BACKGROUND: Large annulus fibrosus (AF) defects often lead to a high rate of reherniation, particularly in the medial AF region, which has limited self-healing capabilities. The increasing prevalence of herniated discs underscores the need for effective repair strategies.
OBJECTIVE: The objectives of this study were to design an AF repair technique to reduce solve the current problems of insufficient mechanical properties and poor sealing capacity.
METHODS: In vitro biomechanical experiments and finite element analysis.
METHODS: The materials used in this study were patches and hydrogels with good biocompatibility and sufficient mechanical properties to withstand loading in the lumbar spine. Five repair techniques were assessed in this study: hydrogel filler (HF), AF patch medial barrier (MB), AF patch medial barrier and hydrogel filler (MB&HF), AF patch medial-lateral barrier (MLB), and AF patch medial-lateral barrier and hydrogel filler (MLB&HF). The repair techniques were subjected to in vitro testing (400 N axial compression and 0-500 N fatigue loading at 5Hz) and finite element analysis (400 N axial compression) to evaluate the effectiveness at repairing large AF defects. The evaluation included repair tightness, spinal stability, and fatigue resistance.
RESULTS: From the in vitro testing, the failure load of the repair techniques was in the following order HF MLB >MB&HF >MLB&HF.
CONCLUSIONS: The combined use of patches and hydrogels exhibited promising mechanical properties postdiscectomy, providing a promising solution for addressing large AF defects and improving disc stability.
CONCLUSIONS: This study introduces a promising method for repairing large annular fissure (AF) defects after disc herniation, combining patch repair with a hydrogel filler. These techniques hold potential for developing clinical AF repair products to address this challenging issue.

Pain generator-based lumbar spinal decompression surgery is the backbone of modern spine care. In contrast to traditional image-based medical necessity criteria for spinal surgery, assessing the severity of neural element encroachment, instability, and deformity, staged management of common painful degenerative lumbar spine conditions is likely to be more durable and cost-effective. Targeting validated pain generators can be accomplished with simplified decompression procedures associated with lower perioperative complications and long-term revision rates. In this perspective article, the authors summarize the current concepts of successful management of spinal stenosis patients with modern transforaminal endoscopic and translaminar minimally invasive spinal surgery techniques. They represent the consensus statements of 14 international surgeon societies, who have worked in collaborative teams in an open peer-review model based on a systematic review of the existing literature and grading the strength of its clinical evidence. The authors found that personalized clinical care protocols for lumbar spinal stenosis rooted in validated pain generators can successfully treat most patients with sciatica-type back and leg pain including those who fail to meet traditional image-based medical necessity criteria for surgery since nearly half of the surgically treated pain generators are not shown on the preoperative MRI scan. Common pain generators in the lumbar spine include (a) an inflamed disc, (b) an inflamed nerve, (c) a hypervascular scar, (d) a hypertrophied superior articular process (SAP) and ligamentum flavum, (e) a tender capsule, (f) an impacting facet margin, (g) a superior foraminal facet osteophyte and cyst, (h) a superior foraminal ligament impingement, (i) a hidden shoulder osteophyte. The position of the key opinion authors of the perspective article is that further clinical research will continue to validate pain generator-based treatment protocols for lumbar spinal stenosis. The endoscopic technology platform enables spine surgeons to directly visualize pain generators, forming the basis for more simplified targeted surgical pain management therapies. Limitations of this care model are dictated by appropriate patient selection and mastering the learning curve of modern MIS procedures. Decompensated deformity and instability will likely continue to be treated with open corrective surgery. Vertically integrated outpatient spine care programs are the most suitable setting for executing such pain generator-focused programs.

Objective: The purpose of this study was to analyze the feasibility of repairing a ruptured intervertebral disc using a patch secured to the inner surface of the annulus fibrosus (AF). Different material properties and geometries for the patch were evaluated. Methods: Using finite element analysis, this study created a large box-shaped rupture in the posterior-lateral region of the AF and then repaired it with a circular and square inner patch. The elastic modulus of the patches ranged from 1 to 50 MPa to determine the effect on the nucleus pulposus (NP) pressure, vertical displacement, disc bulge, AF stress, segmental range of motion (ROM), patch stress, and suture stress. The results were compared against the intact spine to determine the most suitable shape and properties for the repair patch. Results: The intervertebral height and ROM of the repaired lumbar spine was similar to the intact spine and was independent of the patch material properties and geometry. The patches with a modulus of 2-3 MPa resulted in an NP pressure and AF stresses closest to the healthy disc, and produced minimal contact pressure on the cleft surfaces and minimal stress on the suture and patch of all models. Circular patches caused lower NP pressure, AF stress and patch stress than the square patch, but also caused greater stress on the suture. Conclusion: A circular patch with an elastic modulus of 2-3 MPa secured to the inner region of the ruptured annulus fibrosus was able to immediately close the rupture and maintain an NP pressure and AF stress similar to the intact intervertebral disc. This patch had the lowest risk of complications and produced the greatest restorative effect of all patches simulated in this study.

