Full Endoscopic Spinal Surgery Techniques: Advancements, Indications, and Outcomes

Transforaminal posterior lumbar interbody fusion microscopic safe operating area: a three-dimensional model study based on computed tomography imaging

BACKGROUND

Endoscopic spine lumbar interbody fusion (Endo-LIF) is well-regarded within the academic community. However, it presents challenges such as intraoperative disorientation, high rates of nerve damage, a steep learning curve, and prolonged surgical times, often occurring during the creation of the operative channel. Furthermore, the undefined safe operational zones under endoscopy continue to pose risks to surgical safety. We aimed to analyse the anatomical data of Kambin's triangle via CT imaging to define the parameters of the safe operating area for transforaminal posterior lumbar interbody fusion (TPLIF), providing crucial insights for clinical practice.

METHODS

We selected the L4-L5 intervertebral space. Using three-dimensional (3D), we identified Kambin's triangle and the endocircle within it, and recorded the position of point 'J' on the adjacent facet joint as the centre 'O' of the circle shifts by angle 'β.' The diameter of the inscribed circle 'd,' the abduction angle 'β,' and the distances 'L1' and 'L2' were measured from the trephine's edge to the exiting and traversing nerve roots, respectively.

RESULTS

Using a trephine with a diameter of 8 mm in TPLIF has a significant safety distance. The safe operating area under the TPLIF microscope was also clarified.

CONCLUSIONS

Through CT imaging research, combined with 3D simulation, we identified the anatomical data of the L4-L5 segment Kambin's triangle, to clarify the safe operation area under TPLIF. We propose a simple and easy positioning method and provide a novel surgical technique to establish working channels faster and reduce nerve damage rates. At the same time, according to this method, the Kambin's triangle anatomical data of the patient's lumbar spine diseased segments can be measured through CT 3D reconstruction of the lumbar spine, and individualised preoperative design can be conducted to select the appropriate specifications of visible trephine and supporting tools. This may effectively reduce the learning curve, shorten the time operation time, and improve surgical safety.

Outcomes of FETD versus UBE in the treatment of L5S1 foraminal stenosis: A comparative study

Background

The L5S1 level exhibits unique anatomical features compared with other levels. This makes minimally invasive surgery for L5S1 foraminal stenosis (FS) challenging. This study compared the surgical outcomes of full endoscopic transforaminal decompression (FETD) and unilateral biportal endoscopy with the far-lateral approach (UBEFLA) in patients with L5S1FS.

Methods

In this retrospective study, 49 patients with L5S1FS were divided into two groups. Of these, 24 patients underwent FETD, 25 patients underwent UBEFLA. The study assessed demographic data, leg pain visual analog scale (VAS) score, back pain VAS score, Oswestry Disability Index (ODI), modified MacNab outcome scale, and radiographic parameters including postoperative lateral facet preservation (POLFP).

Results

The Mann-Whitney U test revealed that the UBEFLA group exhibited a higher VAS score for back pain at one week after the operation, whereas the FETD group exhibited a higher leg pain VAS score 6 weeks after the operation. All four undesired MacNab outcomes in the FETD group were attributed to residual leg pain, whereas all five undesired MacNab outcomes in the UBEFLA group were due to recurrent symptoms. Radiographically, the FETD group exhibited greater POLFP.

Conclusions

When L5S1FS is performed, there may be challenges in adequately clearing the foraminal space in FETD. On the other hand, UBEFLA allowed for a more comprehensive clearance. However, this advantage of UBEFLA was associated with spinal instability as a future outcome.

Contralateral translaminar endoscopic approach for highly down-migrated lumbar disc herniation using percutaneous biportal endoscopic surgery : Original research

OBJECTIVE

Unilateral biportal endoscopy (UBE)is a minimally invasive spine surgery with reduced traumatization of the posterior lumbar ligament and muscular structures. This study reports contralateral translaminar approach with UBE for highly down-migrated lumbar disc herniation (LDH).

