The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
T Takahashi - One of the best experts on this subject based on the ideXlab platform.
-
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a Caprine Model.
Journal of neurosurgery, 1999Co-Authors: T Takahashi, Naohito Watabe, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Takayuki YoshimotoAbstract: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. Fourteen mature goats underwent three-level anterior discectomies after induction of endotracheal anesthesia. Porous HA grafts that contained 0, 5, and 50 microg 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. Through osteogenesis at the fusion site, the addition of rhBMP-2 to a porous HA ceramic graft enhances the rate of anterior cervical fusion.
-
use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein 2 for cervical fusion in a Caprine Model
Journal of Neurosurgery, 1999Co-Authors: T Takahashi, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Noriaki Watabe, Takashi YoshimotoAbstract: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 ...
-
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a Caprine Model.
Journal of neurosurgery, 1999Co-Authors: T Takahashi, Naohito Watabe, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Takayuki YoshimotoAbstract: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.
Paul C Mcafee - One of the best experts on this subject based on the ideXlab platform.
-
autologous growth factors versus autogenous graft for anterior cervical interbody fusion an in vivo Caprine Model
Journal of Neurosurgery, 2010Co-Authors: Bryan W Cunningham, N Hu, J C Sefter, Paul C McafeeAbstract:OBJECT: Using an in vivo Caprine Model, authors in this study compared the efficacy of autologous growth factors (AGFs) with autogenous graft for anterior cervical interbody arthrodesis. METHODS: Fourteen skeletally mature Nubian goats were used in this study and followed up for a period of 16 weeks postoperatively. Anterior cervical interbody arthrodesis was performed at the C3-4 and C5-6 vertebral levels. Four interbody treatment groups (7 animals in each group) were equally randomized among the 28 arthrodesis sites: Group 1, autograft alone; Group 2, autograft + cervical cage; Group 3, AGFs + cervical cage; and Group 4, autograft + anterior cervical plate. Groups 1 and 4 served as operative controls. Autologous growth factors were obtained preoperatively from venous blood and were ultra-concentrated. Following the 16-week survival period, interbody fusion success was evaluated based on radiographic, biomechanical, and histological analyses. RESULTS: All goats survived surgery without incidence of vascular or infectious complications. Radiographic analysis by 3 independent observers indicated fusion rates ranging from 9 (43%) of 21 in the autograft-alone and autograft + cage groups to 12 (57%) of 21 in the autograft + anterior plate group. The sample size was not large enough to detect any statistical significance in these observed differences. Biomechanical testing revealed statistical differences (p < 0.05) between all treatments and the nonoperative controls under axial rotation and flexion and extension loading. Although the AGF + cage and autograft-alone treatments appeared to be statistically different from the intact spine during lateral bending, larger variances and smaller relative differences precluded a determination of statistical significance. Histomorphometric analysis of bone formation within the predefined fusion zone indicated quantities of bone within the interbody cage ranging from 21.3 +/- 14.7% for the AGF + cage group to 34.5 +/- 9.9% for the autograft-alone group. CONCLUSIONS: The results indicated no differences in biomechanical findings among the treatment groups and comparable levels of trabecular bone formation within the fusion site between specimens treated with autogenous bone and those filled with the ultra-concentrated AGF extract. In addition, interbody cage treatments appeared to maintain disc space height better than autograft-alone treatments.
-
bioactive titanium calcium phosphate coating for disc arthroplasty analysis of 58 vertebral end plates after 6 to 12 month implantation
The Spine Journal, 2006Co-Authors: Bryan W Cunningham, N Hu, Candace M Zorn, Paul C McafeeAbstract:Abstract Background context From a biomechanical perspective, the successful outcome of total disc replacement is largely based on the mechanisms of acute fixation obtained at the index procedure and the extent of porous biological osseointegration at the prosthesis-bone interface, ensuring long-term device fixation. Purpose The present retrospective investigation quantifies the extent of porous osseointegration in cervical and lumbar disc arthroplasty implants containing a bioactive titanium/calcium phosphate coating. Study design Based on radiographic analysis and quantitative histomorphometry, the study was designed to determine the extent of porous osseointegration and whether osseointegration was affected by arthroplasty implant position. Outcome measures Quantitative histomorphometric analysis of trabecular apposition in metallic backed cervical and lumbar arthroplasty devices. Methods Twenty-nine disc arthroplasty devices underwent radiographic and histomorphometric analysis after 6- to 12-month implantation. The specimens included 12 cervical porous-coated motion devices implanted in a Caprine Model, and 17 lumbar Charite devices implanted in a non-human primate baboon. The two prosthetic-bone surfaces (superior and inferior) of each implant were examined for a total of 58 vertebral end plates. The operative motion segments were processed using undecalcified histologic technique with production of high-resolution light photomicrographs and microradiographs used for histomorphometric quantification of trabecular bone area at the implant interface. Based on plain film radiographs and histologic microradiographs, the technical accuracy of implant placement was classified as Ideal, Suboptimal, or Poor, with alignment referenced to the sagittal and coronal planes. Results The technical accuracy of implant placement in the cervical spine based on histologic microradiographs ranged from poor=8% (2 out of 24), suboptimal=17% (4 out of 24), to ideal=75% (18 out of 24), whereas accuracy of lumbar disc arthroplasty ranged from poor=20% (7 out of 34), suboptimal=52% (18 out of 34), and ideal=26% (9 out of 34). Based on histomorphometric analysis of the inferior and superior end plate surfaces, the trabecular apposition ranged from poor placement 21%±30% ingrowth, suboptimal 26%±33%, to ideal=44%±23% (p>.05). Similar findings were observed for the lumbar region; however, the suboptimal and ideal positions were closer in values with regard to trabecular apposition. Poor placement was 34%±29%, suboptimal 49%±19%, and ideal 51%±13%, but this was not statistically significant (p>.05). Conclusions The present study represents the largest analysis to date of any retrieved porous ingrowth disc replacement prostheses. A trend was observed of increase porous osseointegration with improved implant positioning; however, the small sample size and high standard deviations account for lack of statistical significance. Although osseointegration occurs despite nonideal intraoperative positioning, it remains imperative that surgeons strive for Ideal implant position.
