Biportal endoscopic paraspinal decompression for epidural cement leakage removal: A technical note.

OBJECTIVE: We aimed to preliminarily explore the efficacy and safety of unilateral biportal endoscopy (UBE) for the treatment of epidural cement leaks. We report a patient who underwent epidural cement leakage removal and achieved endoscopic spinal decompression. METHODS: A 67-year-old female patient underwent biportal endoscopic paraspinal decompression following percutaneous vertebroplasty for an osteoporotic fracture that resulted in neurologic impairment due to epidural cement leakage. A transforaminal biportal endoscopic surgery was performed to remove the leaked cement, and the left L1 and bilateral L2 nerves were decompressed. RESULTS: The patient's postoperative clinical course was uneventful. CONCLUSIONS: A paraspinal approach that avoids a posterior approach reduces the need to remove stabilizing facet bone, is truly minimally invasive and does not involve an instrumented fusion, maybe a helpful addition in the minimally invasive spine surgeon's armamentarium.

Unilateral biportal endoscopy via two different approaches for upper lumbar disc herniation: a technical note.

BACKGROUND: The traditional surgical procedures for upper lumbar disc herniation (ULDH) usually lead to frequent complications. We aim to investigate the clinical efficacy of the unilateral biportal endoscopy (UBE) technique in treating upper lumbar disc herniation (ULDH). METHODS: From January 2020 to December 2021, the clinical data of 28 patients with ULDH treated with the UBE technique were collected and analyzed for surgery time under UBE, postsurgical drainage, postsurgical hospital stay, and complications. The clinical efficacy was evaluated according to the modified MacNab score, Oswestry disability index (ODI), and visual analogue scale (VAS) of low back pain and lower limb pain before the surgery; one week, one month, and three months after the surgery; and at the last follow-up. RESULTS: All patients underwent the UBE surgery successfully. The surgery time under UBE for non-fusion cases was 47.50 ± 11.84 min (monosegment) and 75.00 ± 20.66 min (two segments), while that for fusion cases was 77.50 ± 21.02 min. The postsurgical drainage for non-fusion cases was 25.00 ± 13.94 mL (monosegment) and 38.00 ± 11.83 mL (two segments), while that for fusion cases was 71.25 ± 31.72 mL. The postsurgical hospital stay was 8.28 ± 4.22 days. The follow-up time was 15.82 ± 4.54 months. The VAS score for each time period after the surgery was significantly lower (P < 0.05), while the ODI was significantly higher than that before the surgery (P < 0.05). According to the modified MacNab scoring standard, the ratio of excellent to good was 96.43% at the last follow-up. Two patients experienced transient numbness and pain in their lower limbs and no activity disorder after the surgery, and they recovered after conservative treatment. CONCLUSIONS: The clinical effect of UBE technique in treating ULDH was reliable. According to the needs of the disease, the interlaminar approach or paraspinal approach of the UBE technique was selected. This technique took into account the effect of treatment, achieved the purpose of minimal invasiveness, and did not require special instruments. Therefore, it has the potential for clinical application.

[Contralateral endoscopic approach for lumbar foraminal stenosis using unilateral biportal endoscopic surgery].

