Minimally Invasive Computer Navigation-Assisted Endoscopic Transforaminal Interbody Fusion with Bilateral Decompression via a Unilateral Approach: Initial Clinical Experience at One-Year Follow-Up

Evolution of Cervical Endoscopic Spine Surgery: Current Progress and Future Directions-A Narrative Review

Cervical endoscopic spine surgery is rapidly evolving and gaining popularity for the treatment of cervical radiculopathy and myelopathy. This approach significantly reduces muscular damage and blood loss by minimizing soft tissue stripping, leading to less postoperative pain and a faster postoperative recovery. As scientific evidence accumulates, the efficacy and safety of cervical endoscopic spine surgery are continually affirmed. Both anterior and posterior endoscopic approaches have surfaced as viable alternative treatments for various cervical spine pathologies. Newer techniques, such as endoscopic-assisted fusion, the anterior transcorporeal approach, and unilateral laminotomy for bilateral decompression, have been developed to enhance clinical outcomes and broaden surgical indications. Despite its advantages, this approach faces challenges, including a steep learning curve, increased radiation exposure for both surgeons and patients, and a relative limitation in addressing multi-level pathologies. However, the future of cervical endoscopic spine surgery is promising, with potential enhancements in clinical outcomes and safety on the horizon. This progress is fueled by integrating advanced imaging and navigation technologies, applying regional anesthesia for improved and facilitated postoperative recovery, and incorporating cutting-edge technologies, such as augmented reality. With these advancements, cervical endoscopic spine surgery is poised to broaden its scope in treating cervical spine pathologies while maintaining the benefits of minimized tissue damage and rapid recovery.

Comparison of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via unilateral approach and open-TLIF with bilateral decompression for degenerative lumbar diseases: a retrospective cohort study

OBJECTIVE

Presently, no study has compared the clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via the unilateral approach (BDUA) and Open-TLIF with bilateral decompression for degenerative lumbar diseases (DLD). We aimed to compare the clinical outcomes of through Mis-TLIF combined with BDUA and Open-TLIF with bilateral decompression for the treatment of DLD, and reported the learning curve of the procedure of MIS-TLIF with BDUA.

METHODS

We retrospectively analyzed the prospectively collected data of consecutive DLD patients in the two groups from January 2016 to January 2020.

RESULTS

The operative time (OT) was significantly longer in the Mis-TLIF group (n = 113) than in the Open-TLIF group (n = 135). The postoperative drainage volume (PDV) and length of stay (LOS) were significantly higher in the Open-TLIF group than in the Mis-TLIF group. Additionally, the complication rate was significantly higher in the Open-TLIF group than in the Mis-TLIF group (14.8% vs. 6.2%, P = 0.030), while there was no significant difference in the reoperation and adjacent segment disease rates between the two groups. There were no significant differences in back pain and leg pain Numerical Rating Scale (NRS) scores and Oswestry Disability Index (ODI) between the two groups preoperatively, at discharge, and 2 years postoperatively. Patients in both groups showed significant improvements in NRS scores and ODI scores after surgery. OT was negatively correlated with the number of surgeries performed (P < 0.001, r =  -0.43). The learning curve of Mis-TLIF with BDUA was steep, with OT tapered to steady state in 43 cases.

CONCLUSION

Compared with Open-TLIF with bilateral decompression, Mis-TLIF with BDUA can achieve equivalent clinical outcomes, lower PDV and LOS, and lower complication rates. Although this procedure took longer, it could be a viable alternative for the treatment of DLD after a steep learning curve.

Applications of navigation in full-endoscopic spine surgery

PURPOSE

Advancement in all surgery continues to progress towards more minimally invasive surgical (MIS) approaches. One of the platform technologies which has helped drive this trend within spine surgery is the development of endoscopy; however, the limited anatomic view experienced when performing endoscopic spine surgery requires a significant learning curve. The use of intraoperative navigation has been adapted for endoscopic spine surgery, as this provides computer-reconstructed visual data presented in three dimensions, which can increase feasibility of this technique to more surgeons.

METHODS

This paper will describe the principles, technical considerations, and applications of stereotactic navigation-guided endoscopic spine surgery.