-
porous coated motion cervical disc replacement a biomechanical histomorphometric and biologic wear analysis in a Caprine Model
Spine, 2006Co-Authors: N Hu, J C Sefter, A Cappuccino, Paul C Mcafee, Bryan W Cunningham, L PimentaAbstract:STUDY DESIGN: The biomechanical, histopathologic, and histomorphometric characteristics of cervical disc replacement were assessed in a Caprine animal Model. OBJECTIVE: To investigate the biomechanical, porous ingrowth, and histopathologic characteristics of the Porous Coated Motion (PCM) Cervical Disc replacement (Cervitech, Inc., Rockaway, NJ). SUMMARY OF BACKGROUND DATA: As an alternative to anterior cervical interbody arthrodesis, an artificial cervical disc serves to replace the symptomatic degenerated disc, restore the functional biomechanical properties of the motion segment, and preserve neurologic function. METHODS: There were 12 mature Nubian goats divided into 2 groups based on postoperative survival periods of 6 (n = 6) and 12 months (n = 6). Using an anterior surgical approach, a complete discectomy was performed at the C3-C4, followed by implantation of the PCM device. Functional outcomes of the disc prosthesis were based on computerized tomography (CT), multidirectional flexibility testing, undecalcified histology, histomorphometric, and immunocytochemical analyses. RESULTS: There was no evidence of prosthesis loosening, or neurologic or vascular complications. CT showed the ability to image and assess the cervical spinal canal for the presence of compressive pathology in the area of the CoCrMo prosthesis. Multidirectional flexibility testing under axial rotation and lateral bending indicated no differences in the full range of intervertebral motion between the disc prosthesis and nonoperative controls (P > 0.05). Based on immunohistochemical and histologic analysis, there was no evidence of particulate debris, cytokines, or cellular apoptosis within the local or systemic tissues. Moreover, review of the spinal cord at the operative levels indicated no evidence of cord lesions, inflammatory reaction, wear particles, or significant pathologic changes in any treatment. Histomorphometric analysis at the metal-bone interface indicated the mean trabecular ingrowth of 40.5% +/- 24.4% and 58.65% +/- 28.04% for the 6 and 12-month treatments, respectively. CONCLUSION: To our knowledge, this serves as the first in vivo time-course study investigating the use of the PCM device for cervical arthroplasty. All 12 animals undergoing cervical disc replacement had no evidence of implant loosening, subluxation, or inflammatory reactions. PCM cervical arthroplasty permits unobstructed visualization of the spinal canal based on CT imaging. Segmental intervertebral motion was preserved under axial rotation and lateral bending loading conditions, while at the same time permitting porous osseointegration at the prosthesis-bone interface. Based on histopathologic review of all local and systemic tissues, there was no evidence of particulate wear debris, cytokines, cellular apoptosis, or significant pathologic changes in any treatment.
-
porous coated motion cervical disk replacement a biomechanical histomorphometric and biologic wear analysis in a Caprine Model
Orthopaedic Proceedings, 2005Co-Authors: B W Cunningham, N Hu, J C Sefter, A Cappuccino, L Pimenta, Paul C McafeeAbstract:Introduction The current study was undertaken to investigate the biomechanical and biologic in-growth characteristics of the Porous Coated Motion™ cervical disc prosthesis following a six and twelve-month implant duration using an in-vivo Caprine Model. Methods Twelve mature Nubian goats were divided into two groups based on post-operative survival periods of six (n=6) and twelve months (n=6). Using an anterior surgical approach, a complete diskectomy was performed at the C3-C4, followed by implantation of the Porous Coated Motion™ device. Functional outcomes of the disc prosthesis were based on computed tomography (CT), multi-directional flexibility testing, undecalcifed histology, histomorphometry and immunocytochemical analyses. Results There was no evidence of prosthesis loosening, neurologic or vascular complications. CT scans demonstrated the ability to image and assess the cervical spinal canal for the presence of compressive pathology in the area of the CoCrMo prosthesis. Multi-directional flexibility testing indicated no differences in full range of intervertebral motion between the disc prosthesis and non-operative controls (n=7) under axial rotation or lateral bending conditions (p>0.05). Flexion-extension produced significantly more motion for the intact spine compared to the cervical disc prosthesis (p Discussion All twelve goats undergoing cervical disc replacement had no evidence of implant loosening or inflammatory reactions from particulate wear debris. Segmental intervertebral motion was preserved based on multi-directional flexibility testing. The TiCaP porous ingrowth surface provided some immediate advantages for endplate osseointegration as there was no evidence of implant subluxation, despite immediate post-operative unrestricted cervical activity. Following cervical disc replacement, histological osseointegration at the implant-bone interface is possible, while preserving segmental motion.
