Disc Space Preparation Research Articles

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: The Double-Cage Technique

Biportal endoscopic transforaminal lumbar interbody fusion (BETLIF) is a novel spinal fusion procedure using the unilateral biportal endoscopic technique. The hydrostatic pressure of saline irrigation suppresses bleeding, enabling us to perform delicate surgery in a crystal-clear and magnified surgical field with almost no bleeding. Adequate neural decompression, disc space preparation, and bony endplate preservation can be achieved safely. The sturdy endplate reduces the incidence of cage subsidence and provides good initial stability. We use 2 interbody fusion cages and a large amount of bone graft to promote fusion. Reduction of the spondylolisthesis can also be achieved using a modern pedicle screw system. This article presents a step-by-step demonstration of the BETLIF technique in a 68-year-old patient with degenerative scoliosis and spondylolisthesis at L4-5, including his clinical presentation and treatment results. BETLIF is a safe, effective, and revolutionary minimally invasive solution for spinal fusion. Its advantages include a magnificent surgical field, direct decompression, minimum blood loss, radical discectomy, meticulous endplate preparation, cage insertion under direct visual control, and excellent treatment results with a high fusion rate and few complications.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: How to Improve Fusion Rate?

Biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) is a minimally invasive surgical technique for treating degenerative lumbar spine conditions. It offers advantages such as reduced soft tissue trauma and lower infection rates, but certain technical aspects may be challenging. The current study aims to identify strategies to enhance the fusion rate in BE-TLIF by addressing these specific challenges. A literature review was conducted on techniques to improve fusion rates in BE-TLIF. The review suggests that lateral-based portals supplemented with medial portals allowed for safe insertion of interbody cages with large footprint. Direct visualization of the disc space with a 30° endoscope assisted with better disc space preparation. Facetectomies performed with osteotomes, rather than burrs, ensured maximum retrieval of autologous bone graft. Utilizing bone morphogenetic proteins with sustained release carriers such as hydroxyapatite can be useful to increase fusion rates of BE-TLIF. To our knowledge, the current literature is the first comprehensive review of strategies to enhance fusion rates in BE-TLIF. The proposed techniques and biological adjuncts are effective means to address key challenges associated with the procedure, and such strategies would potentially shorten the learning curve and improve clinical outcomes. Further clinical studies are required to validate these findings and establish standardized protocols. These findings provide practical solutions to overcome common challenges in BE-TLIF. The suggested techniques would reduce the incidence of pseudarthrosis, improve patient outcomes, and ultimately offer a safer and more reliable option for lumbar interbody fusion patients.

Comparing Efficacy of Lumbar Disc Space Preparation via an Anterior-to-Psoas Approach Between Intraoperative Conventional Fluoroscopy and Computed Tomographic-Based Navigation System: A Cadaveric Study

To compare the efficacy of intervertebral disc space preparation via an anterior-to-psoas (ATP) approach using conventional fluoroscopy (Flu) and computer tomography (CT)-based navigation by evaluating the disc remaining area. We equally assigned 24 lumbar disc levels from 6 cadavers into Flu and CT-based navigation (Nav) groups. Two surgeons performed disc space preparation using the ATP approach in both groups. Digital images of each vertebral endplate were obtained, and the remaining disc tissue was calculated in total and in quadrants. Operative time, number of attempts at disc removal, endplate violation area, number of endplate violation segments, and access angle were recorded. The overall percentage of remaining disc tissue was significantly less in the Nav group than in the Flu group (32.7% vs. 43.3% respectively, P < 0.001). A significant difference was found in the posterior-ipsilateral (4.2% vs. 7.1%, P= 0.005) and posterior-contralateral (6.1% vs. 10.9%, P= 0.002) quadrants, respectively. No significant between-group difference was found concerning operative time, number of attempts at disc removal, endplate violation area, number of endplate violation segments, or access angle. Intraoperative CT-based navigation may improve vertebral endplate preparation quality for an ATP approach, especially in the posterior quadrants. This technique may offer an effective alternative disc space and endplate preparation methods and may help enhance the fusion rates.

Spinal exposure for anterior lumbar interbody fusion (ALIF) in the lateral decubitus position: anatomical and technical considerations.

