Comparison of Endoscopic Facet Joint Denervation to the Percutaneous Technique Regarding Efficacy in Patients With Low Back Pain: A Randomized Controlled Trial.

STUDY DESIGN: This was a single-center prospective randomized controlled study. OBJECTIVE: The aim was to compare the efficacy of endoscopic facet joint denervation (FJD) with that of the percutaneous technique in terms of pain, functional disability, and quality of life in patients with low back pain (LBP). SUMMARY OF BACKGROUND DATA: Different controlled studies in patients with LBP have shown short-term benefits from percutaneous FJD. Observational studies have demonstrated that endoscopic FJD may be more effective. As the superiority of the endoscopic technique has not been clearly demonstrated in previous studies, a prospective randomized controlled study was conducted. MATERIALS AND METHODS: For this study, 40 patients with LBP lasting more than 6 months duration and at least 50% pain reduction on the visual analog scale after medial branch block under fluoroscopy, were assigned randomly to receive percutaneous or endoscopic FJD. The primary outcome was pain, as indicated by visual analog scale. Secondary outcomes were functional disability, as assessed by the Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RDQ), and quality of life, as assessed by the Short Form Health Survey (SF-36). RESULTS: After the intervention, the pain level decreased significantly in both groups ( P <0.001); however, the effect was still significant in the endoscopic group (EG) and diminished to lower than the statistical significance in the percutaneous group (PG) after 12 months. The ODI and RDQ scores also improved significantly in both groups ( P <0.001). However, the ODI and RDQ were significantly better ( P <0.001) in the EG after 12 months. In the SF-36, we observed significant improvement in both groups three months after the intervention. The effect decreased after six months in the PG and was predominantly not demonstrable after 12 months, whereas in the EG there was still a strong significant improvement on all scales ( P <0.001) after 12 months. CONCLUSION: Percutaneous and endoscopic FJD reduced pain and improved functionality and quality of life. However, the effects decreased or disappeared in the PG after 12 months, whereas there was still a strong significant improvement in the EG.

Preliminary Results of Endoscopic Radiofrequency Treatment of the Sacroiliac Joint Syndrome.

BACKGROUND AND STUDY: The sacroiliac joint (SIJ) may be the primary source of pain in 15 to 25% of patients with axial low back pain. Furthermore, 75% of patients who have had fusion surgery develop SIJ pain within 10 years. Treatment options include SIJ blocks, radiofrequency (RF) denervation, and fusion. The RF techniques range from ablation of the nerves supplying the joint, creating lesions to the joint itself, or a combination of both techniques. However, different clinical studies could only identify a limited or, in some cases, no effect in decreasing of pain intensity and duration of the effect. METHODS: In this retrospective study, we selected 23 patients with SIJ pain, with a duration of more than 12 months and a 50% pain reduction on the Numeric Rating Scale (NRS) after diagnostic block. All patients received endoscopic ablation of the medial branch L5/S1 and the lateral branches, exiting the sacral foramina on S1/S2 and S2/S3 on both sides while using only one incision on each side. Telephone interviews were conducted with all patients. The outcome was determined with Odom's criteria, percent reduction NRS, subjective assessment of the patient, and duration of the effect. RESULTS: According to Odom's criteria, 79% of the patients showed acceptable to excellent results and confirmed that denervation helped them to manage their daily lives better. The average pain reduction in the responder group was 57% with an average duration of 13.4 months. CONCLUSION: In this retrospective study, we could demonstrate the practicability and effectiveness of endoscopic SIJ denervation in the treatment of SIJ pain using only one incision for three levels on each side. Further studies should investigate if this procedure is more effective than percutaneous RF.

Comparison between anterior and posterior decompression with instrumentation for cervical spondylotic myelopathy: sagittal alignment and clinical outcome.

