This paper reviews the current published data regarding open transforaminal lumbar interbody fusion (TLIF) in relation to minimally invasive transforaminal lumbar interbody fusion (MI-TLIF).
The advent of minimally invasive surgery has provided surgeons new techniques for treating clinical disease. Within the field of spinal surgery, techniques in lumbar interbody arthrodesis have shown a continued evolution of procedural approach and instrumentation. Minimally invasive spine surgery aims to reduce approach related morbidity, while producing clinical outcomes comparable to its open predecessors. One important example of this is the development of minimally invasive techniques for lumbar interbody fusion, including transforaminal lumbar interbody fusion (TLIF) [
The MI-TLIF technique, has displayed comparable outcomes to open TLIF, while adding the benefits of less approach-related morbidity, decreased intraoperative blood loss, and shorter hospital stays [
In this paper, we evaluate the literature to examine the efficacy of MI-TLIF compared to its open counterpart. In addition, key studies discussing the risks and benefits of MI-TLIF were included to more thoroughly explore the nature of the technique and its application.
In this paper, the authors have used the PubMED/MEDLINE search engines to search for relevant reports addressing the topic of transforaminal lumbar interbody fusion. This was primarily done from Janurary 2000 to Janurary 2012. However, a few historical reports have been added for completeness. Included in this search was the following key phrases: “Minimally invasive,” “transforaminal,” “interbody fusion,” and “lumbar.” We included only English language reports. Further, although articles were first identified by abstract, only full text manuscripts were used to compile this review of the topic. We did not include individual case reports unless associated case series data was included. Further, inclusion criteria were based on the study’s contribution in terms of original data, technical variations, and contrasts between open and minimally invasive versions of the procedure ideally completed at the same institution.
In total, 14 articles were selected on the aforementioned basis. All contributed to the established body of the literature pertaining to lumbar arthrodesis techniques, particularly different variants of TLIF. Six of the 14 articles were prospective studies, while the remaining 8 were retrospective (Table
Summary of research studies reporting data on MI-TLIF.
Author (year) | Study design | Follow-up | Number of patients | Significant results |
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Scheufler et al. (2007) [ |
Retrospective | 8 months, 16 months | 53 | OR time equivalent between pTLIF and mini-open TLIF |
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Villavicencio et al. (2010) [ |
Retrospective | 37.5 months | 63 and 76 patients | Mean blood loss lower in MI-TLIF |
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Schizas et al. (2009) [ |
Prospective | 22 months (MI) |
36 patients |
MI-TLIF: decreased blood loss, shorter hospital stay, and decreased pain |
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Dhall et al. (2008) [ |
Retrospective | 24 months (MI) |
21 (MI) |
MI-TLIF: less blood loss, shorter LOS |
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Jang and Lee (2005) [ |
Pilot | 30 months | 100 consecutive patients | Significant reduction in pain, ODI, and TIS |
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Peng et al. (2009) [ |
Prospective | 6 months, 2 years | 29 (MI), 29 (O) | MI-TLIF: fluoroscopic time increased, longer operative times, less blood loss, decreased morphine use, and decreased LOS |
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Beringer and Mobasser (2006) [ |
Prospective | 6 months | 8 | All had solid bone fusions |
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Park and Foley (2008) [ |
Retrospective | Minimum 24 months, |
40 | Mean ODI 55→16 post-op |
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Deutsch and Musacchio (2006) [ |
Prospective | 6–12 months | 20 | 85% had >20 point reduction in ODI |
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Jang and Lee (2005) [ |
Prospective | 19 months | 23 | NRS back pain 7.5→2.3 |
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Isaacs et al. (2005) [ |
Retrospective | n/a | 20 | METLIF: less blood loss, less postoperative wound drainage, no dural violation, less pain medication, and shorter LOS |
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Shunwu et al. (2010) [ |