RESULTS

Full-endoscopic spine surgery has advanced in recent years such that it can be utilized in both decompressive and fusion surgeries. One of the major pitfalls to any minimally invasive surgery (including endoscopic) is that the limited surgical view can often complicate the surgery or confuse the surgeon, leading to longer operative times, higher risks, among others. This is the real utility to using navigation in conjunction with the endoscope-when registered correctly and utilized appropriately, navigated endoscopic spine surgery can take some of the guesswork out of the minimally invasive approach.

CONCLUSIONS

Using navigation with endoscopy in spine surgery can potentially expand this technique to surgeons who have yet to master endoscopy as the assistance provided by the navigation can alleviate some of the complexities with anatomic understanding and surgical planning.

Comparison between OLIF and MISTLIF in degenerative lumbar stenosis: an age-, sex-, and segment-matched cohort study

To compare outcomes after oblique lateral interbody fusion (OLIF) versus minimally invasive transforaminal lumbar interbody fusion (MISTLIF) with bilateral decompression via unilateral approach for treating mild to moderate symptomatic degenerative lumbar spinal stenosis (DLSS). We retrospectively compared patients who underwent single-level (L4/5) OLIF with an age-, sex-, and segment-matched MISTLIF with bilateral decompression via unilateral approach cohort. Perioperative data were collected for the operative time, intraoperative blood loss, drainage in the first postoperative day, postoperative hospital stay, cost, intraoperative fluoroscopy, and complications. Lumbar radiographs were measured for changes in posterior intervertebral space height (PISH), intervertebral space foramen height (IFH), intervertebral foramen area (IFA), and area of the spinal canal (ASC). Clinical and psychological outcomes included the visual analog scale (VAS), Oswestry Disability Index (ODI), and hospital anxiety and depression scale (HADS). 35 OLIF patients were compared with 35 MISTLIF patients in L4/5 DLSS. The OLIF group had shorter bedtime, postoperative hospital stays, less intraoperative and postoperative blood loss (all P < 0.05), but had more times of intraoperative fluoroscopy, longer operative time, and higher cost (all P < 0.05). The complication rates were equivalent (OLIF vs MISTLIF: 22.86% vs 17.14%). PISH (11.94 ± 1.78 mm vs 9.42 ± 1.94 mm, P < 0.05), IFH (23.87 ± 3.05 mm vs 21.41 ± 2.95 mm, P < 0.05), and IFA (212.14 ± 51.82 mm2 vs 177.07 ± 51.73 mm2, P < 0.05) after surgery were significantly increased in the OLIF group. The ASC was increased significantly after the operation in both groups, but the ASC in the MISTLIF group was increased significantly more than that in the OLIF group (450.04 ± 66.66 mm2 vs 171.41 ± 58.55 mm2, P < 0.05). The lumbar VAS scores at 1 month (1.89 ± 0.87 vs 2.34 ± 0.84, P = 0.028) and 6 months (1.23 ± 0.97 vs 1.80 ± 0.99, P = 0.018) after operation in the OLIF group were significantly lower. There were no significant differences in lower extremity VAS and ODI scores between the two groups. Compared with MISTLIF group, HADS scores on postoperative day 3 (2.91 ± 1.46 vs 4.89 ± 1.78, P < 0.05) and prior to hospital discharge (PTD) (2.54 ± 1.38 vs 3.80 ± 1.78, P = 0.002) in the OLIF group were decreased significantly. OLIF showed more advantages of less surgical invasion, lower incidence of postoperative low back pain, faster postoperative recovery, and less anxiety compared with MISTLIF. Regardless of cost, OLIF seems to be a better option to treat mild to moderate symptomatic DLSS.

Angulation error assessment for the trajectory in the anteroposterior and lateral fluoroscopic views during percutaneous endoscopic transforaminal lumbar discectomy

BACKGROUND

Anteroposterior (AP) and lateral fluoroscopies are often used to evaluate the intraoperative location and angulation of the trajectory in percutaneous endoscopic transforaminal lumbar discectomy (PETLD). Although the location of the trajectory shown in fluoroscopy is absolutely accurate, the angulation is not always reliable. This study aimed to evaluate the accuracy of the angle shown in the AP and lateral fluoroscopic views.