OBJECT: A variety of anterior, posterior, and combined approaches exist to decompress the spinal cord, restore sagittal alignment, and avoid kyphosis, but the optimal surgical strategy remains controversial. The authors compared the anterior and posterior approach used to treat multilevel cervical spondylotic myelopathy (CSM), focusing on sagittal alignment and clinical outcome. METHODS: The authors studied 48 patients with CSM who underwent multilevel decompressive surgery using an anterior or posterior approach with instrumentation (24 patients in each group), depending on preoperative sagittal alignment and direction of spinal cord compression. In the anterior group, a 1-2-level corpectomy was followed by placement of an expandable titanium cage. In the posterior group, a multilevel laminectomy and posterior instrumentation using lateral mass screws was performed. Postoperative radiography and clinical examinations were performed after 1 week, 12 months, and at last follow-up (range 15-112 months, mean 33 months). The radiological outcome was evaluated using measurement of the cervical and segmental lordosis. RESULTS: Both the posterior multilevel laminectomy (with instrumentation) and the anterior cervical corpectomy (with instrumentation) improved clinical outcome. The anterior group had a significantly lower preoperative cervical and segmental lordosis than the posterior group. The cervical and segmental lordosis improved in the anterior group by 8.8 and 6.2 degrees, respectively, and declined in the posterior group by 6.5 and 3.8 degrees, respectively. The loss of correction was higher in the anterior than in the posterior group (-2.0 vs -0.7 degrees, respectively) at last follow-up. CONCLUSIONS: These results demonstrate that both anterior and posterior decompression (with instrumentation) are effective procedures to improve the neurological outcome of patients with CSM. However, sagittal alignment may be better restored using the anterior approach, but harbors a higher rate of loss of correction. In cases involving a preexisting cervical kyphosis, an anterior or combined approach might be necessary to restore the lordotic cervical alignment.

Endoscopic 4-MHz Radiofrequency Treatment of Facet Joint Syndrome Is More Than Just Denervation: One Incision for Three Facets.

BACKGROUND AND STUDY AIMS: Low back pain is well documented as an extremely common health problem. The most frequently used treatment is radiofrequency denervation for chronic low back pain. However, different clinical studies could only show a limited to no improvement regarding the decrease of pain intensity and duration of the effect. The main reasons for these limited effects seem to be due to the size of the lesion and difficulties in locating the exact placement of the cannula near the medial branch as well as or additional pathologies. Using an endoscope, it is possible to coagulate the facet joints and the medial branch under visual control and consider other pathologies such as extraspinal synovial cysts. PATIENTS: In this retrospective study, we included 28 patients with low back pain, with a duration > 6 months and a 50% pain reduction on the numeric analog scale (NAS) after a diagnostic block. All patients received endoscopic facet joint denervation of three facets on the left and right side using only one incision on each side with an exploration of the surrounding tissue. Telephone interviews were conducted with all patients. The outcome was determined with Odom's criteria, percentage reduction NAS, subjective assessment of the patient, and duration of the effect. RESULTS: According to Odom's criteria, 68% of the patients showed "acceptable" to "excellent" results and confirmed that denervation helped them manage their daily lives better. The average pain reduction in the responder group was 47% with an average duration of 7.8 months. CONCLUSION: In this retrospective study, we demonstrated the practicability and effectiveness of the endoscopic facet joint denervation procedure in the treatment of chronic low back pain using only one incision for three facets. Further studies should investigate if this procedure is more effective than percutaneous radiofrequency denervation.

The short- and mid-term effect of dynamic interspinous distraction in the treatment of recurrent lumbar facet joint pain.

Owing to failure to achieve positive long-term effects, the currently performed treatment methods for lumbar facet joint syndrome (LFJS) are still under debate. Interspinous distraction devices unload the facet joints. Thus, these devices might be an alternative surgical treatment method for LFJS. The aim of this study was to evaluate the clinical and radiological outcome of an interspinous distraction device for the treatment of LFJS. Subjects had verified single level LFJS at level L4-5. They received percutaneous facet joint denervation (PFJD). If pain persisted, they were offered implantation of an interspinous device (Coflex) and/or repeat PFJD. Clinical and radiological outcome was determined before and after PFJD or surgery up to 2 years afterwards in all cases. Forty-one patients with LFJS at L4-5 underwent PFJD. Twenty patients with persisting pain underwent a subsequent surgery for implantation of an interspinous device. Five patients with recurrent pain at 6-12 months opted for an additional PFJD. Three obese patients (body weight > 100 kg) had persistent pain at 3 months after surgery and received additionally dorsal semi-dynamic stabilization. The clinical outcome improved significantly in the surgically treated patients; however, it did not differ compared with patients receiving PFJD only after 24 months.Radiological evaluation revealed a restricted range of motion (ROM) of the operated and an elevated ROM of the adjacent segment. Surgical or device-related complications were not observed. In conclusions, the implantation of an interspinous Coflex device in case of recurrent facet joint pain succeeds to improve facet joint pain in clinical shortand mid-term settings. However, it does not exceed the outcome of denervated patients.

