A biphasic calcium phosphate/acylated methacrylate gelatin composite hydrogel promotes osteogenesis and bone repair.

PURPOSE/AIM: Bone defects caused by trauma, tumors, congenital malformation, or inflammation are very common in orthopedics. In recent years, mimicking the composition and structure of natural bone tissue has become a hot topic in biomaterial research, with the aim of developing an ideal biomaterial for bone defect transplantation. Here, the feasibility of a biphasic calcium phosphate (BCP)/acylated methacrylate gelatin (GelMA) composite hydrogel to repair bone defects was evaluated in vitro and in rats. MATERIALS AND METHODS: The biocompatibility of a biphasic calcium phosphate (BCP)/acylated methacrylate gelatin (GelMA) composite hydrogel was evaluated by cytoskeleton staining, live/dead cell staining and cell proliferation assays. The in vitro osteogenic activities of the composite hydrogel were evaluated by alkaline phosphatase and alizarin red staining, as well as osteogenic gene expression analysis at both transcript and protein levels. The in vivo bone repair activities were evaluated using the rat skull defect model. RESULTS: The BCP/GelMA composite hydrogel displayed excellent biocompatibility and promoted osteogenesis of bone marrow mesenchymal stem cells in vitro. In addition, the BCP/GelMA composite hydrogel markedly promoted new bone formation in the rat skull-defect model. CONCLUSIONS: BCP/GelMA composite hydrogel may be an effective artificial material for bone tissue engineering.

Effect of Different Anesthesia and Puncture Methods of Percutaneous Kyphoplasty on More Than 90-Year-Old Osteoporotic Vertebral Fracture: Advantages of the ERAS Concept.

Background: Percutaneous kyphoplasty (PKP) is an effective minimally invasive technique for the treatment of osteoporotic vertebral fracture (OVF) in recent years. This study focuses on the analysis of PKP surgery and anesthesia in osteoporotic vertebral facture patients over 90 years old with the concept of "enhanced recovery after surgery." Methods: This study reviewed 239 patients who were diagnosed with OVF retrospectively between October 2015 and June 2019. According to the method of anesthesia, these patients were divided into Group A (n = 125) and Group B (n = 114). According to the pedicle puncture approach, these patients were divided into Group C (n = 102) and Group D (n = 137). The anterior vertebral height (AVH) and local kyphosis angle (LKA) were used to evaluate the degree of vertebral damage and restoration. The visual analogue scale (VAS) and the Oswestry Disability Index (ODI) scores were used for assessing functional outcomes. Some parameters were used to assess the perioperative conditions such as operation time, amount of bone cement perfusion, intraoperative fluoroscopy times, anesthesia recovery time, time out of the bed, hospital stay, hospitalization cost, and complications. Results: The visual analogue scale (VAS), Oswestry Disability Index (ODI), anterior vertebral height (AVH), and local kyphosis angle (LKA) 1 day, 1 year after surgery, and at the last follow-up all showed significant improvement (P < 0.05) in comparison with those before surgery both in Groups A and B and Groups C and D. The ODI 1 day after surgery was significantly better in Group B than Group A (P < 0.05). Compared with Group B, Group A required longer time of anesthesia, operation time, anesthesia recovery time, time to get out of bed, and length of hospital stay and more hospitalization costs (P < 0.05). Group D required longer operation time, longer time to get out of bed, more bone cement volume, fluoroscopy time, and more operation hospitalization costs compared with Group C (P < 0.05). Conclusion: We recommend unilateral puncture under local anesthesia for OVF in the patients aged over 90 from the perspective of rapid recovery.

Percutaneous vertebroplasty versus kyphoplasty for the treatment of neurologically intact osteoporotic Kümmell's disease.

