Restore Disc Height Research Articles

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.

Revision Strategy of Symptomatic Lumbar Adjacent Segment Degeneration: Full Endoscopic Decompression versus Extended Posterior Interbody Fusion

We evaluated the clinical and imaging outcomes of full endoscopic lumbar decompression (FELD) compared with extended posterior lumbar interbody fusion (PLIF) for adjacent segment degeneration (ASD) after fusion surgery and developed a revision strategy. The present retrospective study enrolled 65 patients with ASD who had undergone FELD (n= 31) or extended PLIF (n= 34) from January 2014 to January 2018. Clinical evaluations had been performed preoperatively and at 3, 12, and 24 months postoperatively and included the Oswestry disability index, Japanese Orthopaedic Association score for function assessment, and visual analog scale scores for pain. Imaging evaluations were performed preoperatively, immediately after surgery, and at the last follow-up examination. No significant differences were found in the baseline data between the FELD and PLIF groups (P > 0.05), except for the proportion of patients with radiographic adjacent segment instability (P < 0.05). The mean operative time, blood loss, and length of hospital stay were significantly decreased for the FELD group (P < 0.001). For patients with stable ASD, no significant differences were found in the clinical outcome between the 2 groups (P > 0.05). The PLIF group had significantly restored disc height after surgery (P < 0.05). For patients with unstable ASD, the low back and leg pain of the PLIF group were more significantly relieved compared with the FELD group within 3-24 months postoperatively (P < 0.05). The function of the PLIF group had significantly improved within 12 months postoperatively (P < 0.05). The use of FELD achieved satisfactory outcomes for the treatment of radiographic stable ASD, which were not worse than those with PLIF. With less trauma and faster recovery, FELD could be an alternative option.

Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion with Endoscopic Disc Drilling Preparation Technique for Symptomatic Foraminal Stenosis Secondary to Severe Collapsed Disc Space: A Clinical and Computer Tomographic Study with Technical Note

Background: Severe collapsed disc secondary to degenerative spinal conditions leads to significant foraminal stenosis. We hypothesized that uniportal posterolateral transforaminal lumbar interbody fusion with endoscopic disc drilling technique could be safely applied to the collapsed disc space to improve patients’ pain score, restore disc height, and correct the segmental angular parameters. Methods: We included patients who met the indication criteria for lumbar fusion and underwent uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion with pre-operative Computer Tomography mid disc height of less than or equal to 5 mm and MRI of Grade 3 Foraminal Stenosis. Visual analogue scale and computer tomography pre-operative and post-operative sagittal disc height in the anterior, middle and posterior part of the disc; sagittal focal segmental angle; mid coronal disc height and coronal wedge angles were evaluated. Results: 30 levels of Endo-TLIF were included, with a mean follow up of 12 months. The mean improvement in decreasing pain score was 2.5 ± 1.1, 3.2 ± 0.9 and 4.3 ± 1.0 at 1 week post operation, 3 months post operation and at final follow up, respectively, p < 0.05. There was significant increase in mid sagittal computer tomographic anterior, middle and posterior disc height of 6.99 ± 2.30, 6.28 ± 1.44, 5.12 ± 1.79 mm respectively, p < 0.05. CT mid coronal disc height showed an increase of 7.13 ± 1.90 mm, p < 0.05. There was a significant improvement in the CT coronal wedge angle of 2.35 ± 4.73 and the CT segmental focal sagittal angle of 1.98 ± 4.69, p < 0.05. Conclusion: Application of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion in patients with severe foraminal stenosis secondary to severe collapsed disc space significantly relieved patients’ pain and restored disc height without early subsidence or exiting nerve root dysesthesia in our cohort of patients.

Comparative Effectiveness of Laterally Placed Expandable versus Static Interbody Spacers: A 1-Year Follow-Up Radiographic and Clinical Outcomes Study.

