Toronto, ON M5T 2S8, Canada; E-mail: raja.rampersaud@uhn.ca

Received 27 October, 2015

Revised 12 January, 2016

Accepted 15 January, 2016

The manuscript submitted that are approved by local agencies for these indications not contains information about medical device(s)/drug(s).

No funds were received in support of this work.

Relevant financial activities outside the submitted work: board membership, consultancy, grants, and travel/accommodations/meeting expenses.

Lumbar spine fusion has been shown to be an effective method of treatment for a number of spinal pathologies, including many degenerative conditions.1 However, traditional open surgical techniques are associated with increased perioperative blood loss, significant complication rates, and prolonged hospital stays. Since the first description of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) by Foley et al 2 in 2003, minimally invasive (MIS) approaches to lumbar spine fusion have been widely adopted. The purported benefits of these techniques include less damage to adjacent spinal structures and faster postoperative recovery. Proponents of open lumbar spine fusion cite the learning curve associated with MIS fusion as well as longer operative times and increased complication rates as potential limitations of MIS lumbar fusion.3

Over the last decade many investigators have examined the outcomes of MIS lumbar fusion for degenerative conditions in case series and cohort studies. In response to the need for studies examining outcomes of alternate treatment methods, termed comparative effectiveness research,4 many authors have conducted comparative studies of open versus MIS lumbar spine fusion. As the number of these comparative studies has increased, systematic reviews and both qualitative and quantitative meta-analyses of the literature have come to consistent conclusions regarding the comparative effectiveness of open versus MIS fusion for degenerative lumbar conditions. These reviews report that MIS techniques are associated with improved perioperative outcomes, including lower blood loss, shorter hospital stay, and decreased postoperative pain and narcotic requirements, with at least equivalent complication rates and no significant difference in intermediate-term health-related quality of life and pain scores.5–8

While the importance of the use of comparative effectiveness research in evidence-based decision-making by spine surgeons is clear, clinical outcomes alone are no longer the sole outcomes of interest to payers and policy-makers. Increasingly, health economic data are being used to drive healthcare reform with the goals of improving the efficiency (i.e., cost-effectiveness) and lowering the costs of contemporary healthcare. Owing to a lack of sufficient economic evaluations, our prior systematic review of the literature pertaining to open versus MIS lumbar spine fusion did not include economic evaluations.5 However, multiple comparative and economic effectiveness studies have been published since our prior review.

The purpose of this systematic review was to provide an updated summary of the literature comparing open versus MIS transforaminal or posterior lumbar interbody fusion (T/PLIF) in the treatment of degenerative conditions of the lumbar spine with the following outcomes of interest: (A) perioperative outcomes, (B) complication and reoperation rates, (C) patient-reported outcomes, and (D) economic outcomes.

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MATERIALS AND METHODS

Systematic Review of the Literature and Study Selection

A detailed description of the methodology of our literature search up to and including May 2012 has previously been published.5 In summary, two independent reviewers then screened study titles, abstracts, and full-text articles to identify randomized controlled trials or comparative studies comparing open and MIS fusion from a posterior approach in a unique sample of patients with degenerative lumbar pathology. To supplement the results of our prior review we performed an updated electronic search of Medline, EMBASE, Web of Science, and Cochrane from June 2012 to August 2015, using the search strategies previously described. Study inclusion criteria were: (A) English-language publication, (B) comparative cohort study or randomized controlled trial of open versus MIS T/PLIF for degenerative lumbar pathology, (C) at least 10 subjects in each treatment arm, and (D) reporting on at least one patient-reported outcome, perioperative clinical outcome or process measure, radiographic outcome, adverse events, or economic analysis.

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Study Quality Assessment

The method of study quality assessment of the publications from our original review has previously been published.5 The Grading of Recommendations Assessment, development and Evaluation (GRADE) system was also used to determine the quality of each new included study.9 Data pertaining to the study design, study quality, consistency of results, directness of evidence, and study precision was extracted by two study reviewers (CLG and YRR). Conflicts regarding quality assessment were resolved through consensus discussion and each study was given a final GRADE rating of high, moderate, low, or very low.