BACKGROUND: Percutaneous vertebroplasty (PVP) and kyphoplasty (PKP) have been widely used to treat neurologically intact osteoporotic Kümmell's disease (KD), but it is still unclear which treatment is more advantageous. Our study aimed to compare and investigate the safety and clinical efficacy of PVP and PKP in the treatment of KD. METHODS: The relevant data that 64 patients of neurologically intact osteoporotic KD receiving PVP (30 patients) or PKP (34 patients) were analyzed. Surgical time, operation costs, intraoperative blood loss, volume of bone cement injection, and fluoroscopy times were compared. Occurrence of cement leakage, transient fever and re-fracture were recorded. Universal indicators of visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated separately before surgery and at 1 day, 6 months, 1 year, 2 years and the final follow-up after operation. The height of anterior edge of the affected vertebra and the Cobb's angle were assessed by imaging. RESULTS: All patients were followed up for at least 24 months. The volume of bone cement injection, intraoperative blood loss, occurrence of bone cement leakage, transient fever and re-fracture between two groups showed no significant difference. The surgical time, the operation cost and fluoroscopy times of the PKP group was significantly higher than that of the PVP group. The post-operative VAS, ODI scores, the height of the anterior edge of the injured vertebrae and kyphosis deformity were significantly improved in both groups compared with the pre-operation. The improvement of vertebral height and kyphosis deformity in PKP group was significantly better than that in the PVP group at every same time point during the follow-up periods, but the VAS and ODI scores between the two groups showed no significant difference. CONCLUSION: PVP and PKP can both significantly alleviate the pain of patients with KD and obtain good clinical efficacy and safety. By contrast, PKP can achieve better imaging height and kyphosis correction, while PVP has the advantages of shorter operation time, less radiation volume and operation cost.

Percutaneous Balloon Kyphoplasty in Treatment of Painful Osteoporotic Occult Vertebral Fracture: A Retrospective Study of 89 Cases.

BACKGROUND The definition of a vertebral fracture is usually based on the presence of a deformation of the vertebral body and this can be misleading in the presence of a fracture without radiologic collapse with the definition of occult osteoporotic vertebral fractures (OOVFs). STIR sequence of MRI images showing hyperintensity signal was the most confirmative screening examination used to determine the presence of painful OOVFs. To date, clinical management of OOVFs has been rarely discussed. MATERIAL AND METHODS Between 2011 and 2013, 89 patients suffering from painful OOVFs underwent 142 percutaneous balloon kyphoplasty (PKP) procedures. Outcome data (mean variation of anterior and middle vertebral body height, visual analog scale [VAS] scores, Oswestry Disability Index [ODI] scores, and SF-36 scores) were recorded preoperatively, postoperatively, and at 1 month, 6 months, and 2 year after treatment, to evaluate the results. RESULTS We successfully treated 89 patients (142 vertebral bodies) with PKP. Cement leakages were observed in 12 (8.45%) treated vertebral bodies and there were 5 new adjacent vertebral fractures during the follow-up period. The mean variation of anterior and middle vertebral body height changed from 96.5±3.4% preoperatively to 97.2±2.5% postoperatively (p>0.05) and from 96.3±2.8% preoperatively to 97.9±3.1% postoperatively (p>0.05), respectively. The mean VAS scores were reduced significantly from pre-surgery to post-surgery (8.3±1.2 to 2.9±0.7; p<0.05), as was the ODI score (76.4±12.5 to 26.7±5.6; p<0.05). The SF-36 scores, including Bodily Pain (BF), Vitality (VT), Physical Function (PF), and Social Functioning (SF), all showed notable improvement (P<0.05). These variations were maintained during the 2-year follow-up period. CONCLUSIONS PKP is a safe and effective method in the treatment of painful OOVFs.

Treatment of comminuted patellar fracture with the nitinol patellar concentrator.

AIM: To evaluate the clinical effect of the nitinol (NiTi)-patellar concentrator (NT-PC) for the treatment of comminuted patellar fractures. MATERIAL AND METHODS: A total of 32 patients with acute comminuted patellar fracture accepted open reduction and internal fixation with the NT-PC, and the curative effects were evaluated using the Böstman clinical grading scale. RESULTS: All fractures were anatomically reduced by surgery and all cases were followed-up for six to 18 months. The mean score of patients according to the Böstman clinical grading scale was 25.6, with 29 of 32 (90.7%) patients achieving excellent or good results. Two patients had traumatic arthritis, one had slippage of the NT-PC, and all patients received pharmacotherapy. CONCLUSIONS: The application of the NT-PC is a satisfactory approach to the treatment of comminuted patellar fractures.

Fabrication of hydroxyapatite on pure titanium by micro-arc oxidation coupled with microwave-hydrothermal treatment.

