Minimally invasive endoscopy in spine surgery: where are we now?

Systemic Inflammatory Markers and Clinical Outcomes of Open versus Biportal Endoscopic Transforaminal Lumbar Interbody Fusion

Purpose

The purpose of this study is to preliminarily assess the change in perioperative systemic inflammatory markers and clinical outcomes between open TLIF and BE-TLIF procedures.

Patients and Methods

In total, 38 patients who underwent single-level lumbar fusion surgery (L4-5 or L5-S1) were retrospectively reviewed. 19 patients were treated by the BE-TLIF technique, while the other patients were managed using open TLIF. The perioperative serum C-reactive protein (CRP), neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR), and platelet/lymphocyte ratio (PLR) of the two groups were compared to determine if there was a statistical difference. Meanwhile, clinical evaluations were conducted to assess various factors including operative duration, estimated blood loss (EBL), drainage catheter stay, length of hospitalization, visual analogue scale (VAS), and Oswestry disability index (ODI) scores.

Results

The perioperative analysis revealed that BE-TLIF cases experienced a longer operative duration than open TLIF cases (open TLIF: 138.63 ± 31.59 min, BE-TLIF: 204.58 ± 49.37 min, p < 0.001). Meanwhile, the EBL showed an increased trend in the BE-TLIF group (260.7 ± 211.9 mL) in comparison with the open TLIF group (200.9 ± 211.9 mL) (p =0.485). In terms of systemic inflammatory markers, the mean postoperative CRP, NLR, LMR, and PLR were lower in the BE-TLIF group than in the open TLIF group, although these differences were not statistically significant (p > 0.05). The VAS and ODI scores in both groups were significantly improved after surgery (p < 0.05).

Conclusion

There was no significant difference found between BE-TLIF and open TLIF in terms of systemic inflammatory markers, and clinical outcomes. Overall, BE-TLIF can be considered a viable choice for lumbar canal decompression and interbody fusion for less invasion. It is worth noting that BE-TLIF does have a longer operation time, indicating that there is still potential for further improvement in this technique.

Full endoscopic surgery for calcium pyrophosphate deposition disease (CPPD) in the cervical ligamentum flavum: report of two cervical myelopathy cases

Calcium pyrophosphate deposition disease (CPPD), known as pseudogout, is characterized by the accumulation of calcium pyrophosphate crystals in musculoskeletal structures, primarily joints. While CPPD commonly affects various joints, involvement in the cervical spine leading to myelopathy is rare. Surgical intervention becomes necessary when conservative measures fail, but reports on full endoscopic surgeries are extremely rare. We present two successful cases where full endoscopic systems were used for CPPD removal in the cervical spine. The surgical technique involved a full endoscopic approach, adapting the previously reported technique for unilateral laminotomy bilateral decompression. Full-endoscopic removal of cervical CPPD inducing myelopathy were successfully removed with good clinical and radiologic outcomes. The scarcity of endoscopic cases for cervical ligamentum flavum CPPD is attributed to the condition's rarity. However, our successful cases advocate for endoscopic surgery as a potential primary treatment option for CPPD-induced cervical myelopathy, especially in elderly patients or those with previous cervical operation histories. This experience encourages the consideration of endoscopic surgery for managing cervical ligamentum flavum CPPD as a viable alternative.

Transforaminal endoscopic lumbar discectomy with two-segment foraminoplasty for the treatment of very highly migrated lumbar disc herniation: a retrospective analysis

BACKGROUND

The surgical resection of very highly migrated lumbar disc herniation (VHM-LDH) is technically challenging owing to the absence of technical guidelines. Hence, in the present study, we introduced the transforaminal endoscopic lumbar discectomy (TELD) with two-segment foraminoplasty to manage VHM-LDH and evaluated its radiographic and midterm clinical outcomes.

MATERIALS AND METHODS

The present study is a retrospective analysis of 33 consecutive patients with VHM-LDH who underwent TELD with two-segment foraminoplasty. The foraminoplasty was performed on two adjacent vertebrae on the basis of the migration direction of disc fragments to fully expose the disc fragments and completely decompress the impinged nerve root. The operation duration, blood loss, intra- and postoperative complications, and recurrences were recorded. Additionally, imageological observations were evaluated immediately after the procedure via magnetic resonance image and computerized tomography. Clinical outcomes were evaluated by calculating the visual analog scale (VAS) score and Oswestry Disability Index (ODI). The MacNab criterion was reviewed to assess the patients' opinions on treatment satisfaction. The resection rate of bony structures were quantitatively evaluated on postoperative image. The segmental stability was radiologically evaluated at least a year after the surgery. Additionally, surgery-related and postoperative complications were evaluated.

