Evaluation of 70/30 poly (l-lactide-co-d,l-lactide) for use as a resorbable interbody fusion cage

2002 ◽  
Vol 97 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Jeffrey M. Toth ◽  
Bradley T. Estes ◽  
Mei Wang ◽  
Howard B. Seim ◽  
Jeffrey L. Scifert ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Bone Morphogenetic Protein 2 ◽  
Content Type ◽  
Chronic Inflammatory Response ◽  
Statistical Measures ◽  
Morphogenetic Protein ◽  
Human Bone Morphogenetic Protein ◽  
Fusion Cage ◽  
Fine Print

Object. Titanium lumbar interbody spinal fusion devices are reported to be 90% effective in cases requiring single-level lumbar interbody arthrodesis, although radiographic determination of fusion has been debated. Methods. Using blinded radiographic, biomechanical, histological, and statistical measures, researchers in the present study evaluated a radiolucent 70/30 poly(l-lactide-co-d,l-lactide) interbody fusion device packed with autograft or recombinant human bone morphogenetic protein—2 on a collagen sponge in 25 sheep at 3, 6, 12, 18, and 24 months. A trend of increased fusion stiffness, radiographic fusion, and histologically confirmed fusion was demonstrated at 3 months to 24 months postimplantation. Device degradation was associated with a mild to moderate chronic inflammatory response at all postoperative sacrifice times. Conclusions. Use of this material in interbody fusion may be a viable alternative to metals.

Safety of transforaminal lumbar interbody fusion and intervertebral recombinant human bone morphogenetic protein—2

2005 ◽  
Vol 3 (6) ◽  
pp. 436-443 ◽  
Author(s):  
Alan T. Villavicencio ◽  
Sigita Burneikiene ◽  
E. Lee Nelson ◽  
Ketan R. Bulsara ◽  
Mark Favors ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Minimally Invasive ◽  
Interbody Fusion ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Bone Morphogenetic Protein 2 ◽  
Content Type ◽  
Morphogenetic Protein ◽  
Human Bone Morphogenetic Protein ◽  
Recombinant Human Bone ◽  
Fine Print

Object. Recombinant human bone morphogenetic protein—2 (rhBMP-2) is being increasingly used for spinal fusion. There are few data regarding its clinical safety, effectiveness, and clinical outcome when applied on an absorbable collagen sponge (ACS) in conjunction with allograft for transforaminal lumbar interbody fusion (TLIF). Methods. Seventy-four consecutive patients undergoing TLIF for degenerative disc disease were divided into five groups depending on whether the patient underwent a minimally invasive or open approach, as well as the number of spinal levels surgically treated. Surgery-related data, fusion results, complications, and clinical outcome were evaluated. The mean follow-up duration was 20.6 months (range 14–28 months). The radiographic fusion rate was 100% at 12 and 24 months after the surgery. No bone overgrowth or other complications related to BMP use were demonstrated. Conclusions. Analysis of the results demonstrated that TLIF combined with a BMP-2—soaked ACS is a feasible, effective, and safe method to promote lumbar fusion. There were no significant intergroup differences in clinical outcome between patients who underwent open compared with minimally invasive procedures. Patient satisfaction rates, however, were higher in the minimally invasive procedure group. The efficacy of BMP-2 was not dependent on which approach was used or the number of spinal levels that were treated.

Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a caprine model

1999 ◽  
Vol 90 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Toshiyuki Takahashi ◽  
Teiji Tominaga ◽  
Noriaki Watabe ◽  
A. Toshimitu Yokobori ◽  
Hiroshi Sasada ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Fusion Rate ◽  
Bone Morphogenetic Protein 2 ◽  
High Dose ◽  
Porous Hydroxyapatite ◽  
Content Type ◽  
Morphogenetic Protein ◽  
Human Bone Morphogenetic Protein ◽  
Recombinant Human Bone ◽  
Fine Print