Porous hydroxyapatite (HA)-containing composite films were prepared by a novel method consisting of micro-arc oxidation (MAO) combined with microwave-hydrothermal (M-H) treatment. The morphology, composition and phase composition of the bioactive films were investigated with scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction. MTT assay was carried out to investigate the in vitro effects of the different surfaces on bone integration properties. The prepared MAO films consisted mainly of anatase, rutile and tricalcium phosphate along with amorphous calcium (Ca) and phosphorus (P) phases. The M-H-treated composite films were composed primarily of anatase, rutile and HA. As the time and temperature of the M-H treatment increased, the number of HA crystals gradually increased. Using the M-H method, HA was obtained at a lower temperature and in a shorter period of time compared to the conventional hydrothermal method. The results suggest that the M-H method significantly decreases the hydrothermal reaction temperature and also greatly shortens the reaction time. Due to the nanocrystallinity and porosity of the prepared composite films, the method presented here shows promise for the formation of bioactive materials for medical applications.

Bioactivity of porous biphasic calcium phosphate enhanced by recombinant human bone morphogenetic protein 2/silk fibroin microsphere.

To prepare a bioactive bone substitute, which integrates biphasic calcium phosphate (BCP) and rhBMP-2/silk fibroin (SF) microsphere, and to evaluate its characteristics. Hydroxyapatite and ß-tricalcium phosphate were integrated with a ratio of 60­40%. RhBMP-2/SF (0.5 µg/1 mg) microsphere was prepared, and its rhBMP-2-release kinetics was assed. After joining pore-forming agent (Sodium chloride, NaCl), porous BCP/rhBMP-2/SF were manufactured, and its characteristics and bioactivity in vitro were evaluated. Mean diameter of rhBMP-2/SF microsphere was 398.7 ± 99.86 nm, with a loading rate of 4.53 ± 0.08%. RhBMP-2 was released in a dual-phase pattern, of which fast-release (nearly half of protein released) focused on the initial 3 days, and slow-release sustained more than 28 days. With the increase in concentration of NaCl, greater was porosity and pore size, but smaller mechanical strength of BCP/rhBMP-2/SF. Material with 150% (w/v) NaCl had an optimal performance, with a porosity of 78.83%, pore size of 293.25 ± 42.77µm and mechanical strength of 31.03 MPa. Proliferation of human placenta-derived mesenchymal stem cells (hPMSCs) on leaching extract medium was similar to the normal medium (P = 0.89), which was better than that on control group (P = 0.03). Activity of alkaline phosphatase on BCP/rhBMP-2/SF surface was higher than on pure BCP at each time point except at 1 day (P < 0.05). RhBMP-2 has a burst release on early times and a sustaining release on later times. BCP/rhBMP-2/SF with 150% (w/v) pore-forming agent has excellent porosity, pore size and mechanical strength. The biomaterial induces proliferation and differentiation hPMSCs effectively.

Biomechanical characteristics of cement/gelatin mixture for prevention of cement leakage in vertebral augmentation.

PURPOSE: This study evaluated whether or not the addition of gelatin micro-particles into the polymethyl methacrylate (PMMA) could reduce cement infiltration in cancellous bone of vertebra. METHODS: Gelatin micro-particles were prepared in various sizes and mixed with PMMA in different densities. Dynamic viscosity of the mixture was measured by a rotational rheometer. Fresh bovine vertebral bodies were sectioned into cylindrical samples. Permeability of the mixture through the samples was tested on a mechanical test machine, and calculated using Darcy's law. The PMMA/gelatin mixture also underwent compressive and bending tests, and their structures were examined by scanning electron microscopy. RESULTS: The cement/gelatin mixture increased the viscosity. Significant reduction of cement permeability in cancellous bone was determined after the addition of the micro-particles. Micro-particles of 2 % in density and 125-250 µm in size decreased the permeability by 1/3 without any significant change of the cement viscosity. The biomechanical strength was unchanged in compression but decreased by up to 20 % in bending. CONCLUSIONS: Gelatin micro-particles significantly increased the cement viscosity, reduced the permeability in cancellous bone of vertebra, decreased the flexural strength, but did not affect the compressive strength. Although it suggested a manageable approach in vertebral augmentation, the outcome should be further verified on a cadaveric model or an animal model before the mixture could be used safely and effectively in the clinical treatment.

Single door laminoplasty plus posterior fusion for posterior atlantoaxial dislocation with congenital malformation: A case report and review of literature.