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Data Extraction and Analysis

Details pertaining to the method of data extraction from articles identified in our original systematic review are available in our prior publication.5 For those newly included citations, a single reviewer extracted the same data points identified in our prior systematic review and entered the data into a Microsoft Excel spreadsheet. Summary tables outlining the study characteristics and patient demographics as well as outcomes of interest for each of the included manuscripts were created. Demographic variables were compared between the open and MIS cohorts using Student t test for means and the X 2 test for proportions. A narrative summary of the results of all published economic analyses was performed.

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RESULTS

Literature Search

The results of the combination of our initial and subsequent literature searches are presented in Figure 1. In total, our electronic literature search yielded 11,760 citations for possible study inclusion, with 2829 being excluded as duplicates. A further 1775 citations were included from our 2012 PubMed search, yielding 10,706 studies. After title, abstract, and full-text review, 44 were identified as meeting our study inclusion criteria. Manual review of citation lists identified five publications that had not been previously included, with four being excluded as duplicate reports on a single patient population. This yielded a total of 45 articles for final study inclusion.

Figure 1

Figure 1

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Study Characteristics and Quality

Of the 45 included studies, only three were prospective randomized controlled trials (PRCTs).10–12 A prospective comparative cohort design was used in 17 of the studies; and the remaining 25 were retrospective cohort studies.6,13–51 Table 1 presents a summary of included papers and Table 2 provides a summary of the patient demographics, diagnoses, and follow-up period of the included studies.

TABLE 1

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TABLE 2

TABLE 2

According to the GRADE protocol all of the included studies suffered from methodological flaws which resulted in downgrading of their quality ratings. All three of the PRCTs, which were assigned an initial quality rating of high, were downgraded to a final rating of low.10–12 None of the prospective studies met the GRADE criteria to be initially listed as moderate level evidence (e.g., sample size and effect size were too small).9 A total of seven of the prospective comparative cohort studies retained their low-quality rating and 10 were downgraded to very low quality.11,13,20,21,24,28,29,31,32,36,38–41,48,49,52 Of the retrospective cohort studies, nine stayed at a low-quality rating and 16 were downgraded to very low quality.6,14–19,22,23,25–27,30,33–35,37,42–45,48,50,51

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Patient Demographics

A total of 9396 subjects were in the 45 included studies, with 3472 undergoing MIS T/PLIF and 5924 having an open procedure (Table 2). The large numbers are a result of the inclusion of one administrative data study with 1667 MIS cases and 4439 open cases.48 There was no significant difference between the two cohorts with regard to mean age (MIS = 53.5 years vs. open = 55.9 years, P = 0.960) or sex (% male MIS = 44.5 vs. open = 44.7, P = 0.853). Patients in the MIS cohort were more likely to undergo a single-level procedure (72.5% vs. 52.3%, P < 0.0001) while more of the open subjects had a 2-level T/PLIF (48.9% vs. 26.7%, P < 0.0001). More than half of the subjects in each treatment arm had a diagnosis of degenerative spondylolisthesis (MIS = 56.1%, open = 54.7%). Mean follow-up time in the MIS group was 25.0 months compared with 21.4 months in the open cohort (P = 0.488).

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Perioperative Outcomes

A summary of perioperative outcomes is presented in Table 3. Operating room (OR) time was reported in 37 of the 45 studies. There was significant variability in the findings related to intraoperative surgical time with 17 of the studies showing longer surgical times in the MIS cohorts and 20 demonstrating shorter surgical times in the MIS groups.6,10–15,17–19,21–24,26,28–35,37–42,44,45,48,51 When comparing the MIS to the open cohorts, the surgical time ranged from being 44.7% longer to 63.1% shorter.