Study DesignRetrospective chart review.PurposeThis study compared the clinical and radiographic outcomes of patients treated with expandable and static interbody spacers following minimally invasive lateral lumbar interbody fusion (MIS-LLIF) with 12-month follow-up.Overview of LiteratureA common surgical option for the treatment of degenerative disk disease (DDD) is MIS-LLIF using static or expandable spacers to restore disk height (DH), neuroforaminal height (NH), and segmental lordosis. Static spacers may require excessive trialing and aggressive impaction, potentially leading to endplate disruption and subsidence. Expandable spacers allow for in situ expansion to help address complications associated with static spacers.MethodsThis is an Institutional Review Board-exempt review of 69 patients (static, n=32; expandable, n=37) diagnosed with DDD who underwent MIS-LLIF at 1–2 contiguous level(s) using static or expandable spacers. Radiographic and clinical outcomes were collected and compared at pre- and postoperative time points up to 12 months.ResultsThe expandable group had a significantly higher mean change in Visual Analog Scale (VAS) scores at 6 weeks, 6 months, and 12 months vs. static (∆VAS at 12 months: expandable, 6.7±1.3; static, 5.1±2.6). Mean improvement of Oswestry Disability Index (ODI) scores at 3, 6, and 12 months were significantly better for the expandable group vs. static (∆ODI at 12 months: expandable, 63.2±13.2; static, 29.8±23.4). Mean DH and NH significantly increased at final follow-up for both groups, with no significant difference in DH improvement between groups. The expandable mean NH improvement at 6 weeks and 6 months was significantly greater vs. static. Segmental lordosis significantly improved in the expandable group at all time intervals vs static. Subsidence rate at 12 months was significantly lower in the expandable group (1/46, 2.2%) vs. static (12/37, 32.4%).ConclusionsExpandable spacers resulted in a significantly lower subsidence rate, improve segmental lordosis, and VAS and ODI outcomes at 12 months vs. static.

Indirect Decompression Through Oblique Lateral Interbody Fusion for Revision Surgery After Lumbar Decompression

Clinical outcome of indirect decompression for a revision surgery, at the same level of a previous lumbar decompression, has not been reported. The purpose of this study was to investigate the efficacy of oblique lateral interbody fusion (OLIF) in revision surgery after decompression for degenerative lumbar spinal disease. We included 34 patients who were preoperatively diagnosed with a recurrence of canal stenosis, foraminal stenosis, or intervertebral instability at the same level of a prior lumbar decompression. These patients underwent OLIF with supplemental pedicle screw fixation without additional posterior decompression. All patients completed a minimum 1-year follow-up. We compared the cross-sectional area (CSA) of the thecal sac on magnetic resonance imaging as well as clinical outcome scores (Japanese Orthopaedic Association [JOA] score) preoperatively and at the final follow-up. Fusion status and disc height/angle were evaluated based on computed tomography scans. The CSA expanded from 136.4 ± 57.9 mm2 preoperatively to 194.1 ± 58.6 mm2 at the final follow-up (mean: 27.4 months; P < 0.001). Clinical symptoms significantly improved (59.0% improvement rate of JOA score) at the average of a 17.1-month follow-up. The fusion rate was 93.0%. The disc height was restored (preoperative: 5.7 mm; postoperative: 8.3 mm; P < 0.001), and foraminal stenosis significantly improved postoperatively. There were no major vascular/ureteral injuries. OLIF at the same level of a prior lumbar decompression provided a successful indirect decompressive effect, including expansion of the thecal sac, restoration of disc height, and subsequent improvement of foraminal stenosis. Specifically, this procedure can prevent incidental durotomy and nerve root injury, which may occur in conventional revision surgeries for direct posterior fusion.

Retrospective Review of Immediate Restoration of Lordosis in Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Comparison of Static and Expandable Interbody Cages.

Sagittal alignment is an important consideration in spine surgery. The literature is conflicted regarding the effect of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) on sagittal parameters and the role of expandable cage technology. To compare lordosis generated by static and expandable cages and to determine what factors affect postoperative sagittal parameters. Preoperative regional lordosis (RL), segmental lordosis (SL), and posterior disc height (PDH) were compared to postoperative values in single-level MI-TLIF performed using expandable or static cages. Patients were stratified based on preoperative SL: low lordosis (<15 degrees), moderate lordosis (15-25 degrees), and high lordosis (>25 degrees). Regression analyses were conducted to determine factors associated with postoperative SL and PDH. Of the 171 patients included, 111 were in the static and 60 in the expandable cohorts. Patients with low preoperative lordosis experienced an increase in SL and maintained RL regardless of cage type. Those with moderate to high preoperative lordosis experienced a decrease in SL and RL with the static cage, but maintained SL and RL with the expandable cage. Although both cohorts showed an increase in PDH, the increase in the expandable cohort was greater. Preoperative SL was predictive of postoperative SL; preoperative SL, preoperative PDH, and cage type were predictive of postoperative PDH. Expandable cages showed favorable results in restoring disc height and maintaining lordosis in the immediate postoperative period. Preoperative SL was the most significant predictor of postoperative SL. Thus, preoperative radiographic parameters and goals of surgery should be important considerations in surgical planning.

Indirect decompression with lateral interbody fusion for severe degenerative lumbar spinal stenosis: minimum 1-year MRI follow-up.