BACKGROUND: Posterior atlantoaxial dislocation (PAD) is a rare type of upper cervical spine disease. We sought to describe a unreported case of old PAD with os odontoideum (OO) and atlas hypoplasia (AH) and our unique treatment approach consisting of C1 single door laminoplasty with C1-3 posterior fixation and fusion. CASE SUMMARY: A 70-year-old male patient who suffered from progressive aggravating numbness and limb weakness for 4 years without trauma, was diagnosed with old PAD with OO and AH. The patient underwent closed reduction and C1 single door laminoplasty with C1-3 posterior fixation and fusion instead of C1 laminectomy with occipitocervical fusion. During the 3-year follow-up, he was able to walk by himself instead of using a wheelchair and with a ± 25° range of head rotation as well as a ± 10° range of flexion-extension. Three-year follow-up images showed satisfactory reduction and fusion. CONCLUSION: C1 single door laminoplasty with cervical fusion in PAD combined with spinal cord compression could be a suitable and effective surgical option. Compared with laminectomy and occipitocervical fusion, it retains more cervical range of motion, has a smaller incision and provides an adequate bone grafting space for atlantoaxial fusion.

Min-invasive surgical treatment for multiple axis fractures: A case report.

BACKGROUND: Fractures of the axis are commonly seen in spinal injuries. Upper cervical fractures are usually managed conservatively. However, the complications due to long-term external immobilization cannot be ignored. The traditional open surgery has the disadvantages of too much blood loss and soft tissue injury. The aim of our paper is to introduce a minimally invasive surgical treatment for multiple axis fractures. CASE SUMMARY: We report a 40-year-old Chinese male who had severe neck pain and difficult neck movement after falling from 3 meters. X-ray and computed tomography (CT) scan revealed an axis injury consisting of an odontoid Type III fracture associated with a Hangman fracture categorized as a Levine-Edwards Type I fracture. The patient underwent anterior odontoid screw fixation and posterior percutaneous screw fixation using intraoperative O-arm navigation. Neck pain was markedly improved after surgery. X-rays and CT scan reconstructions of 3-mo follow-up showed good stability and fusion. The range of cervical motion was well preserved. CONCLUSION: Anterior odontoid screw fixation and posterior direct C2 percutaneous pedicle screw fixation with the aid of O-arm navigation and neurophysiological monitoring can be an interesting alternative option for complicated multiple axis fractures.

Biomechanical evaluation of vertebroplasty using calcium sulfate cement for thoracolumbar burst fractures.

OBJECTIVE: To evaluate the biomechanical performance of vertebroplasty using calcium sulfate cement for thoracolumbar burst fractures. METHODS: Sixteen bovine thoracolumbar spines (T11-L1) were divided into 4 groups (A,B,C and D). After burst-fracture model was created, 12 vertebral bodies in Groups A, B and C were augmented with calcium sulfate cement (CSC), calcium phosphate cement (CPC) and polymethylmethacrylate (PMMA) bone cement, respectively. Each anterior vertebral body height was measured with a caliper at 4 time points: intact conditions (HInt), post-fracture (HFr), post-reduction (HRe) and post-vertebroplasty (HVP). The filling volume of 3 different bone cements was also measured. Each vertebral body was compressed at 0.5 mm/s using a hinged plating system on a materials testing machine to 50% of the post-vertebroplasty height to determine strength and stiffness. Difference was checked using t test or One-way ANOVA. RESULTS: The average strike energy was 66.2 J. Vertebroplasty with different cements could sustain vertebral height. The average filling volume of bone cement in 3 groups was 4.35 ml (CSC), 3.72 ml (CPC) and 3.95 ml (PMMA), respectively, and there was no statistically significant difference among them (P larger than 0.05). Vertebroplasty with PMMA completely restored strength (116%) and stiffness (105%). CSC or CPC partly recovered vertebral strength and stiffness. However, greater strength restoration was got with CSC (1659 N) as compared with CPC (1011N, P less than 0.01). Regarding stiffness, differences between CSC (140 N/mm+/-40 N/mm)and the other two bone cements (CPC:148 N/mm+/-33 N/mm, PMMA:236 N/mm+/-97 N/mm) were not significant (P larger than 0.05). CONCLUSIONS: For a burst-fracture of calf spine, use of CSC for vertebroplasty yields similar vertebral stiffness as compared with PMMA or CPC. Although augmentation with CSC partly obtains the normal strength, this treatment still can be applied in thoracolumbar burst fractures with other instrumental devices in light of its bioactivation.