OBJECTIVE: To assess the feasibility and imaging outcomes of unilateral biportal endoscopic technique in the treatment of lumbar foraminal stenosis through contralateral approach. METHODS: The clinical data of 33 patients with lumbar foraminal stenosis treated with unilateral biportal endoscopic technique from January 2021 to July 2022 were retrospectively analyzed. There were 17 males and 16 females;age ranging from 34 to 72 years old with an average of (56.00±7.89) years old;operation time and perioperative complications were recorded;visual analogue scale (VAS) of pain was recorded, to evaluate the degree of low back pain and lower extremity pain, and Oswestry disability index (ODI) to evaluate the lumbar spine function. At the latest follow-up, the modified Macnab score was used to evaluate the clinical efficacy. RESULTS: All patients successfully completed the operation. The operation time ranged from 47 to 65 minutes, with an average of (56.10±5.19) minutes. The postoperative follow-up ranged from 12 to 18 months, with an average of (14.9±2.3) months. The VAS of low back and lower extermity pain before operation were (7.273±1.442) and (7.697±1.447) scores, ODI was (69.182±9.740)%. Postoperative lumbocrural pain VAS were (3.394±0.966) and (2.818±0.727) scores, ODI was (17.30±4.78) %. At the latest follow-up, VAS of back and lower extermity pain was (2.788±0.650) and (2.394±0.704) scores, ODI was (14.33±350)%. There were significant differences in VAS of low back and lower extremity pain and ODI before and after operation(P<0.05). At the latest follow-up, according to the modified Macnab criteria, 24 patients got excellent result, 5 as good, 2 as fair, and 2 as poor. CONCLUSION: Unilateral biportal endoscopic treatment of lumbar foraminal stenosis through the contralateral approach is a safe and efficient method, with few complications, quick postoperative recovery, and satisfactory clinical outcomes. During the follow-up period, no iatrogenic lumbar instability was observed.

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

OBJECTIVE: Unilateral biportal endoscopy (UBE)is a minimally invasive spine surgery with reduced traumatization of the posterior lumbar ligament and muscular structures. This study reports contralateral translaminar approach with UBE for highly down-migrated lumbar disc herniation (LDH). METHODS: Data of 32 patients with highly down-migrated LDH treated using UBE at our center from January 2020 to July 2022 were retrospectively analyzed. The operation time and perioperative complications were recorded, and the visual analog scale (VAS) of pain was recorded to evaluate the degree of lower back and extremity pain. The Oswestry disability index (ODI) was used to evaluate lumbar spine function. The modified MacNab score was used to evaluate clinical efficacy. RESULTS: All patients successfully underwent the operation, with a time range from 47 to 65 min and an average operation time of 56.09 ± 5.11 min. Overall, 17 and 15 were males and females, respectively, with ages ranging from 34 to 72 years and an average age of 56 ± 7.89 years. The postoperative follow-up period was 12-18 months, with an average of 14.9 ± 2.3 months. The postoperative lower back VAS pain score and ODI were statistically significant compared with preoperatively (P < 0.05). At the final follow-up, according to the modified Macnab criteria, 90.6% of cases were classified as good or excellent. CONCLUSION: UBE treatment of highly down-migrated LDH through the contralateral translaminar approach is safe and efficient. Therefore, this approach can be an efficient alternative for patients with highly downward-migrating LDH.

A case report: Unilateral biportal endoscopic revision for adjacent segmental disease: Case presentations and literature review.

RATIONALE: Biportal endoscopic revision surgery for adjacent segmental disease (ASD) after lumbar arthrodesis is seldomly reported. Herein, we present 3 cases of ASD with radiculopathy wherein satisfactory results were obtained using unilateral biportal endoscopic (UBE) decompression. PATIENT CONCERNS: Case 1 was of a 56-year-old male who presented with a chief complaint of Intermittent claudication since 2-year. Case 2 involved a 78-year-old female who was admitted to the hospital with a chief complaint of radiating pain and weakness in the left leg for at least 1 year. Case 3 was a 67-year-old woman who visited our hospital because of radiating leg pain for 5 months. All the cases had a history of L4 to L5 lumbar interbody fusion surgery. DIAGNOSES: Computed tomography and magnetic resonance imaging showed the spinal epidural lipomatosis at the L3 to L4 level in case 1, the up-migrated lumbar disc herniation at L3 to L4 level in case 2 and unilateral foraminal stenosis at the L5 to S1 level in case 3. INTERVENTIONS: Under UBE guidance, the ipsilateral approach was used to treat adjacent lumbar stenosis caused by spinal epidural lipomatosis. The contralateral approach was used to remove the up-migrated herniated disc. The paraspinal approach was applied to decompress the foraminal stenosis. OUTCOMES: Postoperative parameters were improved clinically, and nerve roots were decompressed radiologically. No complications were developed. LESSONS: UBE revision surgery showed a favorable clinical and radiological result without complications and may be a safe and effective alternative technique for ASD.