The influence of cage positioning and cage type on cage migration and fusion rates in patients with monosegmental posterior lumbar interbody fusion and posterior fixation.

In posterior lumbar interbody fusion, cage migrations and lower fusion rates compared to autologous bone graft used in the anterior lumbar interbody fusion procedure are documented. Anatomical and biomechanical data have shown that the cage positioning and cage type seem to play an important role. Therefore, the aim of the present study was to evaluate the impact of cage positioning and cage type on cage migration and fusion. We created a grid system for the endplates to analyze different cage positions. To analyze the influence of the cage type, we compared "closed" box titanium cages with "open" box titanium cages. This study included 40 patients with 80 implanted cages. After pedicle screw fixation, 23 patients were treated with a "closed box" cage and 17 patients with an "open box" cage. The follow-up period averaged 25 months. Twenty cages (25%) showed a migration into one vertebral endplate of <3 mm and four cages (5%) showed a migration of > or =3 mm. Cage migration was highest in the medio-medial position (84.6%), followed by the postero-lateral (42.9%), and the postero-medial (16%) cage position. Closed box cages had a significantly higher migration rate than open box cages, but fusion rates did not differ. In conclusion, cage positioning and cage type influence cage migration. The medio-medial cage position showed the highest migration rate. Regarding the cage type, open box cages seem to be associated with lower migration rates compared to closed box cages. However, the cage type did not influence bone fusion.

Tacrolimus depresses local immune cell infiltration but fails to reduce cortical contusion volume in brain-injured rats.

The immunosuppressant drug tacrolimus (FK-506) failed to show an anti-edematous effect despite suppressing pro-inflammatory cytokines in cerebrospinal fluid following focal traumatic brain injury. By questioning the role of the inflammatory response as a pharmacological target, we investigated the effects of FK-506 on immune cell infiltration in brain-injured rats. Following induction of a cortical contusion, male Sprague-Dawley rats received FK-506 or physiological saline intraperitoneally. Brains were removed at 24 h, 72 h or 7 days, respectively. Frozen brain sections (7 microm) were stained immunohistologically for markers of endothelial activation (intercellular adhesion molecule-1--ICAM-1), neutrophil infiltration (His-48), and microglial and macrophage activation (Ox-6; ED-1), respectively. Immunopositive cells were counted microscopically. Contusion volume (CV) was quantified morphometrically 7 days after trauma. Inflammatory response was confined to the ipsilateral cortex and hippocampal formation, predominating in the contusion and pericontusional cortex. Strongest ICAM-1 expression coincided with sustained granulocyte accumulation at 72h which was suppressed by FK-506. Ox-6+ cells prevailing at 72 h were also significantly reduced by FK-506. ED-1+ cells reaching highest intensity at 7 days were significantly attenuated at 72 h. Cortical CV was not influenced. FK-506 significantly decreased post-traumatic local inflammation which, however, was not associated with a reduction in cortical CV. These results question the importance of post-traumatic local immune cell infiltration in the secondary growth of a cortical contusion.

Ubiquitin reduces contusion volume after controlled cortical impact injury in rats.

Recent data suggest that ubiquitin has anti-inflammatory properties and therapeutic potential after severe trauma and brain injuries. However, direct evidence for its neuroprotective effects has not yet been provided. We hypothesized that ubiquitin treatment is neuroprotective, and thus reduces brain edema formation and cortical contusion volume after closed traumatic brain injuries. To test this hypothesis, a focal cortical contusion was induced using a controlled cortical impact (CCI) model in Sprague-Dawley rats. Animals (n = 27) were randomized to either 1.5 mg/kg ubiquitin or vehicle (placebo) intravenously within 5 min after CCI. Blood pressure, arterial blood gases (ABG) and intracranial pressure (ICP) were monitored. Ubiquitin serum and cerebrospinal fluid levels were measured by ELISA. Brain water content was quantified gravimetrically after 24 h and cerebral contusion volume was determined in triphenyltetrazolium-chloride stained brains after 7 days. All animals recovered to normal activity. ICP and cerebral perfusion pressures were normal at the end of the observation period. Ubiquitin serum and CSF levels at 24 h and 7 days after CCI were similar in both groups. With ubiquitin brain water content of the injured hemisphere was slightly lower (n = 6/group; 79.97 +/- 0.29% vs. 81.11 +/- 0.52%; p = 0.08). Cortical contusion volume was significantly lower with ubiquitin (n = 7-8/group; 32.88 +/- 2.1 mm(3) vs. 43.96 +/- 4.56 mm(3); p = 0.025). This study shows that ubiquitin treatment after brain injury has direct neuroprotective effects, as demonstrated by improved brain morphology 7 days after brain injury. In connection with its beneficial effects in our previous studies, these data suggest ubiquitin as a promising candidate protein therapeutic for the treatment of brain injuries.

