Objective To investigate the biomechanical properties of porous bioactive bone cement (PBC) in vivo and to observe the degradation of PBC and new bone formation histologically. Methods According to the weight percentage (W/ W, %) of polymethylmethacrylate (PMMA) to bioglass to chitosan, 3 kinds of PBS powders were obtained: PBC I (50 ︰ 40 ︰ 10), PBC II (40 ︰ 50 ︰ 10), and PBC III (30 ︰ 60 ︰ 10). The bilateral femoral condylar defect model (4 mm in diameter and 10 mm in depth) was established in 32 10-month-old New Zealand white rabbits (male or female, weighing 4.0-4.5 kg), which were randomly divided into 4 groups (n=8); pure PMMA (group A), PBC I (group B), PBC II (group C), and PBC III (group D) were implanted in the bilateral femoral condylar defects, respectively. Gross observation were done after operation. X-ray films were taken after 1 week. At 3 and 6 months after operation, the bone cement specimens were harvested for mechanical test and histological examination. Four kinds of unplanted cement were also used for biomechanical test as control. Results All rabbits survived to the end of experiment. The X-ray films revealed the location of bone cement was at the right position after 1 week. Before implantation, at 3 months and 6 months after operation, the compressive strength and elastic modulus of groups C and D decreased significantly when compared with those of group A (P lt; 0.05), but no significant difference was found between groups C and D (P gt; 0.05); the compressive strength at each time point and elastic modulus at 3 and 6 months of group B decreased significantly when compared with those of group A (P lt; 0.05). Before implantation and at 3 months after operation, the compressive strength and elastic modulus of groups C and D decreased significantly when compared with those of group B (P lt; 0.05); at 6 months after operation, the compressive strength of group C and the elastic modulus of group D were significantly lower than those of group B (P lt; 0.05). The compressive strength and elastic modulus at 3 and 6 months after operation significantly decreased when compared with those before implantation in groups B, C, and D (P lt; 0.05), but no significant difference was found in group A (P lt; 0.05). At 3 months after operation, histological observation showed that a fibrous tissue layer formed between the PMMA cement and bone in group A, while chitosan particles degraded with different levels in groups B, C, and D, especially in group D. At 6 months after operation, chitosan particles partly degraded in groups B, C, and D with an amount of new bone ingrowth, and groups C and D was better than group B in bone growth; group A had no obvious change. Quantitative analysis results showed that the bone tissue percentage was gradually increased in the group A to group D, and the bone tissue percentage at 6 months after operation was significantly higher than that at 3 months within the group. Conclusion According to the weight percentage (W/W, %) of PMMA to bioglass to chitosan, PBCs made by the composition of 40 ︰ 50 ︰ 10 and 30 ︰ 60 ︰ 10 have better biocompatibility and biomechanical properties than PMMA cement, it may reduce the fracture risk of the adjacent vertebrae after vertebroplasty.
Objective To evaluate the effectiveness of Confidence high viscosity bone cement system and postural reduction in treating acute severe osteoporotic vertebral compression fracture (OVCF). Methods Between June 2004 and June2009, 34 patients with acute severe OVCF were treated with Confidence high viscosity bone cement system and postural reduction. There were 14 males and 20 females with an average age of 72.6 years (range, 62-88 years). All patients had single thoracolumbar fracture, including 4 cases of T11, 10 of T12, 15 of L1, 4 of L2, and 1 of L3. The bone density measurement showed that T value was less than —2.5. The time from injury to admission was 2-72 hours. All cases were treated with postural reduction preoperatively. The time of reduction in over-extending position was 7-14 days. All patients were injected unilaterally. The injected volume of high viscosity bone cement was 2-6 mL (mean, 3.2 mL). Results Cement leakage was found in 3 cases (8.8%) during operation, including leakage into intervertebral space in 2 cases and into adjacent paravertebral soft tissue in 1 case. No cl inical symptom was observed and no treatment was pearformed. No pulmonary embolism, infection, nerve injury, or other complications occurred in all patients. All patients were followed up 12-38 months (mean, 18.5 months). Postoperatively, complete pain rel ief was achievedin 31 cases and partial pain refief in 3 cases; no re-fracture or loosening at the interface occurred. At 3 days after operation and last follow-up, the anterior and middle vertebral column height, Cobb angle, and visual analogue scale (VAS) score were improved significantly when compared with those before operation (P lt; 0.05)；and there was no significant difference between 3 days and last follow-up (P gt; 0.05). Conclusion Confidence high viscosity bone cement system and postural reduction can be employed safely in treating acute severe OVCF, which has many merits of high viscosity, long time for injection, and easy-to-control directionally.
