Objective To review the progress of the pedicle screw augmentation technique by bone cement. Methods Recent literature about the pedicle screw augmentation technique by bone cement was reviewed and analysed. The characters were summarized. Results Pedicle augmentation technique includes the augmentation of ordinary solid pedicle screw and hollow pedicle screw. Both types could increase the fixation strength and gain satisfactory clinical results. Bone cement leakage had a certain incidence rate, but most of cases were asymptom. Conclusion Bone cement augmentation of pedicle screw is an effective and safe internal fixation for poor bone condition.
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.
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 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.
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 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.
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.
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 evaluate the effect of bone cement filling on articular cartilage injury after curettage of giant cell tumor around the knee. MethodsFifty-three patients with giant cell tumor who accorded with the inclusion criteria were treated between January 2000 and December 2011, and the cl inical data were retrospectively analyzed. There were 30 males and 23 females, aged 16-69 years (mean, 34.2 years). The lesion located at the distal femur in 28 cases and at the proximal tibia in 25 cases. According to Campanacci grade, there were 6 patients at grade I, 38 at grade Ⅱ, and 9 at grade Ⅲ. Of 53 patients, 42 underwent curettage followed by bone cement fill ing, and 11 received curettage followed by bone grafts in the subchondral bony area and bone cement fill ing. Two groups were divided according to whether secondary osteoarthritis occurred or not during postoperative follow-up. The gender, age, lesion site, the subchondral residual bone thickness, tumor cross section, preoperative Campanacci grade, subchondral bone graft, and Enneking function score were compared between 2 groups, and multivariate logistic regression analysis was done. ResultsAll incisions healed by first intention. The average follow-up time was 65 months (range, 23-158 months). Of 53 cases, 37 (69.8%) had no osteoarthritis, and 16 (30.2%) had secondary osteoarthritis. Three cases (5.7%) recurred during the follow-up period. Univariate logistic regression analysis showed no significant difference in gender, age, lesion site, and Campanacci grade between 2 groups (P>0.1); difference was significant in the subchondral residual bone thickness, tumor cross section, Enneking function score, and subchondral bone graft (P<0.1). The multivariate logistic regression analysis showed that the decreased subchondral residual bone thickness, the increased tumor cross section, and no subchondral bone graft are the risk factors of postoperative secondary osteoarthritis (P<0.05). ConclusionCurettage of giant cell tumor around the knee followed by bone cement filling can increase the damage of cartilage, and subchondral bone graft can delay or reduce cartilage injury.
ObjectiveTo explore the effectiveness of induced membrane technique of hollow porous antibioticimpregnated bone cement forming in vitro and lavage in vivo for the treatment of osteomyelitis. MethodsBetween January 2010 and March 2014, 14 cases of osteomyelitis were treated by induced membrane technique of hollow porous antibiotic-impregnated bone cement forming in vitro and lavage in vivo after debridement at the first stage, then the bone cement with bone graft was replaced during the induced membrane after infection was controlled at the second stage. The time from first to second stage operation was 8-12 weeks (average, 10.2 weeks). There were 11 males and 3 females, aged 18 to 69 years (average, 39.2 years). According to Cierny-Mader classification of osteomyelitis, 2 cases were rated as intramedullary type, 5 cases as limited type, and 7 cases as diffusing type. The course of osteomyelitis was 3 months to 20 years, averaged 1.9 years. The healing of bone defect and the functionary recovery of adjacent joint were evaluated according to Paley's method. ResultsDebridement was performed for two times in 1 case, and for one time in 13 cases for control of bone infection at the first stage. All incisions healed by first intention after second stage. All patients were followed up 15-48 months (average, 13.4 months), with no recurrence of infection. All bone defects healed, and the clinical healing time was 4-5 months (average, 4.4 months). The results of bone healing grade were excellent in all cases at 1 year after operation; the functional recovery of adjacent joint at last follow-up was excellent in 4 cases, good in 8 cases, and fair in 2 cases, and the excellent and good rate was 85.7%. ConclusionInduced membrane technique of hollow porous antibiotic-impregnated bone cement forming in vitro and lavage in vivo for treatment of osteomyelitis has the advantages of high rate of elution of antibiotics, ease of lavage of medullary cavity, and no damage to induced membrane and bony interface between bone and bone cement when removing cement, it is effective for control of bone infection and repair of bone defect.