METHODS

Data of 32 patients with highly down-migrated LDH treated using UBE at our center from January 2020 to July 2022 were retrospectively analyzed. The operation time and perioperative complications were recorded, and the visual analog scale (VAS) of pain was recorded to evaluate the degree of lower back and extremity pain. The Oswestry disability index (ODI) was used to evaluate lumbar spine function. The modified MacNab score was used to evaluate clinical efficacy.

RESULTS

All patients successfully underwent the operation, with a time range from 47 to 65 min and an average operation time of 56.09 ± 5.11 min. Overall, 17 and 15 were males and females, respectively, with ages ranging from 34 to 72 years and an average age of 56 ± 7.89 years. The postoperative follow-up period was 12-18 months, with an average of 14.9 ± 2.3 months. The postoperative lower back VAS pain score and ODI were statistically significant compared with preoperatively (P < 0.05). At the final follow-up, according to the modified Macnab criteria, 90.6% of cases were classified as good or excellent.

CONCLUSION

UBE treatment of highly down-migrated LDH through the contralateral translaminar approach is safe and efficient. Therefore, this approach can be an efficient alternative for patients with highly downward-migrating LDH.

An algorithm for selection of full endoscopic approach for symptomatic nerve root decompression

Background Context

Both Transforaminal (TF) and Interlaminar (IL) endoscopic approaches are established techniques of decompression for lumbar compressive radiculopathy. In the absence of adequate literature, there is always some dilemma in selecting the approach for endoscopic decompression leading to long learning curves and high chances of inadequate decompression, iatrogenic instability, dural tear, or dysesthesia. Hence authors propose a new surgical nomenclature and algorithm for selection of endoscopic approach.

Methods

This retrospective study included 396 of 626 consecutive patients who met the inclusion criteria, who underwent either TF (n=302) or IL (n=202) full endoscopic spine surgery. MRI findings of every patient were classified as per FAPDIS (Facet angle, Anterior pathology, Posterior pathology, Dorsal, Inferior, and Superior migration) algorithm. Inter-observer variations were calculated. The targeted nomenclature was used to define the selection of endoscopic TF or IL approach for symptomatic nerve root decompression. All patients were followed up for preop and postop 6 months VAS and Oswestry Disability Index score for validation of FAPDIS algorithm.

Results

Median age: 46.8 years; Sides and levels operated 330 single-level ipsilateral, 54 multiple-level ipsilateral, 6 single-level bilateral, and 6 multiple-level bilateral. Interobserver agreement in the selection of TF approach was 0.873 and IL approach was 0.882. Interobserver variability was also calculated for each FAPDIS factor, selection of P3 and P4 pathology was the main reason for disagreement. All other FAPDIS factors show good to excellent correlation. The overall VAS score decreased from a preoperative value of 9 to 1 at 6 months follow-up (p-value < 0.001), and the overall Oswestry Disability Index score improved from 89 to 12 (p-value <.001).

Conclusions

The author's new FAPDIS surgical nomenclature and algorithm is a reliable tool for describing the symptomatic nerve root compression for the selection of endoscopic surgical approach to achieve adequate decompression of offending neural structure with minimum challenges to minimize perioperative complication rate.

Fully Endoscopic Spine Separation Surgery in Metastatic Disease-Case Series, Technical Notes, and Preliminary Findings

Objective: This report aims to describe the surgical methodology and potential effectiveness of endoscopic separation surgery (ESS) in patients with metastatic spine disease. This concept may reduce the invasiveness of the procedure, which can potentially speed up the wound healing process and, thus, the possibility of faster application of radiotherapy. Materials and Methods: In this study, separation surgery for preparing patients for stereotactic body radiotherapy (SBRT) was performed with fully endoscopic spine surgery (FESS) followed by percutaneous screw fixation (PSF). Results: Three patients with metastatic spine disease in the thoracic spine were treated with fully endoscopic spine separation surgery. The first case resulted in the progression of paresis symptoms that resulted in disqualification from further oncological treatment. The remaining two patients achieved satisfactory clinical and radiological effects and were referred for additional radiotherapy. Conclusions: With advancements in medical technology, such as endoscopic visualization, and new tools for coagulation, we can treat more and more spine diseases. Until now, spine metastasis was not an indication for the use of endoscopy. This method is very technically challenging and risky, especially at such an early stage of application, due to variations in the patient's condition, morphological diversity, and the nature of metastatic lesions in the spine. Further trials are needed to determine whether this new approach to treating patients with spine metastases is a promising breakthrough or a dead end.

