Lumbar posterolateral fusion with biphasic calcium phosphate ceramic

The authors conducted a retrospective observational study of patients who needed lumbar posterolateral fusion (PLF) using a biphasic calcium phosphate ceramic implant as a substitute for bone graft. The findings of clinical, radiographic, and histologic examinations were reviewed. Thirty-two patients underwent single-level PLF with instrumentation. In all cases, to decrease the occurrence of donor-site complications and morbidity, locally harvested morselized bone from the decompressive site was mixed with hydroxyapatite and beta-tricalcium phosphate (HAP-TCP) granules and sticks and used for fusion at the posterolateral aspect of the lumbar spine. The histologic findings of three biopsy specimens obtained during second operations for metallic implant removal were reviewed. The minimum follow-up period was 26 months. There was no evidence of instrument loosening or breakage. However, bone-graft incorporation was difficult to evaluate radiographically, because image quality was inferior to that with conventional autogenous iliac bone graft. Partial graft bone resorption was revealed on radiographs in 75% of cases. The results showed clinical improvement in all but one case. Solid fusion was observed during the second operation in all three cases. Histologic analysis showed excellent bone incorporation around the HAP-TCP granules. These findings suggest that, although the bulk of the fusion mass with HAP-TCP was smaller than that with autogenous bone, this technique combined with rigid instrumentation is a safe and effective procedure.     

纳米磷酸钙陶瓷人工骨的临床应用研究

目的：探讨纳米磷酸钙陶瓷人工骨移植治疗骨缺损的安全性和临床效果。方法：2005年3月至2007年11月应用纳米陶瓷人工骨治疗四肢骨缺损病例32例（人工骨组）,男19例,女13例;年龄17～63岁,平均31.4岁。同期骨折内固定患者36例（内固定组）,男21例,女15例;年龄16～65岁,平均32.6岁。两组患者于术后第1、2周及第1、3、6个月检测外周静脉血中Ca、P、BALP、IgG、IgA、IgM、CIC、C3、SL2R及CD4＋/CD8＋的比值。并随访用Enneking标准评价肢体功能。结果：两组患者伤口术后均顺利愈合,各项免疫学检查无明显差异（P〉0.05）,均未引起血清中钙和磷的明显增高,术后两组B-ALP均升高,3～6个月后内固定组恢复至正常水平,人工骨组仍维持较高水平。随访9～24个月,平均15个月,两组患者均获得了较好的肢体功能,Enneking评价无明显差异（P〉0.05）。结论：所用纳米陶瓷人工骨无免疫原性,未引起排斥反应,不影响血液中钙、磷水平,并有一定的成骨活性,临床用以修复腔隙性骨缺损效果肯定。     

Macroporous calcium phosphate ceramic performance in human spine fusion

With a background of experimental studies on macroporous biphasic calcium phosphate (MBCP) in canine spine fusion, MBCP was investigated in 11- to 18-year-old patients with scoliosis treated by spinal fusion. Twelve cases were chosen for whom enough bone graft was difficult to obtain (severe neurologic scoliosis and osteogenesis imperfecta). MBCP blocks were used in combination with a specific strong fixation (Cotrel-Dubousset instrumentation). Clinical and roentgenogram assessments were performed up to 24 months. In two cases, biopsies were obtained. Histologic, ultrastructural, and microanalysis studies demonstrated the effectiveness of MBCP implants combined with a strong stabilization as bone graft substitutes for spine fusion. Clinical and biologic assessments were normal, and the histologic and ultrastructural evaluation demonstrated the bioactivity and the osteoconduction of this material. Partial resorbability of the MBCP blocks involved lamellar bone formation at the expense of the ceramic.     

鸵鸟钙磷陶瓷支架细胞相容性研究

目的：评价由鸵鸟松质骨制备的钙磷陶瓷支架的细胞相容性。方法：通过物理、化学方法将煅烧的鸵鸟松质骨改性为HAP／β-TCP／NaCaPO4多相钙磷陶瓷，然后分离兔骨髓基质细胞，体外扩增、诱导后接种于鸵鸟钙磷陶瓷支架。骨髓基质细胞与支架复合培养8天，通过相差显微镜、扫描电镜观察细胞在材料上的粘附、伸展及生长情况。通过细胞计数观察细胞增殖情况。结果：骨髓基质细胞在鸵鸟钙磷陶瓷支架表面及孔隙内粘附、伸展、增殖良好。结论：鸵鸟钙磷陶瓷支架具有良好的细胞相容性。     

X-ray diffraction examination of calcium phosphate in dental plaque

Calcified Tissue International - The calcium phosphate in dental plaques allowed to form over a 6-day period on the maxillary and mandibular incisors of 12 subjects was examined by X-ray...     