The use of indirect decompression surgery for severe canal stenosis remains controversial. The purpose of this study was to investigate the efficacy of lateral interbody fusion (LIF) without posterior decompression in degenerative lumbar spinal spondylosis with severe stenosis on preoperative MRI. This is a retrospective case series from a single academic institution. The authors included 42 patients (45 surgical levels) who were preoperatively diagnosed with severe degenerative lumbar stenosis on MRI based on the previously published Schizas classification. These patients underwent LIF with supplemental pedicle screw fixation without posterior decompression. Surgical levels were limited to L3-4 and/or L4-5. All patients satisfied the minimum 1-year MRI follow-up. The authors compared the cross-sectional area (CSA) of the thecal sac and the clinical outcome scores (Japanese Orthopaedic Association [JOA] score) preoperatively, immediately postoperatively, and at the 1-year follow-up. Fusion status and disc height were evaluated based on CT scans obtained at the 1-year follow-up. The CSA improved over time, increasing from 54.5 ± 19.2 mm2 preoperatively to 84.7 ± 31.8 mm2 at 3 weeks postoperatively and to 132.6 ± 37.5 mm2 at the last follow-up (average 28.3 months) (p < 0.001). The JOA score significantly improved over time (preoperatively 16.1 ± 4.1, 3 months postoperatively 24.4 ± 4.0, and 1-year follow-up 25.7 ± 2.9; p < 0.001). The fusion rate at the 1-year follow-up was 88.8%, and disc heights were significantly restored (preoperative, 6.3 mm and postoperative, 9.6 mm; p < 0.001). Patients showing poor CSA expansion (< 200% expansion rate) at the last follow-up had a higher prevalence of pseudarthrosis than patients with significant CSA expansion (> 200% expansion rate) (25.0% vs 3.4%, p < 0.001). No major perioperative complications were observed. LIF with indirect decompression for degenerative lumbar disease with severe canal stenosis provided successful clinical outcomes, including restoration of disc height and indirect expansion of the thecal sac. Severe canal stenosis diagnosed on preoperative MRI itself is not a contraindication for indirect decompression surgery.

Interbody Fusions in the Lumbar Spine: A Review.

Lumbar interbody fusion is among themost common types of spinal surgery performed. Over time, the term has evolved to encompass a number of different approaches to the intervertebral space, as well as differing implant materials. Questions remain over which approaches and materials are best for achieving fusion and restoring disc height. We reviewed the literature on the advantages and disadvantages of various methods and devices used to achieve and augment fusion between the disc spaces in the lumbar spine. Using search terms specific to lumbar interbody fusion, we searched PubMed and Google Scholar and identified 4993 articles. We excluded those that did not report clinical outcomes, involved cervical interbody devices, were animal studies, or were not in English. After exclusions, 68 articles were included for review. Posterior approaches have advantages, such as providing 360° support through a single incision, but can result in retraction injury and do not always restore lordosis or correct deformity. Anterior approaches allow for the largest implants and good correction of deformities but can result in vascular, urinary, psoas muscle, or lumbar plexus injury and may require a second posterior procedure to supplement fixation. Titanium cages produce improved osteointegration and fusion rates but also increase subsidence caused by the stiffness of titanium relative to bone. Polyetheretherketone (PEEK) has an elasticity closer to that of bone and shows less subsidence than titanium cages, but as an inert compound PEEK results in lower fusion rates and greater osteolysis. Combination PEEK-titanium coating has not yet achieved better results. Expandable cages were developed to increase disc height and restore lumbar lordosis, but the data on their effectiveness have been inconclusive. Three-dimensionally (3D)-printed cages have shown promise in biomechanical and animal studies at increasing fusion rates and reducing subsidence, but additive manufacturing options are still in their infancy and require more investigation. All of the approaches to spinal fusion have plusses and minuses that must be considered when determining which to use, and newer-technology implants, such as PEEK with titanium coating, expandable, and 3D-printed cages, have tried to improve upon the limitations of existing grafts but require further study.

Unilateral Versus Bilateral Facetectomy and its Effect on Segmental Lordosis and Disc Height in MIS TLIF

Background: Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) techniques have allowed for improved recovery and other metrics compared to its open counterpart. Our expanding literature has increasingly demonstrated the importance of spinopelvic parameters. One of the concerns with MIS TLIF is that the limited exposure and existing technology make it difficult to restore lumbar lordosis at the degenerative level requiring surgery. We hypothesize that bilateral facetectomy with MIS techniques will allow for increased ability to restore segmental lumbar lordosis versus traditional unilateral facetectomy. Methods: This is a retrospective chart review of all patients who underwent single level MIS TLIF between 2017 and 2018. We collected baseline characteristics and reviewed operative records to determine whether unilateral or bilateral facetectomies were performed. We used intraoperative CT (O-Arm) sagittal reformatted images to measure segmental lordosis as well as anterior, middle, and posterior disc heights. Results: Forty patients were identified. Eighteen underwent bilateral facetectomy, and 22 had unilateral facetectomy. We found a significantly increased middle disc height in the bilateral facetectomy group of 3.6 mm vs 2.8 mm in the unilateral group (p=0.04). We also found increased lordosis (4.4 vs. 3.7, respectively) as well as anterior (4.5 vs 3.5) disc height in the bilateral facetectomy group but neither reached statistical significance. Conclusion: Bilateral facetectomy is a tool that can help achieve maximal lordosis and disc height restoration in MIS TLIF surgery. Benefits besides lordosis and disc height restoration include increased autograft for fusion. Across various papers there seems to be a trend toward greater lordosis and disc height restoration, however most papers including ours have been underpowered to find significance.