Identification of the Magna Radicular Artery Entry Foramen and Adamkiewicz System: Patient Selection for Open versus Full-Endoscopic Thoracic Spinal Decompression Surgery

BACKGROUND

Casually cauterizing the radicular magna during routine thoracic discectomy may have dire consequences.

METHODS

We performed a retrospective observational cohort study on patients scheduled for decompression of symptomatic thoracic herniated discs and spinal stenosis who underwent a preoperative computed tomography angiography (CTA) to assess the surgical risks by anatomically defining the foraminal entry level of the magna radicularis artery into the thoracic spinal cord and its relationship to the surgical level.

RESULTS

Fifteen patients aged 58.53 ± 19.57, ranging from 31 to 89 years, with an average follow-up of 30.13 ± 13.42 months, were enrolled in this observational cohort study. The mean preoperative VAS for axial back pain was VAS of 8.53 ± 2.06 and reduced to a postoperative VAS of 1.60 ± 0.92 (p < 0.0001) at the final follow-up. The Adamkiewicz was most frequently found at T10/11 (15.4%), T11/12 (23.1%), and T9/10 (30.8%). There were eight patients where the painful pathology was found far from the AKA foraminal entry-level (type 1), three patients with near location (type 2), and another four patients needing decompression at the foraminal (type 3) entry-level. In five of the fifteen patients, the magna radicularis entered the spinal canal on the ventral surface of the exiting nerve root through the neuroforamen at the surgical level requiring a change of surgical strategy to prevent injury to this important contributor to the spinal cord's blood supply.

CONCLUSIONS

The authors recommend stratifying patients according to the proximity of the magna radicularis artery to the compressive pathology with CTA to assess the surgical risk with targeted thoracic discectomy methods.

Endoscopic Rhizotomy for Facetogenic Back Pain: A Review of the History, Financial Considerations, Patient Selection Criteria, and Clinical Outcomes

BACKGROUND

Chronic back pain (CBP) is a condition that places a considerable burden on society, with several million people affected in the United States alone. Treatment options to address this problem and relieve CBP are constantly evolving, and one of the most promising treatment modalities for CBP that is refractory to conservative treatment options is endoscopic rhizotomy (ER).

METHODS

A thorough search of the PubMed (MEDLINE) database was conducted to assess the full progression of ER from its earliest uses to present day in a historical narrative review of ER, with treatment of facetogenic pain as a model pathology.

RESULTS

ER allows for direct visualization and ablation of sensory branches of the dorsal ramus to provide pain relief in up to 80% of patients faced with refractory CBP. This technique has been built upon since the early 20th century, and the novel endoscopic approach continues to gain popularity among physicians. Benefits of ER include superior postoperative median pain-free duration compared with traditional percutaneous radiofrequency ablation, as well as direct visualization of regional anatomy. Patient selection criteria for the procedure and a modest list of contraindications allow the use of ER as a viable treatment option for a significant population of patients suffering from CBP. Potential barriers to ER include high cost of the procedure, longer intraoperative time, and expensive proprietary equipment.

CONCLUSIONS

ER is an effective treatment for refractory CBP with notable advantages. As the technology and popularity of this procedure progress, improvements in the cost, training, and intraoperative time may make it a favorable alternative to the current standard of care.

Impact of Body Weight, Height, and Obesity on Selection of Skin Entry Point for Transforaminal Endoscopic Lumbar Discectomy

Background Prospective evaluation of the effect of physical parameters like height, weight and abdominal girth on different skin entry points in transforaminal endoscopic lumbar discectomy (TELD) in lower lumbar discs.

Methods This prospective study involved 174 patients with unilateral radicular pain or discogenic back pain, central, paracentral disc herniations and lateral canal stenosis at the level from L3 to S1 radiologically confirmed by magnetic resonance imaging (MRI) and failed conservative trial for 6 weeks. All patients underwent measurements of height, weight, body mass index (BMI), and abdominal girth preoperatively. All the four possible entry points, i.e., 45 to 45, posterolateral (PL), tip of spinous process (TOSP), and dorsum of the facet joint, were marked and point midway between PL and TOSP (PL-TOSP) skin entry was used.