METHODS

A technical study was performed to assess the angulation errors of PETLD trajectories shown in AP and lateral fluoroscopic views. After reconstructing a lumbar CT image, a virtual trajectory was placed into the intervertebral foramen with gradient-changing coronal angulations of the cephalad angle plane (CACAP). For each angulation, virtual AP and lateral fluoroscopies were taken, and the cephalad angles (CA) of the trajectory shown in the AP and lateral fluoroscopic views, which indicated the coronal CA and the sagittal CA, respectively, were measured. The angular relationships among the real CA, CACAP, coronal CA, and sagittal CA were further demonstrated with formulae.

RESULTS

In PETLD, the coronal CA is approximately equal to the real CA, with a small angle difference and percentage error, whereas the sagittal CA shows a rather large angle difference and percentage error.

CONCLUSION

The AP view is more reliable than the lateral view in determining the CA of the PETLD trajectory.

[Clinical study on real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion]

OBJECTIVE

To analyze the technical notes, effectiveness, and current issues of real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion.

METHODS

Between April 2020 and October 2021, a total of 27 patients received real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion. There were 18 males and 9 females with an average age of 63.2 years (range, 48-84 years). There were 6 cases of lumbar spinal stenosis, 1 case of lumbar instability, 9 cases of lumbar spinal stenosis with instability, 3 cases of degenerative spondylolisthesis, 6 cases of isthmus spondylolisthesis, and 2 cases of recurrent lumbar disc herniation. All patients showed neurological symptoms before operation (ipsilateral symptom for 15 cases and bilateral symptom for 12 cases). The symptom duration was 1-300 months (median, 24 months). The operations were performed via transforaminal approach in 8 cases, trans-facet joint approach in 18 cases, and combined approaches in 1 case. A total of 32 levels were fused, including 23 single-level cases, 3 two-level cases, and 1 three-level case. Lumbar fusion segment was L _{2, 3} in 1 case, L _{3, 4} in 4 cases, L _{4, 5} in 20 cases, and L ₅, S ₁ in 7 cases. The operation time, intraoperative estimated blood loss (IEBL), and perioperative complications were recorded. The improvement of intervertebral space height at fusion level was measured, and the accuracy of percutaneous pedicle screw (PPS) and Cage placement was also evaluated based on CT images performed at 1 week postoperatively. Visual analogue scale (VAS) score for both low back pain and leg pain, Japanese Orthopaedic Association (JOA) score, and Oswestry disability index (ODI) were evaluated before operation, at 1 week postoperatively, and at last follow-up. Satisfaction to effectivenss were assessed by patients using modified MacNab criteria at last follow-up.

RESULTS

The operation time was ranged from 255 to 805 minutes (mean, 424.9 minutes). IEBL was 150-290 mL (mean, 219.3 mL). All patients received follow-up with the duration from 4 to 22 months (mean, 12.4 months). At 1 week postoperatively and last follow-up, VAS scores of low back pain and leg pain, JOA score, and ODI were significantly improved when compared with those before operation ( P<0.05). At last follow-up, the clinical indicators were similar in comparison with those at 1 week postoperatively ( P>0.05). There were 26 patients and 1 patient who respectively ranked excellent and mild in terms of effectiveness according to the modified MacNab criteria, with the excellent and good rate of 96.3%. There was 1 patient who suffered from incomplete injury of L ₅ nerve root and partial neurological function recovered after 3-month conservative treatments. There were 118 implanted PPSs, and 116 of them were implanted under navigation. There were 33 Cages that were implanted under navigation. The accuracy of PPS and Cage placement was 99.1% and 97.0% respectively based on CT performed at 1 week postoperatively. The postoperative intervertebral space height was significantly increased in comparison with that before operation ( P<0.05). During follow-up, mild Cage subsidence was observed in 1 patient, whereas no fixation loosing was found.

