Bilateral tubular minimally invasive surgery for low-dysplastic lumbosacral lytic spondylolisthesis (LDLLS): analysis of a series focusing on postoperative sagittal balance and review of the literature

The challenge of measuring spinopelvic parameters: inter-rater reliability before and after minimally invasive lumbar spondylodesis

BACKGROUND

The common manual measurement technique of spinal sagittal alignment on X-rays is susceptible to rater-dependent variability, which has not been adequately considered in previous publications. This study investigates the effect of those variations in the characterization of patients receiving lumbar spondylodesis.

METHODS

General alignment parameters on pre- and postoperative X-rays were evaluated by four raters in 43 prospectively sampled patients undergoing monolevel spondylodesis. The Intra-class Correlation Coefficient (ICC) for each rater pair and all raters together was calculated for inter-rater reliability. For the operation-induced change of the sagittal alignment in every patient the Wilcoxon test was applied to compare for each rater separately.

RESULTS

The ICCs were "good" (>0.75) to "excellent" (>0.9) for all raters together and for 45 of the 48 single rater pairs (93.75%). All revealed a significant increase of the addressed segmental lordosis and disc height and no significant change for spinopelvic parameters and sagittal vertical axis from pre- to postoperative. The lumbar lordosis showed a significant increase through the operation of +2.5° (p = 0.014) and +3.7° (p = 0.015) in two raters and no difference for the other ones (+2.1°, p = 0.171; -2.2°, p = 0.522).

CONCLUSIONS

The pre- to postoperative change of lumbar lordosis revealed different significance levels for different raters, although the ICCs were formally good. Accordingly, the evaluation by only one rater would lead to different conclusions. Due to this susceptibility of alignment measurements to rater-dependent variability, the exact evaluation process should be described in every publication and the consistency of significant results be validated through multiple raters.

TRIALS REGISTRATION

The trial was approved by the local ethics committee and listed at the national clinical trials register ( DRKS00004514 , date of registration: 08/11/2012).

Comparison of O-arm navigation and microscope-assisted minimally invasive transforaminal lumbar interbody fusion and conventional transforaminal lumbar interbody fusion for the treatment of lumbar isthmic spondylolisthesis

Objective

The objective of this study is to compare the clinical efficacy of O-arm navigation and microscope-assisted minimally invasive transforaminal lumbar interbody fusion (modified MIS-TLIF) versus conventional TLIF in the lumbar isthmic spondylolisthesis.

Materials and methods

Forty patients with 1-level lumbar isthmic spondylolisthesis were enrolled in the study. Perioperative indexes including operation time, intraoperative bleeding, bed rest time, time of hospitalisation stay and the accuracy rate of screw placement were analysed. Preoperative and postoperative visual analogue scale (VAS) and Oswestry disability index (ODI) were assessed.

Results

The operation time in the modified MIS-TLIF group was longer than the conventional TLIF group (p ​< ​0.05). However, intraoperative blood loss in the modified MIS-TLIF group was less than the comparative group (p ​< ​0.05). The average bed rest time and hospitalisation stay in the modified MIS-TLIF group was shorter than conventional TLIF group (p ​< ​0.05). The screw placement in the modified MIS-TLIF group was more precisely than that in the conventional TLIF group (p ​< ​0.05). Meanwhile, the improvement of VAS and ODI in the modified MIS-TLIF group were lower than that in the conventional TLIF group 1 and 6 months after operation (p ​< ​0.05). There was no difference in the VAS and ODI score between the two group at the last follow-up (p ​> ​0.05).

Conclusion

Navigation and microscope-assisted MIS-TLIF is safe and reliable for treatment of lumbar isthmic spondylolisthesis (Meyerding degree I or II) with potential advantages including less injury, less blood loss, higher screw accuracy and faster recovery after operation.

The translational potential of this article

Compared with conventional transforaminal lumbar interbody fusion, O-arm navigation and microscope-assisted minimally invasive transforaminal lumbar interbody fusion has a huge advantage in surgery treatment of lumbar isthmic spondylolisthesis. Hence, this article provided a better surgery method to deal with lumbar isthmic spondylolisthesis, and robot-assisted minimally invasive transforaminal lumbar interbody fusion will be adopted in the future.