A review of discogenic pain management by interventional techniques.

This review article describes the various image guided interventional techniques used for treating chronic backache attributed to disc related pathologies. With the aim of minimum invasion and maximum relief, these procedures comprise predominantly of annuloplasty and disc decompression via different mechanisms. Newer therapies are discussed in this review article with the objective of restoring disc height and its biomechanical function by substitution of biochemical constituents, regeneration of cartilaginous end plate and finally artificial disc implantation.

Multimodal AGuIX® Nanoparticles: Size Characterization by HF5 and Optimization of the Radiolabeling with Various SPECT/PET/Theranostic Tracers

Low back pain (LBP) is one of the highest prevalence problems of public health. LBP affects up to 85% people worldwide. Somebody will be affected at less in one point of his life. LBP represent an enormous economic burden on society; its total cost includes: Direct medical costs, work absenteeism, insurance, lost production and disability benefits. Current treatments range from bed rest, physiotherapy, oral analgesic, muscle relaxants, injection of corticosteroids, local anesthetic, surgery, cell based therapies aiming repair a herniated intervertebral disc and an emerging technique which use injectable hydrogels to restore disc height and function.

Comparison of Technical Outcomes in Instrumented Posterolateral Fusion (PLF) with and without Transforaminal Lumbar Interbody Fusion (TLIF) performed using Silicon Nitride cages

Background: Posterior lumbar fusion is performed for lumbar degeneration that leads to spinal stenosis and spondylolisthesis. Two common approaches include PLF and TLIF, with a current lack of consensus as to the superior approach. The objective of this study is to compare fusion rates, spinal parameters and complications for both surgical approaches using the silicon nitride cage (Si3N4). Our hypothesis is TLIF with a Si3N4 cage will have higher fusion rates, improved technical outcomes and fewer complications when compared to PLF alone. The Si3N4 cage has advantageous surface properties compared to other interbody cages, promoting theoretically higher fusion rates for TLIF procedures.&#x0D; Methods: A retrospective chart review of 102 spinal fusion patients (PLF=17, TLIF=85) was performed. One spine surgeon performed the fusions and reviewed pre-operative and post-operative radiographs. Measurable outcomes included fusion rates, surgical complications and pelvic/spinal radiographic parameters. Radiographic parameters included restoration of lumbar lordosis (LL), segmental lordosis (SL), pelvic incidence (PI), pelvic tilt (PT), disc height (DH) and foraminal height (FH). Patients who had ≥1 year follow up radiographs were included in analysis (PLF=16, TLIF=48).&#x0D; Results: TLIF patients with a Si3N4 cage had improved fusion rates (PLF=81.8%, TLIF=100% p=0.003), lumbar lordosis (PLF=-4.38o TLIF=3.15o p=0.001), disc height (PLF=0.55mm, TLIF=4.61mm p=&lt;0.001), foraminal height (PLF=-0.05mm, TLIF=2.41mm p=0.036) and a lower incidence of PI-LL mismatch (PLF=46.15%, TLIF=7.5% p=0.004). No statistically significant difference was found for surgical complications (PLF=11.1%, TLIF=17.6%) or segmental lordosis (PLF=-1.00mm, TLIF=1.17mm). An age difference of statistical significance was also found between the two patient populations (PLF=61.9, TLIF=54.1 p=0.018).&#x0D; Conclusion: Despite the difference in age between the procedure groups, TLIF with a Si3N4 cage proved to be superior in fusion rates, lumbar lordosis, PI-LL mismatch, disc height and foraminal height restoration.&#x0D;

Efficacy of HYADD®4-G single intra-discal injections in a rabbit model of intervertebral disc degeneration.