CONCLUSION

Real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion has great safety and effectiveness with satisfactory preliminary clinical results. Design and further improvement of surgical equipment and instruments are expected to resolve the current technical difficulties.

Enhanced Recovery after an Innovative Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion for the Treatment of Lumbar Spinal Stenosis: A Prospective Observational Study

Background

The objective of this study was to investigate the enhanced recovery clinical effects of an innovative percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of patients with LSS and degenerative instability.

Methods

From January 2019 to March 2020, 51 patients with single-segment LSS and degenerative instability were prospectively included in our study (ChiCTR1900020679). The Oswestry Disability Index (ODI), the visual analogue scale (VAS) on lumbar and leg pain (VAS-LBP and VAS-LP), serum creatine kinase (CK), the peak intensity of sulphur hexafluoride microbubble contrast agent (PI), and the maximal cross-sectional area of multifidus muscle (Max-CSA) around the surgical incision were assessed preoperatively, postoperatively, and at regular follow-up.

Results

All patients were followed up. The mean postoperative bedridden time was 20.45 ± 2.66 hours. The ODI, VAS-LBP, and VAS-LP were improved significantly after operation compared to these data before operation in all the patients (P < 0.05). The CK at 1 day after operation was higher compared to the data before the operation (P < 0.05), and there was no significant difference on CK at 1 week after operation (P > 0.05). The PI at 1 week after operation was higher compared to this item before operation (P < 0.05), and there was no significant difference on PI at 1 month or 3 months after operation (P > 0.05). The Max-CSA at 1 week after operation was higher compared to this item before the operation (P < 0.05), and there was no significant difference in Max-CSA at 1 month or 3 months after operation compared with before the operation (P > 0.05).

Conclusions

Our results and systematic review presented the innovative PE-TLIF technique could obtain satisfactory and effective outcomes for the treatment of patients with LSS and degenerative instability. Our PE-TLIF technique also had the ability to decrease the MF injury and obtain an enhanced recovery.

Clinical outcomes of minimally invasive transforaminal lumbar interbody fusion via a novel tubular retractor

Objective

To assess the feasibility and clinical results of microscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a novel tapered tubular retractor that preserves the multifidus.

Method

A total of 122 patients underwent MIS-TLIF using a tapered tubular retractor system from March 2016 to August 2017. Perioperative parameters and follow-up outcomes were reviewed.

Results

The follow-up period was 23.95 ± 1.43 months. The operative time averaged 130.48 ± 34.44 minutes. The estimated blood loss was 114.10 ± 96.70 mL. The mean time until ambulation was 16.33 ± 6.29 hours. The average visual analogue scale (leg/waist) and Oswestry Disability Index scores (preoperative to last follow-up) improved from 4.93 ± 2.68/3.74 ± 2.28 to 0.34 ± 0.77/0.64 ± 0.74 and from 59.09% ± 22.34 to 17.04% ± 8.49, respectively. At the last follow-up, 98.36% of the patients achieved solid fusion. Cerebrospinal fluid leakage occurred in two cases. The asymptote of the surgeon’s learning curve occurred at the 25th case. There were no significant differences between the preoperative qualitative and quantitative analyses of multifidus muscle fatty infiltration and those at the final follow-up.

Conclusion

MIS-TLIF can be performed safely and effectively using this tapered tubular retractor system, which helps preserve the multifidus.

Surgical Outcomes After Single-Level Endoscopic Transforaminal Lumbar Interbody Fusion: A Systematic Review and Meta-Analysis

