The research of calcium phosphate cement (CPC) has been developing for more than 20 years. In this review, we present a brief introduction to recent advances in researches on apatite CPC, brushite CPC, composite CPC materials; on factors affecting CPC capability and application; and on new application of CPC. The view that emphasizes the significance of studies on CPC with quicker degradation and osteoblast activity is put forward, particularly.
Absorbable Implants ; Bone Cements ; chemistry ; therapeutic use ; Bone Substitutes ; chemistry ; therapeutic use ; Calcium Phosphates ; chemistry ; therapeutic use ; Humans

OBJECTIVE: The 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. CONCLUSION The 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.
Humans ; Bone Cements/therapeutic use* ; Delayed-Action Preparations ; Bone Neoplasms/therapy* ; Anti-Bacterial Agents/therapeutic use* ; Nanoparticles/therapeutic use*

OBJECTIVETo evaluate the biomechanical performance of vertebroplasty using calcium sulfate cement for thoracolumbar burst fractures.

METHODSSixteen 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.

RESULTSThe 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).

CONCLUSIONSFor 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.

Animals ; Biomechanical Phenomena ; Bone Cements ; therapeutic use ; Calcium Sulfate ; therapeutic use ; Cattle ; Male ; Spinal Fractures ; physiopathology ; surgery ; Vertebroplasty

OBJECTIVETo observe therapeutic effects of preventing degenerative osteoarthritis by injecting bone cement into tibial condyle.

METHODSFrom January 2006 to Junary 2009, 24 patients with degenerative osteoarthritis were treated by injecting bone cement into tibial condyle, including 10 males and 14 females, ranging in age from 46 to 65 years, with an average of 50 years. The mean course of duation was 1 year. HSS scoring system was used to evaluate therapeutic effects preoperatively and one year after follow-up.

RESULTSAll patients were followed up over 2 years. HSS score after two years follow-up was 66.65 +/- 6.30, which was higher than that of preoperative 35.70 +/- 4.80. There was no significant difference between preoperation and one year after follow-up in anatomy angle of tibia.

CONCLUSIONBone cement injection into tibial condyle can prevent degenerative osteoarthritis and varus knee.

Aged ; Bone Cements ; therapeutic use ; Female ; Humans ; Injections ; Male ; Middle Aged ; Osteoarthritis, Knee ; prevention & control ; Tibia

BACKGROUNDPrevious studies have suggested that percutaneous vertebroplasty might alter vertebral stress transfer, leading to adjacent vertebral failure. However, no three-dimensional finite element study so far accounted for the stress distributions on different cement volumes. The purpose of this study was to evaluate the stress distributions on the endplate under different loading conditions after augmentation with various volumes of bone cement.

METHODSL2-L3 motion segment data were obtained from CT scans of the lumbar spine from a cadaver of a young man who had no abnormal findings on roentgenograms. Three-dimensional model of L2-L3 was established using Mimics software, and finite element model of L2-L3 functional spinal unit (FSU) was established using Ansys10.0 software. For simulating percutaneous vertebral augmentation, polymethylmethacrylate (PMMA) was deposited into the bipedicle of the L2 vertebra. The percentage of PMMA volume varied between 15% and 30%. The stress distributions on the endplate of the augmented vertebral body were calculated under three different loading conditions.

RESULTSIn general, the stress level monotonically increased with bone cement volume. Under each loading condition, the stress change on the L2 superior and inferior endplates in three kinds of finite element models shows monotonic increase. Compared with the stress-increasing region of the endplate, the central part of the L2 endplate was subject to the greatest stress under three kinds of loading conditions, especially on the superior endplate and under flexion.

CONCLUSIONSThe finite element models of FSU are useful to optimize the planning for vertebroplasty. The bone cement volume might have an influence on the endplate of the augmentation, especially the superior endplate. It should be noted that the optimization of bone cement volume is patient specific; the volume of the bone cement should be based on the size, body mineral density, and stiffness of the vertebrae of individual patients.

Bone Cements ; therapeutic use ; Finite Element Analysis ; Humans ; Osteoporosis ; Spinal Fractures ; surgery ; Stress, Mechanical ; Vertebroplasty ; methods

Polymethl methacrylate (PMMA) screw reinforcement is frequently used in osteoporotic bone as well as in damaged pilot holes. However, PMMA use can be dangerous, since the amount of applied cement is uncontrolled. A 47-year-old male with traumatic cervical spondylolisthesis at C6-7 underwent anterior cervical plate fixation. During repeated drilling and tapping for false trajectory correction, a pilot hole was damaged. Although it was an unconventional method, PMMA augmentation was tried. However, PMMA was accidentally injected to the cervical spinal cord owing to lack of fluoroscopic guidance. The PMMA was surgically removed after corpectomy and durotomy. The patient had left side hemiparesis (Grade 2/5) immediately post operation. The patient improved spontaneously (Grade 4/5) except for 4th and 5th digit extension. Here, we report a rare complication of PMMA extrusion in the spinal cord during a damaged pilot hole injection, which has not previously been described.
Bone Cements/*adverse effects/therapeutic use ; Bone Screws ; Cervical Vertebrae/*surgery ; Humans ; Male ; Middle Aged ; Polymethyl Methacrylate/adverse effects/therapeutic use

BACKGROUNDA new treatment strategy is to target specific areas of the skeletal system that are prone to clinically significant osteoporotic fractures. We term this strategy as the "local treatment of osteoporosis". The study was performed to investigate the effect of alendronate-loaded calcium phosphate cement (CPC) as a novel drug delivery system for local treatment of osteoorosis.