Various biomaterials/technologies have been tested for treatment of intervertebral disc (IVD) degeneration (IDD). Only few non-surgical options exist. Assessment of efficacy and safety of the hyaluronic acid derivative hydrogel HYADD®4-G in IDD using a well-established rabbit annular puncture model. Rabbits were punctured at two IVDs to induce IDD. Thirty days after, IVDs were injected with HYADD®4-G or saline. IVD hydration, height, appearance and tissue organization were assessed by radiographs, MRI and histopathology. Safety of HYADD®4-G injection was evaluated in non-punctured IVDs. HYADD®4-G injection restored disc height to over 75% of the pre-punctured disc, saline injections led to 50% of initial disc height. Compared to saline, HYADD®4-G treatment resulted in improved water retention as revealed by MRI quantification. 83.3% of HYADD®4-G injected discs had normal appearance and reached grade I of the Pfirrmann scale. Regarding tissue organization and cellularity, HYADD®4-G treatment resulted in significantly lower IDD scores than saline (p <0.01). HYADD®4-G injected into healthy IVDs did not induce inflammation or foreign body reactions. Intra-discal HYADD®4-G injection is safe and has therapeutic benefits: IDD could be limited through restoration of disc height and hydration and maintenance of normal IVD tissue organization.

Indirect decompression of lumbar stenosis

Degenerative lumbar stenosis can lead to symptoms of neurogenic claudication and lumbar radiculopathy. Lumbar stenosis can be caused by static compression of the neural elements in the central canal, along the lateral recess, and in the neuroforamen, as well as by dynamic changes to the total area of the central canal and neuroforamen. Previously, surgical options for the treatment of degenerative lumbar stenosis were primarily based on direct posterior open decompressions and fusions. However, novel techniques of indirect decompression have now been developed that restore disc height to increase the area of the central canal and neuroforamen and address the dynamic aspect of stenosis, while avoiding the extensive soft tissue injury involved in posterior open decompressions and fusions. Interbody fusions and interspinous devices are two methods of indirect decompression that are being commonly used.In this study, we provide a broad overview of the advantages, disadvantages, indications, evidence, and complications of ALIF, LLIF, and OLIF, as well as interspinous devices including Coflex. Though there is limited comparative evidence demonstrating that one approach is superior to another in terms of clinical and radiographic outcomes, evidence does show that interbody techniques are effective at treating lumbar stenosis by increasing the total area of the central canal and neuroforamen while having high fusion rates. Though the newer generation of interspinous devices have lower failure rates than their predecessors, they still are not comparable to the interbody devices in terms of long term outcomes. The optimal approach for the indirect treatment of lumbar stenosis therefore depends on multiple variables, including but not limited to the spinal level of disease, the anatomy of the individual patient, the pathology being treated, and the familiarity of the surgeon.

Injectable cellulose-based hydrogels as nucleus pulposus replacements: Assessment of in vitro structural stability, ex vivo herniation risk, and in vivo biocompatibility

Current treatments for intervertebral disc degeneration and herniation are palliative only and cannot restore disc structure and function. Nucleus pulposus (NP) replacements are a promising strategy for restoring disc biomechanics and height loss. Cellulose-based hydrogel systems offer potential for NP replacement since they are stable, non-toxic, may be tuned to match NP material properties, and are conducive to cell or drug delivery. A crosslinked, carboxymethylcellulose-methylcellulose dual-polymer hydrogel was recently formulated as an injectable NP replacement that gelled in situ and restored disc height and compressive biomechanical properties. The objective of this study was to investigate the translational potential of this hydrogel system by examining the long-term structural stability in vitro, the herniation risk and fatigue bending endurance in a bovine motion segment model, and the in vivo biocompatibility in a rat subcutaneous pouch model. Results showed that the hydrogels maintained their structural integrity over a 12-week period. AF injury significantly increased herniation risk and reduced fatigue bending endurance in bovine motion segments. Samples repaired with cellulosic hydrogels demonstrated restored height and exhibited herniation risk and fatigue endurance comparable to samples that underwent the current standard treatment of nucleotomy. Lastly, injected hydrogels elicited a minimal foreign body response as determined by analysis of fibrous capsule development and macrophage presence over 12 weeks. Overall, this injectable cellulosic hydrogel system is a promising candidate as an NP substitute. Further assessment and optimization of this cellulosic hydrogel system in an in vivo intradiscal injury model may lead to an improved clinical solution for disc degeneration and herniation.

Feasibility of the annulus fibrosus repair with in situ gelating hydrogels - A biomechanical study.