RESULTS

The average age of the patients was 56.87 ± 7.77 years, with a mean follow-up of 20.95 ± 2.09 months. The pain was relieved in all patients immediately after the surgery. The VAS score and ODI decreased significantly at each postoperative follow-up compared with those observed before the surgery (P < 0.05). The mean operation duration, blood loss, and hospital stay were 56.17 ± 16.21 min, 10.57 ± 6.92 mL, and 3.12 ± 1.23 days, respectively. No residual disc fragments, iatrogenic pedicle fractures, and segmental instability were observed in the postoperative images. For both up- and down- migrated herniation in the upper lumbar region, the upper limit value of resection percentage for the cranial SAP, caudal SAP, and pedicle was 33%, 30%, and 34%, respectively; while those in the lower lumbar region was 42%, 36%, and 46%, respectively. At the last follow-up, the satisfaction rate of the patients regarding the surgery was 97%. Surgery-related complications including dural tear, nerve root injury, epidural hematoma, iatrogenic pedicle fractures, and segmental instability were not observed. One patient (3%) suffered from the recurrence of LDH 10 months after the initial surgery and underwent revision surgery.

CONCLUSIONS

The TELD with two-segment foraminoplasty is safe and effective for VHM-LDH management. Proper patient selection and efficient endoscopic skills are required for applying this technique to obtain satisfactory outcomes.

Image-Guided Spine Surgery

The realm of spine surgery is undergoing a transformative shift, thanks to the integration of image-guided navigation technology. This innovative system seamlessly blends real-time imaging data with precise location tracking. While the indispensable expertise of experienced spine surgeons remains irreplaceable, navigation systems bring a host of valuable advantages to the operating room. By offering a comprehensive view of the surgical anatomy, these systems empower surgeons to conduct procedures with accuracy, while minimizing radiation exposure for both patients and medical professionals. Moreover, image-guided navigation paves the way for integration of other state-of-the-art technologies, such as augmented reality and robotics. These innovations promise to further revolutionize the field, providing greater precision and expanding the horizons of what is possible in the world of spinal procedures. This article explores the evolution, classification, and impact of image-guided spine surgery, underscoring its pivotal role in enhancing efficacy and safety while setting the stage for the incorporation of future technological advancements.

The Evolution of Spinal Endoscopy: Design and Image Analysis of a Single-Use Digital Endoscope Versus Traditional Optic Endoscope

Spinal endoscopy has evolved significantly since its inception, offering minimally invasive solutions for various spinal pathologies. This study introduces a promising innovation in spinal endoscopy-a single-use digital endoscope designed to overcome the drawbacks of traditional optic endoscopes. Traditional endoscopes, despite their utility, present challenges such as fragility, complex disinfection processes, weight issues, and susceptibility to mechanical malfunctions. The digital endoscope, with its disposable nature, lighter weight, and improved image quality, aims to enhance surgical procedures and patient safety. The digital endoscope system comprises a 30-degree 1000 × 1000 pixel resolution camera sensor with a 4.3 mm working channel, and LED light sources replacing optical fibers. The all-in-one touch screen tablet serves as the host computer, providing portability and simplified operation. Image comparisons between the digital and optic endoscopes revealed advantages in the form of increased field of view, lesser distortion, greater close-range resolution, and enhanced luminance. The single-use digital endoscope demonstrates great potential for revolutionizing spine endoscopic surgeries, offering convenience, safety, and superior imaging capabilities compared to traditional optic endoscopes.

Unilateral laminotomy with bilateral spinal canal decompression: systematic review of outcomes and complications

BACKGROUND

Unilateral laminotomy with bilateral spinal canal decompression has gained popularity recently.

AIM

To systematically review the literature of unilateral laminotomy with bilateral spinal canal decompression for lumbar spinal stenosis (LSS) aiming to assess outcomes and complications of the different techniques described in literature.