Results The change in the value, i.e., distance from midline of all the entry points with physical parameters like height, weight, BMI, and abdominal circumference was statistically significant. The visual analog scale score decreased from a preoperative value of 7.98 to 1.84 at 6 months follow-up. The Oswestry disability index score improved from 72.53 to 16.26.

Conclusion The entry point in TELD is not a fixed value as it varies with the physical parameters like weight and abdominal girth of the patient. PL-TOSP is a safe entry point for common pathologies like central, paracentral herniations and lateral canal stenosis in lower lumbar levels and can be predicted preoperatively by proposed formula.

Global and Current Research Trends of Unilateral Biportal Endoscopy/Biportal Endoscopic Spinal Surgery in the Treatment of Lumbar Degenerative Diseases: A Bibliometric and Visualization Study

The study aimed to make a bibliometric analysis of the current research situation in unilateral biportal endoscopy/biportal endoscopic spinal surgery (UBE/BESS). Research data sets were acquired from the Web of Science database. The study chosed “biportal endoscopic spinal surgery” OR “two portal endoscopic spinal surgery” OR “percutaneous biportal endoscopic decompression” OR “unilateral biportal endoscopy” OR “irrigation endoscopic discectomy” as the search terms. The literature search was limited to articles published before March 5, 2021. We only included original articles and reviews. VOS viewer and Citespace software were used to analyze the data and generate visualization knowledge maps. Annual trend of publications, distribution, H‐index status, co‐authorship status, and research hotspots were analyzed. A total of 74 publications met the requirement. The sum number of citations was 31,204, in which 19,336 were no self‐citations. The average citation of all the papers was 21.84 times. The H‐index of all the publications was 85. South Korea's total number of articles was far higher than that of other countries and regions (61, 82.4%), followed by United Arab Emirates, Egypt, and Peoples Republic of China (three, ranking second, accounting for 12.2% of the total). For the most productive authors, Choi ranked first with 21 articles, Kim ranked second with 16 articles, and Heo ranked third with 12 articles. The journal with the greatest number of publications was World Neurosurgery, with a total of 18 (39.1%) papers. Clinics in Orthopedic Surgery ranked second with six (13.0%) papers. In third place, there were fix articles published by Asian Spine Journal and Neurospine, accounting for 21.8% of the total articles. These top three journals accounted for 73.9% of all the papers. Spondylolisthesis and endoscopic decompression were the research hotspots in recent years. The number of publications has showed an upward trend with a stable rise in recent years. South Korea is the country with the highest productivity, not only in quality, but also in quantity. Barun Hosp and Leon Wiltse Mem Hosphave published most articles. Choi is the most productive author. World Neurosurgery is the most productive journal. Spondylolisthesis and endoscopic decompression are the research hotspots in recent years. Indeed, this study provides new insight into the growth and development of UBE/BESS.

Better Functional Outcome and Pain Relief in the Far-Lateral-Outside-in Percutaneous Endoscopic Transforaminal Discectomy

Background

Even though percutaneous endoscopic transforaminal discectomy (PETD) has been widely used for the surgical treatment of lumbar herniated disc, there are only a few studies directly comparing the clinical outcomes between microdiscectomy (MD) and PETD. Therefore, further studies are needed in order to compare the clinical outcomes between PETD and MD on a single level more thoroughly.

Methods

We proposed a far-lateral-outside-in technique for PETD to get an entry point without complex planning and facet violation. From September 2017 to September 2019, a total of 155 patients (69 with PETD and 86 with MD) were enrolled for this retrospective study, with the inclusion criteria: single level between L2 and S1, clinical sciatica for at least 6 weeks, and failed attempts with non-surgical treatments. Patients were excluded due to cauda equina syndrome, progressive neurologic deficits, history of lumbar spinal surgery, endplate modic changes, severe disc degeneration and less than 24 months of follow-up.

