Objective To evaluate the biomechanicalproperties and structuralcharacteristics of various composites of partially decalcified allogenic bone matrix gelatin and bone cement at different ratios. Methods According to Urist method, partially decalcified allogenic bone matrix gelatin was prepared and mixedwith bone cement at different ratios of 0, 400, 500, and 600mg/g. Then the comparisons of these composites were performed in microstructure, ultimate compression strength and ultimate bending strength properties. Results The electronic microscope showed that the bone particles and bone cement were distributed evenly in the composite, irregularly connecting by multiple points; with the increase ofbone particles and decrease of bone cement in the composite, there were more and more natural crevices, varying from 100 μm to 400 μm in width, in the biomaterials. Of all the composites with the ratios of 0, 400,500, and 600 mg/g, the measurements of ultimate compression strength were (71.7±2.0) MPa, (46.9±3.3) MPa, (39.8±4.1) MPa, and (32.2±3.4) MPa, respectively; and the measurements ofultimate bending strength were (65.0±3.4) MPa, (38.2±4.0) MPa, (33.1±4.3) MPa and (25.3±4.6) MPa, respectively. Conclusion The compositeof partially decalcified allogenic bone matrix gelatin and bone cement has a good biomechanical property and could be easily fabricated and re-shaped, which make it available to be used clinically as an idea bone graft biomaterial.
ObjectiveTo explore the safety and effectiveness of graded infusion of bone cement in the unipedicular percutaneous vertebroplasty (PVP) for Kummell's disease. MethodsEighteen patients with Kummell's disease were treated by unipedicular PVP with graded infusion of bone cement between January 2012 and January 2014. Of 18 cases, 6 were male and 12 were female, aged from 65 to 88 years (mean, 75 years), with a disease duration from 3 to 32 months (mean, 11.6 months). The bone mineral density was measured by dual-energy X-ray absorptiometry; the T value ranged from -4.0 to -2.8 (mean, -3.4). Affected segments included T11 in 3 cases, T12 in 10 cases, L1 in 3 cases, and L2 in 2 cases. X-ray films were taken after operation to observe bone cement leakage and anterior height changes of affected vertebrae. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to assess pain status and functional activity. ResultsAll cases underwent smoothly unipedicular PVP and were followed up 12-26 months (mean, 14 months). Cement leakage occurred in 4 patients, including 1 case of anterior paravertebral soft tissue leakage, 2 cases of intervertebral disc leakage, and 1 case of canal venous leakage, but there was no other complications. The anterior height of affected vertebrae were significantly improved (P<0.05) from 29.1%±6.7% at preoperation to 68.1%±7.3% at 3 days after operation and 67.8%±5.9% at last follow-up; the VAS scores were significantly decreased (P<0.05) from 8.11±1.32 at preoperation to 2.14±0.78 at 3 days and 1.97± 0.50 at last follow-up; and ODI were significantly decreased (P<0.05) from 84.6%±8.5% to 24.1%±9.7% and 23.8%±10.2%; but no significant difference was found between at 3 days and at last follow-up (P>0.05). ConclusionGraded infusion of bone cement in unipedicular PVP is a safe and effective procedure for Kummell's disease and this technique could decrease the incidence of bone cement leakage.