Single position surgery has demonstrated to reduce hospital length of stay, operative times, blood loss, postoperative pain, ileus, and complications. ALIF and LLIF surgeries offer advantages of placing large interbody devices under direct compression and can be performed by a minimally invasive approach in the lateral position. Furthermore, simultaneous access to the anterior and posterior column is possible in the lateral position without the need for patient repositioning. The purpose of this study is to outline the anatomical and technical considerations for performing anterior lumbar interbody fusion (ALIF) in the lateral decubitus position. Surgical technique and technical considerations for reconstruction of the anterior column in the lateral position by ALIF at the L4-5 and L5-S1 levels. Topics outlined in this review include: Operating room layout and patient positioning; surgical anatomy and approach; vessel mobilization and retractor placement for L4-5 and L5-S1 lateral ALIF exposure, in addition to comparative technique of disc space preparation, trialing and implant placement compared to the supine ALIF procedure. Anterior exposure performed in the lateral decubitus position allows safe-, minimally invasive access and implant placement in ALIF. The approach requires less peritoneal and vessel retraction than in a supine position, in addition to allowing simultaneous access to the anterior and posterior columns when performing 360° Anterior-Posterior fusion.

A pilot study of endoscope-assisted MITLIF with fluoroscopy-guided technique: intraoperative objective and subjective evaluation of disc space preparation

BackgroundAdequate discectomy and endplate preparation are extremely crucial steps for spinal interbody fusion. Minimally invasive transforaminal lumbar interbody fusion MITLIF technique is safe and effective. However, concerns exist regarding sufficient disc space preparation from unilateral access. The purpose of this study, was to demonstrate our preliminary experience in objective and subjective evaluation of disc space preparation intraoperatively during endoscope-assisted MITLIF with fluoroscopy-guided, describing some of its possible advantages, and analyzing its safety and feasibility.MethodsFrom March 2018 to July 2019, three patients with degenerative spinal stenosis with radiculopathy and instability underwent endoscope-assisted MITLIF with fluoroscopy-guided. Patients’ demographic data, clinical parameters, subsidence, and fusion were collected.ResultsPatients were successfully treated by endoscope-assisted MITLIF with fluoroscopy-guided at single-level or two-level. Symptoms improved postoperatively in all patients, and no complications occurred during follow-up. No cage subsidence was observed. At 6-month postoperatively, there was bony fusion observed on computed tomography in two patients.ConclusionEndoscope-assisted MITLIF with fluoroscopy-guided is a safe and feasible technique to improve visualization during discectomy and endplate preparation objectively and subjectively, possibly increasing fusion rate and early time to fusion.

Navigate and Succeed: MI-Transforminal Lumbar Interbody Fusion with Three-Dimensional Navigation

Introduction: Lumbar Interbody Fusion (TLIF) has become a popular technique for achieving segmental interbody fusion and minimal access approach has its advantages. We have described the various Components in Spine Navigation Systems and how they have evolved in time and also describing our technique in detail. We have discussed on the advantages and disadvantages of the minimal access and use of Navigation. Method: The authors ventured to assess the impact of 3D navigation in 117 patients that were treated with single level 3D navigated MI-TLIF in evaluating, Navigation setting time , Radiation exposure, Disc space preparation, Cage placement, Accuracy of pedicle screw placement, Cranial facet violation and Evaluation of canal decompression. Result: Total time taken for setting up of navigation was 46.65±9.45 min. Average Radiation exposure was 5.69 mSv. In our study, the amount of disc removed was 75% in the ipsilateral anterior, 81% in ipsilateral posterior, 63% in contralateral anterior and 43% in contralateral posterior quadrants. The cage position was central in 87 patients, contralateral antero-central in six patients and ipsilateral postero-central in eight patients. The mean intraoperative blood loss was 89.65 ± 23.67 ml. Regarding accuracy 95.6% showed grade 0 and 4.4% had Grade 1 pedicle breach. Only 25 out of 408 pedicle screws (6.1%) violated the cranial facet joint. The navigation array probe was utilized to verify the adequacy of decompression and to confirm the anatomical landmarks. In our study, no surgical site infection was seen. Conclusion: We find MIS to be associated with less post-operative infection rates as compared to open techniques. With 3D navigation, MIS becomes safer and highly accurate. MIS-TLIF with 3D navigation have satisfactory clinical outcomes and fusion rates with the additional benefits of less initial postoperative pain, less blood loss, earlier rehabilitation, and shorter hospitalization. MIS–TLIF with 3D navigation is a more cost-effective treatment than MIS-TLIF with fluoroscopy.