双相生物钙磷陶瓷生物相容性及异位骨诱导的实验研究

目的检测运用羟基磷灰石及β-磷酸三钙制备的双相钙磷陶瓷的生物相容性及其异位骨诱导效率。方法采用化学共沉淀法及过氧化氢发泡法,将羟基磷灰石及β-磷酸三钙以6∶4的比例在1 100 ℃条件下烧结3 h获得双相钙磷陶瓷,利用X线衍射评估材料组成成分。分离SD大鼠骨髓间充质干细胞,接种于双相钙磷陶瓷,通过扫描电镜、鬼笔环肽及DAPI染色观察细胞的黏附,CCK8法评估细胞增殖,碱性磷酸酶测定法评估骨髓间充质干细胞的碱性磷酸酶表达活性。将不含骨髓间充质干细胞的双相钙磷陶瓷置入比格犬竖脊肌内,于4、8、12周对样本行大体检测、组织染色,测算新骨生成率,从而评估双相钙磷陶瓷的异位骨诱导效率。结果成功制备双相钙磷陶瓷,X线衍射分析可见羟基磷灰石及β-磷酸三钙特异性的衍射峰。扫描电镜可见双相钙磷陶瓷表面广泛分布大孔及连通孔,孔壁粗糙不平,孔内可见均匀分布的微孔。鬼笔环肽及DAPI染色显示,骨髓充质干细胞在材料表面伸展黏附,共培养后逐渐从不规则形转变为均一的长梭形。CCK8法提示共培养后第1天,细胞活力降低,而第3、4、5、7天,细胞增殖活力逐渐增加。碱性磷酸酶活性检测提示,与对照组相比,共培养后第1、7天,双相钙磷陶瓷组的骨髓间充质干细胞可分泌更多的碱性磷酸酶。双相钙磷陶瓷顺利置入比格犬竖脊肌内,术后8周材料孔隙内可见骨样组织沉积,术后12周大孔成骨比例为0.77±0.11,孔内成骨面积比例为0.71±0.14。结论双相钙磷陶瓷具有良好的生物相容性及异位骨诱导效率。     

Silicate-substituted calcium phosphate ceramic bone graft replacement for spinal fusion procedures

STUDY DESIGN.: Retrospective study. OBJECTIVE.: To assess the clinical and radiographical outcomes in spinal fusion procedures using silicate-substituted calcium phosphate (Si-CaP). SUMMARY OF BACKGROUND DATA.: Si-CaP is a newer-generation synthetic ceramic designed to maximize osteoinduction and osteoconduction. METHODS.: This is a retrospective analysis of a prospectively collected patient database including 108 patients (204 individual spinal levels). Different surgical procedures performed included 25 anterior cervical discectomy and fusions, 17 posterior cervical fusions, 7 combined anterior and posterior cervical fusions, 10 thoracic fusion surgeries, 18 transforaminal lumbar interbody fusions with 12 axial lumbar interbody fusions, 11 transpsoas discectomy and fusions, and 8 combined thoracolumbar fusion procedures. Si-CaP was used as bone extender without any additional graft material, bone marrow aspirate, or bone morphogenetic protein. Clinical outcomes were assessed using the visual analogue scale (VAS), Oswestry Disability Index, and Neck Disability Index. Fusion was determined by the presence of bony bridging on 2 consecutive sections in at least 2 planes on computed tomographic imaging. RESULTS.: At a follow-up of 12 (±4.7) months, 90% of all patients demonstrated radiographical fusion. Fusion rates were highest in the cervical spine (97%) followed by thoracic and lumbar spines (86% and 81%, respectively). There were significant improvements in all clinical outcome measures-Oswestry Disability Index, 11.1 (±10.2) and Neck Disability Index, 9.0 (±11.4); VAS-back, 3.1(±3.0); VAS-leg, 3.5 (±3.6); VAS-neck, 3.7 (±2.5); and VAS-arm 4.0 (±3.2). There was no radiographical loosening of instrumentation due to infection or nonunion in this series, and no subsequent revisions for nonunion were required. CONCLUSION.: Si-CaP is an alternative to autogenous bone graft in spinal arthrodesis procedures. At 12-month follow-up, we detected high levels of bony fusion using Si-CaP in combination with various surgical spinal techniques.     