ObjectiveTo investigate the risk factors of cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF). MethodsBetween March 2011 and March 2012, 98 patients with single level OVCF were treated by PVP, and the cl inical data were analyzed retrospectively. There were 13 males and 85 females, with a mean age of 77.2 years (range, 54-95 years). The mean disease duration was 43 days (range, 15-120 days), and the mean T score of bone mineral density (BMD) was-3.8 (range, -6.7--2.5). Bilateral transpedicular approach was used in all the patients. The patients were divided into cement leakage group and no cement leakage group by occurrence of cement leakage based on postoperative CT. Single factor analysis was used to analyze the difference between 2 groups in T score of BMD, operative level, preoperative anterior compression degree of operative vertebrae, preoperative middle compression degree of operative vertebrae, preoperative sagittal Cobb angle of operative vertebrae, preoperative vertebral body wall incompetence, cement volume, and volume ratio of intravertebral bone cement to vertebral body. All relevant factors were introduced to logistic regression analysis to analyze the risk factors of cement leakage. ResultsAll procedures were performed successfully. The mean operation time was 40 minutes (range, 30-50 minutes), and the mean volume ratio of intravertebral bone cement to vertebral body was 24.88% (range, 7.84%-38.99%). Back pain was alleviated significantly in all the patients postoperatively. All patients were followed up with a mean time of 8 months (range, 6-12 months). Cement leakage occurred in 49 patients. Single factor analysis showed that there were significant differences in the volume ratio of intravertebral bone cement to vertebral body and preoperative vertebral body wall incompetence between 2 groups (P < 0.05), while no significant difference in T score of BMD, operative level, preoperative anterior compression degree of operative vertebrae, preoperative middle compression degree of operative vertebrae, preoperative sagittal Cobb angle of operative vertebrae, and cement volume (P > 0.05). The logistic regression analysis showed that the volume ratio of intravertebral bone cement to vertebral body (P < 0.05) and vertebral body wall incompetence (P < 0.05) were the risk factors for occurrence of cement leakage. ConclusionThe volume ratio of intravertebral bone cement to vertebral body and vertebral body wall incompetence are risk factors of cement leakage in PVP for OVCF. Cement leakage is easy to occur in operative level with vertebral body wall incompetence and high volume ratio of intravertebral bone cement to vertebral body.
ObjectiveTo investigate the classification and treatment strategies of symptomatic severe osteoporotic vertebral fracture and collapse. MethodsBetween August 2010 and January 2014, 42 patients with symptomatic severe osteoporotic vertebral fracture and collapse were treated, and the clinical data were retrospectively analyzed. According to clinical symptom and imaging materials, 23 cases were classified as type I (local pain, limitation of motion, no neurological symptom, and no obvious deformity), 12 cases as type II (slight neurological symptom and kyphotic Cobb angle ≤ 30°), and 7 cases as type III (severe neurological symptom and kyphotic Cobb angle <30°). In 23 type I patients, 17 underwent percutaneous vertebral augmentation, 6 underwent posterior pedicle screw fixation strengthened with bone cement combined with percutaneous vertebral augmentation. In 12 type II patients, they were treated with local spinal decompression and internal fixation strengthened with bone cement. In 7 type III patients, 5 underwent posterior osteotomy, and 2 underwent one stage posterior approach of vertebral resection and reconstruction. The visual analogue scale (VAS), Oswestry disability index (ODI), and local kyphotic Cobb angle were used to evaluate the neurological function. The complications were recorded. ResultsThe operation was successfully completed in all patients. Wound infection and ketoacidosis secondary to stress blood glucose rise occurred in 1 case of type III patients respectively, and were cured after corresponding treatment; primary healing of wound was obtained in the other patients. The patients were followed up from 6 to 36 months (mean, 11.6 months). The nerve function was improved in 17 cases, and micturition disability was observed in 2 cases. Asymptomatic cement leakage occurred in 13 cases (30.95%) (7 cases in type I, 4 cases in type II, and 2 cases in type III). No bone cement dislocation and internal fixation failure were found during follow-up. The VAS score, ODI, and the local kyphotic Cobb angle at 1 week and last follow-up were significantly improved when compared with preoperative ones (P<0.05), but no significant difference was found between at 1 week and last follow-up (P>0.05). ConclusionIn order to improve the effectiveness and reduce the risk and complications of operation, individualized strategies should be performed according to different types of severe osteoporotic vertebral fracture and collapse.