Restoration of lumbar lordosis after minimally invasive transforaminal lumbar interbody fusion: a systematic review

BACKGROUND

Transforaminal lumbar interbody fusion (TLIF) is a well-accepted surgical technique for the treatment of degenerative spinal conditions and spinal deformity. The TLIF procedure can be performed open or using minimally invasive techniques. While several studies have found that minimally invasive TLIF (MI-TLIF) has advantages over open TLIF procedures with less blood loss, postoperative pain and hospital length of stay, opponents of the minimally invasive technique cite the lack of restoration of lumbar lordosis as a major drawback. With the increasing awareness of restoring sagittal alignment parameters in degenerative and deformity procedures, surgeons should understand the capabilities of different procedures to achieve surgical goals. To our knowledge, few studies have specifically studied the radiographic restoration of lumbar lordosis after MI-TLIF procedures. The purpose of this study was to perform a systematic review of the literature describing the sagittal lumbar radiographic parameter changes after MI-TLIF.

METHODS

Following PRISMA guidelines, systematic review was performed. With the assistance of a medical librarian, a highly-sensitive search strategy formulated on 1/19/2018 utilized the following search terms: "minimally invasive procedures," "transforaminal lumbar interbody fusion," "lumbar interbody fusion," "diagnostic imaging," "radiographs," "radiography," "x-rays," "lordosis," "lumbar vertebrae," "treatment," "outcome," and "lumbosacral" using Boolean operators 'AND' and 'OR'. Three databases were searched (PubMed/Medline, Embase, and Cochrane Library). An online system (www.covidence.org) was used to standardize article review. All studies were independently analyzed by two investigators and discrepancies mitigated by a third reviewer. Study selection for each cycle was Yes/No/Maybe. Cycles were: (1) (Title/Abstract); (2) (Full Text); (3) (Extraction). Inclusion criteria were: (1) All study designs, (2) MI-TLIF procedures, (3) Reporting total lumbar lordosis (LL) and/or segmental lordosis (SL) pre- and postoperatively. Exclusion criteria were: (1) non MI-TLIF procedures (ALIF, XLIF, LLIF, conventional TLIF, OLIF), (2) No reported LL or SL.

RESULTS

The search yielded 4,036 results with 836 duplicates leaving 3,200 studies for review. Cycle 1 eliminated 3,153 studies as irrelevant, thus, 47 were eligible for full-text review. Cycle 2 excluded 31 studies for No English full text (9), Oral/Poster (8), Wrong intervention/outcome (10), Duplicate listing (2), Full text not available (1), Literature review (1) resulting in 16 included studies. Study designs were: Randomized-controlled trial (3), Case series (6) and Retrospective (7). Mean # of subjects were 32.0 (range 8-95). Weighted-mean LL was 39.6°±9.2 (range 28-57) and postoperative LL was 45.0°±7.4 (range 36-67) with a LL post-pre difference of 5.2°±5.9 (range -7 to 15). Weighted-mean preoperative SL was 12.7°±4.3 (range 5-21) and postoperative SL was 15.0°±4.5 (range 5-22) with a SL post-pre difference of 2.1°±1.7 (range 0-8).

CONCLUSIONS

The current literature on MI-TLIF and restoration of LL/SL is limited to 16 published studies, 44% of which are retrospective. The published evidence supporting LL and SL restoration with MI-TLIF is sparse with variable results. This systematic review demonstrates the need for future high-level studies to fully elucidate the capabilities of MI-TLIF procedures for restoring lumbar and segmental lordosis.

Sagittal Balance Correction Following Lumbar Interbody Fusion: A Comparison of the Three Approaches

STUDY DESIGN

Retrospective cohort study.

PURPOSE

The objective of this study was to compare three widely used interbody fusion approaches in regard to their ability to correct sagittal balance, including pelvic parameters.

OVERVIEW OF LITERATURE

Restoration of sagittal balance in lumbar spine surgery is associated with better postoperative outcomes. Various interbody fusion techniques can help to correct sagittal balance, with no clear consensus on which technique offers the best correction.

METHODS

The charts and imaging of patients who have undergone surgery through either open transforaminal lumbar interbody fusion (TLIF), minimally invasive TLIF (MIS TLIF), or oblique lumbar interbody fusion (OLIF) were retrospectively reviewed. The following sagittal balance parameters were measured pre- and postoperatively: segmental lordosis, lumbar lordosis, disk height, pelvic tilt, and pelvic incidence. Data on postoperative complications were gathered.

RESULTS

Only OLIF managed to significantly improve segmental lordosis (4.4°, p <0.001) and lumbar lordosis (4.8°, p =0.049). All approaches significantly augmented disk height, with OLIF having the greatest effect (3.7°, p <0.001). No approaches were shown to significantly correct pelvic tilt. Pelvic incidence remained unchanged in all approaches. Open TLIF was the only approach with a higher rate of postoperative complications (33%, p =0.009).