Results

PETD showed significantly shorter surgery time and less intraoperative blood loss compared to MD. The difference between PETD and MD in VAS back pain (but not VAS leg pain) at follow-up time was significant. The ODI improvement in the follow-up time of 6 months between the 2 groups showed a significant difference (PETD: 31.23±6.59, MD: 39.85±7.81, p < 0.001). MD had a significantly higher chance of postoperative wound infection and poor healing, while PETD was more likely to have recurrence of the herniated disc.

Conclusion

MD has been the gold standard procedure for LDH. However, with the advanced endoscopic technology and surgical technique, PETD has emerged as an alternative method due to higher functional outcome and less wound problems.

Efficacy and Complications of Unilateral Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis: A Meta-Analysis and Systematic Review

OBJECTIVE

As an emerging minimally invasive endoscopic technique, unilateral biportal endoscopic spinal surgery (UBESS) has the advantages of flexibility, a wide and clear field of view, and less soft tissue damage. However, the clinical evidence is insufficient and controversy exists regarding UBESS for the treatment of lumbar spinal stenosis (LSS). In the present meta-analysis, we investigated the clinical efficacy and complications of UBESS for the treatment of LSS.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were searched through to June 1, 2021 to identify all reported studies on UBESS for LSS. Only English-language studies with original reported data from ≥30 cases were considered for inclusion. The patient demographics, operative time, hospital stay, complications, visual analog scale (VAS) score, Oswestry disability index, and Macnab criteria were extracted. Quality assessment was performed using the Cochrane collaboration tool for randomized controlled trials and the Newcastle-Ottawa scale for retrospective studies. A meta-analysis was performed using a random or fixed effect model according to the heterogeneity.

RESULTS

Thirteen studies with 586 patients and 607 operation levels were included. The mean single-level operative time, hospital stay, and follow-up duration were 61.10 minutes, 2.32 days, and 14.7 months, respectively. At the final follow-up visit, the mean VAS score for leg pain had decreased from 7.23 preoperatively to 1.83 postoperatively, the mean VAS score for back pain had decreased from 6.30 to 1.95, and the mean Oswestry disability index had significantly improved from 56.99 to 17.83. The average satisfied outcome (excellent or good using the Macnab criteria) was 86%. The overall complication rate was 5%, and the most common complication was a dural tear, with an incidence of 2%, followed by epidural hematoma with an incidence of 1%. The remaining complications were nerve root injury, inadequate decompression, and postoperative headache.

CONCLUSIONS

From the available clinical results and experience from reported studies, UBESS for LSS is a feasible and effective approach and a worthwhile choice for clinicians. However, the complications associated with the procedure should also be seriously considered.

Decompression Using Minimally Invasive Surgery for Lumbar Spinal Stenosis Associated with Degenerative Spondylolisthesis: A Review

Lumbar spinal stenosis (LSS), which often occurs concurrently with degenerative spondylolisthesis (DS), is a common disease in the elderly population, affecting the quality of life of aged people significantly. Notwithstanding the frequently good effect of conservative therapy on LSS, a minority of the patients ultimately require surgery. Surgery for LSS aims to decompress the narrowed spinal canals with preservation of spinal stability. Traditional open surgery, either pure decompression or decompression with fusion, was considered effective for the treatment of LSS with or without DS. However, the long-term clinical outcomes of traditional open surgery are still unclear. Moreover, the disadvantages of conventional open surgery are extensive, examples including tissue injuries or secondary instability, with limited outcomes and significant reoperation rates. With the development and improvement of surgical tools, various minimally invasive spine surgery (MISS) methods, including indirect decompression techniques of interspinous process devices (IPDs) and direct decompression techniques such as microscopic spine surgery or endoscopic spine surgery (ESS), have been updated with enhancement. IPDs, such as Superion devices, were reported to behave with comparable physical function, disability, and symptoms outcomes to laminectomy decompression. As an emerging technique of MISS, ESS has beneficial hallmarks including minimal tissue injuries, reduced complication rates, and shortened recovery periods, thus gaining popularity in recent years. ESS can be classified in terms of endoscopic hallmarks and approaches. Predictably, with the continuous development and gradual maturity, MISS is expected to replace traditional open surgery widely in the surgical treatment of LSS associated with DS in the future.