A new qualitative interleukin-6 bedside test can predict pneumonia in patients with severe head injury--comparison to the standard Immulite test and a semiquantitative bedside test.

Severe head injury (SHI) leads to systemic immunosuppression, which is processed by central mechanisms and is associated with a high risk of pneumonia. The timely identification of an immunodepressed condition in SHI patients might help prevent infections by changing the intensive care strategy. The aim of this prospective study is to evaluate a new method for identifying immunodepression and predicting pneumonia. We correlated interleukin (IL)-6 levels determined by the standard test (Immulite) and performed by specialized laboratories with those obtained using the new bedside test (PicoScan) with the occurrence of pneumonia in patients with SHI. Thirty-two patients with isolated SHI were investigated. Analyses were performed on serum samples taken 2 to 24 hours after trauma. Pearson correlation coefficient was 0.924 (P<0.001) for IL-6 values determined by PicoScan versus Immulite and Spearman rho was 0.572 for visual interpretation versus Immulite (P=0.01). Immulite and PicoScan have a positive predictive value of 91% and 100%, respectively, and a negative predictive value of 76% and 86%. The present study investigated for the first time the determination of IL-6 concentrations by PicoScan in patients. Our findings show a good correlation with the results of the standard Immulite test and suggest that the PicoScan may be used as a handy tool to predict pneumonia in SHI patients.

Four-year results of a prospective single-arm study on 200 semi-constrained total cervical disc prostheses: clinical and radiographic outcome.

OBJECTIVE Recent studies have described encouraging outcomes after cervical total disc replacement (cTDR), but there are also critical debates regarding the long-term effects of heterotopic ossification (HO) and the prevalence of adjacent-level degeneration. The aim in this paper was to provide 4-year clinical and radiographic outcome results on the activ C disc prosthesis. METHODS A total of 200 subjects underwent single-level activ C (Aesculap AG) implantation between C-3 and C-7 for the treatment of symptomatic degenerative disc disease. Clinical and radiographic assessments were performed preoperatively, intraoperatively, at discharge, and again at 6 weeks, 6 months, 1 year, 2 years, and 4 years. Radiographic evaluations were done by an independent core laboratory using a specific software for quantitative motion analysis. RESULTS Neck Disability Index (NDI) and visual analog scale (VAS) score for neck and arm pain decreased significantly from baseline to the 4-year follow-up. The mean improvement for NDI was 20, for VAS severity and frequency of neck pain 26.4 and 28, and for VAS severity and frequency of arm pain 30.7 and 35.1, respectively. The neurological situation improved for the majority of patients (86.4%); 76.1% of cases were asymptomatic. Subsequent surgical interventions were reported in 7% of the cases, including device removals in 3%. In 2.5% a subsidence greater than 3 mm was recorded; 1 of these cases also had a migration greater than 3 mm. No device displacement, expulsion, disassembly, loose or fractured device, osteolysis, or facet joint degeneration at the index level was observed. Segmental lordotic alignment changed from -2.4° preoperatively to -6.2° at 4 years, and postoperative height was maintained during the follow-up. Advanced HO (Grade III and IV) was present in 27.1% of the cases; 82.4% showed segmental mobility. A progression of radiographic adjacent-segment degeneration occurred in 28.2%, but only 4.5% required surgical treatment. CONCLUSIONS The activ C is a safe and effective device for cervical disc replacement confirming the encouraging results after cTDR. Clinical trial registration no.: NCT02492724 ( clinicaltrials.gov ).

Heme oxygenase as a therapeutic target in immunological pregnancy complications.