Objective To summarize the effectiveness of bone cement combined with screws for repairing tibial plateau defect in total knee arthroplasty (TKA). Methods Between March 2013 and March 2016, 30 patients were treated with TKA and bone cement combined with screws for repairing tibial plateau defect. Of the 30 patients, 8 were male and 22 were female, with an average age of 64.7 years (range, 55-71 years). And 17 cases were involved in left knees and 13 cases in right knees; 22 cases were osteoarthritis and 8 cases were rheumatoid arthritis. The disease duration ranged from 9 to 27 months (mean, 14 months). Knee Society Score (KSS) was 41.63±6.76. Hospital for Special Surgery Knee Score (HSS) was 38.10±7.00. The varus deformity of knee were involved in 19 cases and valgus deformity in 11 cases. According to the Rand classification criteria, tibial plateau defect were rated as type Ⅱb. Results All incisions healed by first intention, without infection or deep vein thrombosis. All the patients were followed up 27.5 months on average (range, 10-42 months). At last follow-up, HSS score was 90.70±4.18 and KSS score was 93.20±3.75, showing significant differences when compared with preoperative values (t=–58.014, P=0.000; t=–60.629, P=0.000). Conclusion It is a simple and safe method to repair tibial plateau defect complicated with varus and valgus deformities with bone cement and srews in TKA.
Objective To evaluate the effectiveness of induced membrane technique in the treatment of infectious bone defect. Methods Thirty-six patients (37 bone lesions) with infectious bone defects were treated with induced membrane technique between January 2011 and June 2014. There were 28 males and 8 females with an average age of 36 years (range, 20-68 years). All bone defects were post-traumatic infectious bone defect. The bone defect was located at the tibia and fibula in 24 cases (25 bone lesions), at femurs in 6 cases (6 bone lesions), at ulnas and radii in 2 cases (2 bone lesions), at calcanei in 3 cases (3 bone lesions), and at clavicle in 1 case (1 bone lesion). The average time between onset and the treatment of induced membrane technique was 6.2 months (range, 0.5-36.0 months); 15 patients were acute infections (disease duration was less than 3 months). At the first stage, after the removal of internal fixator (applicable for the patients who had internal fixation), complete debridement of infection necrotic bone tissue and surrounding soft tissue was performed and the bone defects were filled with antibiotic-impregnated cement spacers. If the bone was unstable after debridement, external fixator or plaster could be used for stabilization. Patients received sensitive antibiotics postoperatively. At the second stage (usually 6-8 weeks later), the cement spacer were removed, with preservation of the induced membrane formed by the spacer, and filled the bone defect with autologous iliac bone graft within the membrane. Results The hospitalization time after debridement was 17-30 days (mean, 22.2 days), and the hospitalization time after the second stage was 7-14 days (mean, 10 days). All the flaps healed uneventfully in 16 cases treated with local flap transposition or free flap grafting after debridement. One patient of femur fracture received Ilizarov treatment after recurrence of infection at 11 months after operation; 1 patient of distal femoral fracture received amputation after recurrence of infection at 1 month after operation; 1 patient of distal end of tibia and fibula fractures received ankle arthrodesis after repeated debridements due to the recurrence of infection; 1 patient of tibia and fibula fractures lost to follow-up. The other 32 patients (33 bone lesions) were followed up 1-5 years (mean, 2 years) without infection recurrence, and the infection control rate was 91.7% (33/36). All the patients had bony union, and the healing time was 4-12 months (mean, 7.5 months); no refracture occurred. One patient of femur bone defect had a lateral angulation of 15° and leg discrepancy of 1.5 cm. Superficial pin infection was observed in 7 cases and healed after intensive wound care and oral antibiotics. Adjacent joint function restriction were observed in 6 cases at last follow-up. Conclusion Induced membrane technique is a simple and reliable technique for the treatment of infectious bone defect. The technique is not limited to the size of the bone defect and the effectiveness is satisfactory.