BACKGROUND: Successful implementation of endoscopic spinal surgery programs hinges on reliable performance and case cost similar to traditional decompression surgeries of the lumbar spine.
METHODS: To improve the statistical power of studying the durability of endoscopes with routine lumbar endoscopy, the authors performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeon\'s responses recorded in multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, their preferred decompression instruments, and their experience with endoscopic equipment failure.
RESULTS: A total of 485 surgeons responded, of whom 85 submitted a valid survey recording, rendering a completion rate of 27.1%. These 85 respondents reported a case volume of 12,650 lumbar endoscopies within the past year and, to date, had performed a total of 120,150 spinal endoscopies over their collective career years. The majority of respondents performed endoscopic surgery for herniated disc (65.9%) vs spinal stenosis (34.1%) in a hospital setting, preferentially employing the transforaminal (76.5%), interlaminar (51.8%), and unilateral biportal endoscopic (UBE; 15.3%) approach technique. The most commonly used endoscopic spine systems were Wolf/Riwo Spine (38.8%), Joimax (36.5%), Storz (24.7%), unspecified Chinese brand (22.4%), Maxmore (15.3%), Spinendos (12.9%), Elliquence (10.6%), unspecified Korean brand (7.1%), and asap Endosystems GmbH (2.4%). The most frequent failure mode of the endoscope reported by survey respondents was a blurry image (71.8%), followed by the loss of focus (21.2%), the loss of illumination of the surgical site (18.8%), and the failure of the irrigation/suction system integrated into the endoscope (4.7%). Most respondents thought they had problems with the lens (67.1%), the fiberglass light conductor (23.5%), the prism (16.5%), or the rod system (4.7%). Motorized high-speed power burrs and hand reamers and trephines were the reported favorite decompression tools that were presumably associated with the endoscope\'s failure. The majority of respondents (49.5%) performed up to 50 endoscopies before the endoscope had to be either exchanged or repaired. Another 15.3% of respondents reported their endoscope lasted between 101 and 200 cases and only 12.9% reported more than 300 cases. Besides abuse during surgery (25.9%), bad handling by staff was the most common suspected reason (45.9%), followed by the wrong sterilization technique (21.2%). Some 23.5% of respondents noted that the endoscope failed during their surgery. In that case, 66.3% asked for a replacement endoscope, and 36.1% completed the surgery with the broken endoscope. However, 10.8% stopped and another 6% of respondents woke the patient up and rescheduled the surgery to complete the decompression at another time.
CONCLUSIONS: Spinal endoscopes used during routine lumbar decompression surgeries for herniated disc and spinal stenosis have an estimated life cycle between 50 and 100 surgeries. Abusive use by surgeons, mishandling by staff, and deviation for prescribed cleaning and sterilization protocols may substantially shorten the life cycle. Contingency protocols should be in place to readily replace a broken spinal endoscope during surgery. More comprehensive implementation of endoscopic spine surgery techniques will hinge on technology advancements to make these hightech surgical instruments more resistant to the stress of daily use and abuse of expanded clinical indications\' for surgery. The regulatory burden on endoscope makers is likely to increase, calling for increased reimbursement for facilities to cover the added expense for capital equipment purchase, disposables, and the endoscopic spine surgery program\'s maintenance.
METHODS: 3.
CONCLUSIONS: End user surgeon survey study.