The allogeneic fetus has been considered to be an allograft and the tolerance mechanisms involved in pregnancy maintenance resemble those leading to graft acceptance. Up-regulation of Heme Oxygenase-1 (HO-1) promotes graft acceptance. Additionally, HO-1 has been proposed to have tissue-protective properties. Previous studies reported the presence of HO-1 and HO-2 in mammalian placenta and postulated a protective role for HO during pregnancy. Here, we analyze HO-1 and HO-2 expression at the feto-maternal interface from normal pregnant and abortion mice and correlate these findings with inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) expression as well as with Th1/Th2 cytokine production by immune cells. DBA/2-mated CBA/J females undergoing abortion and BALB/c-mated CBA/J females having normal pregnancies were included in our study. The mice received no treatment. On day 14 of pregnancy, the mice were sacrificed, the abortion rate was calculated and the ex vivo Th1/Th2 production by decidual immune cells was analyzed by flow cytometry. The expression of HO-1 and HO-2, iNOS and eNOS was analyzed by immunohistochemistry (IHC) and Western blot in placenta samples. The Th1/Th2 cytokines ratio was augmented in decidua from abortion mice. We further observed a significant down-regulation of HO-1, HO-2, iNOS and eNOS molecules in placental tissue from mice undergoing abortion when compared to normal pregnant mice. Since we found diminished HOs and nitric oxide synthase (NOS) levels at the feto-maternal interface from abortion mice when compared to normal pregnant mice, which were further associated with increased Th1/Th2 cytokine production, we propose HO as a putative therapeutic target in immunological abortions. Up-regulation of HO-1 or HO-2 would favour the Th2-cytokine production, which could avoid abortion onset.

An atypical spinal meningioma with CSF metastasis: fatal progression despite aggressive treatment. Case report.

The authors report the case of a 23-year-old man who presented with a C1-3 spinal mass. Following intraspinal decompression the tumor was histologically classified as an atypical meningioma (World Health Organization grade II). Two further surgical interventions resulted in almost total removal of the meningioma. In addition, radiotherapy was performed. During the 1.5-year follow-up period the diagnostic examinations identified a local tumor recurrence, an intraspinal C-6 metastasis, and a segmental instability with anterior C2-3 slippage and C3-4 kyphosis. The tumor was resected and occipitocervical stabilization was performed. Histological examination showed no change in malignancy. Despite additional hydroxyurea-based chemotherapy, the patient presented 4 months later with a hemiparesis and a massive recurrence of the tumor mass involving the posterior fossa and the upper thoracic spine. Because there were no further therapeutical options, the patient died. The authors discuss more aggressive therapeutic options in addition to surgery in patients with metastatic atypical meningiomas. The results in the reported case indicate that meningiomas associated with cerebrospinal fluid metastasis may represent a higher grade of malignancy.

A spine frame for intra-operative fixation to increase accuracy in spinal navigation and robotics.

OBJECTIVE: Intra-operative movements due to mechanical ventilation or manipulations are a limiting factor for accurate spinal navigation or robotic-assisted spinal surgery. The purpose of this study was to assess the accuracy of an intra-operative spinal fixation device in an experimental setup. MATERIALS AND METHODS: We developed a fixation device, attached to the operating table, that combines soft tissue retraction with spinal process fixation. Using a lumbar spine cadaver, tightness of fixation was evaluated using two measurement systems. Accuracy measurements using changes in spatial co-ordinates of implanted reference markers were performed in three segments, following different manipulations of the spine. In addition, for intra-operative movements of the spine during mechanical ventilation, the range of motion was determined in 10 patients during lumbar interbody fusion. RESULTS: The spine frame was easy to use and did not restrict screw insertion. Mean deviations of the markers' in all segments were measured at between 0.35 and 0.8 mm, following pedicle screw insertion and lateral traction. Intra-operative range of motion of the spine was measured with a mean value of 8.7 +/- 3.3 mm. CONCLUSION: Using our spine frame, a rigid fixation following manipulation of the spine was demonstrated. By overcoming the intra-operative movement-dependent inaccuracy, safety in navigated spine surgery and robotic-assisted procedures might be improved.

Intratumoral infusion of interleukin-1beta and interferon-gamma induces tumor invasion with macrophages and lymphocytes in a rat glioma model.