METHODS

On August 7, 2022, Pubmed and EMBASE were searched by 2 reviewers independently, and all the relevant studies published up to date were considered based on predetermined inclusion and exclusion criteria. The subject headings "unilateral laminotomy", "bilateral decompression" and their related key terms were used. The Preferred Reporting Item for Systematic Reviews and Meta-Analyses statement was used to screen the articles.

RESULTS

A total of seven studies including 371 patients were included. The mean age of the patients was 69.0 years (range: 55-83 years). The follow up duration ranged from 1 to 3 years. Rate of postoperative pain and functional improvement was favorable based on VAS, JOA, JOABPEQ, RMDW, ODI and SF-36, for example improved from a range of 4.2-7.5 preoperatively on the VAS score to a range of 1.4-3.0 postoperatively at the final follow up. Insufficient decompression was noted in 3% of the reported cases. The overall complication rate was reported at 18-20%, with dural tear at 3.6-9% and hematoma at 0-4%.

CONCLUSION

Unilateral laminotomy with bilateral decompression has favorable short- and mid-term pain and functional outcomes with low recurrence and complication rates. This, however, needs to be further confirmed in larger, long-term follow-up, prospective, comparative studies between open, and minimally invasive techniques.

A Century of Evolution in Spine Surgery Publications: A Bibliometric Analysis of the Field From 1900 to 2023

BACKGROUND AND OBJECTIVES

Spine surgery has advanced in concert with our deeper understanding of its elements. Narrowly focused bibliometric analyses have been conducted previously, but never on the entire corpus of the field. Using big data and bibliometrics, we appraised the entire corpus of spine surgery publications to study the evolution of the specialty as a scholarly field since 1900.

METHODS

We queried Web of Science for all contents from 13 major publications dedicated to spine surgery. We next queried by topic [topic = (spine OR spinal OR vertebrae OR vertebral OR intervertebral OR disc OR disk)]; these results were filtered to include articles published by 49 other publications that were manually determined to contain pertinent articles. Articles, along with their metadata, were exported. Statistical and bibliometric analyses were performed using the Bibliometrix R package and various Python packages.

RESULTS

Eighty-five thousand five hundred articles from 62 journals and 134 707 unique authors were identified. The annual growth rate of publications was 2.78%, with a surge after 1980, concurrent with the growth of specialized journals. International coauthorship, absent before 1970, increased exponentially with the formation of influential spine study groups. Reference publication year spectroscopy allowed us to identify 200 articles that comprise the historical roots of modern spine surgery and each of its subdisciplines. We mapped the emergence of new topics and saw a recent lexical evolution toward outcomes- and patient-centric terms. Female and minority coauthorship has increased since 1990, but remains low, and disparities across major publications persist.

CONCLUSION

The field of spine surgery was borne from pioneering individuals who published their findings in a variety of journals. The renaissance of spine surgery has been powered by international collaboration and is increasingly outcomes focused. While spine surgery is gradually becoming more diverse, there is a clear need for further promotion and outreach to under-represented populations.

Unilateral biportal endoscopic technique combined with percutaneous transpedicular screw fixation for thoracolumbar burst fractures with neurological symptoms: technical note and preliminary report

BACKGROUND

Previous studies on thoracolumbar fractures with neurological symptoms have focused on how to achieve satisfactory fracture reduction, adequate nerve decompression, and stable spinal alignment. With the development of the minimally invasive spine surgery technique, achieving satisfactory treatment results and reducing iatrogenic trauma at the same time has become a new goal of spinal surgery. This research used percutaneous transpedicular screw distraction to partially reduce the fractured vertebrae, followed by completing nerve decompression and reducing residual displacement bone fragments with the assistance of the unilateral biportal endoscopic (UBE) technique to achieve full protection of bone-ligament tissue and obtain good clinical efficacy.