TABLE 3

TABLE 3

Estimated blood loss (EBL) was reported in all but seven of the included studies.16,20,27,29,36,48,50 Lau et al 26 in 2011 were the only authors who failed to identify decreased blood loss in the MIS compared with the open cohorts. When comparing MIS to open T/PLIF, patients lost from 16.1 to 88.7% less blood when they underwent an MIS procedure.

Length of stay (LOS) was an outcome in all but eight of the included papers.10,11,24,25,36,37,44,50 Of those reporting on LOS, all but one study demonstrated shorter hospitalizations in patients undergoing MIS procedures. While Gu et al 21 in 2014 identified a 2.9% increase in LOS in the MIS cohort, the remainder of the studies showed a decrease in LOS ranging from 15.0 to 64.0%.

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Radiographic Outcomes

Rates of radiographic nonunion were examined in just over half of the included studies (Table 3, n = 23), with the techniques and timing of fusion assessment and criteria for diagnosing nonunion varying widely between the investigations.6,10–12,14,17–19,21,22,24,28,30–32,38,39,44,46,48,49,51 The same criteria were used for open and MIS within each individual paper, with none of the studies identifying a statistically significant difference in union rates between the surgical techniques. In the MIS cohorts reported nonunion rates ranged from 0 to 16.7% and in the open cohorts nonunions occurred in 0 to 7.9% of patients.

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Complication Rates

Complications were reported in 35 of the included 45 studies (Table 3). Of the studies reporting on complication rates, not a single study reported higher complication rates in the MIS cohort. Nine of the studies identified significantly higher complication rates in patients undergoing open T/PLIF, and the remainder failed to find a difference in complication rates.6,11–19,21–26,28–32,34,35,38,39,41–43,45–47,49,51 The complication rate in the MIS cohorts ranged from 0 to 40% while that in the open cohorts ranged from 0 to 52%.

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Patient-Reported Outcomes

Of the 45 included studies, 32 included some form of patient-reported outcome (Table 3). VAS scores for pain were the most commonly used patient-reported outcome. Twenty-six of these studies reported either total VAS or back VAS and/or leg VAS.6,11–15,17,18,21,22,28,30–33,36,39,40,42,43,45,46,48,49,51 In the MIS cohorts follow-up total, back VAS and leg VAS ranged from 2.0 to 4.7, 0.9 to 5.5, and 0.8 to 5.5 respectively. In the open cohorts follow-up total, back VAS and leg VAS ranged from 2.1 to 5.2, 0.9 to 5.9, and 1.0 to 7.0 respectively. There was no significant difference reported in final total, back VAS, or leg VAS between the MIS and open cohorts in the majority of the studies.

The ODI was the second most frequently used subjective outcome measure in the included studies, with 25 studies reporting on this outcome.6,12–15,17,21,22,24,28–30,32,34–36,38,39,42,43,46–48,51 At final follow-up the mean ODI scores in the MIS cohorts ranged from 10.0 to 44.0 and those in the open cohorts ranged from 6.4 to 46.1. Less frequently reported patient-reported outcome measures (PROMs) included the SF-36 (n = 3),28,36,39 SF-12 (n = 1),28 and EQ-5D (n = 2).14,32 No significant difference was observed in any of the studies on these PROMs at final follow-up between the open and MIS cohorts.

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Economic Outcomes

An examination of the economics of open versus MIS T/PLIF was included in nine of the included studies in our systematic review, three from the original publication, and seven from the updated search.18,32,33,35,40,42,48,49,53 A summary of the results of these economic evaluations is presented in Table 4. All papers demonstrated reduced hospital cost/charges in the MIS cohorts with a very wide range of 2.5% to 49.3%.