Macroporous calcium phosphate ceramic: a prospective study of 106 cases in lumbar spinal fusion

Macroporous biphasic calcium phosphate (MBCP, Triosite) is well known for its safety, absence of allergenicity, and excellent bone-bonding capacity, and it has been widely used as a bone graft substitute in orthopaedic, ENT, and dental surgery. This study investigates the clinical performance of this synthetic porous ceramic in a series of 106 patients, mainly with degenerative spine aetiologies (95/106) and with a minimum follow-up of 2 years. All patients were treated with posterior correction involving the semi-rigid New Orleans instrumentation. Spinal fusion was always performed using MBCP granules mixed with autogenous bone chips and bone marrow obtained from the local spine. Fusion of the spine was confirmed for 100 patients, and 6 non-unions were observed (3 resulting from primary spondylolisthesis). This study shows that MBCP provides suitable results in spinal fusion involving a semi-rigid instrumentation. Because the indication of degenerative spine is not very favorable to fusion, this technique appears to be a good alternative to autografts and could decrease patient morbidity resulting from iliac bone grafting.     

The evaluation of a biphasic calcium phosphate ceramic for use in grafting long-bone diaphyseal defects

The effectiveness of a sintered hydroxyapatite-tricalcium phosphate (HA-TCP) ceramic in bridging large diaphyseal defects in the canine ulna was studied. One-hundred percent morselized HA-TCP, a 50:50 mixture of morselized HA-TCP, and autogenous cancellous bone, and 100% autogenous cancellous bone were used to bridge 2.5-cm defects in the left ulnae of three groups of six dogs each. At 24 weeks the ulnae were explanted and studied by radiography, microradiography, mechanical testing, and histology. Pure HA/TCP was not osteoinductive, and four of six ulnae in this group progressed to a fibrous nonunion. The HA/TCP-cancellous bone mixture and pure cancellous bone were approximately equal in effect, leading to good callus formation at 4 weeks and strong bony union by 24 weeks, with no evidence of bioincompatibility. Morselized HA/TCP promises to be useful as a graft extender when mixed with autogenous cancellous bone.     

多孔双相钙磷陶瓷在脊柱后路融合中成骨作用和降解特性的组织学观察(附20例活检分析)

[目的]了解多孔双相钙磷陶瓷在人体脊柱后路融合中的成骨变化及降解过程。[方法]对20例脊柱后路融合的双相钙磷陶瓷活检标本行不脱钙硬组织切片检查。观察陶瓷周围和内部的新生组织、陶瓷的形态改变、降解颗粒及伴随的细胞吞噬反应。其中14例标本行组织形态计量，根据患者的年龄、植入时间及临床结果分组比较成骨及材料降解的速度。[结果]所有的双相钙磷陶瓷标本均可见新生骨组织，与自体骨接触越多，陶瓷内的新生骨组织越多。绝大部分陶瓷内可见降解颗粒，部分颗粒位于巨噬细胞内。不同标本的新生骨和材料降解速度差异较大。陶瓷内的新生骨随植入时间的增加而增多，但随患者年龄的增大而减少。陶瓷的降解率随患者年龄的增大而减少，但不受植入时间的影响。后路融合成功组的活检标本的新生骨量高于融合失败组，但材料降解率则反之。[结论]多孔双相钙磷陶瓷是一种骨传导材料，但植入体内降解缓慢，不能被新生骨组织完全替代。植入时必须将陶瓷与自体骨充分混合以获得良好的骨长入。陶瓷产生的降解颗粒及诱发的细胞吞噬反应必须引起注意。     

Ectopic bone formation by microporous calcium phosphate ceramic particles in sheep muscles

Calcium phosphate ceramics are widely used in bone reconstructive surgery because of their osteconductive properties. However, these materials generally lack osteoinductive properties required to support bone healing in large defects. In this article, we study the osteoinductive potential of calcium phosphate ceramic particles implanted for 6 months into the dorsal muscles of eight adult female sheep. Microporous biphasic calcium phosphate (MBCP) granules of 1–2 mm composed of hydroxyapatite and beta-tricalcium phosphate (60/40) had macropores of 450 μm, micropores of 0.43 μm, and a specific surface area of 1.8 m²/g. After 6 months in the back muscles of sheep, the explants composed of MBCP granules were hard and encapsulated by normal muscle tissue. Ectopic bone formation with Haversian structures was observed in close contact with the MBCP granules in histological sections. Back-scattered electron microscopy and micro-computed tomography indicated that approximately 10% of well-mineralized bone with mature osteocytes had formed between or upon the granules. The ectopic bone showed trabeculae bridging the MBCP granules. Both the number and thickness of the trabeculae formed between the MBCP particles were comparable to those measured in spongious bone. The overall results therefore confirmed the presence of mature bone after intramuscular implantation of MBCP granules. The different hypotheses explaining ectopic bone formation induced by MBCP granules are discussed. Synthetic bone substitutes with osteoinductive properties could be used in bone reconstructive surgery.     