Background and objective Novel surgical advancements have introduced endoscopic operative techniques for low back surgery, including transforaminal lumbar interbody fusion (TLIF), which theoretically allows for improved decompression with minimal invasiveness. In addition, endoscopically performed TLIF has allowed for the use of local anesthesia as an alternative method to general anesthesia for patients. We aimed to evaluate the clinical outcomes in patients undergoing endoscopic TLIF and also compare the outcomes in patients undergoing general versus local anesthesia. Methods The databases of PubMed, Medline, Embase, and the Cochrane Library were queried for all studies involving patients undergoing endoscopic TLIF. After the extraction of the data and assessment of study quality via the Newcastle-Ottawa Scale, statistical analysis was performed with the R software (The R Foundation, Vienna, Austria) metafor package. The random-effects model was used as the data was largely heterogeneous (I2 >50%). Results In total, 15 studies involving a total of 441 patients were selected for the final quantitative meta-analysis. The overall mean difference between the postoperative visual analog scale (VAS) leg scores and preoperative VAS scores was 3.45 (95% CI: 4.93-1.97, p: <0.01). Postoperative VAS low back scores revealed a mean difference of 3.36 (95% CI: 5.09-1.63, p: <0.01). The overall mean difference of ODI scores was 4.58 (95% CI: 6.76-2.40, p: <0.01). Mean blood loss was 136.32 mL and the mean operative time was 149.15 minutes. The mean length of stay postoperatively was lower in the local anesthesia group compared to the general anesthesia group (1.40 vs 5.99 days respectively). There were no outcome variables of patients undergoing general anesthesia versus local anesthesia that showed statistically significant differences in this analysis due to the small amount of data published on patients undergoing endoscopic TLIF with local anesthesia. In addition, the failure of studies in reporting standard deviations as data parameters further limited the quantitative analysis. Conclusion Endoscopic TLIF appears to be a viable option for patients undergoing lumbar interbody fusion. Initial data reveal that endoscopic TLIF with local anesthesia may offer patients outcomes similar to those in patients undergoing endoscopic TLIF with general anesthesia, with lower operative times and length of stay.

Ten-Step Biportal Endoscopic Transforaminal Lumbar Interbody Fusion Under Computed Tomography-Based Intraoperative Navigation: Technical Report and Preliminary Outcomes in Mexico

BACKGROUND

The principal advantage of intraoperative spinal navigation is the ease of screw placement. However, visualization and the integration of navigation can be explored with the use of navigation-guided full-endoscopic techniques.

OBJECTIVE

To describe the stepwise intraoperative navigation-assisted unilateral biportal endoscopic transforaminal lumbar interbody fusion (UBE-TLIF) technique and to present our preliminary results in a Mexican population.

METHODS

A 10-step summary of the UBE-TLIF operative technique was described, and the clinical and radiological results are presented and analyzed.

RESULTS

A total of 7 patients were treated. We observed the value of integrating navigation and endoscopic visualization when decompression had to be performed.

CONCLUSION

Together, intraoperative navigation and direct visualization through the endoscope may be a useful surgical tool for surgeons with experience in endoscopic spinal surgery.

Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion with Endoscopic Disc Drilling Preparation Technique for Symptomatic Foraminal Stenosis Secondary to Severe Collapsed Disc Space: A Clinical and Computer Tomographic Study with Technical Note

Background: Severe collapsed disc secondary to degenerative spinal conditions leads to significant foraminal stenosis. We hypothesized that uniportal posterolateral transforaminal lumbar interbody fusion with endoscopic disc drilling technique could be safely applied to the collapsed disc space to improve patients’ pain score, restore disc height, and correct the segmental angular parameters. Methods: We included patients who met the indication criteria for lumbar fusion and underwent uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion with pre-operative Computer Tomography mid disc height of less than or equal to 5 mm and MRI of Grade 3 Foraminal Stenosis. Visual analogue scale and computer tomography pre-operative and post-operative sagittal disc height in the anterior, middle and posterior part of the disc; sagittal focal segmental angle; mid coronal disc height and coronal wedge angles were evaluated. Results: 30 levels of Endo-TLIF were included, with a mean follow up of 12 months. The mean improvement in decreasing pain score was 2.5 ± 1.1, 3.2 ± 0.9 and 4.3 ± 1.0 at 1 week post operation, 3 months post operation and at final follow up, respectively, p < 0.05. There was significant increase in mid sagittal computer tomographic anterior, middle and posterior disc height of 6.99 ± 2.30, 6.28 ± 1.44, 5.12 ± 1.79 mm respectively, p < 0.05. CT mid coronal disc height showed an increase of 7.13 ± 1.90 mm, p < 0.05. There was a significant improvement in the CT coronal wedge angle of 2.35 ± 4.73 and the CT segmental focal sagittal angle of 1.98 ± 4.69, p < 0.05. Conclusion: Application of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion in patients with severe foraminal stenosis secondary to severe collapsed disc space significantly relieved patients’ pain and restored disc height without early subsidence or exiting nerve root dysesthesia in our cohort of patients.