Objective To explore the application of intramedullary nail fixation combined with auxiliary plate and bone cement in the palliative treatment of pathologic fracture of extremities caused by metastatic tumors. Methods Clinical data of 11 cases with pathologic fracture of extremities caused by metastatic tumors between April 2015 and October 2016 were retrospectively analyzed. All the patients were treated by intramedullary nail fixation combined with auxiliary plate and bone cement. There were 6 males and 5 females with an age of 54-72 years (mean, 62.9 years). The disease duration was 1.0-1.5 months. Of the 11 patients, 4 metastatic tumors were diagnosed at humerus, 6 at femur, and 1 at tibia, respectively. And the tumor infiltration length ranged from 3.3 to 5.6 cm (mean, 4.6 cm), the depth could reach the bilayer of limb bones. All the patients had suffered the limbs pain and incapability of physical movement. The preoperative visual analogue scale (VAS) score was 6.36±1.03, and the Karnofsky Performance Status (KPS) score was 42.73±10.09. The operation time, intraoperative blood loss, and postoperative complications were recorded. The VAS score, KPS score, and Musculoskeletal Tumor Society (MSTS) score were used to evaluate the effectiveness at 3 months after operation. Results The operation time was 1.1-1.8 hours (mean, 1.5 hours), the intraoperative blood loss was 102.5-211.3 mL (mean, 135.6 mL). Postoperative limb incisions healed well without infection, necrosis, and delayed healing or other complications. All the patients were followed up 7-10 months (mean, 8.2 months). At 3 months after operation, the functions of limbs recovered. The VAS score decreased to 0.82±0.75 and the KPS score increased to 85.45±5.22, both showing significant difference when compared with preoperative ones (t=35.218, P=0.000; t=–18.470, P=0.000); and the MSTS score was 23.91±2.47. At last follow-up, the anteroposterior and lateral X-ray films showed that all the limbs healing well and no breakage of intramedullary nail and steel plate, or loosening in bone cement, limb shortening, malalignment, or other complications occurred. Conclusion In treating metastatic tumors of extremities, the combination of intramedullary nail fixation with auxiliary plate and bone cement will contribute to an invariable length and fixed location for limbs, resulting in biomechanical stability for skeleton. Under this premise, the tumor lesions can be eliminated and pathological pains be relieved, so as to improve patients’ life quality.
Objective To evaluate the effectiveness of percutaneous vertebroplasty (PVP) in the treatment of osteoporotic vertebral compression fracture (OVCF) through unilateral puncture of extreme extrapedicular approach and bilateral injection of bone cement. Methods The clinical data of 156 patients with OVCF who met the selection criteria between January 2014 and January 2016 were retrospectively analyzed. All patients were treated with PVP through unilateral puncture. According to different puncture methods, the patients were divided into two groups. In group A, 72 cases were performed PVP through the unilateral puncture of extreme extrapedicular approach and bilateral injection of bone cement, while in group B, 84 cases were performed PVP through the unilateral puncture of transpedicular approach. There was no significant difference in general data of gender, age, weight, bone mineral density, lesion segment, and disease duration between the two groups (P>0.05). The radiation exposure time, operation time, volume of bone cement injection, rate of bone cement leakage, pre- and post-operative visual analogue scale (VAS) score and local Cobb angle were recorded and compared between the two groups. Results There was no significant difference in radiation exposure time and operation time between the two groups (P>0.05), but the volume of bone cement injection in group A was significantly more than that in group B (t=20.024, P=0.000). Patients in both groups were followed up 24-32 months (mean, 26.7 months). There were 9 cases (12.5%) and 10 cases (11.9%) of cement leakage in group A and B, respectively. There was no significant difference in the incidence (χ2=0.013, P=0.910). No neurological symptoms and discomfort was found in the two groups. The VAS scores of the two groups were significantly improved after operation (P<0.05). There was no significant difference in local Cobb angle between before and after operation in group A (P>0.05); but the significant difference was found in local Cobb angle between at 2 years after operation and other time points in group B (P<0.05). The VAS score and local Cobb angle in group A were significantly better than those in group B at 2 years after operation (P<0.05). Conclusion It is simple, safe, and feasible to use the unilateral puncture of extreme extrapedicular approach and bilateral injection of bone cement to treat OVCF. Compared with the transpedicular approach, the bone cement can be distributed bilaterally in the vertebral body without prolonging the operation time and radiation exposure time, and has an advantage of decreasing long-term local Cobb angle losing of the fractured vertebrae.