Cage containing a biphasic calcium phosphate ceramic (Triosite) for the treatment of cervical spondylosis

BACKGROUND: We evaluated the fusion efficacy and clinical outcomes of a cage containing a biphasic calcium phosphate ceramic (Triosite) in treating cervical spondylosis. METHODS: We randomly divided 100 patients with cervical spondylosis undergoing anterior discectomy with interbody polyetheretherketone (PEEK) fusion into 2 groups in the past 2 years: group A (n = 50), PEEK cage containing a biphasic calcium phosphate ceramic (Triosite), and group B (n = 50), PEEK cage containing an autogenous iliac bone graft. We compared the fusion rate, fusion time, spinal curvature, and neuroforamen size between the 2 groups. We also compared excess operation time, excess blood loss, hospital stay, complications, and neurological recovery status between the groups. RESULTS: The fusion rates were 57%, 67%, 77%, 82%, 92%, and 100% in group A and 81%, 86%, 95%, 95% 100%, and 100% in group B in the first 6 postoperative months. The fusion rate in group A was significantly lower than that in group B in the first 5 months after the procedure (P < .05 and P < .01, respectively), but the fusion rate reached 100% in both groups by the sixth month. Within the first 6 months, as the fusion level increased, the fusion rates reduced and time to fusion was delayed in both groups. There were no donor site complications in group A. However, 3 patients (6%) from group B experienced complications (1, wound infection; 1, numbness of thigh; and 1, subcutaneous hematoma) (P < .001). The hospital stay was shorter in group A (4.43 +/- 2.36 days) than in group B (7.00 +/- 3.77 days) (P = .001). The mean excessive blood loss and excessive operative time for an iliac bone graft in group B were 15 +/- 5 mL and 10 +/- 6 minutes. There was no statistical significance in spinal curve correction, neuroforamen enlargement, and neurological recovery. CONCLUSIONS: A cage containing a biphasic calcium phosphate ceramic resulted in complete fusion by the sixth postoperative month, although the fusion rate was lower than that in a cage containing an autograft during the first 5 months after the operation and the time to fusion was delayed. Using a cage containing a biphasic calcium phosphate ceramic leads to a shorter hospital stay, less blood loss, shorter operative time, and no donor site complications. It seemed to be a good substitute for cervical spondylotic fusion.     

Antigenicity of alumina ceramic and calcium phosphate ceramics--genetic control of the immune response

Antigenicity of alumina ceramic, hydroxyapatite ceramic and tricalcium phosphate ceramic was studied by induction of footpad swelling in C57BL/6 mice immunized by ceramics with Freund's complete adjuvant. Significant footpad swelling was observed in mice immunized with tricalcium phosphate ceramic at 2 and 4 weeks after immunization. Antigenic specificity was demonstrated between tricalcium phosphate ceramic and fetal bovine serum in crisscross. Time course of the reaction suggested that delayed-type hypersensitivity played an important role in footpad swelling. These results indicate that tricalcium phosphate ceramic has antigenicity to C57BL/6 mice. Antigenicity of alumina ceramic and hydroxyapatite ceramic was not demonstrated in this study. A positive footpad reaction to tricalcium phosphate ceramic was shown in C57BL/10 (H-2b) and C57BL/10 X BR (H-2k), but was not observed in C57BL/10 X D2(H-2d). These results suggest that this response to tricalcium phosphate ceramic was under control by a gene located within the major histocompatibility complex.     