Comparison of Outcomes of Oblique Lateral Interbody Fusion with Percutaneous Posterior Fixation in Lateral Position and Minimally Invasive Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis

Study Design

Single-center retrospective study.

Purpose

To compare the physical function and quality of life (QOL) parameters of two minimally invasive surgical (MIS) procedures: oblique lateral interbody fusion with percutaneous posterior fixation in lateral position (OLIF-LPF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for single-level degenerative spondylolisthesis (DS).

Overview of Literature

To date, many options for the surgical treatment of lumbar DS and reports have described the effectiveness of minimally invasive lateral access surgery and MIS-TLIF. However, there is still a paucity of comparative data regarding the physical function and QOL outcomes of OLIF and MIS-TLIF.

Methods

Eighty-six patients were enrolled in this study (group O: OLIF-LPF, n=38; group T: MIS-TLIF, n=48). We evaluated the operation time, estimated blood loss (EBL), postoperative laboratory data, preoperative and postoperative radiographic parameters, overall functional outcome with the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) effectiveness rate, and Visual Analog Scale (VAS) score for low back pain, leg pain, and leg numbness.

Results

No statistical differences in operation time, EBL, and C-reactive protein level, 5 days postoperatively, between groups O and T. With respect to radiological outcome, preoperative and postoperative disc height change was significantly greater in group O than in group T (3.8 vs. 1.8 mm, p<0.05). Both groups showed postoperative improvements in the clinical outcome scores of all JOABPEQ domains, but the effectiveness rate increase in the psychological domain was significantly higher in group O than in group T (47.1% vs. 14.6%, p<0.05). No differences in the preoperative and postoperative VAS score change were noted between the two groups in any of the items.

Conclusions

The changes in physical function and QOL parameters after OLIF-LPF and MIS-TLIF were almost equivalent; however, OLIF-LPF had significant superiority in the psychological domain.

Technical Considerations of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion: A Review of Its Early Clinical Results in Application in Adult Degenerative Scoliosis

BACKGROUND

Uniportal endoscopic posterolateral lumbar interbody fusion (Endo-TLIF) provides one of the least invasive forms of minimally invasive surgery, allowing large size cages which are commercially available for open and tubular microscopic transforaminal lumbar interbody fusion (TLIF) to be inserted through this approach. We studied the effect of such a technique on a series of patients with low-grade degenerative scoliosis.

METHODS

Endo-TLIF was applied to patients who had 10°-40° of degenerative adult scoliosis. Pre- and postoperative 1-week, 3-month, and final follow-up clinical status of visual analog scale, Oswestry Disability Index, perioperative complications, and Macnab criteria were collected. Roentgenogram to assess changes in Cobb angles was done.

RESULTS

There was statistically significant improvement of preoperative, 1-week postoperative, 3-month postoperative, and final follow-up mean of visual analog scale scores with 7.72 (5-10), 3.68 (3-6), 2.88 (2-4), and 1.96 (1-3), respectively, and with Oswestry Disability Index mean of 70.4 (52-86), 35.12 (26-56), 27.68 (24-38), and 24 (20-28), respectively (P < 0.05). In terms of Macnab criteria, 100% had good to excellent result. In terms of scoliosis measured by Cobb angle, there was statistically significant improvement.

CONCLUSIONS

Endo-TLIF is a safe and effective procedure in mild to moderate degenerative scoliosis with good early clinical results and improvement in coronal Cobb angle. It can be considered as an option if a short segment(s) fusion is planned for adult degenerative scoliosis.

Defining the MIS-TLIF: A Systematic Review of Techniques and Technologies Used by Surgeons Worldwide

STUDY DESIGN

Systematic review.