Analysis of the Osteogenic Effects of Biomaterials Using Numerical Simulation.

We describe the development of an optimization algorithm for determining the effects of different properties of implanted biomaterials on bone growth, based on the finite element method and bone self-optimization theory. The rate of osteogenesis and the bone density distribution of the implanted biomaterials were quantitatively analyzed. Using the proposed algorithm, a femur with implanted biodegradable biomaterials was simulated, and the osteogenic effects of different materials were measured. Simulation experiments mainly considered variations in the elastic modulus (20-3000 MPa) and degradation period (10, 20, and 30 days) for the implanted biodegradable biomaterials. Based on our algorithm, the osteogenic effects of the materials were optimal when the elastic modulus was 1000 MPa and the degradation period was 20 days. The simulation results for the metaphyseal bone of the left femur were compared with micro-CT images from rats with defective femurs, which demonstrated the effectiveness of the algorithm. The proposed method was effective for optimization of the bone structure and is expected to have applications in matching appropriate bones and biomaterials. These results provide important insights into the development of implanted biomaterials for both clinical medicine and materials science.

Deterioration of the mechanical properties of calcium phosphate cements with Poly (γ-glutamic acid) and its strontium salt after in vitro degradation.

The mechanical reliability of calcium phosphate cements has restricted their clinical application in load-bearing locations. Although their mechanical strength can be improved using a variety of strategies, their fatigue properties are still unclear, especially after degradation. The evolutions of uniaxial compressive properties and the fatigue behavior of calcium phosphate cements incorporating poly (γ-glutamic acid) and its strontium salt after different in vitro degradation times were investigated in the present study. Compressive strength decreased from the 61.2±5.4MPa of the original specimen, to 51.1±4.4, 42.2±3.8, 36.8±2.4 and 28.9±3.2MPa following degradation for one, two, three and four weeks, respectively. Fatigue life under same loading condition also decreased with increasing degradation time. The original specimens remained intact for one million cycles (run-out) under a maximum stress of 30MPa. After degradation for one to four weeks, the specimens were able to withstand maximum stress of 20, 15, 10 and 10MPa, respectively until run-out. Defect volume fraction within the specimens increased from 0.19±0.021% of the original specimen to 0.60±0.19%, 1.09±0.04%, 2.68±0.64% and 7.18±0.34% at degradation time of one, two, three and four weeks, respectively. Therefore, we can infer that the primary cause of the deterioration of the mechanical properties was an increasing in micro defects induced by degradation, which promoted crack initiation and propagation, accelerating the final mechanical failure of the bone cement. This study provided the data required for enhancing the mechanical reliability of the calcium phosphate cements after different degradation times, which will be significant for the modification of load-bearing biodegradable bone cements to match clinical application.

Promoting spinal fusions by biomineralized silk fibroin films seeded with bone marrow stromal cells: An in vivo animal study.

OBJECTIVES: To prepare a biomineralized nano silk fibroin film seeded with bone marrow stromal cells (BMSCs), and to evaluate its performance in spinal fusion. METHODS: The silk fibroin film was mineralized in a modified, simulated body fluid, seeded with BMSCs, and evaluated in a rat model of posterolateral lumbar fusion, compared with pure silk fibroin, silk fibroin/bone marrow stromal cells, mineralized silk fibroin, mineralized silk fibroin/bone marrow stromal cells, iliac crest bone, and no graft. After 12 weeks, all rats were sacrificed and underwent manual palpation, micro-CT scanning, biomechanical testing, and histology. RESULTS: The infrared spectrum, X-ray diffraction, and scanning electron microscopy demonstrated deposition of mineral layers on the silk fibroin film surface. The fusion rate, bone volume, relative strength and stiffness, and histological score of the mineralized silk fibroin/bone marrow stromal cells were slightly lower than the autograft, but without any significant difference (p > 0.05). In addition, the mineralized silk fibroin was significantly greater in most parameters than the silk fibroin/bone marrow stromal cells (p < 0.05). CONCLUSION: The mineralized silk fibroin resembles natural bone structurally, and the cellular and mineral layers of silk fibroin are both critical to bone regeneration. The ability to promote spinal fusion is enhanced when the mineralized silk fibroin is seeded with bone marrow stromal cells.

