Feasibility of Full Percutaneous Segmental Stabilization of the Lumbar Spine With a Combination of an Expandable Interbody Cage and an Interspinous Spacer: Preliminary Results

Full-Endoscopic Posterior Lumbar Interbody Fusion: A Review and Technical Note

Remarkable innovations in spinal endoscopic surgery have broadened its applications over the past 20 years. Full-endoscopic fusions have been widely reported, and several full-endoscopic approaches for interbody fusion have been published. In general, full-endoscopic lumbar interbody fusion (LIF) is called Endo-LIF, and facet-preserving Endo-LIF through the transforaminal route is called trans-Kambin's triangle LIF, which has a relatively longer history than facet-sacrificing Endo-LIF via the posterolateral route. Both approaches can reduce intraoperative and postoperative bleeding. However, there is a higher risk of subsidence and exit nerve root injury. There is no direct decompression in either of the interbody fusions, and additional decompression is required if there is severe lumbar bony canal stenosis. However, the posterior interlaminar approach, which is a well-known standard in full-endoscopic spine surgery, has rarely been applied in the field of endoscopic lumbar fusion surgery. Full-endoscopic posterior LIF (FE-PLIF) via an interlaminar approach can accomplish direct decompression of bony canal stenosis and safe interbody fusion. FE-PLIF via an interlaminar approach demonstrated a longer operation time, less blood loss, and shorter hospitalization duration than minimally invasive transforaminal LIF. FE-PLIF, which can accomplish direct decompression for bony spinal canal stenosis, is superior to other Endo-LIFs. However, FE-PLIF requires technical dexterity to improve efficiency and reduce technical complexity.

Advancements in Custom 3D-Printed Titanium Interbody Spinal Fusion Cages and Their Relevance in Personalized Spine Care

3D-printing technology has revolutionized spinal implant manufacturing, particularly in developing personalized and custom-fit titanium interbody fusion cages. These cages are pivotal in supporting inter-vertebral stability, promoting bone growth, and restoring spinal alignment. This article reviews the latest advancements in 3D-printed titanium interbody fusion cages, emphasizing their relevance in modern personalized surgical spine care protocols applied to common clinical scenarios. Furthermore, the authors review the various printing and post-printing processing technologies and discuss how engineering and design are deployed to tailor each type of implant to its patient-specific clinical application, highlighting how anatomical and biomechanical considerations impact their development and manufacturing processes to achieve optimum osteoinductive and osteoconductive properties. The article further examines the benefits of 3D printing, such as customizable geometry and porosity, that enhance osteointegration and mechanical compatibility, offering a leap forward in patient-specific solutions. The comparative analysis provided by the authors underscores the unique challenges and solutions in designing cervical, and lumbar spine implants, including load-bearing requirements and bioactivity with surrounding bony tissue to promote cell attachment. Additionally, the authors discuss the clinical outcomes associated with these implants, including the implications of improvements in surgical precision on patient outcomes. Lastly, they address strategies to overcome implementation challenges in healthcare facilities, which often resist new technology acquisitions due to perceived cost overruns and preconceived notions that hinder potential savings by providing customized surgical implants with the potential for lower complication and revision rates. This comprehensive review aims to provide insights into how modern 3D-printed titanium interbody fusion cages are made, explain quality standards, and how they may impact personalized surgical spine care.

Clinical Outcome of Full Endoscopic Trans Kambin's Triangle Lumbar Interbody Fusion: A Systematic Review

Full-endoscopic (FE) lumbar interbody fusion (LIF) is now a widely used type of minimally invasive surgery (MIS). Although FE-LIF includes LIF with foraminoplasty via a Kambin's triangle approach (FE-KLIF) and LIF with foraminotomy via an interlaminar approach, these techniques are rarely discussed separately. This review evaluates the outcomes and complications of FE-KLIF reported in the literature. The PubMed, Medline, Embase, Web of Science, and Cochrane Library databases were searched for studies reporting the outcomes of FE-KLIF. Of 464 publications assessed, 11 met our inclusion criteria. Although the most frequently treated level was L4/5, L5/S1 was also treated. FE-KLIF was performed under local anesthesia and sedation or under epidural anesthesia without general anesthesia. Visual analog scale and Oswestry Disability Index scores were improved postoperatively in all uncontrolled studies; however, there was no significant difference in these scores in studies that compared FE-KLIF with posterior LIF (PLIF) or MIS-transforaminal LIF (TLIF). There was also no significant difference in the fusion rate between FE-KLIF and PLIF or MIS-TLIF. In terms of complications, although there were no reports of hematoma, dural tear and surgical site infection were reported in 1 paper each, with transient nerve disorders reported in 5 studies (frequency, 1.8%-23.5%). This review indicates that FE-KLIF is a feasible and viable surgical option for lumbar degenerative disease. However, the amount and level of evidence is low for the studies included in this review, and the data on long-term outcomes remain limited.