OBJECTIVE

To date there is no consensus among surgeons as to what defines an MIS-TLIF (transforaminal lumbar interbody fusion using minimally invasive spine surgery) compared to an open or mini-open TLIF. This systematic review aimed to examine the MIS-TLIF techniques reported in the recent body of literature to help provide a definition of what constitutes the MIS-TLIF, based on the consensus of the majority of surgeons.

METHODS

We created a database of articles published about MIS-TLIF between 2010 and 2018. We evaluated the technical components of the MIS-TLIF including instruments and incisions used as well the order in which key steps are performed.

RESULTS

We could identify several patterns for MIS-TLIF performance that seemed agreed upon by the majority of MIS surgeons: use of paramedian incisions; use of a tubular retractor to perform a total facetectomy, decompression, and interbody cage implantation; and percutaneous insertion of the pedicle-screw rod constructs with intraoperative imaging.

CONCLUSION

Based on this review of the literature, the key features used by surgeons performing MIS TLIF include the use of nonexpandable or expandable tubular retractors, a paramedian or lateral incision, and the use of a microscope or endoscope for visualization. Approaches using expandable nontubular retractors, those that require extensive subperiosteal dissection from the midline laterally, or specular-based retractors with wide pedicle to pedicle exposure are far less likely to be promoted as an MIS-based approach. A definition is necessary to improve the communication among spine surgeons in research as well as patient education.

Computer Navigation in Minimally Invasive Spine Surgery

PURPOSE OF REVIEW

The goal of the review is to discuss the common general applications of navigation in the context of minimally invasive spine surgery and assess its value in the published literature comparing against non-navigated or navigated techniques.

RECENT FINDINGS

There is increasing utilization of computer navigation in minimally invasive spine surgery. There is synergy between navigation and minimally invasive technologies, such that one enhances or facilitates the other, thus leading to wider applications for both. Specifically, navigation has been shown to improve performance of percutaneous pedicle screw placement, vertebral augmentation, and minimally invasive fusion procedures. Overall, clinical studies have shown better accuracy and less radiation exposure with the use of navigation in spine surgery. The use of navigation in minimally invasive spine surgery enhances the accuracy of instrumentation and decreases radiation exposure. It is yet to be determined whether patient-reported outcomes will differ. Further research on its effect on clinical outcomes may further define the future impact of navigation in minimally invasive spine surgery.

A Pilot Study of Percutaneous Interlaminar Endoscopic Lumbar Sequestrectomy: A Modern Strategy to Tackle Medically-Refractory Radiculopathies and Restore Spinal Function

Objective

Angled scopes allow 360° visualization, which makes percutaneous endoscopic techniques (percutaneous endoscopic lumbar discectomy, PELD) particularly attractive for sequestrectomies, which entail the removal of extruded lumbar disc fragments that have migrated caudally or cranially between the ligaments, foramina, and neural structures, while preserving the disc. Although many different PELD techniques are currently available, not all of them are suitable for sequestrectomies; furthermore, long-term follow-up data are unfortunately lacking.

Methods

A pilot study was conducted on a cohort of 270 patients with lumbar radiculopathy undergoing minimally invasive spine surgery (PELD or microdiscectomy), of whom only 7 were eligible for endoscopic interlaminar sequestrectomy with disc preservation. The patients’ baseline conditions and clinical outcomes were measured with the Oswestry Disability Index and a visual analogue scale. Long-term follow-up was conducted using satisfaction questionnaires that were based on the MacNab criteria and administered by medical/nursing personnel not involved in their primary surgical management.

Results

EasyGo system was eventually used in 5 PELD cases. No dural tears, infections, or nerve root injuries were recorded in patients undergoing sequestrectomy. Surgical events, including blood loss and overall length of hospital stay, did not differ significantly among the 270 patients. In the group treated with endoscopic sequestrectomy, no recurrences or complications were noted during a follow-up of 3 years, and an excellent degree of satisfaction was reported.

Conclusion

We provide OCEBM (Oxford Centre for Evidence-Based Medicine) level 3 evidence that interlaminar endoscopic sequestrectomy is a tailored and well-tolerated surgical option; nonetheless, a cost-effectiveness analysis assessing the interval until return to working activities and long-term benefits is warranted.