METHODS

Guide wires were safely inserted into the fractured vertebra and adjacent upper and lower vertebra under the surveillance of anteroposterior and lateral X-ray fluoroscopy. Transpedicular screws were implanted via guide wires on the side with mild neurological deficits or bone fragment compression (the opposite side of the endoscopic operation). A titanium rod was installed and moderately distracted to reduce the fractured vertebra. Then, under the guidance of the endoscopic view, the laminectomy and ligamentum flavum resection were completed according to the position of the protruding bone fragment into the spinal canal, and the compressed dural sac or nerve root was fully exposed and decompressed. An L-shaped replacer was used to reduce residual bone fragments. The ipsilateral transpedicular screws and rod were installed and adjusted to match the contralateral side. The drainage tube was indwelled, and the incision was closed. The preoperative and postoperative images of the patients were evaluated, and the recovery of neurological symptoms was observed.

RESULTS

Surgery was successfully completed on all six patients, and no intraoperative conversion to open surgery was performed. Postoperative images showed good reduction of the protruding bone fragment and good placement of all screws. At the last follow-up, the neurological symptoms of all patients returned to normal.

CONCLUSION

The UBE technique combined with percutaneous transpedicular screw fixation in the treatment of thoracolumbar fractures with neurological symptoms can effectively achieve the reduction of displaced bone fragments, improve damaged nerve function, stabilize spinal alignment, and protect the integrity of bone-ligament tissue.

Expandable versus static cages in unilateral biportal endoscopy lumbar interbody fusion (ULIF) for treating degenerative lumbar spondylolisthesis (DLS): comparison of clinical and radiological results

BACKGROUND

In recent years, early rehabilitation after spinal fusion and the recovery of physiological curvature have attracted much attention. Therefore, expandable cages have entered the field of vision of scientists. The goal of the current study was to compare the clinical and radiological results of unilateral portal endoscopic lumbar interbody fusion (ULIF) in the treatment of degenerative lumbar spondylolisthesis (DLS) with expandable versus static cages.

METHODS

We retrospectively analysed patients who received ULIF treatment for DLS from May 2019 to February 2021. Patients were categorized by cage type (static vs. expandable), and the main study was the preop and postop clinical and radiological index changes of the patients.

RESULTS

Eighty-four patients were included (38 in the static cages group; 46 in the expandable cages group). There was no difference in the preop results between the two groups. The VAS scores for low back and leg pain and ODI scores in the expandable cages group 7 d postop were significantly superior to those in the static cages group (P < 0.05), and the segmental angle and PDH in the expandable cages group postop were significantly higher than those in the static cages group (P < 0.05). The fusions at 6 m postop in the expandable cages group were superior to those in the Static Cages group (P < 0.05).

CONCLUSIONS

The results of this study showed that compared with the stable cage group, the expandable cage group had unique advantages in restoring the physiological curvature of the lumbar spine, increasing the fusion rate, and relieving pain in the early postoperative period. ULIF can be used to treat single-segment, mild lumbar spondylolisthesis patients using expandable cages instead of static cages.

Visible trephine-based foraminoplasty in PTED leads to asymmetrical stress changes and instability in the surgical and adjacent segments: a finite element analysis

This study aimed to construct a multi-segment lumbar finite element model (FEM) of PTED surgery to analyze the changes in stress and ROM after visible trephine-based foraminoplasty. The CT scans of a 35-year-old healthy male were used to develop a multi-segment lumbar FEM with Mimic, Geomagic Studio, Hypermesh and MSC.Patran. Different foraminoplasty was performed on the model, and these were grouped into normal group (A), the ventral resection group (B), the apex resection group (C), the ventral + apex + isthmus resection group (D), and the SAP + isthmus + lateral recess resection group (E). A vertical load of 500N and a torque of 10N·M were applied to the upper surface of the L3 vertebral body to simulate the biomechanical characteristics under the motion of flexion, extension, lateral bending, and rotation. The von Mises stress maps of the intervertebral f, vertebral body, facet joints, and the ROM of the L3-S1 intervertebral disk were calculated and analyzed. The changes of peak stress on the vertebral body for each group were not significant in the same motion state. Significant stress differences were observed in the L4/5 intervertebral disks, while no obvious stress changes were observed for the L3/4 and L5/S1 intervertebral disks. The stress of the L3/4 and L5/S1 facet joints decreased after L4/5 foraminoplasty, while the stress of L4/5 facet joints displayed an overall increasing trend. Significant asymmetrical stress changes of bilateral facet joints were observed in all three segments, particularly during bilateral rotation movements. The ROM of L3-S1 gradually increased from Group A to Group E, especially during flexion, left lateral bending, and right rotation, with the highest elevation observed for the L45 ROM. Our FEM indicated that enlarged resection and exposure of the articular surface could lead to significant asymmetrical stress changes in the bilateral facet joints and ROM instability of the surgical and adjacent segments. These findings suggested that unnecessary and excessive resection should be avoided in PTED to reduce the incidence of low back pain and the risk of postsurgical degeneration.