METHODSAn in vitro study was performed using CPC fabricated with different concentrations of alendronate (ALE, 0, 2, 5, 10 weight percent (wt%)). The microstructure, setting time, infrared spectrum, biomechanics, drug release, and biocompatibility of the composite were measured in order to detect changes when mixing CPC with ALE. An in vivo study was also performed using 30 Sprague-Dawley rats randomly divided into six groups: normal, Sham (ovariectomized (OVX) + Sham), CPC with 2% ALE, 5%ALE, and 10% ALE groups. At 4 months after the implantation of the composite, animals were sacrificed and the caudal vertebrae (levels 4-7) were harvested for micro-CT examination and biomechanical testing.

RESULTSThe setting time and strength of CPC was significantly faster and greater than the other groups. The ALE release was sustained over 21 days, and the composite showed good biocompatibility. In micro-CT analysis, compared with the Sham group, there was a significant increase with regard to volumetric bone mineral density (BMD) and trabecular number (Tb.N) in the treated groups (P < 0.05). Trabecular spacing (Tb.Sp) showed a significant increase in the Sham group compared to other groups (P < 0.01). However, trabecular thickness (Tb.Th) showed no significant difference among the groups. In biomechanical testing, the maximum compression strength and stiffness of trabecular bone in the Sham group were lower than those in the experimental groups.

CONCLUSIONSThe ALE-loaded CPC displayed satisfactory properties in vitro, which can reverse the OVX rat vertebral trabecular bone microarchitecture and biomechanical properties in vivo.

Alendronate ; therapeutic use ; Animals ; Bone Cements ; chemistry ; therapeutic use ; Bone Density ; drug effects ; Calcium Phosphates ; chemistry ; Female ; Osteoporosis ; drug therapy ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo compare the clinical efficacy of percutaneous kyphoplasty (PKP) with pedicle screw system (PS) in the treatment of vertebral compression fracture(VCF).

METHODSEighty-six patients with VCF were treated either by PKP (Group A, n equal to 30) or PS (Group B, n equal to 56). The anterior, intermediate, and posterior heights of the vertebrae body, visual analogue pain scale (VAS) before and after operation, the duration of operation, and amount of blood loss between two groups were compared.

RESULTSNo statistical difference was noted regarding the vertebral height between two groups. Significant difference was seen in VAS, duration of operation and amount of blood loss between the two groups (P less than 0.01).

CONCLUSIONSPercutaneous kyphoplasty has the similar therapeutic efficacy with pedicle screw system in treatment of VCF with a minimal invasion, less operation time and blood loss. For those with posterior wall destruction, PS is deemed favorable.

Adult ; Aged ; Bone Cements ; therapeutic use ; Bone Screws ; Female ; Fractures, Compression ; therapy ; Humans ; Internal Fixators ; Male ; Middle Aged ; Orthopedic Procedures ; Polymethyl Methacrylate ; therapeutic use ; Spinal Fractures ; therapy

PURPOSETo develop a novel injectable strontium-containing calcium phosphate cement with collagen.

METHODSA novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated.

RESULTSThe results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained (48.0 MPa ± 2.3 MPa); histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth.

CONCLUSIONA novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.

Animals ; Bone Cements ; chemistry ; therapeutic use ; Calcium Phosphates ; chemistry ; Collagen ; chemistry ; Compressive Strength ; Histocompatibility Testing ; Injections ; Rabbits ; Strontium ; chemistry

Bone cement, consisting of polymethyl methacrylate, is a bioinert material used for prothesis fixation in joint arthroplasty. To treat orthopedic infections, such as periprosthetic joint infection, antibiotic-loaded bone cement (ALBC) was introduced into clinical practice. Recent studies have revealed the limitations of the antibacterial effect of ALBC. Moreover, with the increase in high infection risk patients and highly resistant microbes, more researches and modification of ALBC are required. This paper reviewed latest findings about ALBC for most popular and destructive pathogens, summarized the influence of antibiotic kind, drug dosage, application method, and environment towards characteristic of ALBC. Subsequently, new cement additives and clinical applications of ALBC in joint arthroplasty were also discussed.
Anti-Bacterial Agents/therapeutic use* ; Arthroplasty, Replacement, Knee ; Bone Cements ; Humans ; Polymethyl Methacrylate ; Prosthesis-Related Infections/drug therapy*