[Experimental study of proteasome inhibitor MG132 up-regulates Wnt/ß-catenin signaling pathway to improve osteoporosis].

OBJECTIVE: To explore the mechanism of proteasome inhibitor MG132 in improving osteoporosis. METHODS: Total of 32 female SD rats, weighing 220 to 250 g and 8 weeks old, were selected. They were randomly divided into 4 groups(n=8). Rats of group A and group B were cut off ovaris on both sides to make model of osteoporosis, and then they were given proteasome inhibitors MG132 and dimethyl sufoxide (DMSO) respectively. Group C was a sham group and rats were given MG132. Group D was a normal group and rats were given MG132 too. The rats were killed in batches at 6 and 12 weeks after administration, and the femoral neck tissues were obtained. Relevant data were analyzed, such as pathomorphological observation, micro-CT analysis, detection of 20S proteasome activity in tissues, and expression of Wnt and ß-catenin. RESULTS: Morphological observation showed that the trabecular were slightly thinner, reticulated, and occasionally interrupted in group A, while the trabecular were obviously thinner and discontinuous in group B. And the trabecular were intact and arranged reticulated in group C and D. The analysis results of bone mineral density(BMD), bone surface(BS), bone volume/total volume(BV/TV) and trabecular thickness(Tb.Th) showed that group B was worse than other groups in all parameters at different time points(P<0.05), and group A was worse than group C and group D in BS(P<0.05), there was no significant difference in all parameters between group C and group D. RFU value of 20S proteasome in group B was significantly higher than that in other groups(P<0.05). According to the results of Western blot, the gray values of Wnt protein and ß-catenin protein in group A were significantly higher than those in other groups (P<0.05). CONCLUSION: MG-132, a ubiquitin proteasome inhibitor, can regulate Wnt/ß-catenin signaling pathway by inhibiting the degradation of ß-catenin protein, and delaying the occurrence and development of osteoporosis.

LncRNA-GAS5 promotes spinal cord repair and the inhibition of neuronal apoptosis via the transplantation of 3D printed scaffold loaded with induced pluripotent stem cell-derived neural stem cells.

BACKGROUND: Stem cell transplantation has been increasingly used for spinal cord repair, and some achievements have been made. However, limited stem cell sources as well as immune rejection and ethical issues have restricted its wide application. Therefore, to achieve further breakthroughs regarding the application of stem cell transplantation to treat spinal cord injury (SCI), it is important to develop a stem cell line that can effectively avoid immune rejection and ethical issues. METHODS: Urine cells (UCs) were induced to differentiate into induced pluripotent stem cells (iPSCs), which then further differentiated into neural stem cells (NSCs). Relevant tests were performed, and three-dimensional (3D) printed scaffolds were prepared. Thirty C57BL/6 mice were divided into 5 groups based on a random number table: a sham group, an SCI group, an SCI + control group, an SCI + siNC group, and an SCI + siGAS5 group (n=6). The latter 4 groups replicated SCI models. Mice in the SCI + control group were transplanted with 3D scaffolds loaded with iPSC-derived NSCs (iPSd-NSCs). Mice in the SCI + siNC group and the SCI + siGAS5 group were transplanted with scaffolds loaded with iPSd-NSCs-siNC and 3D scaffolds loaded with iPSd-NSCs-siGAS5, respectively. Mice in the other groups were injected with the same amount of normal saline. Hematoxylin-eosin staining was used to observe the histopathology of the injured spinal cord, the Basso-Mouse Scale was used to assess the motor function of the hind limbs of the mice, and Western blot was used to detect the expression of apoptosis-related proteins after SCI. RESULTS: iPSd-NSCs were successfully induced and differentiated, and 3D printed heparin sulfate-collagen scaffolds were prepared, inside which a 3D loose porous structure was shown by electron microscopy. Morphological observations showed that iPSd-NSC transplantation improved SCI in mice, while GAS5 silencing inhibited the reparative effect of iPSd-NSC transplantation on SCI in mice. Western blot results indicated that iPSd-NSC transplantation significantly increased the expression level of B cell lymphoma/leukemia-2 (Bcl-2) (P<0.01) but decreased the expression levels of Bcl-2 associated X protein, cytochrome C, and cleaved caspase-3 (P<0.001). CONCLUSIONS: The overexpression of lncRNA-GAS5 can promote spinal cord repair and inhibit neural apoptosis via the transplantation of 3D printed scaffolds loaded with iPSd-NSCs.