BACKGROUND: Successful implementation of endoscopic spinal surgery programs hinges on reliable performance and case cost similar to traditional decompression surgeries of the lumbar spine.
METHODS: To improve the statistical power of studying the durability of endoscopes with routine lumbar endoscopy, the authors performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeon\'s responses recorded in multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, their preferred decompression instruments, and their experience with endoscopic equipment failure.
RESULTS: A total of 485 surgeons responded, of whom 85 submitted a valid survey recording, rendering a completion rate of 27.1%. These 85 respondents reported a case volume of 12,650 lumbar endoscopies within the past year and, to date, had performed a total of 120,150 spinal endoscopies over their collective career years. The majority of respondents performed endoscopic surgery for herniated disc (65.9%) vs spinal stenosis (34.1%) in a hospital setting, preferentially employing the transforaminal (76.5%), interlaminar (51.8%), and unilateral biportal endoscopic (UBE; 15.3%) approach technique. The most commonly used endoscopic spine systems were Wolf/Riwo Spine (38.8%), Joimax (36.5%), Storz (24.7%), unspecified Chinese brand (22.4%), Maxmore (15.3%), Spinendos (12.9%), Elliquence (10.6%), unspecified Korean brand (7.1%), and asap Endosystems GmbH (2.4%). The most frequent failure mode of the endoscope reported by survey respondents was a blurry image (71.8%), followed by the loss of focus (21.2%), the loss of illumination of the surgical site (18.8%), and the failure of the irrigation/suction system integrated into the endoscope (4.7%). Most respondents thought they had problems with the lens (67.1%), the fiberglass light conductor (23.5%), the prism (16.5%), or the rod system (4.7%). Motorized high-speed power burrs and hand reamers and trephines were the reported favorite decompression tools that were presumably associated with the endoscope\'s failure. The majority of respondents (49.5%) performed up to 50 endoscopies before the endoscope had to be either exchanged or repaired. Another 15.3% of respondents reported their endoscope lasted between 101 and 200 cases and only 12.9% reported more than 300 cases. Besides abuse during surgery (25.9%), bad handling by staff was the most common suspected reason (45.9%), followed by the wrong sterilization technique (21.2%). Some 23.5% of respondents noted that the endoscope failed during their surgery. In that case, 66.3% asked for a replacement endoscope, and 36.1% completed the surgery with the broken endoscope. However, 10.8% stopped and another 6% of respondents woke the patient up and rescheduled the surgery to complete the decompression at another time.
CONCLUSIONS: Spinal endoscopes used during routine lumbar decompression surgeries for herniated disc and spinal stenosis have an estimated life cycle between 50 and 100 surgeries. Abusive use by surgeons, mishandling by staff, and deviation for prescribed cleaning and sterilization protocols may substantially shorten the life cycle. Contingency protocols should be in place to readily replace a broken spinal endoscope during surgery. More comprehensive implementation of endoscopic spine surgery techniques will hinge on technology advancements to make these hightech surgical instruments more resistant to the stress of daily use and abuse of expanded clinical indications\' for surgery. The regulatory burden on endoscope makers is likely to increase, calling for increased reimbursement for facilities to cover the added expense for capital equipment purchase, disposables, and the endoscopic spine surgery program\'s maintenance.
METHODS: 3.
CONCLUSIONS: End user surgeon survey study.

Herniated disc (HD) is one of the most common causes of lower back pain. Treatment for HD includes conservative therapy and surgical intervention. Following conservative treatment, spontaneous absorption of HD occurs in some patients. To assess whether modic changes are associated with spontaneous absorption of HD, 85 patients with or without modic changes were followed up after 6 months of conservative treatment. As result, we found modic changes of lumbar endplates are associated with poor absorption of HD after conservative treatment. In addition, patients with modic changes exhibit significantly increased cartilage content and decreased neovascularization and macrophage infiltration in HD tissues, all of which are known to impair spontaneous absorption of herniated tissues. At molecular level, modic changes are associated with decreased expression of matrix metalloproteinase-3 gene, which is a key matrix-degrading enzyme for tissue absorption. Our study established a strong association between modic changes of lumbar endplates and spontaneous absorption of lumbar HD, which provided a potential novel method for prediction of spontaneous absorption.

OBJECTIVE: To evaluate the effects of percutaneous ozone injection via the posterior-lateral route and inner margin of the facet joint in the treatment of large lumbar disc herniation.
METHODS: Fifty-eight patients with large lumbar disc herniation were treated with percutaneous injection of ozone via the posterior-lateral route and inner margin of the facet joint under digital subtraction angiography. Second injections were performed 5 d after the initial injection. All patients were followed up for 6-18 mo. A modified Macnab method was used for assessing clinical outcomes after oxygen-ozone therapy.
RESULTS: Successful puncture was obtained in all patients. The overall efficacy was 91.4%; the outcome was the excellent in 37 cases (63.8%), good in 16 cases (27.6%) and fair/poor in 5 cases (8.6%) according to the Macnab criteria. No severe complications were found throughout this study.
CONCLUSIONS: Percutaneous intradiscal ozone injection via the posterior-lateral route and inner margin of the facet joint is effective and safe for treatment of large lumbar disc herniation.