Malignant gliomas are hard to treat successfully. Like other treatments immune therapy fails presumably due to low concentration of immune modifiers within the tumor. However, convection-enhanced delivery (CED) may overcome this problem. So, we analyzed the effect of intratumoral delivery of interleukin (IL)-1beta and interferon (IFN)-gamma by CED on tumor immune cell invasion in a rat glioma model. Tumors were implanted into the left caudate nucleus and tumor growth was demonstrated by MRI. Afterwards intratumoral infusion of IL-1beta or IFN-gamma was started for 48 h. Then animals were sacrificed and the number of tumor infiltrating CD4+ and CD8+ lymphocytes as well as macrophages was analyzed by immunohistochemistry. Our results demonstrate that intratumoral cytokine infusion using CED leads to a strong tumor invasion with macrophages and lymphocytes suggesting a tumor specific immune response.

Oligodeoxynucleotides induce brain inflammation in rats when infused intracerebroventricularly.

Antisense oligodeoxynucleotides (ODNs) can inhibit gene expression in a specific manner. However, several studies described problems with cerebral ODN application. Here, we investigated the immune effects (interleukin-6 (IL-6) release, cell invasion into cerebrospinal fluid (CSF) and brain parenchyma) of 'non-sense' randomized ODNs with different counterions (NH(4)(+), Na(+)) and modifications (with or without thioat-backbone) which were administered intracerebroventricularly for 48 h using osmotic mini-pumps in a rat model. All animals receiving ODNs showed increased IL-6 levels in the CSF as well as cell invasion into the CSF and brain parenchyma (P<0.05). However, the use of thioat-backbone and ammonium as the counterion induced the highest IL-6 levels (7210+/-1696 pg/ml, P<0.05) and the highest cell numbers in the CSF (31.6+/-15.5x10(5)/ml, P<0.05) as well as brain parenchyma (268.1+/-143.2 HIS-48+ cells/mm(2), P<0.01; and 31.3+/-10.7 OX-6+cells/mm(2), P<0.05) compared with the other groups.

Multiple cerebral aneurysms and subarachnoid hemorrhage in a patient with Alagille syndrome.

Although intracranial hemorrhage has frequently been found responsible for mortality in adult patients with Alagille syndrome (AGS), no specific underlying cause has been identified. We describe the case of severe subarachnoid hemorrhage in a 30-year-old woman harboring five intracranial aneurysms and multiple peripheral vascular anomalies. To evaluate a possible higher incidence of intracranial aneurysms, a study of the cerebral vasculature in all AGS patients by using noninvasive imaging techniques should be considered.

Regeneration of nucleus pulposus tissue in an ovine intervertebral disc degeneration model by cell-free resorbable polymer scaffolds.

Degeneration of intervertebral discs (IVDs) occurs frequently and is often associated with lower back pain. Recent treatment options are limited and treat the symptoms rather than regenerate the degenerated disc. Cell-free, freeze-dried resorbable polyglycolic acid (PGA)-hyaluronan implants were used in an ovine IVD degeneration model. The nucleus pulposus of the IVD was partially removed, endoscopically. PGA-hyaluronan implants were immersed in autologous sheep serum and implanted into the disc defect. Animals with nucleotomy only served as controls. The T2-weighted/fat suppression sequence signal intensity index of the operated discs, as assessed by magnetic resonance imaging (MRI), showed that implantation of the PGA-hyaluronan implant improved (p = 0.0066) the MRI signal compared to controls at 6 months after surgery. Histological analysis by haematoxylin and eosin and safranin O staining showed the ingrowth of cells with typical chondrocytic morphology, even cell distribution, and extracellular matrix rich in proteoglycan. Histomorphometric analyses confirmed that the implantation of the PGA-hyaluronan scaffolds improved (p = 0.027) the formation of regenerated tissue after nucleotomy. Disc heights remained stable in discs with nucleotomy only as well as after implantation of the implant. In conclusion, implantation of cell-free polymer-based implants after nucleotomy induces nucleus pulposus tissue regeneration and improves disc water content in the ovine model.

Towards biological anulus repair: TGF-ß3, FGF-2 and human serum support matrix formation by human anulus fibrosus cells.