Autophagy activation promotes the effect of iPSCs-derived NSCs on bladder function restoration after spinal cord injury.

The role of autophagy in the transplantation of induced pluripotent stem cells (iPSCs)-derived neural stem cells (NSCs) to treat spinal cord injury (SCI) and neurogenic bladder was investigated in this study. NSCs derived from human iPSCs were identified by and immunofluorescence assay. To clarify the role of autophagy, iPSCs were treated with either an autophagy inducer (rapamycin), or an autophagy inhibitor (chloroquine). Cell Counting kit-8 (CCK-8), western blot and flow cytometry were used to detect the effect of autophagy on the viability and differentiation of iPSCs. Sixty Wistar rats were selected to establish the SCI model and treated with iPSCs-derived NSCs transplantation. The effect of autophagy on the bladder function of rats with different treatments was evaluated by Basso, Beattie, and Bresnahan (BBB) score, bladder function score, bladder weight measurement, Hematoxylin & Eosin (H&E) staining, and Masson staining. The results of in vitro experiment showed that rapamycin enhanced the cell activity of iPSCs, increased the number of nestin positive cells, up-regulated Beclin-1 and LC3BI/II expressions, and down-regulated p62 expression. And the results of in vivo experiment showed that rapamycin improved exercise ability and bladder function, partially restored bladder weight, and significantly reduced bladder tissue damage in SCI rats. However, chloroquine showed the opposite results. The differentiation of iPSCs into NSCs could be promoted by induced autophagy, while neurogenic bladder of SCI was restored by autophagy activation.

Changes in alkaline phosphatase, calcium, C-reactive protein, D-dimer, phosphorus and hemoglobin in elderly osteoporotic hip fracture patients.

BACKGROUND: This study aims to evaluate the association between serum alkaline phosphatase (ALP), calcium (Ca) and phosphorus (P), C-reactive protein (CRP) and D-dimer (D-D), and hemoglobin (Hb) in postoperative and preoperative osteoporotic hip fracture elderly patients. METHODS: A total of 32 operation patients with osteoporotic hip fracture over the age of 65 years old were admitted to the orthopedic unit and prospectively evaluated. All patients were treated according to specific protocols, according to the type of fracture. Fasting blood samples were taken, and serum ALP, Ca and P measurements were respectively performed in six periods: at the time of admission, post-operation, and at postoperative one week, two weeks, one month and three months. Hb, CRP and D-D were also analyzed, and the fracture healing was recorded. RESULTS: Finally, 32 cases were selected for the present study. The analysis results revealed that the level of serum Ca and ALP slowly increased at two weeks after surgery, and slightly dropped back at three months after the operation. Furthermore, D-D and CRP had a significant effect at pre- and post-operation, and exhibited an obvious downward trend after postoperative one week. The fracture healing and recovery of activities were associated with the Hb levels. The serum levels of ALP, which were adjusted by Ca and P, were associated with Hb and CRP, but not with D-D. CONCLUSIONS: Interestingly, there was an association between CRP and D-D. These findings suggest that early control of inflammation and loss of Ca could play a positive role for the healing of osteoporotic hip fractures.

Effects of hypoxia and ASIC3 on nucleus pulposus cells: From cell behavior to molecular mechanism.