CONCLUSIONS

The OLIF approach might offer greater correction of sagittal balance over open and MIS TLIF, mainly in regard to segmental lordosis, lumbar lordosis, and disk height. MIS TLIF, although offering more limited access than open TLIF, was not inferior to open TLIF in regard to sagittal balance correction. A higher rate of complications was shown for open TLIF than the other approaches, possibly due to its more invasive nature.

Does minimally invasive fusion technique influence surgical outcomes in isthmic spondylolisthesis?

OBJECTIVE

To compare the clinical and radiographic results between open transforaminal interbody fusion (TLIF-O) and minimally invasive TLIF (TLIF-M) for single-level low grade isthmic spondylolisthesis (IS).

METHODS

This study enrolled 45 patients who underwent single-level TLIF with low grade IS. The patients were divided into two groups according to operative method: TLIF-M (20 patients) and TLIF-O (25 patients). TLIF-O group was matched with TLIF-M.

RESULTS

At one-year postoperatively, there were no significant differences in any radiologic parameters between the two groups. Perioperative results such as blood loss, operation time, and hospital stay were superior in TLIF-M than in TLIF-O. Fusion was achieved in 17 of 20 patients (85.0%) in TLIF-M and 23 of 25 (92.0%) patients in TLIF-O. Back Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores of TLIF-O were significantly lower than TLIF-M at one (back VAS, ODI) and six months (ODI) postoperatively.

CONCLUSIONS

TLIF-M and TLIF-O produced similar clinical and radiological outcomes, including reduction of spondylolisthesis and disc space height restoration at one-year follow-up for single-level low grade IS. However, considering perioperative outcomes, back pain, and quality of life, TLIF-M might be a better option for single-level low grade IS compared to TLIF-O.

The unfeasible made feasible: lumbar minimally invasive hybrid stabilization with dynamic rod and mini-open transforaminal lumbar interbody fusion

Posterior dynamic stabilization of the lumbar spine is spreading as a viable alternative to spinal fusion, aiming to achieve an equally satisfactory clinical outcome without making the spine completely rigid. We describe the feasibility of a minimally invasive surgical technique used to implant a hybrid system and perform a mini-open (m-open) transforaminal lumbar interbody fusion (TLIF) in patients suffering from degenerative spondylolistesis and adjacent level's degenerative disc disease (DDD). Three patients (2 females), suffering from degenerative spondylolistesis and adjacent level's DDD, underwent two-level hybrid stabilization combining a rigid, circumferential fusion (with m-open TLIF) at the level involved by spondylolistesis and a dynamic stabilization at the adjacent one. Screws, hybrid rods as well as interbody cages were introduced using a simple minimally invasive technique. Clinical and radiological evaluation was performed pre- and postoperatively, and at 3, 6 and 12 months, respectively, using the Visual Analogue Scale and the Oswestry Disability Index questionnaire. Mean VAS and ODI score reduced from 8.3, preoperatively, to 5 and from 72.66 to 43.98, respectively. No surgery-related complications were observed and the mean postoperative hospitalization was 2.5 days. Postoperative and follow-up flexion-extension X-rays showed persisting motion at dynamically stabilized levels. Follow-up CT imaging confirmed interbody fusion at TLIF levels in all patients. Dynamic and hybrid stabilizations of the lumbar spine are typically performed using open surgery. This study reports the feasibility of a hybrid stabilization with m-open TLIF performed using a minimally invasive technique.

Total 3D Airo® Navigation for Minimally Invasive Transforaminal Lumbar Interbody Fusion

Introduction. A new generation of iCT scanner, Airo®, has been introduced. The purpose of this study is to describe how Airo facilitates minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Method. We used the latest generation of portable iCT in all cases without the assistance of K-wires. We recorded the operation time, number of scans, and pedicle screw accuracy. Results. From January 2015 to December 2015, 33 consecutive patients consisting of 17 men and 16 women underwent single-level or two-level MIS-TLIF operations in our institution. The ages ranged from 23 years to 86 years (mean, 66.6 years). We treated all the cases in MIS fashion. In four cases, a tubular laminectomy at L1/2 was performed at the same time. The average operation time was 192.8 minutes and average time of placement per screw was 2.6 minutes. No additional fluoroscopy was used. Our screw accuracy rate was 98.6%. No complications were encountered. Conclusions. Airo iCT MIS-TLIF can be used for initial planning of the skin incision, precise screw, and cage placement, without the need for fluoroscopy. “Total navigation” (complete intraoperative 3D navigation without fluoroscopy) can be achieved by combining Airo navigation with navigated guide tubes for screw placement.