The surgical standard of care for lumbar discectomy leaves the annulus fibrosus (AF) defect unrepaired, despite considerable risk for a recurrent herniation. Identification of a viable defect repair strategy has until now been elusive. The scope of this ex vivo biomechanical study was to evaluate crosslinking hydrogels as potentially promising AF defect sealants, and provide a baseline for their use in combination with collagen scaffolds that restore disc volume. This study directly compared genipin crosslinked fibrin hydrogel (FibGen) as a promising preclinical candidate against a clinically available adhesive composed of glutaraldehyde and albumin (BioGlue). Forty-two bovine coccygeal functional spine units (FSU) were randomly allocated into four groups, namely untreated (control, n = 12), repaired with either one of the tested hydrogels (BioGlue, n = 12; FibGen, n = 12), or FibGen used in combination with a collagen hydrogel scaffold (FibGen+Scaffold, n = 6). All specimens underwent a moderate mechanical testing protocol in intact, injured and repaired states. After completion of the moderate testing protocol, the samples underwent a ramp-to-failure test. Lumbar discectomy destabilized the FSU as quantified by increased torsional range of motion (28.0° (19.1, 45.1) vs. 41.39° (27.3, 84.9), p<0.001), torsional neutral zone (3.1° (1.2, 7.7) vs. 4.8° (2.1, 12.1), Z = -3.49, p < 0.001), hysteresis(24.4 J (12.8, 76.0) vs. 27.6 J (16.4, 54.4), Z = -2.61, p = 0.009), with loss of both disc height (7.0 mm (5.0, 10.5) vs 6.1 mm (4.0, 9.3), Z = -5.16, p < 0.001) and torsional stiffness (0.76 Nmdeg-1 (0.38, 1.07) vs. 0.66 Nmdeg-1 (0.38, 0.97), Z = -3.98, p < 0.001). Most FibGen repaired AF endured the entire testing procedure whereas only a minority of BioGlue repaired AF and all FibGen+Scaffold repaired AF failed (6/10 vs. 3/12 vs. 0/6 respectively, p = 0.041). Both BioGlue and FibGen+Scaffold repaired AF partially restored disc height (0.47 mm (0.07, 2.41), p = 0.048 and 1.52 mm (0.41, 2.57), p = 0.021 respectively) compared to sham treatment (0.08 mm (-0.63, 0.88)) whereas FibGen-only repaired AF had no such effect (0.04 mm (-0.73, 1.13), U = 48.0, p = 1). The AF injury model demonstrated considerable change of FSU mechanics that could be partially restored by use of an AF sealant. While inclusion of a volumetric collagen scaffold led to repair failure, use of FibGen alone demonstrated clinically relevant promise for prevention of mechanical reherniation, outperforming an FDA approved sealant in this ex vivo test series.

Controlled immobilization-traction based on intervertebral stability is conducive to the regeneration or repair of the degenerative disc: an in vivo study on the rat coccygeal model

Previous studies have shown the potential for intervertebral disc tissue regeneration is very limited. While in vivo and in vitro studies have shown that traction can restore disc height and internal pressure, in many clinical studies it was shown that axial mechanical traction for the treatment of low back pain is ineffective. The aim of this study was to identify how the disc could be distracted, how to define the state of traction, and to further examine the feasibility of regenerating or restoring the degenerative disc by means of traction. A macro- and microlevel structural analysis of degenerative discs of rat tail before and after controlled immobilization-traction. In this study, 49 6-month-old male Sprague-Dawley rats were randomly assigned to one of seven groups. Group A was the sham control group in which caudal vertebrae were instrumented with K-wires only. In Group B (model group), caudal vertebrae were immobilized using a custom-made external device to fix four caudal vertebrae (Co7-Co10) and Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration. In Group C, vertebrae Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration, followed by removal of the external apparatus. Rats in the other four groups (Groups D-G), Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration followed by 2 weeks, 4 weeks, 6 weeks, and 8 weeks of distraction, respectively. Caudal vertebrae were harvested and disc height, T2 signal intensity of the discs, disc morphology, total glycosaminoglycan content of the nucleus pulposus and the structure of the Co8-Co9 end plate were evaluated. After 4 weeks of compression, the intervertebral height and T2 signal intensity of Co8-Co9 vertebrae of rats in Groups B to G were significantly reduced compared with Group A (sham group, all p<.0001). Histological scores of rats in Group B averaged 10.14 and the total glycosaminoglycan (GAG) of nucleus pulposus averaged 238.21μg GAG/ng DNA. The bony end plate structure showed significant changes in comparison with the control Group. After 2 weeks to 8 weeks of traction, the disc space and T2 signal intensity of Co8-Co9 vertebrae in Group E were significantly recovered compared to that of rats in Group B (p<.0001), and the intervertebral height of the Co8-Co9 in Group D, Group F, and Group G when compared with Group B (p<.0001). Meanwhile, the T2 signal intensity of Co8-Co9 in Group D, F, and G when compared with Group B (p<.001). Histological scores dropped from an average of 10.14 in Group B to 5.57 in Group E, and 5.86 in Group F (all p<.0001). Furthermore, the total GAG content of the nucleus pulposus increased from an average of 238.21μg GAG/ng DNA in Group B to 601.02μg GAG/ng DNA in Group E (p<.0001). The number of pores of end plates in rats in Groups D and E both were significantly increased when compared to that of rats in Group B (Groups D vs Groups B, p<.05; Groups E vs Groups B, p<.0001). A mechanical degenerative model was successfully established by using a custom-made device. We demonstrated that disc degeneration is a cascade of biochemical, mechanical, and structural changes mediated by cells in an abnormal mechanical environment. Not all levels of disc degeneration can be regenerated or repaired. Regeneration or recovery of disc degeneration requires specific conditions. Based on the immobilization-traction mode, the cascade cycle of disc degeneration is interrupted. Traction of 2 to 6 weeks is a sensitive period for regeneration of the degenerative disc. Moreover, the duration and extent of the traction loading must be moderately controllable, and beyond the limits that can lead to significant degeneration. These data may help improve our understanding of the pathogenesis of clinical disc degeneration and how to optimize the use of traction devices for possible regeneration.