Minimally Invasive Transforaminal Lumbar Interbody Fusion With Intraoperative Fluoroscopy for Disc Space Preparation: Analysis of Fusion Rate and Clinical Results

Lin, Guang-Xun MD, PhD; Sharma, Sagar MD; Rui, Gang MD, PhD; Song, Myung-Soo MD; Kim, Jin-Sung MD, PhD

Minimally Invasive Transforaminal Lumbar Interbody Fusion With Intraoperative Fluoroscopy for Disc Space Preparation: Analysis of Fusion Rate and Clinical Results.

Meticulous disc space preparation is an important step toward ensuring arthrodesis in the interbody fusion procedure. Although minimally invasive techniques are becoming increasingly advanced in lumbar interbody fusion, concerns exist regarding adequate discectomy and sufficient endplate preparation from a transforaminal lumbar approach. To describe the radiographic and clinical outcomes of single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using the intraoperative fluoroscopy-guided method for disc space preparation. This is a retrospective study of 25 patients operated between June 2016 and Dec 2017. The radiographic outcomes included the intraoperative percentage of disc space preparation, fusion, and subsidence. Percentage of disc space preparation was calculated through intraoperative fluoroscopic imaging. Clinical outcomes included visual analog scale (VAS), Oswestry Disability Index (ODI), and satisfaction rate. Mean age of patients was 62.9 yr. The mean follow-up period was 22 mo. Mean extents of disc space preparation were 61.5% in the anteroposterior view and 80.3% in the lateral view. Fusion rates were 86% and 92% at 6 and 12-mo postoperatively, respectively. All patients showed clinical improvement according to VAS and ODI. MI-TLIF with intraoperative fluoroscopy-guided disc space preparation is shown to lead to potentially improved fusion rate. It is a safe and effective surgical method for degenerative lumbar disease. Additionally, in cases of cage subsidence caused by the endplate violation during disc space preparation, thorough sufficient bone grafting of the defect region avoids pseudoarthrosis.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: 2-Dimensional Surgical Video.

This operative video is a detailed look at minimally invasive transforaminal lumbar interbody fusion. We provide a step-by-step guide with appropriate narration and operative video to enhance the educational experience. We review clinical and radiographic evaluation, patient positioning, intraoperative navigation, localization, percutaneous pedicle screw placement, minimally invasive approach, disc space preparation, placement of interbody device, and closure. By presenting up-to-date minimally invasive and intraoperative navigation techniques, this video provides educational benefit to all neurosurgeons regardless of training level.

Cervical disc arthroplasty: tips and tricks.

Cervical disc arthroplasty (CDA) is a powerful, motion-sparing treatment option for managing cervical radiculopathy or myelopathy. While CDA can be an excellent surgery for properly indicated patients, it is also less forgiving than cervical fusion. Optimally resolving patient symptoms while maintaining range of motion relies on near perfection in the surgical technique. Different CDA options exist on the market, with some having long-term proven success and others in early stages of clinical trials. We discuss the different options available for use, as well as strategies of positioning, approach, disc space preparation, implantation, and fusion prevention that we believe can help improve performance and outcomes of CDA.

Transforaminal Lumbar Interbody Fusion (TLIF).