This study aimed to explore the effects of hypoxia and acid-sensing ion channel 3 (ASIC3) on nucleus pulposus cells from cell behavior to molecular mechanism. Primary rabbit nucleus pulposus cells were isolated and identified by HE, toluidine blue and immunohistochemical staining of collagen II. 2% O2 and 48 h were screened as optimal oxygen concentration and effect time, respectively, by determining cell apoptosis and mRNA expression of ASIC3, hypoxia inducible factor-1α (HIF-1α) and aquaporin 3. FLuo-3 AM labeling showed that the Ca2+ concentration in cells increased under hypoxia condition. shRNA-ASIC3 and ASIC3 expression vector were transfected into cells. Subsequently, cells were divided into six groups: Control, 2% O2, shRNA-NC+2% O2, shRNA-ASIC3 + 2% O2, Vector+2% O2 and ASIC3 + 2% O2. Flow cytometry, CCK-8 assay, transmission electron microscopy, immunofluorescent labeling, RT-PCR and western blot demonstrated that hypoxia and ASIC3 over-expression inhibited the proliferation, arrested cell cycle in G1 phase, promoted the apoptosis, initiated the autophagy and up-regulated the expression of ASIC3, HIF-1α, light chain 3, p-ERK1/2 and p-MAPK. However, ASIC3 silencing could significantly relieve these phenomena. Co-immunoprecipitation assay found ASIC3 was interacted with HIF-1α&ERK1/2. Evaluation of the effect of HIF-1αsilencing on ASIC3 expression showed that the high expression of ASIC3 induced by hypoxia was reduced significantly by HIF-1α silencing. In conclusion, hypoxia and ASIC3 changed the behavior of nucleus pulposus cells by activating the MAPK pathway. HIF-1α and ASIC3 could regulate each other in nucleus pulposus cells.

[Treatment of thoracolumbar burst fractures with intelligent inflated reduction combined with percutaneous pedicle screw fixation].

OBJECTIVE: To evaluate the clinical outcome of intelligent inflated reduction combined with percutaneous pedicle screw fixation in treating thoracolumbar burst fractures. METHODS: The clinical data of 22 patients with thoracolumbar burst fractures of single segment treated from January 2013 to December 2015 were retrospectively analyzed. There were 12 males and 10 females, aged from 32 to 56 years old with an average of (42.4±8.6) years. Self-made intelligent pneumatic reset instrument was applied to 22 cases under anaesthesia reduction, and then percutaneous pedicle screw fixation was performed. Clinical features were observed and the clinical effects were evaluated by VAS, ODI, kyphotic angle (Cobb angle) and the injured vertebral anterior border height before and after operation. RESULTS: All the patients were followed up from 1 to 2.5 years with an average of 18 months. All fractures obtained bone healing, no complications such as loosening, displacement, breakage of pedicle screw and kyphosis were found. Preoperative, 1 week postoperative, and final follow-up, VAS scores of lumbar pain were 7.82±0.85, 3.09±0.92, 1.05±0.72;ODI scores were 84.2±11.2, 46.3±9.0, 12.2±4.3;Cobb angle were (16.3±5.4)°, (3.7±2.2)°, ( 5.5±2.6)°; the injured vertebral anterior border heights were (59.5±7.8)%, (86.9±6.0)%, (83.5±5.5)%, respectively. There was significant differences in VAS, ODI scores between any two times(P<0.05). At 1 week postoperative and final follow-up, Cobb angle, injuried vertebral anterior border height were obviously improved (P<0.05), and there was no significant difference between postoperative 1 week and final follow-up (P>0.05). CONCLUSIONS: It is safe and feasible surgical technique that intelligent inflated reduction combined with percutaneous pedicle screw fixation for thoracolumbar burst fractures. It has advantage of little trauma, reliable fixation, and less complication, etc. Therefore, it is a better choice for single-segment thoracolumbar burst fractures.

Morphology of the lumbar multifidus muscle in lumbar disc herniation at different durations and at different ages.