Objective To investigate the effectiveness of posterior short-segmental fixation with bone cement augmentation in treatment of stage Ⅲ Kümmell’s disease with spinal canal stenosis. Methods Between June 2012 and January 2017, 36 patients with stage Ⅲ Kümmell’s disease and spinal canal stenosis were treated by posterior short-segmental fixation and bone cement augmentation. There were 12 males and 24 females, aged 55-83 years (mean, 73.5 years). The disease duration ranged from 2 to 8 months, with an average of 4.6 months. Preoperative bone mineral density examination showed that all patients had different degrees of osteoporosis in the spines. The lesion segments included T10 in 4 cases, T11 in 7 cases, T12 in 8 cases, L1 in 9 cases, and L2 in 8 cases. The preoperative neural function was classified as grade B in 4 cases, grade C in 12 cases, grade D in 13 cases, and grade E in 7 cases according to Frankle classification. The operation time, intraoperative blood loss, and the volume of injected bone cement, and hospital stay were recorded. The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), kyphotic Cobb angle, and the height of anterior edge of injured vertebra were recorded before operation, at 1 week after operation, and at last follow-up; and the leakage of bone cement was observed. Results All operations were completed successfully. The operation time was 90-145 minutes (mean, 110.6 minutes); the intraoperative blood loss was 198-302 mL (mean, 242.5 mL); the volume of injected bone cement was 8.3-10.5 mL (mean, 9.2 mL); the hospital stays were 7-12 days (mean, 8.3 days). All patients were followed up 12-26 months (mean, 24.5 months). At 1 week after operation, the neural function was classified as grade B in 2 cases, grade C in 8 cases, grade D in 12 cases, and grade E in 14 cases, which was significantly improved when compared with that before operation (Z=2.000, P=0.047). The VAS score, ODI, the height of anterior edge of injured vertebra, and Cobb angle were significantly improved at 1 week and last follow-up when compared with preoperative values (P<0.05); but there was no significant difference between 1 week and last follow-up (P>0.05). Two cases had asymptomatic cement leakage to the intervertebral disc at 1 week after operation; and 1 case had adjacent vertebral fracture at 8 months after operation. No complication such as loosening or breaking of internal fixator occurred during the follow-up. Conclusion Posterior short-segmental fixation with bone cement augmentation is a safe and effective surgical scheme for stage Ⅲ Kümmell’s disease combined with spinal canal stenosis, which can avoid the aggravation of nerve injury and complications related to staying in bed.
ObjectiveTo discuss the safety and effectiveness of the improved technique by comparing the effects of low temperature bone cement infusion before and after the improvement in the percutaneous vertebroplasty (PVP).MethodsThe clinical data of 170 patients (184 vertebrae) with osteoporotic vertebral compression fracture who met the selection criteria between January 2016 and January 2018 were retrospectively analyzed. All patients were treated with PVP by low-temperature bone cement perfusion technology. According to the technical improvement or not, the patients were divided into two groups: the group before the technical improvement (group A, 95 cases) and the group after the technical improvement (group B, 75 cases). In group A, the patients were treated by keeping the temperature of bone cement at 0℃ and parallel puncture; in group B, the patients were treated by increasing the temperature of bone cement or reducing the time of bone cement in ice salt water and cross puncture. There was no significant difference in gender, age, disease duration, T value of bone mineral density, operative segment, and preoperative vertebral compression rate, visual analogue scale (VAS) score between the two groups (P>0.05). CT examination was performed immediately after operation, and the leakage rate of bone cement was calculated. The amount of bone cement perfusion and the proportion of bone cement in contact with the upper and lower endplates at the same time were compared between the two groups. The vertebral compression rate was calculated and the VAS score was used to evaluate the pain before operation, at immediate after operation, and last follow-up.ResultsThere was no complication such as incision infection, spinal nerve injury, or pulmonary embolism in both groups. There was no significant difference in the amount of bone cement perfusion between groups A and B (t=0.175, P=0.861). There were 38 vertebral bodies (36.89%) in group A and 49 vertebral bodies (60.49%) in group B exposed to bone cement contacting with the upper and lower endplates at the same time, showing significant difference (χ2=10.132, P=0.001). Bone cement leakage occurred in 19 vertebral bodies (18.45%) in group A and 6 vertebral bodies (7.41%) in group B, also showing significant difference (χ2=4.706, P=0.030). The patients in group A and group B were followed up (13.3±1.2) months and (11.5±1.1) months, respectively. The vertebral compression rates of the two groups at immediate after operation were significantly lower than those before operation (P<0.05), but the vertebral compression rate of group A at last follow-up was significantly higher than that at immediate after operation (P<0.05), and there was no significant difference in group B between at immediate after operation and at last follow-up (P>0.05). The VAS scores of the two groups at immediate after operation were significantly lower than those before operation (P<0.05); but the VAS scores of group A at last follow-up were significantly higher than those at immediate after operation (P<0.05) and there was no siginificant difference in group B (P>0.05). There was no significant difference in VAS scores between the two groups at immediate after operation (t=0.380, P=0.705); but at last follow-up, VAS score in group B was significantly lower than that in group A (t=3.627, P=0.000).ConclusionThe improved advanced low-temperature bone cement perfusion technology during PVP by increasing the viscosity of bone cement combined with cross-puncture technology, can reduce bone cement leakage, improve the distribution of bone cement in the vertebral body, and reduce the risk of vertebral collapse, and achieve better effectiveness.