Objective To investigate the causes and preventive methods of the bone cement leakage in percutaneous kyphoplasty (PKP) for osteoporotic vertebral body compression fracture (OVCF). Methods From April 2003 to November 2007, 116 patients with OVCF were treated with PKP, including 57 males and 59 females aged 65-92 years old (average 67.7 years old). All the patients suffered from trauma and the course of disease was 1-14 days (average 5.7 days). There were 159compressed and fractured vertebral bodies, including one vertebral body in 83 cases, two vertebral bodies in 24 cases, three vertebral bodies in 8 cases, and four vertebral bodies in 1 case. The diagnosis of OVCF was confirmed by imaging examination before operation. All the patients had intact posterior vertebral walls, without symptoms of spinal and nerve root injury. During operation, 3.5-7.1 mL bone cement (average 4.8 mL) was injected into single vertebral body. Results The operation time was 30-90 minutes (average 48 minutes). Obvious pain rel ief was achieved in all the patients after operation. X-rays examination 2 days after operation revealed that the injured vertebral bodies were well replaced without further compression and deformation, and the bone cement was evenly distributed. Fourteen vertebral bodies had bone cement leakage (4 of anterior leakage, 4 of lateral leakage, 3 of posterior leakage, 2 of intervertebral leakage, 1 of spinal canal leakage). The reason for the bone cement leakage included the individual ity of patient, the standardization of manipulation and the time of injecting bone cement. During the follow-up period of 12-30 months (average 24 months), all the patients got their normal l ife back, without pain, operation-induced spinal canal stenosis, obvious height loss of injured vertebral bodies and other compl ications. Conclusion For OVCF, PKP is a mini-invasive, effective and safe procedure that provides pain rel ief and stabil ization of spinal stabil ity. The occurrence of bone cement leakages can be reduced by choosing the suitable case, improving the viscosity of bone cement, injecting the proper amount of bone cement and precise location during operation.
ObjectiveThe research progress of new multifunctional bone cement in bone tumor therapy in recent years was reviewed, in order to provide help for the future research of anti-tumor bone cement. Methods The related literature on the treatment of bone tumors with new multifunctional bone cement at home and abroad in recent years was extensively reviewed and summarized. Results The new multifunctional bone cements include those with the functions of photothermotherapy, magnetic thermotherapy, chemoradiotherapy, and antibacterial after operation, which are discussed from the aspects of anti-tumor, drug controlled release, and cytotoxicity. Controlled drug release has been achieved in multifunctional bone cements by adjusting heat and pH or incorporating particles such as chitosan oligosaccharides and γ-cyclodextrin. At present, multifunctional bone cement with hyperthermia, radiotherapy, and chemotherapy has effectively inhibited the local recurrence and distant metastasis of bone tumors. Broadening the application of bone cement for photothermal and magnetic thermal therapy to deeper bone tumors, investigating more precise controlled release of drug-loaded bone cement, and introducing nanoparticles with both thermal conversion and intrinsic enzymatic activities into bone cement for synergistic anti-tumor therapy are promising research directions. ConclusionThe new multifunctional bone cement inhibits bone tumor cells, promotes new bone formation in bone defects, and prevents incision infection after tumor resection. Certain progress has been made in anti-tumor, antibacterial, drug-controlled release, and reduction of cytotoxicity. Expanding the deeper application range of the new multifunctional bone cement, verifying the safety in clinical application, and focusing on the individualized treatment of the new multifunctional bone cement are the problems that need to be solved in the future.
Objective To study the methods of promoting the injectability of calcium phosphate cement.Methods Evaluation methods of bone cements, injectability and methods of promoting injectability were reviewed by extensive investigating of latest literatures.Results It was very important to improve the injectability of calcium phosphate cement. Commonly used methods to evaluate the injectability included testing injectability coefficient, pushing force and injection pressure.Injectability of calcium phosphatecement were promoted by increasing liquid/solid ratio, modulating the componentof solid or liquid phase, and adding various additives.Conclusion Promoting the injectability of calcium phosphate cement is the clinical requirement.