Historically, posterior lumbar interbody fusion was performed using a directly posterior procedure (PLIF). Transforaminal lumbar interbody fusion (TLIF) utilizes a more lateral window in order to access the interbody space without excessive dural retraction. Theoretical advantages of TLIF include increased fusion success, more complete foraminal decompression, better correction of deformity, and more effective treatment of discogenic pain. The procedure is done with the following steps:1 and 2. Preoperative planning and patient positioning are important to maximize the efficiency of the procedure. There is a wide variety of instrumentation and technique options; therefore, a systematic approach starting with setup is important.3. The spine is approached through a standard posterior midline incision. It is not necessary to expose the lateral gutters, but the addition of posterolateral fusion is common.4. Pedicle screw placement is undertaken via a standard approach.5. Decompression is initiated with a laminectomy in the midline, exposing the ligamentum.6. The ligamentum is carefully removed, and hemostasis is obtained. A facetectomy is then performed.7. Once the posterior bone elements are resected and the decompression is complete, the dura and neural elements are mobilized. The goal is to be able to access the posterior anulus and disc space easily without any dural tension.8. Distraction through the TLIF level helps facilitate interbody placement. We describe a triple distraction technique that uses the midline elements, and both contralateral and ipsilateral distraction methods.9. A window is formed on the disc, with care taken to protect the exiting and traversing roots. The window is enlarged using a combination of box osteotomes and Kerrison rongeurs. A window that is a minimum of 10 mm in size facilitates disc space preparation.10 and 11. Disc space preparation is performed using a combination of curets, pituitary rongeurs, and end-plate preparation tools. Thorough disc-space preparation is critical for both correcting the deformity and obtaining a solid fusion.12. The disc space is sized for an appropriate interbody cage. The anterior aspect of the disc space and the cage are both packed with bone graft. This may involve the use of iliac crest graft, local bone, or bone substitutes, depending on the specific clinical situation.13. Cage and screw placement is verified by biplane radiography, and lordosis is restored by compression across the screws bilaterally. Osteotomy of the contralateral facet may be necessary to achieve substantial restoration of lordosis.14. If the lateral gutters have been exposed, grafting in this region is undertaken as well. Care must be taken with graft placement on the TLIF side as facet and pars resection leaves the exiting route exposed.15. Closure is undertaken in a standard fashion.Postoperative recovery does not differ substantially from other standard fusion procedures. Mobilization is undertaken over the first several weeks, and fusion healing is expected in the 6-month to 1-year time frame.

Disc Space Preparation in Transforaminal Lumbar Interbody Fusion: A Comparison of Minimally Invasive and Open Approaches

Minimally invasive surgical (MIS) approaches to transforaminal lumbar interbody fusion (TLIF) have been developed as an alternative to the open approach. However, concerns remain regarding the adequacy of disc space preparation that can be achieved through a minimally invasive approach to TLIF. The purpose of this cadaver study is to compare the adequacy of disc space preparation through MIS and open approaches to TLIF. Specifically we sought to compare the two approaches with respect to (1) the time required to perform a discectomy and the number of endplate violations; (2) the percentage of disc removed; and (3) the anatomic location where residual disc would remain after discectomy. Forty lumbar levels (ie, L1-2 to L5-S1 in eight fresh cadaver specimens) were randomly assigned to open and MIS groups. Both surgeons were fellowship-trained spine surgeons proficient in the assigned approach used. Time required for discectomy, endplate violations, and percentage of disc removed by volume and mass were recorded for each level. A digital imaging software program (ImageJ; US National Institutes of Health, Bethesda, MD, USA) was used to measure the percent disc removed by area for the total disc and for each quadrant of the endplate. The open approach was associated with a shorter discectomy time (9 versus 12 minutes, p = 0.01) and fewer endplate violations (one versus three, p = 0.04) when compared with an MIS approach, percent disc removed by volume (80% versus 77%, p = 0.41), percent disc removed by mass (77% versus 75%, p = 0.55), and percent total disc removed by area (73% versus 71%, p = 0.63) between the open and MIS approaches, respectively. The posterior contralateral quadrant was associated with the lowest percent of disc removed compared with the other three quadrants in both open and MIS groups (50% and 60%, respectively). When performed by a surgeon experienced with MIS TLIF, MIS and open approaches are similar in regard to the adequacy of disc space preparation. The least amount of disc by percentage is removed from the posterior contralateral quadrant regardless of the approach; surgeons should pay particular attention to this anatomic location during the discectomy portion of the procedure to minimize the likelihood of pseudarthrosis.

Minimally invasive unilateral approach for bilateral decompression of spinal stenosis and modified transforaminal lumbar interbody fusion for degenerative spondylolisthesis

This video describes a minimally invasive approach for treatment of symptomatic grade I spondylolisthesis and high-grade spinal stenosis. In this procedure, a unilateral approach for bilateral decompression is utilized in conjunction with a modified transforaminal lumbar interbody fusion and percutaneous pedicle screw fixation. The key steps in the procedure are outlined, and include positioning, fluoroscopic positioning/guidance, exposure with tubular retractor system, technique for ipsilateral and contra-lateral decompression, disc space preparation and interbody grafting, percutaneous pedicle screw and rod placement, and closure. The video can be found here: http://youtu.be/QTymO4Cu4B0.

Lumbar spine intervertebral disc gene delivery: a pilot study in lewis rats.