TABLE 4

TABLE 4

The simplest form of health economic evaluation cost identification, in which the absolute costs of open and MIS T/PLIF were compared with no examination of the role of clinical effectiveness, was used in seven of the studies.18,33,40,42,48,49,53 The largest of these was an examination of data collected from the Premier Perspective Database from 2002 to 2009 of 1667 patients undergoing MIS T/PLIF and 4439 who underwent open T/PLIF.48 In this study no significant difference in costs was identified in patients undergoing 1-level fusions; however, MIS surgery was associated with a $2106 (5.8%) cost decrease in 2-level fusions, with the majority of the cost-savings being attributable to lower hospital accommodation fees, OR costs, pharmacy costs, and laboratory costs for MIS surgery. In the five single-institution cost identification studies, MIS T/PLIF consistently demonstrated lower direct costs compared with open surgery, with cost-savings ranging from 6.1% to 49.3%.

The remaining two economic evaluations examined both costs and clinical outcome to assess cost utility of open versus MIS T/PLIF. In 2011, Rampersaud et al 35 determined 1-year cost utility using direct hospital costs and determined that the cost per quality adjusted life year (QALY) gained was $128,936 for an MIS fusion versus $232,912 in the open cohort. More recently, Parker et al 32 included both direct and indirect health care costs in their 2-year evaluation of the cost utility of MIS and open lumbar fusion. They found that at 2 years the cost per QALY gained for MIS surgery was $50,017 compared with $68,860 in the open group. This finding resulted from a lower indirect cost in the MIS group. Indirect costs accounted for 28% of total cost for MIS TLIF patients and 41% of total cost for open TLIF patients.

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DISCUSSION

In our first examination of the literature pertaining to this topic, 26 comparative studies had been published between 1950 and May 2012.5 In the subsequent 3 years, 19 more comparative studies of MIS versus open T/PLIF, including two new randomized controlled trials, have been published, with the number of investigations including some form of economic analysis increasing from three to nine. This rapid increase in the cumulative data pertaining to this topic confirms increased application of MIS techniques to lumbar fusion as well as the increasing need for spine surgeons to demonstrate both comparative clinical and economic effectiveness of the procedures they perform.

This updated qualitative systematic review of 45 low to very-low quality comparative studies demonstrates findings that are consistent with our initial publication. Though there is no clear difference in operative times between MIS and open fusion, MIS T/PLIF is associated with 16.1% to 88.7% less blood loss and 15.0% to 64.0% shorter hospital stays. At a mean follow-up of 25.0 and 21.4 months in the MIS and open cohorts respectively, there are also no differences in patient-reported outcomes including VAS, ODI, SF-36, SF-12, or EQ-5D scores. An increasing number of studies have reported complications rates in favor of MIS fusion, with nine of the studies demonstrating significantly higher complication rates in the open cohorts with none of the studies showing higher complication rates in the MIS cohort.

Even greater than the 73% increase in the number of publications examining open versus MIS T/PLIF has been the number of studies incorporating some form of economic analysis as one of their outcomes, with six new economic evaluations being published between June 2012 and September 2015, representing a 200% increase. All nine of the economic evaluations demonstrated cost-savings in the MIS group compared with the open cohort ranging from 2.5% to 49.3%. While the majority of these studies included only direct hospital costs, Parker et al 32 have shown that inclusion of indirect health care expenditures, specifically patient and caregiver loss of productivity, and longer-term follow-up is extremely important to successfully demonstrate the cost-utility of MIS T/PLIF. As a result of the durability of the improvements in health-related quality of life associated with lumbar fusion as well as lower complication rates and faster return to work, these authors have demonstrated that MIS lumbar fusion is a cost-effective surgical procedure for the treatment of spondylolisthesis at the $50,000 per QALY threshold.54,55

In addition to being consistent with the results of our initial investigations, the findings of this systematic review are also in line with three other recently published reviews of the literature pertaining to MIS versus open lumbar interbody fusion.6,7,56 In 2012, Habib et al 56 published the results of their search of PubMED/MEDLINE from January 2000 to January 2012 with inclusion of a “few historical reports” for completeness. A total of 14 comparative studies were identified, including six prospective and eight retrospective investigations. While seven of the included publications were not included in our review as a result of differences in databases searched and study inclusion criteria, their results pertaining to surgical times, EBL, and LOS were consistent with our findings, while reported complication rates ranged from 2% to 31.7% in the open cohorts and 0 to 31.6% in the MIS cohorts.57–61 However, these authors failed to include an analysis of patient-reported outcomes or economic evaluations in their review.