Prospective cohort study | 24–42 months | 32 (MI), 30 (O) | MI: reduced blood loss, les postoperative back pain, lower serum creatine kinase, shorter time to ambulation, and shorter LOS |
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Wang et al. (2010) [ |
Prospective | Minimum 13-month follow-up | MI = 42, O = 43 | MI: reduced blood bloss, less postoperative back pain, shorter LOS, greater radiation time |
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Foley et al. (2003) [ |
Retrospective | 12–20 months, mean 22 months | 39 patients | Twenty-six had excellent outcomes and 12 had good ones, as determined by the modified MacNab criteria |
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Schwender et al. (2005) [ |
Retrospective | 22.6 mean follow-up | 49 patients | Estimated blood loss of 140 mL, mean length of hospital stay 1.9 days, and all 45 patients presenting with preoperative radiculopathy had resolution of symptoms |
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Dong et al. (2008) [ |
Retrospective | 38.6 mean follow-up | 27 patients | Solid fusion in 77.8% of patients, clinical success achieved in 88.9% of cases |
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Anand et al. (2006) [ |
Prospective | 30 | 100 | Improvement in VAS, ODI, TIS, and NRS for back, 99% fusion |
After failed conservative management for a minimum of 6 months, surgery becomes the next therapeutic option for patients presenting with degenerative disc disease (DDD), radiculopathy with spinal instability, and/or grade 1 spondylolisthesis. Initially patients are assessed through radiological investigations including X-ray (AP, lateral, flexion, and extention), and noncontrast lumbosacral MRI. Length of hospitalization is determined by postoperative pain control and functional dependence, with patients of advanced age or medical comorbidities often requiring longer postoperative recovery. However, a majority of patients are admitted the day of surgery and discharged within 24–72 hours after operation.
Under general anesthesia, patients are fixed in a Wilson frame in a prone position. The patient is prepped and draped in standard fashion, and a fluoroscopic C-arm is positioned in the sterile field. Under fluoroscopic guidance the appropriate level is marked and a 3 cm incision is made 4.5 cm of off midline. A k-wire is targeted to the bony complex at the surgical level and serial dilators are consecutively passed to split the muscle fibers. Proper orientation is confirmed by fluoroscopic imaging. A working channel is placed, the dilators are removed, and the channel is secured appropriately for adequate visualization of the medial portion of the facet and inferior lamina. A curette is used to detach the ligamentum flavum from the inferior edge of the lamina, and a kerrison is used to perform the hemilaminectomy. The unilateral facet can be removed using an osteotome or high-speed drill. Following adequate exposure of the disc space, a discectomy is performed using a pituitary rongeur and curette.
Curved and angled curettes and a disc scraper are then used to prepare the end plate. An appropriately sized interbody spacer is inserted into the disc space, and a half sponge of BMP is packed into the disc space. Fluoroscopy is used to confirm proper positioning of the interbody cage. After removal of the working channel, a jamshidi needle is localized to the unilateral pedicle either above or below the discectomy level, and positioning is checked using fluoroscopic imaging. A K-wire driver is used to insert a guide wire into the superficial portion of the pedicle. A SEXTANT percutaneous screw system (Medtronic Inc; Memphis, TN) is used to pass a cannulated pedicle screw over the K-wire and into the pedicle under fluoroscopic guidance. This is repeated at all desired pedicles on either side. The SEXTANT holding sleeves are mated, the percutaneous rod holder and guide are attached, and a small skin incision is made to pass the rod percutaneously through the screw head. After correct positioning of the rod is confirmed with fluoroscopy, the screw head is tightened, the rod holder is released, and the holding sleeve is removed. Skin closure is accomplished in the standard fashion. For a full detailed description see Lawton et al. [
(a) Preoperative lateral MR image of a 72 y/o female patient with back and left leg pain and L4/L5 spondylolisthesis; (b) post-operative lateral MR image from a patient who underwent an MI-TLIF for spondylolisthesis at L4/L5.
(a) Preoperative lateral MR image of a 66 y/o female with L4/L5 and L5/S1 spondylolisthesis and neuroforaminal stenosis; (b) Post-operative lateral MR image from a patient who underwent an MI-TLIF for spondylolisthesis at L4/L5, L5/S1.