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.

Minimally Invasive Spine Surgery: Techniques, Technologies, and Indications

Over the past few decades, interest in minimally invasive spine surgery (MISS) has increased tremendously due to its core principle of minimizing approach-related injury while providing outcomes similar to traditional open spine procedures. With technical and technological advancements, MISS has expanded its utility not only to simple spinal stenosis, but also to complex spinal pathologies such as metastasis, trauma, or adult spinal deformity. In this article, we review the techniques and technology in MISS and discuss the indications, benefits, and limitations of MISS.

Uniportal Endoscopic Lumbar Interbody Fusion

The cause of radiculopathy is the compression of the nerve root which can be secondary to sliding of the vertebra and reduced disc height. In some patients, decompression alone does not resolve this problem. We describe the uniportal endoscopic transforaminal lumbar interbody fusion technique. Full-endocopic foraminotomy and discectomy are followed by cage implementation and percutaneous instrumentation. The goal of this surgical method is decompression of nerve roots, segment stabilization, disc height, and sagittal alignment restoration. Uniportal endoscopic facet sparing transforaminal transkambin lumbar interbody fusion is a good surgical option to treat degenerative disc disease, mechanical instability, and spondylolisthesis. This method shows favourable clinical outcomes in selected patients.

Percutaneous Unilateral Biportal Endoscopic Spine Surgery Using a 30-Degree Arthroscope in Patients With Severe Lumbar Spinal Stenosis: A Technical Note

BACKGROUND

Unilateral biportal endoscopic surgery (UBESS) for severe lumbar central canal stenosis (LCCS) remains challenging.

OBJECTIVE

To describe the use of UBESS with a 30-degree arthroscope in patients with severe LCCS.

MATERIALS AND METHODS

Working and viewing portals were created in each unilateral paravertebral area at the target interlaminar level. After ensuring the visual field with a 30-degree arthroscope, effective tissue removal was possible through safe access to the bilateral hypertrophic yellow ligament with minimal osteotomy. The authors evaluated 58 patients and analyzed the clinical outcomes using the visual analog scale, Macnab criteria, and self-predicted walking distance.

RESULTS

The visual analog scale scores for low back and leg pains decreased from 7.1 to 1.9 and from 7.9 to 1.6, respectively, at 18 months after the procedure. According to the Macnab criteria, "excellent," "good," and "fair" results were obtained in 51.7%, 41.4%, and 6.9% subjects, respectively. Before surgery, the subjects could walk a mean of 305.8±468.1 m. After surgery, 43.1% of the patients could walk for >1 hour, whereas the remaining patients could walk 1521.8±1831.1 m.

CONCLUSION

UBESS using a 30-degree arthroscope can be an efficient and safe intervention in patients with severe LCCS.

Efficacy and Safety of Full-endoscopic Decompression via Interlaminar Approach for Central or Lateral Recess Spinal Stenosis of the Lumbar Spine: A Meta-analysis

STUDY DESIGN

A meta-analysis of five retrospective cohort studies.

OBJECTIVE

The aim of the study was to delineate the efficacy and safety of full-endoscopic decompression via the interlaminar approach for central or lateral recess spinal stenosis of the lumbar spine using a meta-analysis.

SUMMARY OF BACKGROUND DATA

The paradigm of spinal endoscopy is shifting from treatment of soft disc herniation to that of lumbar spinal stenosis. Technical advancements have enabled full-endoscopic decompression in spinal stenosis surgery. There is few strong evidence supporting this surgical technique, and clinicians usually rely on their own opinions and experiences.

METHODS

A systematic search of electronic databases, including PubMed, EMBASE, Cochrane Library, Web of science, and KoreaMed, up to August 2017 was performed to identify studies concerning full-endoscopic decompression via the interlaminar approach for lumbar spinal stenosis. Changes in clinical outcomes [Oswestry Disability Index (ODI) and Visual Analog Scales (VAS) for back and leg pain] were compared with the minimal clinically important difference (MCID) for each item. We then calculated the mean differences and 95% confidence intervals (95% CIs) using random-effects models.