N-Acetyl cysteine (NAC)-mediated reinforcement of alpha-tricalcium phosphate/silk fibroin (α-TCP/SF) cement.

Calcium phosphate cements (CPCs) are popular bone filling materials and drug carriers. However poor mechanical properties and lack of osteoinduction restrict their clinical applications. Recent studies suggested the osteogenic properties of NAC. In our study, we incorporated NAC with α-TCP/SF. We found that the compressive strength of α-TCP/SF-NAC composites increased with increase in NAC concentration, possibly due to complex three-dimensional networks of SF induced by NAC, which was large and chemically heterogeneous and induced compact oriented growth of HA crystals. However the setting time increased slightly with the addition of NAC, due to the ruptured disulfide bonds in SF. The α-TCP/SF-NAC composites also showed decent biocompatibility in vitro. As a result, these composites hold great potential as bone filling materials for clinical applications, including minimally invasive surgeries.

Percutaneous Kyphoplasty for Kummell Disease with Severe Spinal Canal Stenosis.

BACKGROUND: Percutaneous kyphoplasty (PKP) has been proven as an effective, minimally invasive procedure for the treatment of Kummell's disease in the early stages. However, a risk of cement leakage and further neurological damage remains during and after PKP, especially in chronic osteoporotic stage III Kummell's disease with severe spinal canal stenosis. OBJECTIVE: To evaluate the feasibility and efficacy of PKP for the treatment of chronic osteoporotic stage III Kummell's disease with severe spinal canal stenosis. STUDY DESIGN: A retrospective evaluation of postoperative radiographs. SETTING: Pain management clinic. METHODS: A retrospective study was performed on 9 patients with 11 levels managed with PKP for chronic osteoporotic stage III Kummell's disease with severe spinal canal stenosis. Clinical and radiological outcomes were assessed. RESULTS: Substantial pain relief was attained in all the patients. Both visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores improved significantly from pre- to post-operation (P < 0.05), and remained unchanged at every follow-up. No neurological deterioration was found. Postoperatively, the anterior and midline vertebral body heights were significantly corrected (P < 0.05), and were sustained at the final follow-up. Similar results were seen in the correction of kyphotic angle. Neither cement leakage into the spinal canal nor further dislodging of the posterior vertebral fragments occurred. Two cases experienced subsequent fractures with one having a second PKP and the other being treated conservatively. LIMITATIONS: Retrospective study of 9 cases with 11 levels due partly to the rarity of the disorder. CONCLUSIONS: PKP is an effective, minimally invasive procedure for the treatment of chronic osteoporotic stage III Kummell's disease with severe spinal stenosis, leading to a significant relief of symptoms and improvement of functional status. INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board.

[The contrast study between single and double balloon bilateral dilatation of kyphoplasty].

OBJECTIVE: To contrast single and double balloon-inflated kyphoplasty for vertebral compression fractures (VCFs) and evaluate its clinical efficacy. METHODS: From May 2000 to May 2004, 90 consecutive procedures were performed in 58 patients who suffered from painful vertebral compression fractures, transferring tumour and angioma. Ninety vertebrae were inflated while 62 as A group were double balloon and 28 as B group were single balloon, fracture reduction and bone cement augmentation. Preoperative and postoperative symptom levels, variables, complications were recorded and the vertebral height and Cobb angle were measured and analyzed. RESULTS: All patients' pain was alleviated or disappeared without syndrome, and the vertebral height and Cobb angle of both groups were improved. The average recovery rate was 72.6% (22.9% approximately 100%), Cobb angle from 17.9 degrees (3.1 degrees approximately 31.6 degrees ) were corrected to 9.6 degrees (0.6 degrees approximately 28.2 degrees ), the average angle was 8.7 degrees (0.3 degrees approximately 27.2 degrees ), and the contrast between preoperative and postoperative showed obvious differences (P <0.001). The average recovery rate of A group was 77.6% (55.3% approximately 100%), B group was 64.3% (22.9% approximately 100%). The average postoperative Cobb angle of A group was 9.9 degrees (0.3 degrees approximately 27.2 degrees ), B group was 8.6 degrees (0.6 degrees approximately 19.8 degrees ) (P >0.05). CONCLUSIONS: As a promising minimally invasive surgery, balloon kyphoplasty can provide early relief of pain and improve the function as well as spinal alignment in treatment of painful compression fracture owing to recovering the vertebral height and Cobb angle of the vertebral body. Single balloon-inflated kyphoplasty can improve VCFs as double balloon.