As noted, our review included 14 articles. Follow-up times ranged across all articles from 6 months to 42 months. The mean follow-up was 20 months, with a mean patient cohort of 52 patients. Within seven of the articles that directly compared outcomes of open TLIF with MI-TLIF, mean duration of MI-TLIF surgery was 220 minutes, compared to 218 minutes for its open counterpart. Furthermore, blood loss was found to be on average 282 mL in MI-TLIF cases, while open TLIF resulted in 693 mL of blood loss. The length of stay for MI-TLIF was found to be 5.6 days, while open TLIF had patients in the hospital for an average of 8.1 days (see Table
Comparative studies basic data.
Author | Mean duration of surgery MIS | Mean duration of surgery open | MIS blood loss | Open blood loss | Length of stay MIS | Length of stay open |
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Villavicencio et al. | 222.5 | 214.9 | 163 mL | 366.8 | 3 | 4.2 |
Shunwu et al. | 159.2 | 142.8 | 399.8 | 517 | 9.3 | 12.5 |
Wang et al. | 156 (X-ray 84) | 145 (37) | 264 | 673 | 10.6 | 14.6 |
Peng et al. | 216.4 (fluoro 105.5 s) | 170 (35.2) | 150 | 681 | 4 | 6.7 |
Schizas et al. | 348 (X-ray 2.7 cGy/cm2) | 312 (1.8) | 456 | 961 | 6.1 | 8.2 |
Dhall et al. | 199 | 237 | 194 | 505 | 3 | 5.5 |
Isaacs et al. | 300 | 276 | 226 | 1147 | 3.4 | 5.1 |
Though the literature displayed possible benefit of MI-TLIF relative to its open counterpart, both procedures are associated with possible complications. Major sources of complications shared by MI-TLIF and Open TLIF are allograft malposition, pedicle screw malposition, and infection [
Each approach was also associated with its own unique complications. Complications more likely to be found in the open TLIF approach include infections and muscular trauma as a result of the increased exposure and soft tissue dissection [
Complications found in studies comparing open TLIF to MI-TLIF.
Complication type | Complication rate | ||||
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Author | Year | Open | MI | Open | MI |
Peng et al. [ |
2009 | Atelectasis-(1) |
Infection-(1) | 13.5% | 6.9% |
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Dhall et al. [ |
2008 | Radiculitis (1) |
Transient L-5 sensory loss (2) |
2% | 5% |
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Schizas et al. [ |
2009 | NR | Increased pseudarthrosis | 2% | 6% |
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Isaacs et al. [ |
2005 | Infection |
Transient leukopenia (1) | 6% | 0% |
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Wang et al. [ |
2010 | Pedicle screw malposition (1) |
Radiculopathy (2) |
4% | 5% |
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Villavicencio et al. [ |
2010 | CSF leak | Neurological deficit > 3 mos |
31.7% | 31.6% |
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Shunwu et al. [ |
2010 | Superficial wound infection (1) |
Screw malposition (2) |
5% | 6% |
In the MI-TLIF literature reviewed, many authors discussed the challenging learning curve associated with MI-TLIF, which makes certain complications, particularly those related to instrumentation more likely [
Complication rate by TLIF approach.
Complications | MI | Open |
---|---|---|
Infection | 6.9% | 23.5% |
UTI | 3.4% | 11.8% |
Neurologic deficits | 20.7% | 11.8% |
Screw/Cage complications | 44.8% | 11.8% |
CSF leak | 10.3% | 5.9% |
Blood transfusion/coagulation | 3.4% | 11.8% |
Other | 10.5% | 23.4% |
The operative surgeon additionally must be familiar with 3D lumbar anatomy and be able to carefully interpret 2D radiographic images to make a mental reconstruction. This is a unique skill and one that is not as critical with a traditional, open approach. The surgeon must be able to read anterior-posterior and lateral imaging in order to accurately insert percutaneous pedicle screws, thereby allowing for possible misinterpretation leading to complications [
Radiation exposure is another area of interest. MI-TLIF itself presents with increased risk to the surgeon related to increased radiation exposure due to lengthened intraoperative fluoroscopy times. Though many may claim that a surgeon’s experience level with minimally invasive procedures will dictate their fluoroscopy times, some studies found no significant difference as experience increased [
Following data collection and the literature review, it is clear that there is a paucity of data comparing MI-TLIF and open TLIF. To our knowledge, there remains no high-class studies that directly compare these two techniques. However, smaller studies, both prospective and retrospective in nature, have shown promise in regards to novel MI techniques for TLIF.