The aim of the present study was to evaluate the relative functional volume of bilateral lumbar multifidus (LM) muscles across different stages and ages of patients with lumbar disc herniation (LDH). The relative functional volumes of LM muscles in both non-affected and affected sides in the L4-L5 and L5-S1 segmental level were measured in a resting prone position, and visual analogue score (VAS) for pain and Japanese Orthopedic Association (JOA) scores were recorded. The correlation between changes in the relative net volume of LM muscles and times of onset, ages, VAS and JOA scores were analyzed. A total of 327 cases were selected. The affected sides of LM muscles could present a certain degree of atrophy in stages >3 weeks. During the duration of the course, all cases presented different degrees of LM muscle atrophy. In addition, the degree of LM muscle atrophy was positively correlated with its duration. Age could influence the degree of LM muscle atrophy. Patients with unilateral LDH had <10% asymmetry on relative functional volume in the youth group. At the L4-L5 segments, patients with unilateral LDH had >10% asymmetry within the course of 3 months in the elderly group. The reduced rate of the relative functional net LM muscle volume was positively correlated with VAS scores, age, duration and JOA scores. In conclusion, the reduced rate of relative functional net LM muscle volume was positively correlated with age, duration, VAS scores and JOA scores. Although these findings are unreliable markers of lumbar pathology in an individual level for use in clinical or research settings, there is a notable importance of early intervention in LM muscle atrophy.

Effects of a bone graft substitute consisting of porous gradient HA/ZrO2 and gelatin/chitosan slow-release hydrogel containing BMP-2 and BMSCs on lumbar vertebral defect repair in rhesus monkey.

Dense biomaterial plays an important role in bone replacement. However, it fails to induce bone cell migration into graft material. In the present study, a novel bone graft substitute (BGS) consisting of porous gradient hydroxyapatite/zirconia composite (PGHC) and gelatin/chitosan slow-release hydrogel containing bone morphogenetic protein 2 and bone mesenchymal stem cells was designed and prepared to repair lumbar vertebral defects. The morphological characteristics of the BGS evaluated by a scanning electron microscope showed that it had a three-dimensional network structure with uniformly distributed chitosan microspheres on the surfaces of the graft material and the interior of the pores. Then, BGS (Group A), PGHC (Group B), or autologous bone (Group C) was implanted into lumbar vertebral body defects in a total of 24 healthy rhesus monkeys. After 8 and 16 weeks, anteroposterior and lateral radiographs of the lumbar spine, microcomputed tomography, histomorphometry, biomechanical testing, and biochemical testing for bone matrix markers, including Type I collagen, osteocalcin, osteopontin, basic fibroblast growth factor, alkaline phosphatase, and vascular endothelial growth factor, were performed to examine the reparative efficacy of the BGS and PGHC. The BGS displayed excellent ability to repair the lumbar vertebral defect in rhesus monkeys. Radiography, microcomputed tomography scanning, and histomorphological characterization showed that the newly formed bone volume in the interior of the pores in the BGS was significantly higher than in the PGHC. The results of biomechanical testing indicated that the vertebral body compression strength of the PGHC implant was lower than the other implants. Reverse-transcription polymerase chain reaction and western blot analyses showed that the expression of bone-related proteins in the BGS implant was significantly higher than in the PGHC implant. The BGS displayed reparative effects similar to autologous bone. Therefore, BGS use in vertebral bone defect repair appears promising.

VEGF165 induces differentiation of hair follicle stem cells into endothelial cells and plays a role in in vivo angiogenesis.