Object. The efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) for enhancing anterior cervical spine interbody fusion when added to a porous hydroxyapatite (HA) graft was investigated. Methods. Fourteen mature goats underwent three-level anterior discectomies after induction of endotracheal anesthesia. Porous HA grafts that contained 0, 5, and 50 µg of rhBMP-2 were placed concurrently with anterior cervical spine plates to achieve interbody fusion. The fusion rate, radiological findings, biomechanical stiffness, and histological appearance were evaluated in 42 spinal units immediately and again at 4 and 12 weeks after graft and plate placement. At 12 weeks postsurgery, manual testing showed a 100% fusion rate in the spines with HA grafts containing high-dose rhBMP-2; however, only a 50% fusion rate was shown in spines with grafts that contained no or low-dose rhBMP-2. On radiographic and histological studies the process of solid fusion was seen to be more advanced in relation to the use of larger amounts of rhBMP-2. Biomechanical testing demonstrated significantly higher stiffness values for grafts that contained high-dose rhBMP-2 than those without rhBMP-2 in flexion at 4 weeks, as well as in flexion, extension, and lateral bending tests at 12 weeks. Histological analysis demonstrated that rhBMP-2 increased the amount of bone apposition on the surface of the implants and promoted bone formation in the porous structure without increasing the penetration distance. Conclusions. Through osteogenesis at the fusion site, the addition of rhBMP-2 to a porous HA ceramic graft enhances the rate of anterior cervical fusion.

Bone morphogenetic protein—2 application by a poly(d,l-lactide)—coated interbody cage: in vivo results of a new carrier for growth factors

2002 ◽  
Vol 97 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Frank Kandziora ◽  
Hermann Bail ◽  
Gerhard Schmidmaier ◽  
Georg Schollmeier ◽  
Matti Scholz ◽  
...  
Keyword(s):  
Growth Factors ◽  
Interbody Fusion ◽  
Callus Formation ◽  
Collagen Sponge ◽  
Bone Morphogenetic Protein 2 ◽  
Content Type ◽  
Titanium Cage ◽  
Morphogenetic Protein ◽  
Flexion Extension ◽  
Fine Print

Object. Growth factors such as bone morphogenetic protein—2 (BMP-2) have been proven to promote spine fusion and to overcome the disadvantages of an autologous bone graft. The optimum method to deliver such growth factors remains a matter of discussion. The purpose of this study was to determine the safety and efficacy of a new poly(d,l-lactide) (PDLLA) carrier system for BMP-2 and to compare this carrier system with a collagen sponge carrier in a sheep cervical spine interbody fusion model. Methods. Thirty-two sheep underwent C3–4 discectomy and fusion: Group 1, titanium cage (eight animals); Group 2, titanium cage coated with a PDLLA carrier (eight animals); Group 3, titanium cage coated with a PDLLA carrier including BMP-2 (150 µg) (eight animals); and Group 4, titanium cage combined with a collagen sponge carrier including BMP-2 (150 µg) (eight animals). Blood samples, body weight, and temperature were assessed. Radiographs were obtained pre- and postoperatively and after 1, 2, 4, 8, and 12 weeks. At the same time points, disc space height, intervertebral angle, and lordosis angle were measured. After the sheep were killed 12 weeks postoperatively, flexion—extension radiography was performed to evaluate fusion sites. Quantitative computerized tomography scans were obtained to assess bone mineral density (BMD), bone mineral content (BMC), and bone callus volume (BCV). Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending. Stiffness, range of motion, neutral, and elastic zone were determined. Histomorphological and -morphometrical analyses were performed, and polychrome sequential labeling was used to determine the timeframe of new bone formation. There were no differences among the groups concerning blood counts, body weight, and temperature. Compared with the noncoated cages, all PDLLA-coated cages showed significantly higher values for BMD of the callus, as well as slightly higher values for BMC, BCV, and the bone volume/total volume ratio. In comparison with the cage-alone group, the BMP-2 groups showed significantly higher values for BMD and biomechanical stiffness. Histomorphological, -morphometrical, and polychrome sequential labeling analyses demonstrated greater progression of callus formation in the BMP-2 groups than in any other group. Compared with BMP-2 delivered using a collagen sponge carrier, BMP-2 application with a PDLLA carrier resulted in a higher BCV and a greater progression of interbody callus formation in the histomorphometrical analysis. Conclusions. The use of cervical spine interbody fusion cages coated with PDLLA as a delivery system for growth factors was effective. In this 12-week follow-up study, the PDLLA coating showed no adverse effects. The slight but not significant positive effect of the PDLLA carrier on interbody fusion might be a result of the degradation process of the biodegradable carrier. Compared with collagen sponge delivery of BMP-2, the PDLLA-coated interbody cages significantly increased the results of interbody bone matrix formation. In this new combination (implant + PDLLA + growth factor) the cage represents a “real fusion” cage, because it not only serves as a mechanical device for spinal fixation but also as a local drug delivery system.