Scheufler et al. compared percutaneous transforaminal lumbar interbody fixation (pTLIF) with mini-open transforaminal lumbar interbody fixation (oTLIF) while utilizing the Wiltse method [
In a study examining 42 patients with mean follow-up time of 29 months, Dhall et al. compared mini-open and open TLIF [
Schwender et al. performed one of the earlier studies (2001-2002) on 49 patients who had MI-TLIF. Majority of patients in the study either had degenerative disc disease with herniated nucleus pulposus (HNP) or spondylolisthesis [
A variation of the accepted microendoscopic discectomy was completed by Isaacs and colleagues, which was termed METLIF [
Schizas et al. examined their institutional experience executing both MITLIF and open midline transforaminal lumbar interbody fusion [
MI-TLIF complication types and complication rates.
Author | Year | MI-TLIF complication type | MI-TLIF complication rates |
---|---|---|---|
Scheuffler et al. [ |
2007 | CSF leak (1) | 1.9% |
Deutsch and Musacchio [ |
2006 | Misplaced screw (1) |
4 |
Dong et al. [ |
2008 | UTI (1) |
7.4% |
Jang and Lee [ |
2005 | Subsidence (3) |
17.4% |
Scwender et al. [ |
2005 | Misplaced screws (2) |
8.2% |
Beringer and Mobasser [ |
2006 | NR | NR |
Park and Foley [ |
2008 | NR | NR |
Anand et al. [ |
2006 | NR | NR |
Lumbar arthrodesis is an effective method for treating spinal pathology such as spondylolisthesis, DDD, and spinal instability. As minimally invasive spine procedures have emerged, variants such as minimally invasive discectomy and minimally invasive cervical foraminotomies have allowed for reduced complications related to tissue trauma, while reducing blood loss and shortening recovery time [
Once the procedure is mastered, its application can positively impact patient care in numerous ways. But, the fundamental advantage of MI-TLIF comes from its decrease in tissue trauma and overall exposure of the patient. This can reduce infection, blood loss, and time to recovery. A prospective cohort study was carried out by Shunwu et al. with 62 patients that had undergone single level TLIF by a single surgeon in a single hospital [
As a minimally invasive procedure, MI-TLIF can be utilized to treat particular pathologies, while maintaining the same high levels of clinical success as the open TLIF, even with over two years of follow-up. Thus, the long-term results are comparable to that of open TLIF. Park and Foley contributed an article to the literature that described MI-TLIF in 40 consecutive patients who were diagnosed with spondylolisthesis [
Aside from particular pathologies that would benefit from MI-TLIF, there are certain populations that could benefit from the decreased tissue disruption and decreased blood loss. In elderly patients, Lee et al. completed a retrospective review of 27 consecutive cases and found a low complication rate and beneficial outcomes for patients over the age of 65 [
Though the studies presented displayed heterogeneous patient populations with different indications for lumbar arthrodesis, there were many patterns seen across studies. Aside from possible complications such as screw displacement and neurological deficit, which were often related to a steep learning curve, MI-TLIF displayed no significant disadvantages when compared to open TLIF or other standard lumbar fusion techniques. The risks of blood loss, narcotic administration, pseudorthrosis, and infection all are equivalent if not decreased when utilizing MI-TLIF as a possible technique. Various postoperative recovery and pain rating scales often showed consistent improvement across many of the studies presented herein. MI-TLIF and open TLIF are quite similar in absolute indications and often present with similar complications, thus a randomized clinical trial would be beneficial in further elucidating the risks and benefits associated with each. As other variations emerge for MI-TLIF, such as METLIF, there is still need for an overall meta-analysis of all available data, comparing minimally invasive technique to traditional, open procedures.
Posterior lumbar interbody fusion
Anterior lumbar interbody fusion
Transforaminal lumbar interbody fusion
Minimally invasive transforaminal lumbar interbody fusion
Degenerative disc disease
Length of stay
Visual analog scale
Oswestry Disability Index.
There is no conflict of interests or funding source for this paper or the data contained within it.