Basic research toward understanding and treating disc pathology in the spine has utilized numerous animal models, with delivery of small molecules, purified factors, and genes of interest. To date, gene delivery to the rat lumbar spine has only been described utilizing genetically programmed cells in a matrix which has required partial disc excision, and expected limitation of treatment diffusion into the disc. This study was designed to develop and describe a surgical technique for lumbar spine exposure and disc space preparation, and use of a matrix-free method for gene delivery. Naïve or genetically programmed isogeneic bone marrow stromal cells were surgically delivered to adolescent male Lewis rat lumbar discs, and utilizing quantitative biochemical and qualitative immunohistological assessments, the implanted cells were detected 3days post-procedure. Statistically significant differences were noted for recovery of the β-galactosidase marker gene comparing delivery of naïve or labeled cells (10(5) cells per disc) from the site of implantation, and between delivery of 10(5) or 10(6) labeled cells per disc at the site of implantation and the adjacent vertebral body. Immunohistology confirmed that the β-galactosidase marker was detected in the adjacent vertebra bone in the zone of surgical implantation. The model requires further testing in larger cohorts and with biologically active genes of interest, but the observations from the pilot experiments are very encouraging that this will be a useful comparative model for basic spine research involving gene or cell delivery, or other locally delivered therapies to the intervertebral disc or adjacent vertebral bodies in rats.

Vertebral osteolysis originating from subchondral cyst end plate defects in transforaminal lumbar interbody fusion using rhBMP-2. Report of two cases

Background Context Vertebral osteolysis has been reported as a complication of off-label recombinant human bone morphogenetic protein-2 (rhBMP-2) use in transforaminal lumbar interbody fusion (TLIF). It has been postulated that end plate violation during disc space preparation, rhBMP-2 overdosing, or a combination thereof can contribute to the development of vertebral osteolysis when rhBMP-2 is used in the lumbar interspace. Purpose To present two cases of vertebral osteolysis that occurred after TLIF in which rhBMP-2 was used. In each case, the osteolysis originated from subchondral cysts that were present on preoperative computed tomographic (CT) scans. Study Design Case report. Methods Two patients underwent instrumented TLIF using INFUSE (Medtronic, Inc., Littleton, MA, USA) on an absorbable collagen sponge carrier. In each patient, approximately 4 mg of rhBMP-2 was placed anteriorly in the disc space with 0.1 mg of rhBMP-2 being placed inside a polyetheretherketone interbody cage. Morcellized allograft bone mixed with demineralized bone matrix was also placed in the disc space and cage. The remaining rhBMP-2 was placed posterolaterally on the contralateral side. Each patient presented with worsening back pain approximately 3 to 4 months postoperatively and CT scans revealed osteolysis affecting the L4 and L5 vertebral bodies. The osteolysis appeared to originate from preoperative vertebral defects caused by subchondral cysts. Results One patient underwent removal of the interbody cage at the L4–L5 level and revision of the fusion with iliac crest autograft. At 15-month follow-up, he had no complaints of back pain, and CT scanning revealed solid fusion across the L4–L5 disc space. The other patient was offered revision of his fusion but declined any further surgery. At 2-year follow-up, that patient had persistent back pain but still declined any further surgery. A CT scan revealed unchanged osteolysis at the L4 and L5 levels. Conclusions It has been proposed that rhBMP-2-induced vertebral osteolysis occurring in TLIF procedures may be secondary to end plate violation during disc preparation or overdosing of rhBMP-2. Although overdosing may have also contributed to vertebral osteolysis in our two cases, the end plate violation from subchondral cyst formation that was present on preoperative CT scans seemed to be the origin of the osteolysis suggesting that the presence of preoperative subchondral cysts may be an additional risk factor for development of osteolysis in these patients.

P50. Disc Space Preparation in Transforaminal Interbody Fusion: A Comparison of Open and Minimally Invasive Technique

P50. Disc Space Preparation in Transforaminal Interbody Fusion: A Comparison of Open and Minimally Invasive Technique

Surgical approaches to the cervical spine

Characterization of surgical approaches to the cervical spine is based on the direction of the approach relative to the sternocleidomastoid muscle, the carotid sheath, and the longus coli muscle. With regard to anterior approaches, described are (1) the anterior medial approach to the mid-cervical spine, (2) the anterior medial approach to Cl, C2, and C3, and (3) the supraavicular approach. A detailed description of disc space preparation is offered. Also, the posterior approach to the cervival spine is included.