Within the vascular endothelial growth factor (VEGF) family of five subtypes, VEGF165 secreted by endothelial cells has been identified to be the most active and widely distributed factor that plays a vital role in courses of angiogenesis, vascularization and mesenchymal cell differentiation. Hair follicle stem cells (HFSCs) can be harvested from the bulge region of the outer root sheath of the hair follicle and are adult stem cells that have multi-directional differentiation potential. Although the research on differentiation of stem cells (such as fat stem cells and bone marrow mesenchymal stem cells) to the endothelial cells has been extensive, but the various mechanisms and functional forms are unclear. In particular, study on HFSCs' directional differentiation into vascular endothelial cells using VEGF165 has not been reported. In this study, VEGF165 was used as induction factor to induce the differentiation from HFSCs into vascular endothelial cells, and the results showed that Notch signalling pathway might affect the differentiation efficiency of vascular endothelial cells. In addition, the in vivo transplantation experiment provided that HFSCs could promote angiogenesis, and the main function is to accelerate host-derived neovascularization. Therefore, HFSCs could be considered as an ideal cell source for vascular tissue engineering and cell transplantation in the treatment of ischaemic diseases.

Evaluation of a Novel HA/ZrO2-Based Porous Bioceramic Artificial Vertebral Body Combined with a rhBMP-2/Chitosan Slow-Release Hydrogel.

A new HA/ZrO2-based porous bioceramic artificial vertebral body (AVB), carried a recombinant human bone morphogenetic protein-2 (rhBMP-2)/chitosan slow-release hydrogel was prepared to repair vertebral bone defect in beagles. An ionic cross-linking was used to prepare the chitosan hydrogel (CS gel) as the rhBMP-2 slow-release carrier. The vertebral body defects were implanted with the rhBMP-2-loaded AVB in group A, or a non-drug-loaded AVB in group B, or autologous iliac in group C. The encapsulation rate of rhBMP-2 in rhBMP-2-loaded CS gel was 91.88±1.53%, with a drug load of 39.84±2.34 ng/mg. At 6, 12, 24 weeks postoperatively, radiography showed that the bone calluses gradually increased with time in group A, where the artificial vertebral body had completely fused with host-bone at 24 weeks after surgery. In group C, an apparent bone remodeling was occurred in the early stages, and the graft-bone and host-bone had also fused completely at 24 weeks postoperatively. In group B, fusion occurred less than in groups A and C. At 24 weeks after surgery, micro-computed tomography (Micro-CT) revealed that the volume of newly-formed bone in group A was significantly more than in group B (p<0.05). At 24 weeks after surgery, ultra-compressive strengths of the operated segments were 14.03±1.66 MPa in group A, 8.62±1.24 MPa in group B, and 13.78±1.43 MPa in group C. Groups A and C were both significantly higher than group B (p < 0.05). At 24 weeks postoperatively, the hard tissue sections showed that the AVB of group A had tightly fused with host bone, and that pores of the AVB had been filled with abundant nearly mature bone, and that the new bone structured similarly to a trabecular framework, which was similar to that in group C. In contrast, implant fusion of the AVB in group B was not as apparent as group A. In conclusion, the novel HA/ZrO2-based porous bioceramic AVB carried the rhBMP-2-loaded CS gel can promote the repair of bony defect, and induce bone tissue to grow into the pores, which may replace iliac bone grafts as commonly applied in clinical practice.

Transforaminal Lumbar Interbody Fusion with Unilateral Pedicle Screw and Contralateral Percutaneous Transfacet Screw Fixation for the Treatment of Lumbar Degenerative Disorders.

AIM: To assess the feasibility and efficacy of TLIF with unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation for the treatment of lumbar degenerative disorders. MATERIAL AND METHODS: A series of computed tomography (CT) digital images from 60 patients (30 males and 30 females) with L3-S1 segments, were reconstructed in three dimensions using a software named Xelis 3D. Linear and angular measurements of the facets were recorded. Fifty-six patients were divided to either bilateral pedicle screw fixation (BPS) (n=30) or unilateral pedicle screw and contralateral percutaneous transfacet screw fixation (UPFS) (n=26) groups. The operating time, blood loss, length of hospital stay, clinical outcomes, fusion and complication rates were compared between the two groups. RESULTS: The parameters of the facets we recorded were no significant differences between the left and right sides (p > 0.05). No statistically significant differences between males and females were observed, except the maximum width of superior facet at L4 and S1, and length of screw at all levels. Intraoperative parameters, such as operating time, blood loss and postoperative hospital stay had significantly larger in the BPS group than UPFS group (p < 0.05). No significant differences were found between the two groups in clinical results, fusion and complication rates (p > 0.05). CONCLUSION: Because of the similar clinical outcomes but less operative time, blood loss and length of postoperatively hospital stay, unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation might be an attractive technique compared to bilateral pedicle screw fixation for treating lumbar degenerative disorders with TLIF. Nevertheless differences of the anatomical parameters for the lumbosacral facets fixation between Chinese and Westerners should be noted.