The safety and utility of recombinant human bone morphogenetic protein-2 for cranial procedures in a nonhuman primate model

2003 ◽  
Vol 98 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Jason P. Sheehan ◽  
Jonas M. Sheehan ◽  
Howard Seeherman ◽  
Mark Quigg ◽  
Gregory A. Helm
Keyword(s):  
Mr Imaging ◽  
Bone Morphogenetic Protein ◽  
Human Bone ◽  
Bone Morphogenetic Protein 2 ◽  
Primate Model ◽  
Content Type ◽  
Morphogenetic Protein ◽  
Human Bone Morphogenetic Protein ◽  
Recombinant Human Bone ◽  
Fine Print

Object. The goal of this study was to evaluate the safety and efficacy of recombinant human bone morphogenetic protein 2 (rhBMP-2) in cranial applications. Methods. Critical-sized calvarial defects were created bilaterally in four rhesus monkeys, and bilateral rectangular bone flaps were created in six others. Control and rhBMP-2—treated sides were randomly chosen for each animal, and an absorbable collagen sponge was used to deliver the growth factor. Over a 6-month period postoperatively, the animals were serially evaluated for bone healing and adverse BMP-related consequences by using the following methods: computerized tomography (CT) scanning, magnetic resonance (MR) imaging, electroencephalography, histological investigations, and cerebrospinal fluid (CSF) analysis. The critical-sized defects for the rhBMP-2—treated and control sides attained 71 ± 12% and 28 ± 11% closure, respectively (four animals; p = 0.04). The CT scans demonstrated that the bone flaps treated with rhBMP-2 had complete osteointegration in five of six animals, whereas scans of the untreated bone flaps demonstrated uniformly poor osteointegration with the intact skull. Histological analysis confirmed well-formed bridges of bone on the rhBMP-2—treated sides. No epileptogenic activity was detected in any of the animals, and MR imaging revealed no evidence of adverse effects on the brain parenchyma. Meningitic irritation was not found on postoperative CSF sample analysis. Conclusions. Treatment of bone flaps and critical-sized cranial defects with rhBMP-2 leads to improved bone formation and osteointegration in nonhuman primates. Initial evaluation of rhBMP-2 appears to indicate a good safety profile for use in cranial procedures in primates.

Murine spinal fusion induced by engineered mesenchymal stem cells that conditionally express bone morphogenetic protein—2

2005 ◽  
Vol 3 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Amir Hasharoni ◽  
Yoram Zilberman ◽  
Gadi Turgeman ◽  
Gregory A. Helm ◽  
Meir Liebergall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Spinal Fusion ◽  
Genetically Engineered ◽  
Bone Morphogenetic Protein 2 ◽  
Content Type ◽  
Histological Studies ◽  
Morphogenetic Protein ◽  
Fine Print

Object. The authors hypothesized that spinal fusion can be achieved and monitored by using cell-mediated gene therapy. Mesenchymal stem cells (MSCs) genetically engineered to express recombinant human bone morphogenetic protein—2 (rhBMP-2) conditionally, were implanted into the paraspinal muscles of mice to establish spinal fusion. The goal was to demonstrate an MSC-based gene therapy platform in which controlled gene expression is used to obtain spinal fusion in a murine model. Methods. Mesenchymal stem cells expressing the rhBMP-2 gene were injected into the paravertebral muscle in mice. Bone formation in the paraspinal region was longitudinally followed by performing micro—computerized tomography scanning, histological studies, and an analysis of osteocalcin expression to demonstrate the presence of engrafted engineered MSCs. The minimal period of rhBMP-2 expression by the engineered MSCs required to induce fusion was determined. The results of this study demonstrate that genetically engineered MSCs induce bone formation in areas adjacent to and touching the posterior elements of the spine. This newly formed bone fuses the spine, as demonstrated by radiological and histological studies. The authors demonstrate that injected cells induce active osteogenesis at the site of implantation for up to 4 weeks postinjection. They found that a 7-day induction of rhBMP-2 expression in genetically engineered MSCs was sufficient to form new bone tissue, although the quantity of this bone increased as longer expression periods were implemented. Conclusions. After their injection genetically engineered MSCs can efficiently form new bone in the paraspinal muscle of the mouse to obtain spinal fusion. The extent and quantity of this newly formed bone can be monitored by controlling the duration of rhBMP-2 gene expression.

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