新型多孔双相磷酸钙支架与兔骨髓间充质干细胞相容性的体外实验研究

目的：研究新型多孔双相磷酸钙支架与兔骨髓间充质干细胞的体外相容性。方法：体外分离、扩增兔骨髓间充质干细胞。取传二代细胞,按照经典组织工程构建方法,分别接种双相磷酸钙（对照组）和双相磷酸钙复合纳米羟基磷灰石（实验组）支架。单纯细胞培养为空白对照组。体外成骨诱导培养14天。倒置相差显微镜、扫描电镜观察细胞生长情况;MTT法检测细胞增殖功能;碱性磷酸酶（ALP）检测细胞成骨分化功能。结果：细胞在新型支架上吸附、生长良好。各组MTT及ALP值随培养时间延长而增大。培养各时段实验组均高于其他两组,差别有统计学意义（P〈0.01）。结论：新型BCP支架与兔BMSC在体外具有良好的相容性,二者具有体外构建工程骨的潜力。     

Modern surgical treatment of aneurysmal bone cyst using a synthetic bone substitute (Ceraform, a calcium phosphate ceramic)

Aneurysmal bone cyst is a benign pseudotumoral dystrophy of bone, presenting expansive, destructive, nonresolutive features and often recurrence. A "stand-by" therapeutically attitude, in a survey manner, based on some spontaneous regression of certain areas of the aneurysmal cyst, due to thrombosis and fibrosis, is rarely advocated. When tumoral lesions are located in long bones and the bone length must be preserved, the bioptic curettage, followed or not by auto-grafting or cortical/cancellous allografting to bridge defect, represents the treatment of choice. The inconveniences encountered in using auto- or allografts have raised a growing interest towards synthetic bone substitutes. The most used of them are phosphocalcic ceramics due to their basic properties regarding interaction between bone and the substitution material, especially macroporosity Lately, we started to use (as clinical application) a bone substitute based on synthetic biphasic macroporous ceramic (CERAFORM), covering a wide range of procedures: benign tumors and dystrophies, spinal or joint arthrodesis, periprosthetic fractures, revisions following failures of primary total hip replacements. We obtained promising results, suggesting that in a situation with limited bone defects, as in clinical case presentation, if there exist a good contact and strong mechanical fixation, CERAFORM represents a reliable option comparing to allograft.     

Ectopic bone formation by composite graft of culture-expanded human marrow cells and porous calcium phosphate ceramic

Human bone marrow cells derived from three different sources; (1) cancellous bone of the femur; (2) cancellous bone of the rib from cadavers; (3) aspirate from the iliac bone were introduced into tissue culture. The adherent cells were cultivated, mitotically expanded, passaged, harvested then placed in small cubes of porous calcium phosphate ceramics and finally grafted into subcutaneous sites of athymic mouse or athymic rat. The ceramics loaded with cultured marrow cells from cancellous bone of femur showed strong osteogenic potential with bone forming in the pore regions of ceramics as early as two weeks after in vivo implantation. Osteogenesis could be observed after seventh passage (Five times passaged, frozen, stored, thawed, and replated twice). Although the aspirated marrow cells cultured also exhibited bone formation, the osteogenesis initiated later and the bone formation rate was lower. The ceramics loaded with fresh red blood cells separated from the aspirated marrow showed no evidence of bone formation. Moreover, osteogenic cells were found to have an ability to proliferate selectively in tissue culture.     

Bone integration within calcium phosphate ceramic by creation of posterior inter-articular lumbar spine fusions in dogs

Following earlier experiments in which several calcium phosphate ceramics were tested, the aim of this study was to evaluate bone integration within a macroporous biphasic calcium ceramic (M.B.C.P.) in comparison to autologous bone grafts, by producing posterior lumbar spine fusions in dogs. Five dogs were used. 40 posterior lumbar joints were exposed; 38 articular surfaces were removed, 27 M.B.C.P. and 5 autologous bone grafts were implanted; 6 joints were kept free of implant for control purposes. Fixation with a metal rod was performed using Luque's method. Tetracycline was used for a double marking of bone growth. Joints were removed at 4 weeks in 1 dog, 8 weeks in two and 13 weeks in the remaining 2 dogs. Demineralized and non demineralized sections were examined. After 1 month, sections with M.B.C.P. showed early signs of mineralization of the scar tissue between the biomaterial and one of the facets of the joint. Fluoroscopy revealed an absence of bone growth in the pores at the center of the ceramic implant. After 3 months, a number of M.B.C.P. blocks had become integrated into both sides of the joint; however some microfractures in the biomaterial with discontinuity between the mineralized areas was seen. Macroporous calcium phosphate ceramic leads to revascularization allowing bone reconstruction. Similarities in the kinetics and mechanisms of bone integration between the ceramic and autologous bone grafts are demonstrated.