ObjectiveTo determine the feasibility of fabricating molds using a three-dimensional (3D) printer for producing customized bone cement for repairing bone defect. MethodsBetween February 2015 and March 2016, 13 patients with bone defects were treated. There were 9 males and 4 females with an average age of 38.4 years (range, 20-58 years), including 7 cases of chronic osteomyelitis, 3 cases of bone tuberculosis, 2 cases of bone tumor, and 1 case of ischemic necrosis. The defect located at the humerus in 3 cases, at the femur in 4 cases, and at the tibia in 6 cases. The defect ranged from 4.5 to 8.9 cm in length (mean, 6.7 cm). Before operation, Mimics10.01 software was used to design cement prosthesis, 3-matic software to design shaping module which was printed by 3D technology. After removal of the lesion bone during operation, bone cement was filled into the shaping module to prepare bone cement prosthesis for repairing defect. ResultsThe measurement result from Image J software showed that the match index of interface between the mirror restored digital and bone interface was 95.1%-97.4% (mean, 96.3%); the match index of interface between bone cement prosthesis and bone interface was 91.2%-94.7% (mean, 93.2%). It was one time success during separation between formed bone cement and shaping module without any shatter or fall off. All incisions healed by first intention. The cases were followed up 5-17 months (mean, 9.4 months). X-ray films and CT scans showed good position of bone cement prosthesis without any fracture; no peripheral fracture occurred. Conclusion3D printing customized bone cement shaping module can shorten the operation time, and customized bone cement prothesis has good match with bone interface, so it can avoid further adjustment and accord with the biomechanical rules of surgical site.
Objective To investigate the diagnosis and effectiveness of improved percutaneous kyphoplasty (PKP) for patients with thoracolumbar metastatic tumors, who could not tolerate anesthesia and open operation. Methods Between September 2009 and September 2010, 16 patients with thoracolumbar metastatic tumors underwent improved PKP. Of 16 patients, 7 were male and 9 were female with an average age of 64.5 years (range, 60-73 years). All patients had vertebralmetastasis tumor. The disease duration was 3-6 months with an average of 4 months. The visual analogue scale (VAS) score was 8.9 ± 0.8. No spinal cord compression and nerve root compression was observed. The involved vertebrae included T7 in 1 case, T8 in 1, T12 in 1, L2 in 2, L3 in 2, L4 in 3, T1, 2 in 1, T3, 4 in 1, T7, 8 in 1, T11, 12 in 1, T7-L1 in 1, and T12-L4 in 1. Nine patients had vertebral compression fracture with a vertebral compression rate below 75%. Results All patients were successfully performed PKP. There was no serious adverse reactions in cardiopulmonary and brain vascular systems and no perioperative death. The biopsy results showed that all were metastatic adenocarcinoma. All patients were followed up 9-18 months mean, 14 months). Complete pain rel ief was achieved in 14 cases and partial rel ief in 2 cases 6 months after operation according to World Health Organization criterion, with a pain-rel ief rate of 87.5%. The VAS score was 1.8 ± 0.6 at 6 months postoperatively, showing significant difference when compared with the preoperative score (P lt; 0.05). Two patients had cement leakages in 3 vertebrae with no symptoms at 6 months postoperatively. During follow-up, 12 patients died and the others survived with tumor. Conclusion For patients with thoracolumbar metastatic tumors who can not tolerate anesthesia and open operation, improved PKP has the advantages such as minimal invasion, high diagnostic rate, and early improvement of pain in the biopsy and treatment. It can improve patient’s qual ity of l ife in the combination of radiotherapy or chemotherapy.