Pulmonary cement embolism associated with percutaneous vertebroplasty or kyphoplasty: a systematic review.

Therapeutic vertebral cement augmentation for the treatment of painful skeletal diseases, although widely applied for more than several decades, still has not thoroughly resolve the problem of cement extravasation. Based on a review of literature published, the present study was to provide a systematic review of the current understanding of pulmonary cement embolism (PCE) associated with percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP), and to summarize the incidence, clinical features, prophylaxis and therapeutic management of PCE after vertebral cement reinforcement. The reported incidence of PCE ranges widely, from 2.1% to 26%. Asymptomatic PCE is a common condition without permanent clinical sequelae. Nevertheless, it is emergent once a symptomatic PCE is presented. Close attention and effective pre-measures should be taken to avoid this catastrophic complication.

Evaluation of an injectable silk fibroin enhanced calcium phosphate cement loaded with human recombinant bone morphogenetic protein-2 in ovine lumbar interbody fusion.

The objective of this study was to investigate the efficacy of an injectable calcium phosphate cement/silk fibroin/human recombinant bone morphogenetic protein-2 composite (CPC/SF/rhBMP-2) in an ovine interbody fusion model. Twenty-four mature sheep underwent anterior lumbar interbody fusion at the levels of L1/2, L3/4, and L5/6 with random implantation of CPC/SF, CPC/rhBMP-2, CPC/SF/rhBMP-2, or autogenous iliac bone. After the sheep were sacrificed, the fusion segments were evaluated by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. The fusion rates of CPC/SF/rhBMP-2 were 55.56% and 77.78% at 6 and 12 months, respectively. The fusion was superior to all the biomaterial grafts in stiffness, and reached the same stiffness as the autograft at 12 months. The new bone formation was less than autograft at 6 months, but similar with that at 12 months. However, the ceramic residue volume of CPC/SF/rhBMP-2 was significantly decreased compared with CPC/SF and CPC/rhBMP-2 at both times. The results indicated that CPC/SF/rhBMP-2 composite had excellent osteoconduction and osteoinduction, and balanced degradation and osteogenesis.

Surgical treatment of chronic C1-C2 dislocation with absence of odontoid process using C1 hooks with C2 pedicle screws: a case report and review of literature.

STUDY DESIGN: A case report. OBJECTIVE.: A rare case of chronic C1-C2 dislocation with absence of odontoid process that underwent posterior C1-C2 arthrodesis using C1 hooks and C2 pedicle screws. SUMMARY OF BACKGROUND DATA: C1-C2 dislocation is a rare but fatal upper cervical injury. To date, there have been many reports about C1-C2 dislocation of traumatic origin. However, very few C1-C2 dislocation cases of congenital odontoid deformities had been presented. This was particularly the case when the odontoid process was absent. METHODS: Plain radiograph of his cervical spine revealed a C1-C2 dislocation, and subsequent computed tomographic scan as well as magnetic resonance imaging (MRI) detected absence of odontoid process and cord compression. Upon admission, the patient was placed on skull traction and the weight increased from 3.5 to 5.5 kg. After 10 days of traction, reduction was achieved radiographically and the posterior C1-C2 arthrodesis by C1 hooks with C2 pedicle screws was performed. RESULTS: After surgery, the patient showed significant improvement in gait function despite slightly raised muscle tone in his lower extremities. Four-month postoperative radiographs indicated restoration of C1-C2 alignment and bony fusion. No residual cord compression was present. CONCLUSION: In clinical evaluation of patients who present with neck pain and limited cervical motion with or without neurologic deficits, C1-C2 dislocation should be considered. If the patient has no history of trauma or infection, congenital C1-C2 deformity, especially odontoid malformation, has to be included as a possible factor. Once the diagnosis is confirmed, posterior C1-C2 arthrodesis may become necessary for stabilizing C1-C2 and preventing it from deterioration or new development of neurologic symptoms.