RESULTS

We included data from five studies involving 156 patients at 6- and 12-month follow-ups. The majority of enrolled papers included patients with neurogenic claudication due to central stenosis refractory to conservative management and excluded patients with significant instability or previous surgery. The overall mean difference of patients with ODI and VAS scores for leg and back pain exceeded the criteria for MCID. ODI scores improved by 41.71 (95% CI, 39.80-43.62) after the surgery, which was twice the MCID. The VAS leg and back pain scores improved by 5.95 (95% CI, 5.70-6.21) and 4.22 (95% CI, 3.88-4.56), respectively, indicating statistically significant improvement over the MCID.

CONCLUSION

Successful clinical outcomes can be achieved with full-endoscopic decompression via the interlaminar approach for lumbar central spinal stenosis in patients for the defined indications.

LEVEL OF EVIDENCE

2.

Endoscopic Sacrolumbar Facet Joint Denervation in Osteoarthritic and Degenerated Zygapophyseal Joints

Chronic low-back pain (CLBP) has an increasing incidence and yields a tremendous health economic burden. There are different anatomic structures that may be responsible for CLBP, such as lumbar intervertebral discs, sacroiliac joints, nerve root dura, fascia, ligaments, and muscles. However, to a large extent, CLBP is associated with structural changes in and around the facet (zygapophyseal) joint. If conservative treatment strategies fail, symptoms and pain can effectively be reduced by denervation or rhizotomy of the medial branch of the dorsal ramus of the spinal nerve through radiofrequency ablation. In this technical description with video, we present an endoscopic technique for radiofrequency rhizotomy. This technique has the advantage of directly visualizing the facet joint as well as its surrounding structures including the medial branches.

Selection of Tubular and Endoscopic Transforaminal Disc Procedures Based on Disc Size, Location, and Characteristics

The clinical effectiveness of percutaneous and transforaminal endoscopic discectomy procedures has been evaluated by the system used or compared to open laminectomy or micro-discectomy but are not evaluated based on the location and characteristics of the abnormal disc. This review proposes that outcomes are primarily related to disc size, biomechanics, location, and associated segmental fibrotic and bone changes as well as the surgeon's skill in using various systems rather than the specific system used. In these cases, the surgeon needs to decide if the goal of the procedure is simply internal decompression of an abnormal but contained herniated disc or release of the entrapped nerve root by a large contained disc, extruded and migrated disc fragment, or coexistent foraminal stenosis. Percutaneous and tubular transforaminal procedures are quite different, technically ranging from simple discectomy aspirating probes to larger endoscopic systems, providing the capability to remove large extruded free disc fragments, with or without foraminotomy. Recently, the ability to perform interbody fusion has been added to the range of procedures able to be performed endoscopically. At the same time, biologic solutions to disc degeneration are rapidly evolving and may have a place in combination with these procedures. This article reviews the interrelationship between clinical signs and symptoms, radiologic findings, and the biochemistry and biomechanics of the affected disc segment. Understanding the role played by all these factors enables the surgeon to evaluate both the disc and surrounding bone structures pre-operatively to determine if the clinical signs and symptoms are related to enlargement and displacement of a contained disc or compression or impingement of the nerve root. Based on this, the surgeon can choose different surgical systems, allowing simple decompression of a contained disc, possibly adding biologics, with a 'small' system, while a large herniated disc, or extruded fragment, causing root impingement, would require a ‘larger’ system that provides direct endoscopic visualization within the epidural space, foraminal decompression with drills, and direct surgical manipulation and freeing of the nerve root. By choosing the surgical system based on characteristics such as disc size, location, and associated inflammatory and fibrotic changes, the effectiveness of minimally invasive procedures will be more consistent and improve as the surgeon's diagnostic and operative skills improve.

Removal of fixation construct could mitigate adjacent segment stress after lumbosacral fusion: A finite element analysis

BACKGROUND DATA

Combined usage of posterior lumbar interbody fusion and transpedicular fixation has been extensively used to treat the various lumbar degenerative disc diseases. The transpedicular fixator aims to increase stability and enhance the fusion rate. However, how the fused disc and bridged vertebrae respectively affect adjacent-segment diseases progression is not yet clear.