Subsequently, Tian et al (2013) published their systematic review and meta-analysis of 11 studies identified in a search of MEDLINE from database inception to July 2012, all of which have been included in this review.6,13,14,19,26,28,37,38,45–48 In their qualitative analysis of results of clinical function the authors concluded that back pain VAS improvement was better in the MIS with five of six studies reporting on ODI showing better improvement after MIS surgery. They also demonstrate no significant difference in operative times, less blood loss, and shorter hospital stay in the MIS cohorts. Complication and reoperation rates were similar between the treatment groups.

Sidhu et al 7 completed a systematic review of studies published in MEDLINE, Scopus, and the Cochrane Register of Controlled Trials until May 24, 2013. The authors reported that there had been no randomized controlled trials published examining the outcomes of MIS versus open posterior lumbar interbody fusion (PLIF) and thus the included prospective and retrospective comparative cohort studies. A total of seven publications were included, with two studies enrolling 72 patients being ones that were not included in this review.18,62,63 The authors reported inconsistent results with regards to operative time but less intraoperative blood loss in five of the seven studies in the MIS PLIF groups and shorter LOS in the MIS groups in all seven studies. Five of the seven studies failed to identify a benefit for MIS PLIF with regards to validated outcome scores including VAS and ODI. No differences in complication rates were observed between the groups. All of these findings are consistent with those of the current review.

Though the consistency of the results from the 45 studies included in this review is highly suggestive of the validity of the findings, several limitations remain. Diagnostic heterogeneity continues to be an issue affecting our ability to draw definitive conclusions from these results with 27 of the studies including patients diagnosed with a variety of clinical conditions including spondylolisthesis (isthmic and/or degenerative), degenerative disc disease, spinal stenosis, or lumbar disc herniation. Given that the outcome of lumbar fusion depends on the diagnosis it is intended to treat, with spondylolisthesis being associated with incrementally improved clinical outcomes, it remains to be seen whether extrapolation of the results of these studies to all degenerative lumbar conditions is equally valid.64

In addition, fusion rates were not provided in a majority of papers studied and there was no standardized radiographic protocol for assessment of fusion with techniques ranging from plain radiographs with or without dynamic studies to CT scans with the timing of these studies varying across the articles included. This limited our ability to report more granular details pertaining to radiographic versus clinically significant nonunion requiring reoperation. However, as the same assessment method was used in each treatment arm in each study, and as little evidence to suggest that radiographic fusion is a reliable predictor of clinical or economic outcomes exists, we do not believe this would impact our conclusions.

We further acknowledge that while it appears complication rates are equal between open and MIS fusion based on our results, not all complications carry the same morbidity and potential for long-term effects. As complication reporting was inconsistent between the studies with regards to severity, timing, and method of collection, it is possible that while overall rates are similar, the long-term impact of complications may vary depending on which types of complications occur with open versus MIS procedures.

Furthermore, only two of the 19 new studies are randomized controlled trials. As a result, the general limitations of retrospective study designs remain as evidenced by the persistent low to very low quality of the prospective and retrospective nonrandomized studies. Small sample sizes may continue to prevent these investigations from being adequately powered to detect a minimal clinically important difference in patient-reported outcomes. Selection bias in accordance with patient symptomatology, surgeon and/or patient preferences, changes in practice patterns, payer status, or disease severity may also explain the absence of a difference in VAS and HRQoL scores between the open and MIS cohorts. In addition, we did include a large administrative data study that may have included some of the same patients from the other US studies. However, this only reported LOS and hospital cost data which was used only in a qualitative manner. Given that the findings were consistent with the other smaller studies, it did not have any weighted impact on the conclusions of our review.