Comparison of long-term effect between minimally invasive and open approaches in one-level posterior lumbar interbody fusion: a 10-12 year prospective study

Objective To compare the long-term effect between minimally invasive (MIS) and open approaches in one-level posterior lumbar interbody fusion (O-PLIF) after more than 10 years follow up. Methods All 131 patients (lumbar spine lesions) in our hospital were randomized into MIS-PLIF group and O-PLIF group from March 2006 to March 2008. In MIS-PLIF group, there are 66 patients, 34 males and 32 females, with the average of 52.3±6.7 years old (range from 40 to 63). In O-PLIF group, there are 65 patients, 29 males and 36 females, with the average of 51.1±6.9 years old (range from 46 to 63). Regarding March 2018 as last follow-up, differences in intervertebral disc height and segmental lordosis restoration of the operation segment, lumbar lordosis restoration, multifidus cross section area (CSA), multifidus atrophy rate, fusion rate, visual analogue scale(VAS) for back and leg pain, Oswestry Disability Index(ODI), Japanese Orthopaedic Association cores (JOA) and postoperative long-term complications were evaluated between the two groups. The related risk factors of postoperative long-term complications were evaluated in further analysis. Results Complete follow-up data were available on 37 patients in MIS-PLIF group and 35 patients in O-PLIF group, with the follow-up rate of 56.1% and 53.8% respectively, and with the mean follow-up time of 134.5 ±8.4 and 137.1±5.8 months respectively. At three time nodes of one year after operation, five years after operation and last follow-up after operation, there were significant differences in lumbar lordosis restoration (one year after operation and last follow-up after operation)(5.0°±2.3° vs. 3.9°±1.4°; 4.7°±2.4° vs. 3.7°±1.5°), multifidus CSA (965.4±164.9 mm2vs. 884.9±168.2 mm2; 891.1±155.9 mm2vs. 783.2±163.0 mm2; 764.8±148.3 mm2 vs. 643.5±150.0 mm2), multifidus atrophy rate (8.5%±2.5% vs. 16.6%±5.8%; 15.6%±3.5% vs. 26.2%±7.4%; 27.6%±6.5% vs. 39.3%±9.3%), postoperative VAS for back pain (2.2±1.0 vs. 2.9±1.2; 1.7±0.9 vs. 2.2±1.0; 1.4±1.0 vs. 2.2±1.2), JOA score (22.3±3.8 vs. 19.9±4.2; 23.1±4.3 vs. 19.3±3.9; 22.4±4.2 vs. 19.6±4.0) and ODI (11.6%±4.8% vs. 22.0%±7.7%; 9.4%±3.9% vs. 12.3%±4.9%; 8.6%±4.0% vs. 11.0%±4.6%) between the two groups (P 0.05). Intractable back pain and adjacent segment disease were the major postoperative long-term complications for MIS-PLIF group (3 cases and 2 cases) and O-PLIF group (10 cases and 7 cases), and the difference was statistically significant in the intractable back pain incidence rate (8.5% vs. 28.6%, χ2=5.090, P=0.024), but not in the adjacent segment disease(5.4% vs. 20%, χ2=0.002, P=0.061). What's more, patients with intractable back pain suffered more obviously multifidus atrophy than patients without intractable back pain at three time nodes of one year after operation (19.4±4.4% vs. 10.9±5.1%, P<0.05), five years after operation (30.2±5.4% vs. 18.7±6.7%, P<0.05) and last follow-up after operation (44.5±5.7% vs. 30.8±8.9%, P<0.05). Conclusion In the long-term follow up, compared with O-PLIF, MIS-PLIF had advantages in better maintenance of lumbar lordosis, protection of the multifidus muscle, reduced lower back pain, JOA score, ODI score and intractable back pain incidence rate. Multifidus atrophy may be a related risk factor of intractable back pain. Key words: Lumbar vertebrae; Surgical procedures, minimally invasive; Spinal fusion

Efficacy of administered mesenchymal stem cells in the initiation and co-ordination of repair processes by resident disc cells in an ovine (Ovis aries) large destabilizing lesion model of experimental disc degeneration.