Expandable Interbody Fusion Cages: An Editorial on the Surgeon's Perspective on Recent Technological Advances and Their Biomechanical Implications

BACKGROUND

Expandable cages have gone through several iterations since they first appeared on the market in the early 2000s. Their development was prompted by some common problems associated with static interbody cages, including migration, expulsion, dural or neural traction injury, and pseudarthrosis.

OBJECTIVE

To summarize current technological advances from earlier expandable lumbar interbody fusion devices to implants with vertical and medial-to-lateral expansion mechanisms.

METHODS

The authors review the currently available expandable cage designs, the incremental technological advances, and how these devices impact minimally invasive surgery interbody procedures and clinical outcomes. The strategic concepts intended to improve the minimally invasive application of expandable interbody fusion implants are reviewed from a surgeon's perspective in a clinical context to discuss how their use may improve patient outcomes.

CONCLUSIONS

The geometrical configuration, effective stiffness of composite multi-material cage designs may impact the bone-implant contact area with the endplates. Hybridization strategies of expandable cage technology with modern minimally invasive and endoscopic spinal surgery techniques are presented by outlining their advantages and disadvantages.

LEVEL OF EVIDENCE

1 CLINICAL RELEVANCE: Systematic review.

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.

Full Percutaneous Treatment of Degenerative Disc Disease with Intradiscal Lumbar Interbody Fusion and Posterior Stabilization: Preliminary Results

PURPOSE

To report the preliminary results of a novel full percutaneous interbody fusion technique for the treatment of degenerative disc disease (DDD) resistant to conservative treatment with posterior stabilization with rods and screws and transforaminal placement of an 8-mm-width intradiscal cage.

MATERIALS AND METHODS

A total of 79 patients with lumbar spine DDD resistant to medical therapy and/or spondylolisthesis up to grade 2 were treated. We performed preoperative X-rays, CT and MRI. The outcomes were assessed using the VAS score and the Oswestry Disability Index at a 1-, 6- and 12-month follow-up and also included X-rays to evaluate the correct bone fusion and the absence of complications.

RESULTS

Mean operation time was 130 min, and mean postoperative time until hospital discharge was 2 days. Postoperative values for VAS scores and ODI improved significantly compared to preoperative data: Mean preprocedural VAS was 7.49 ± 0.69 and decreased at 12-month follow-up to 1.31 ± 0.72, and mean preprocedural ODI was 29.94 ± 1.67 and decreased at 12-month follow-up to 12.75 ± 1.44. No poor results were reported, and no postprocedural sequelae were observed.

CONCLUSIONS

In our experience, this preliminary report shows a feasible and safe full percutaneous alternative procedure and represents a minimally invasive management of degenerative disc disease with low back pain resistant to medical therapy with or without lumbar spondylolisthesis up to grade 2.

Full Percutaneous Transforaminal Lumbar Interbody Fusion Using the Facet-sparing, Trans-Kambin Approach

STUDY DESIGN

This was a prospective, multicenter, consecutive case series' study.

OBJECTIVE

The objective of this study was to evaluate a novel facet-sparing, percutaneous transforaminal lumbar interbody fusion (pTLIF) technique consisting of percutaneous insertion of an expandable interbody cage through an endoscopic cannula with the trans-Kambin approach and complemented with percutaneous transpedicular screws and rods.

SUMMARY OF BACKGROUND DATA

Lumbar interbody fusion by open or minimally invasive surgery is the usual treatment for degenerative disk disease but requires a relatively long recovery period. The transforaminal trans-Kambin approach is a standard in endoscopic spine surgery for safe intradiscal access without facet resection.

METHODS

Preoperative and postoperative Visual Analogue Scale (VAS) and Oswestry Disability Index scores were quantitatively assessed at 1, 3, 6, and 12 months after surgery and then every 12 months for patients treated with pTLIF between 2009 and 2018 in 2 health care centers. An immediate postoperative control computed tomography scan was performed, whereas conventional postoperative x-ray controls were performed at 1 month and 1 year. Statistical evaluation was performed with the Student t test.

RESULTS

A total of 51 patients (mean age, 59.3 y) were evaluated. The overall mean VAS score for axial lumbar pain improved from 6.6 to 1.8 (P<0.01), mean VAS score for leg pain from 5.5 to 1.2 (P<0.01), and mean Oswestry Disability Index scores from 30.3 to 11.8 (P<0.01) postoperatively with a mean follow-up of 27.9 months (range, 1-77.8 mo). Median estimated blood loss was 103.6 mL. Postoperative complications included 12 (22%) cases with transitory ipsilateral dysesthesia, 2 (4%) cases with transitory ipsilateral muscle weakness, and 3 (6%) clinically asymptomatic cases with radiologic cage subsidence. Median hospital stay was 1.4 days (range, 1-3.2 d).

CONCLUSIONS

Postoperative scores for pTLIF significantly improved with minimal blood loss and no long-term complications. On the basis of this experience, the facet-sparing pTLIF is a reliable and safe technique with early hospital discharge, opening the way to outpatient instrumented spine surgery.

LEVEL OF EVIDENCE

Level III.