The Role and Clinical Outcomes of Endoscopic Spine Surgery of Treating Spinal Metastases; Outcomes of 29 Cases From 8 Countries

OBJECTIVE

We aim to report the outcomes and feasibility of endoscopic spine surgery used to treat symptomatic spinal metastases patients. This is the most extensive series of spinal metastases patients who underwent endoscopic spine surgery.

METHODS

A worldwide collaborative network group of endoscopic spine surgeons, named 'ESSSORG,' was established. Patients diagnosed with spinal metastases who underwent endoscopic spine surgery from 2012 to 2022 were retrospectively reviewed. All related patient data and clinical outcomes were gathered and analyzed before the surgery and the followtime period of 2 weeks, 1 month, 3 months, and 6 months.

RESULTS

A total of 29 patients from South Korea, Thailand, Taiwan, Mexico, Brazil, Argentina, Chile, and India, were included. The mean age was 59.59 years, and 11 of them were female. The total number of decompressed levels was 40. The technique was relatively equal (15 uniportal; 14 biportal). The average length of admission was 4.41 days. Of all patients with an American Spinal Injury Association Impairment Scale of D or lower before surgery, 62.06% reported having at least one recovery grade after the surgery. Almost all clinical outcomes parameters statistically significantly improved and maintained from 2 weeks to 6 months after the surgery. Few surgical-related complications (4 cases) were reported.

CONCLUSION

Endoscopic spine surgery is a valid option for treating spinal metastases patients as it could yield comparable results to other minimally invasive spine surgery techniques. As the aim is to improve the quality of life, this procedure is valuable and holds value in palliative oncologic spine surgery.

Comparison of minimally invasive transforaminal lumbar interbody fusion and endoscopic lumbar interbody fusion for lumbar degenerative diseases: a retrospective observational study

BACKGROUND

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and endoscopic lumbar interbody fusion (Endo-LIF) are both minimally invasive interbody fusion procedures for lumbar degenerative diseases. In this study, we attempted to compare the clinical efficacy and postoperative outcomes of MIS-TLIF and Endo-LIF for lumbar degenerative diseases.

METHODS

The study cohort comprised 99 patients with lumbar degenerative diseases treated by MIS-TLIF or Endo-LIF from January 2019 to July 2021. The clinical outcomes (visual analogue scale (VAS), Oswestry disability index (ODI), and MacNab criteria) preoperatively, 1 month postoperatively, 3 months postoperatively, and 1 year postoperatively were compared between the two groups.

RESULTS

There were no significant differences between the two groups in sex, age, disease duration, affected spine segment, and complications (P > 0.05). The operation time was significantly longer in the Endo-LIF group than the MIS-TLIF group (155.25 ± 12.57 vs. 123.14 ± 14.50 min; P < 0.05). However, the Endo-LIF group had a significantly smaller blood loss volume (61.79 ± 10.09 vs. 259.97 ± 14.63 ml) and shorter hospital stay (5.46 ± 1.11 vs. 7.06 ± 1.42 days) than the MIS-TLIF group. In both groups, the ODI and VAS scores for lower back pain and leg pain were significantly lower at each postoperative timepoint than preoperatively (P < 0.05). Although there were no significant differences between the two groups in the ODI and VAS scores for lower back pain and leg pain (P > 0.05), the VAS for lower back pain was lower in the Endo-LIF group than the MIS-TLIF group at each postoperative timepoint. The MacNab criteria showed that the improvement rate was 92.2% in the MIS-TLIF group and 91.7% in the Endo-LIF group, with no significant difference between the two groups (P > 0.05).

CONCLUSIONS

There were no significant differences in short-term surgical outcomes between the MIS-TLIF and Endo-LIF groups. Compared with the MIS-TLIF group, the Endo-LIF group incurred less damage to surrounding tissues, experienced less intraoperative blood loss, and had less lower back pain, which is more conducive to recovery.