Finally, the increase in the number of economic evaluations included in this review suggests that spine surgeons are becoming increasingly aware of the relative importance of health economic data to health care payers and policy makers when making decisions regarding allocation of health care resources. In light of relative clinical equipoise, the results highlight adoption of MIS lumbar fusion for 1- or 2-level degenerative conditions as a possible source of legitimate cost-minimization in the current health care climate where neck and back problems cost the United States almost $90 billion dollars annually.65,66 However, the very limited quality of these studies, varying costing data, and very wide range of the effect size (2.5–49.3%) prevents definitive conclusions regarding the comparative cost-effectiveness of MIS versus open T/PLIF from being drawn.67

Only one of the nine investigations considered costs from a societal perspective, with the remainder focusing solely on direct health care expenditures.32 Though this study did demonstrate cost effectiveness of MIS TLIF at 2 years, a finding consistent with the predictions of Rampersaud et al,35 it is the only study that has done so. Since at least 85% of the total costs of treatment of low back pain are related to loss of productivity and patients undergoing MIS TLIF return to work approximately 50% faster than their open counterparts, it is imperative that further cost evaluations include both direct and indirect costs for the results to adequately reflect the potential benefits of MIS T/PLIF.14,68 Going forward, we would also caution spine surgeons reporting health economic data to have a better understanding of the fundamental methodology and definitions utilized in health economic evaluations.66,67 For example, Sulaiman and Singh42 use the term “cost-utility analysis” in their article title and conclude that MIS-TLIF is more “cost-effective.” Unfortunately, they did not utilize a health utility measure, nor did they report any components of a cost-effectiveness analysis to justify their title or support their conclusion. More appropriately, the authors presented a component of a cost consequence analysis (CCA) where costs were presented in a disaggregated manner from a variety of important clinical and patient-reported outcomes.69–71 Interestingly, the clinical and patient-reported findings of this and other systematic reviews would actually suggest that a CCA approach may be better suited to comparing two relatively equal interventions.71 Practically, a CCA approach accepts that there are different types of benefits that cannot be measured in the same units (e.g., health utility score vs. earlier return to work) and allows for the fact that different decision makers will place different weights on the different benefits and costs associated with a given health intervention.

In conclusion, this updated systematic review provides consistent, evidence, albeit of limited methodological quality, in support of MIS T/PLIF as a viable option for the treatment of 1- and 2-level degenerative conditions of the lumbar spine. The current comparative literature demonstrates improved perioperative outcomes including operative time, estimated blood loss, and length of stay with no significant difference in patient-reported outcomes or complication rates between the MIS versus open groups at final follow-up. From an economic perspective, a limited number of studies suggest both direct and indirect cost-savings in favor of MIS fusion for 1–2 level cases. Though further comparative studies are unlikely to alter the results pertaining to perioperative clinical measures such as operative time, blood loss and hospital stay, or to intermediate-term patient-reported outcomes, adequately powered randomized trials or large multicenter prospective studies enrolling patients with a single diagnosis and including parallel health economic evaluations from a societal perspective are needed to cement MIS T/PLIF as a safe, clinically effective, and cost-effective treatment for degenerative conditions of the lumbar spine.

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Key Points

  • Minimally invasive techniques for lumbar spine fusion demonstrate lower estimated blood loss and shorter hospital stay compared with conventional open techniques.
  • Surgical complication rates appear equivalent between MIS and open cohorts.
  • Patient-reported outcome scores, including health-related quality of life and visual analog scale leg and back, are equivalent for open and minimally invasive lumbar fusion at intermediate-term follow-up.
  • Cost consequence analyses demonstrate consistent cost-savings in favor of MIS versus open T/PLIF.
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Acknowledgments

The authors thank Kyle Malone and Sarika Tandon from NuVasive for their administrative and editorial support.

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Keywords:

comparative effectiveness; complications; cost effectiveness; economic analysis; lumbar fusion; minimally invasive spine surgery; posterior lumbar interbody fusion; systematic review; transforaminal lumbar interbody fusion

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