BackgroundForty percent of low back pain cases are due to intervertebral disc degeneration (IVDD), with mesenchymal stem cells (MSCs) a reported treatment. We utilized an ovine IVDD model and intradiscal heterologous MSCs to determine therapeutic efficacy at different stages of IVDD.MethodologyThree nonoperated control (NOC) sheep were used for MSC isolation. In 36 sheep, 6 × 20 mm annular lesions were made at three spinal levels using customized blades/scalpel handles, and IVDD was allowed to develop for 4 weeks in the Early (EA) and late Acute (LA) groups, or 12 weeks in the chronic (EST) group. Lesion IVDs received injections of 10 × 106 MSCs or PBS, and after 8 (EA), 22 (LA) or 14 (EST) weeks recuperation the sheep were sacrificed. Longitudinal lateral radiographs were used to determine disc heights. IVD glycosaminoglycan (GAG) and hydroxyproline contents were quantified using established methods. An Instron materials testing machine and customized jigs analyzed IVD (range of motion, neutral zone [NZ] and stiffness) in flexion/extension, lateral bending and axial rotation. qRTPCR gene profiles of key anabolic and catabolic matrix molecules were undertaken. Toluidine blue and hematoxylin and eosin stained IVD sections were histopathologically scoring by two blinded observers.ResultsIVDD significantly reduced disc heights. MSC treatment restored 95% to 100% of disc height, maximally improved NZ and stiffness in flexion/extension and lateral bending in the EST group, restoring GAG levels. With IVDD qRTPCR demonstrated elevated catabolic gene expression (MMP2/3/9/13, ADAMTS4/5) in the PBS IVDs and expession normalization in MSC‐treated IVDs. Histopathology degeneracy scores were close to levels of NOC IVDs in MSC IVDs but IVDD developed in PBS injected IVDs.DiscussionAdministered MSCs produced recovery in degenerate IVDs, restored disc height, composition, biomechanical properties, down regulated MMPs and fibrosis, strongly supporting the efficacy of MSCs for disc repair.

Comparing stand-alone oblique lumbar interbody fusion with posterior lumbar interbody fusion for revision of rostral adjacent segment disease: A STROBE-compliant study.

Spinal fusion has become a standard treatment for symptomatic intervertebral degenerative disc disease. The present study aimed to compare perioperative parameters, clinical outcomes, and radiographic results of stand-alone oblique lumbar interbody fusion (OLIF) with posterior lumbar interbody fusion (PLIF) for the revision of rostral adjacent segment disease (ASD) following prior posterior lumbar fusion.Thirty-six patients who underwent revision surgeries for rostral ASD were retrospectively reviewed. Among them, 17 patients underwent stand-alone OLIF (OLIF group) and 19 patients underwent PLIF (PLIF group). The length of operation, intraoperative hemorrhage, bed rest duration, and length of hospital stay were compared between the 2 groups. Clinical results were evaluated with the Oswestry Disability Index (ODI) and visual analog scale (VAS). Radiological results were evaluated with disc height (DH), foraminal height (FH), retrolisthesis index (RI), and lumbar lordosis (LL), as well as the fusion rate and cage subsidence. Follow-up results at 1 week, 3 months, and 12 months postoperatively were compared between the 2 groups.The OLIF group had less intraoperative blood loss, shorter operative time, bed rest time, and hospital stay than did the PLIF group (P < .05). The OLIF group had lower VAS scores for back pain than the PLIF group at 1 week and 3 months postoperatively (P < .05), and lower VAS scores for leg pain than the PLIF group at 1 week postoperatively (P < .05). The OLIF group had lower ODI than the PLIF group at 1 week and 3 months postoperatively (P < .05). No significant differences were found in DH and FH between the 2 groups preoperatively (P > .05); the OLIF group showed higher DH and FH than the PLIF group at all time points (P < .05). No significant differences were found in RI and LL between the 2 groups at any time point. All patients achieved fusion at 12 months postoperatively, and cage subsidence was not observed in either group.OLIF is effective and safe for the treatment of rostral ASD following prior posterior lumbar fusion, and is superior to PLIF in terms of perioperative parameters, short-term clinical outcomes, and DH restoration, with similar fusion and reduction rates.