Evaluation of porous gradient hydroxyapatite/zirconia composites for repair of lumbar vertebra defect in dogs.

OBJECTIVE: To evaluate the effects of porous gradient composites with hydroxyapatite/zirconia and autologous iliac in repair of lumbar vertebra body defects in dogs. METHODS: (1) New porous gradient hydroxyapatite/zirconia composites were prepared using foam immersion, gradient compound and high temperature sintering; (2) A total of 18 adult beagle dogs, aged five to eight months and weighted 10-13 kg, were randomly assigned into two subgroups, which were implanted with new porous gradient hydroxyapatite/zirconia composites (subgroup A in 12) or autologous iliac bone (subgroup B in 6); (3) The post-operative data were analyzed and compared between the subgroups to repair the vertebral body defect by roentgenoscopy, morphology and biomechanics. RESULTS: The porosity of new porous gradient hydroxyapatite/zirconia composites is at 25 poles per inch, and the size of pores is at between 150 and 300 µm. The post-operative roentgenoscopy displayed that new-bone formation is increased gradually, and the interface between composites and host-bone becomes became blur, and the new-bone around the composites were integrated into host-bone at 24 weeks postoperatively in subgroup A. As to subgroup B, the resorption and restructure were found at six weeks after the surgery, and the graft-bone and host-bone have been integrated completely without obvious boundary at 24 weeks postoperatively. Histomorphologic study showed that the amount of bone within pores of the porous gradient hydroxyapatite/zirconia composites increased continuously with a prolonged implantation time, and that partial composites were degradated and replaced by new-bone trabeculae. There was no significant difference between subgroups (P > 0.05) in the ultimate compressive strengths. CONCLUSION: New porous gradient hydroxyapatite/zirconia composites can promote the repair of bony defect, and induce bone tissue to ingrow into the pores, which may be applied widely to the treatment of bony defect in the future.

[Treatment of low lumbar degenerative disease with unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation].

OBJECTIVE: To explore the operative skills and effect of unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation in treating degenerative low lumbar disease. METHODS: From January 2009 to December 2011,22 patients with degenerative low lumbar disease were treated with transforaminal lumbar interbody fusion, during the operations, unilateral pedicle screw and contralateral percutaneous transfacet screw fixation were performed. There were 16 males and 6 females, aged from 32 to 71 years old with an average of (51.1 ± 10.6) years, including single segment in 20 cases and two segments in 2 cases. Clinical effects were evaluated according to visual analogue score (VAS) and Oswestry Disability Index (ODI). RESULTS: All patients were followed up from 1 to 2.5 years with an average of 18 months. One case complicated with leakage of cerebrospinal fluid after operation and 1 case with lower limb pain of decompression-side on the 3rd day after operation. Twenty-two patients got bony fusion. There were no instability and evidence of instrument failure during follow-up. The VAS and ODI score decreased from preoperative 8.24 ± 0.72, 36.72 ± 6.84 respectively to 3.18 ± 0.66, 4.36 ± 1.12 at the final follow-up (P < 0.05). CONCLUSION: Unilateral pedicle screw combined with contralateral percutaneous transfacet screw fixation is safe and feasible surgical technique in treating low lumbar degenerative disease. It has advantages of little trauma, rigid fixation, high fusion rate, and less complication. etc.