Objective To investigate the clinical therapeutic effects on malignant spinal tumors treated by percutaneous vertebroplasty(PVP) under the guidance of the digital subtraction angiography(DSA). Methods A retrospective analysis was performed in 196 patients (99 males and 97 females, aged 23-85 years, averaged 60.4 years) with malignant spinal tumors, who underwent the PVP treatment combined with standard chemotherapy and other comprehensive treatment from January 2002 to January 2005. The malignant spinal tumors had their origins as follows: lung cancer (66 cases), breast cancer (55 cases), liver cancer (19 cases), colon cancer (15 cases), stomach cancer (9 cases), prostate cancer (12 cases), multiple myeloma (16 cases), and malignant lymphoma of the spine (4 cases).The metastatic tumors involved the cervical vertebra (32 cases), thoracic vertebra (93 cases), lumbar vertebra (71 cases), and spinal column, including 1 vertebral segment (135 cases), 2 segments (50 cases), and more than 3 segments (11 cases). During the follow-up survey, changes in the visual analogue pain scale(VAS) and changes in the X-ray measurements of the average anterior height, midline height, and posterior height of the diseased vertebra were observed. Results The follow-up for 6 months to 3 years revealed that the percutaneous vertebroplasty on279 vertebral segments had a success with an operational success rate of 100%. Bone cement was injected into the lesions 1-9 ml per segment of the spine. The postoperative X-ray and CT evaluations revealed that spinal stabilization was obtained in all the patients. After operation, 193（98.5%）patients had an obvious decrease or disappearance of the pain in the lower back, and only 3 (1.5%) patients had no obvious improvement in the pain. There was a significant statist-ical difference in the VAS scores between before operation and after operation (Plt;0.05). There were also significant statistical differences in the average anterior height of the diseased vertebra between before operation and after operation（15.71±2.80 mm vs 16.61±3.01 mm）, in the midline height（13.65±2.93 mm vs 14.52±2.72 mm）, and in the posterior height（23.67±2.81 mm vs 23.70±3.13 mm,Plt;0.05). The patients with lung or liver cancer had a mean survival time of 9 monthsafter PVP; the patients with breast cancer, stomach cancer, prostate cancer, lymphoma, or other metastatic tumors had a mean survival time of 18 months. The patients with multiple myeloma had a mean survival time of 27 months. The differences were statistically different (Plt;0.01). Conclusion PVP under the guidance of the DSA is an easier operation witha small wound and few complications. It can effectively alleviate the patient’s pain due to metastatic spinal tumor, stabilize the spine, improve the patient’s quality of life, and reduce the incidence of paraplegia.
To investigate the effects of augmentation with bone cement on the biomechanics of the dynamic hip screw (DHS) fixation in the intertrochanteric fracture specimen that has a normal bone density.MethodsTwentyfour matched pairs of the embalmed male upper femora (48sides) were used to make the specimens of the intertrochanteric fracture of Type A2. All the specimens were fixed with DHS. The right femur specimen from each pair was fixed by augmentation with DHS (the augmentation group) and the left femur specimen was fixed with the conventional fixation (the control group). Thebiomechanical tests on the bending stiffness and the torsional stiffness were performed with the servohydraulic testing machine in the two groups.ResultsThe maximum load and the maximum torque were 3 852.160 2±143.603 1 N and 15.5±2.6 Nm in the augmentation group and 3 702.966 7±133.860 1 N and 14.7±3.4 Nm in the control group. There was no significant difference in the biomechanical effects between the two groups (P＞0.05). Conclusion The augmenting fixation with bone cement in the intertrochanteric fracture specimen with a normal bone density has no significant effect on the strength of the DHS augmentation or on the overall stability of the fractured bone.
Objective To summarize the progress of Masquelet technique to repair bone defect. Methods The recent literature concerning the application of Masquelet technique to repair bone defect was extensively reviewed and summarized. Results Masquelet technique involves a two-step procedure. First, bone cement is used to fill the bone defect after a thorough debridement, and an induced membrane structure surrounding the spacer formed; then the bone cement is removed after 6-8 weeks, and rich cancellous bone is implanted into the induced membrane. Massive cortical bone defect is repaired by new bone forming and consolidation. Experiments show that the induced membrane has vascular system and is also rich in vascular endothelial growth factor, transforming growth factor β1, bone morphogenetic protein 2, and bone progenitor cells, so it has osteoinductive property; satisfactory results have been achieved in clinical application of almost all parts of defects, various types of bone defect and massive defect up to 25 cm long. Compared with other repair methods, Masquelet technique has the advantages of reliable effect, easy to operate, few complications, low requirements for recipient site, and wide application. Conclusion Masquelet technique is an effective method to repair bone defect and is suitable for various types of bone defect, especially for bone defects caused by infection and tumor resection.