METHODS

Using a validated lumbosacral finite-element model, three variations at the L4-L5 segment were analyzed: 1) moderate disc degeneration, 2) instrumented with a stand-alone cage and pedicle screw fixators, and 3) with the cage only after fusion. The intersegmental angles, disc stresses, and facet loads were examined. Four motion tests, flexion, extension, bending, and twisting, were also simulated.

FINDINGS

The adjacent-segment disease was more severe at the cephalic segment than the caudal segment. After solid fusion and fixation, the increase in intersegmental angles, disc stresses and facet loads of the adjacent segments were about 57.6%, 47.3%, and 59.6%, respectively. However, these changes were reduced to 30.1%, 22.7%, and 27.0% after removal of the fixators. This was attributed to the differences between the biomechanical characteristics of the fusion and fixation mechanisms.

INTERPRETATION

Fixation superimposes a stiffer constraint on the mobility of the bridged segment than fusion. The current study suggested that the removal of spinal fixators after complete fusion could decrease the stress at adjacent segments. Through a minimally invasive procedure, we could reduce secondary damage to the paraspinal structures while removing the fixators, which is of utmost concern to surgeons.

STITCHLESS Percutaneous Endoscopic Cervical Discectomy: Are We Moving Towards Day Care Discectomy Procedure?

BACKGROUND

STITCHLESS percutaneous endoscopic cervical discectomy s[PECD] is safe, precise, targeted, and a complete endoscopic procedure to treat soft cervical disc herniation with unilateral radiculopathy. It allows direct visualization of herniated fragment and its removal, inspection of decompressed nerve root in an awake and aware patient. It reduces the risk related to general anesthesia and to the neurological structures. However, all the patients treated with PECD can be candidates for anterior cervical discectomy and fusion (ACDF). ACDF requires a longer period of stay, expense, and more risk to neurological structures and ultimately loss of the disc space by fusion.

MATERIALS AND METHODS

Twenty consecutively treated patients by sPECD over a period of 2 years with soft cervical disc herniation and unilateral radiculopathy were included in the study. PECD enables removal of offending fragment under vision and irrigation and ablation of inflammation with few complications. All patients were followed for minimum of 6 months with visual analog score (VAS) and neck disability index (NDI).

RESULTS

All treated patients had a good outcome in terms of pain relief (VAS) and functional recovery (NDI). One patient had episodes of cough lying in the supine position and another patient had transient hoarseness of voice, (both recovered).

CONCLUSION

Potential benefits of sPECD include safety as it is done under local anesthesia, smaller incision, short hospitalization, fewer complications, avoidance of fusion, preservation of segmental motion, preventing the adjacent segment degeneration, and avoidance of the risk related to the hardware (nonunion and pseudarthrosis). sPECD is an effective treatment modality for soft cervical disc herniation.

The Effect of Lumbar Lordosis on Screw Loosening in Dynesys Dynamic Stabilization: Four-Year Follow-Up with Computed Tomography

INTRODUCTION

This study aimed to evaluate the effects of Dynesys dynamic stabilization (DDS) on clinical and radiographic outcomes, including spinal pelvic alignment.

METHOD

Consecutive patients who underwent 1- or 2-level DDS for lumbar spondylosis, mild degenerative spondylolisthesis, or degenerative disc disease were included. Clinical outcomes were evaluated by Visual Analogue Scale for back and leg pain, Oswestry Disability Index, and the Japanese Orthopedic Association scores. Radiographic outcomes were assessed by radiographs and computed tomography. Pelvic incidence and lumbar lordosis (LL) were also compared.

RESULTS

In 206 patients with an average follow-up of 51.1 ± 20.8 months, there were 87 screws (8.2%) in 42 patients (20.4%) that were loose. All clinical outcomes improved at each time point after operation. Patients with loosened screws were 45 years older. Furthermore, there was a higher risk of screw loosening in DDS involving S1, and these patients were more likely to have loosened screws if the LL failed to increase after the operation.

CONCLUSIONS

The DDS screw loosening rate was overall 8.2% per screw and 20.4% per patient at more than 4 years of follow-up. Older patients, S1 involvement, and those patients who failed to gain LL postoperatively were at higher risk of screw loosening.