Closure and biological repair of anulus fibrosus (AF) defects in intervertebral disc diseases is a therapeutic challenge. The aim of our study was to evaluate the anabolic properties of bioactive factors on cartilaginous matrix formation by AF cells. Human AF cells were harvested from degenerated lumbar AF tissue and expanded in monolayer culture. AF cell differentiation and matrix formation was initiated by forming pellet cultures and stimulation with hyaluronic acid (HA), human serum (HS), fibroblast growth factor-2 (FGF-2), transforming growth factor-ß3 (TGF-ß3) and TGF-ß3/FGF-2 for up to 4 weeks. Matrix formation was assessed histologically by staining of proteoglycan, type I and type II collagens and by gene expression analysis of typical extracellular matrix molecules and of catabolic matrix metalloproteinases MMP-2 and MMP-13. AF cells, stimulated with HS, FGF-2 and most pronounced with TGF-ß3 or TGF-ß3/FGF-2 formed a cartilaginous matrix with significantly enhanced expression of matrix molecules and of MMP-13. Stimulation of AF cells with TGF-ß3 was accompanied by induction of type X collagen, known to occur in hypertrophic cartilage cells having mineralizing potential. HA did not show any chondro-inductive characteristics. These findings suggest human serum, FGF-2 and TGF-ß3 as possible candidates to support biological treatment strategies of AF defects.

A 3D environment for anulus fibrosus regeneration.

OBJECT: Biological repair strategies for the treatment of degenerated intervertebral discs are of growing interest. In addition to the development of nucleus pulposus implants to restore disc height and relieve pain, there is growing demand for an appropriate method for reconstructing the anulus fibrosus (AF). The aim of this pilot study was to evaluate the applicability of a resorbable 3D polymer of pure polyglycolic acid (PGA) combined with hyaluronan for the use in cell-free and cell-based regeneration and repair of the AF. METHODS: Adult human AF cells were expanded in vitro using human serum and rearranged three dimensionally in hyaluronan-PGA scaffolds that were stabilized with fibrin for in vitro analyses. The capacity of dedifferentiated AF cells to redifferentiate was evaluated after 2 weeks of culture, using propidium iodide/fluorescein diacetate staining, gene expression analysis of typical marker genes, and histological staining of proteoglycans. RESULTS: The propidium iodide/fluorescein diacetate staining demonstrated that vital human AF cells were evenly distributed within the construct. The induction of typical AF marker genes such as collagen Types I-III indicated the initiation of AF redifferentiation by 3D assembly in hyaluronan-PGA. Histological analysis of the constructs showed initial formation of an AF-like matrix comprising proteoglycans. CONCLUSIONS: The results suggest that the 3D arrangement of human AF cells in resorbable hyaluronan-PGA scaffolds cultured in the presence of human serum is an excellent system for AF cell redifferentiation.

Adequacy of herniated disc tissue as a cell source for nucleus pulposus regeneration.

OBJECT: The object of this study was to characterize the regenerative potential of cells isolated from herniated disc tissue obtained during microdiscectomy. The acquired data could help to evaluate the feasibility of these cells for autologous disc cell transplantation. METHODS: From each of 5 patients (mean age 45 years), tissue from the nucleus pulposus compartment as well as from herniated disc was obtained separately during microdiscectomy of symptomatic herniated lumbar discs. Cells were isolated, and in vitro cell expansion for cells from herniated disc tissue was accomplished using human serum and fibroblast growth factor-2. For 3D culture, expanded cells were loaded in a fibrin-hyaluronan solution on polyglycolic acid scaffolds for 2 weeks. The formation of disc tissue was documented by histological staining of the extracellular matrix as well as by gene expression analysis of typical disc marker genes. RESULTS: Cells isolated from herniated disc tissue showed significant signs of dedifferentiation and degeneration in comparison with cells from tissue of the nucleus compartment. With in vitro cell expansion, further dedifferentiation with distinct suppression of major matrix molecules, such as aggrecan and Type II collagen, was observed. Unlike in previous reports of cells from the nucleus compartment, the cells from herniated disc tissue showed only a weak redifferentiation process in 3D culture. However, propidium iodide/fluorescein diacetate staining documented that 3D assembly of these cells in polyglycolic acid scaffolds allows prolonged culture and high viability. CONCLUSIONS: Study results suggested a very limited regenerative potential for cells harvested from herniated disc tissue. Further research on 2 major aspects in patient selection is suggested before conducting reasonable clinical trials in this matter: 1) diagnostic strategies to predict the regenerative potential of harvested cells at a radiological or cell biology level, and 2) clinical assessment strategies to elucidate the metabolic state of the targeted disc.