-
POROUS COATED MOTION CERVICAL DISK REPLACEMENT – A BIOMECHANICAL, HISTOMORPHOMETRIC AND BIOLOGIC WEAR ANALYSIS IN A Caprine Model.
2005Co-Authors: B W Cunningham, N Hu, J C Sefter, A Cappuccino, L Pimenta, Paul C McafeeAbstract:Introduction The current study was undertaken to investigate the biomechanical and biologic in-growth characteristics of the Porous Coated Motion™ cervical disc prosthesis following a six and twelve-month implant duration using an in-vivo Caprine Model. Methods Twelve mature Nubian goats were divided into two groups based on post-operative survival periods of six (n=6) and twelve months (n=6). Using an anterior surgical approach, a complete diskectomy was performed at the C3-C4, followed by implantation of the Porous Coated Motion™ device. Functional outcomes of the disc prosthesis were based on computed tomography (CT), multi-directional flexibility testing, undecalcifed histology, histomorphometry and immunocytochemical analyses. Results There was no evidence of prosthesis loosening, neurologic or vascular complications. CT scans demonstrated the ability to image and assess the cervical spinal canal for the presence of compressive pathology in the area of the CoCrMo prosthesis. Multi-directional flexibility testing indicated no differences in full range of intervertebral motion between the disc prosthesis and non-operative controls (n=7) under axial rotation or lateral bending conditions (p>0.05). Flexion-extension produced significantly more motion for the intact spine compared to the cervical disc prosthesis (p Discussion All twelve goats undergoing cervical disc replacement had no evidence of implant loosening or inflammatory reactions from particulate wear debris. Segmental intervertebral motion was preserved based on multi-directional flexibility testing. The TiCaP porous ingrowth surface provided some immediate advantages for endplate osseointegration as there was no evidence of implant subluxation, despite immediate post-operative unrestricted cervical activity. Following cervical disc replacement, histological osseointegration at the implant-bone interface is possible, while preserving segmental motion.
Takayuki Yoshimoto - One of the best experts on this subject based on the ideXlab platform.
-
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a Caprine Model.
Journal of neurosurgery, 1999Co-Authors: T Takahashi, Naohito Watabe, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Takayuki YoshimotoAbstract: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. Fourteen mature goats underwent three-level anterior discectomies after induction of endotracheal anesthesia. Porous HA grafts that contained 0, 5, and 50 microg 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. Through osteogenesis at the fusion site, the addition of rhBMP-2 to a porous HA ceramic graft enhances the rate of anterior cervical fusion.
-
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a Caprine Model.
Journal of neurosurgery, 1999Co-Authors: T Takahashi, Naohito Watabe, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Takayuki YoshimotoAbstract: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.
Bryan W Cunningham - One of the best experts on this subject based on the ideXlab platform.
-
autologous growth factors versus autogenous graft for anterior cervical interbody fusion an in vivo Caprine Model
Journal of Neurosurgery, 2010Co-Authors: Bryan W Cunningham, N Hu, J C Sefter, Paul C McafeeAbstract:OBJECT: Using an in vivo Caprine Model, authors in this study compared the efficacy of autologous growth factors (AGFs) with autogenous graft for anterior cervical interbody arthrodesis. METHODS: Fourteen skeletally mature Nubian goats were used in this study and followed up for a period of 16 weeks postoperatively. Anterior cervical interbody arthrodesis was performed at the C3-4 and C5-6 vertebral levels. Four interbody treatment groups (7 animals in each group) were equally randomized among the 28 arthrodesis sites: Group 1, autograft alone; Group 2, autograft + cervical cage; Group 3, AGFs + cervical cage; and Group 4, autograft + anterior cervical plate. Groups 1 and 4 served as operative controls. Autologous growth factors were obtained preoperatively from venous blood and were ultra-concentrated. Following the 16-week survival period, interbody fusion success was evaluated based on radiographic, biomechanical, and histological analyses. RESULTS: All goats survived surgery without incidence of vascular or infectious complications. Radiographic analysis by 3 independent observers indicated fusion rates ranging from 9 (43%) of 21 in the autograft-alone and autograft + cage groups to 12 (57%) of 21 in the autograft + anterior plate group. The sample size was not large enough to detect any statistical significance in these observed differences. Biomechanical testing revealed statistical differences (p < 0.05) between all treatments and the nonoperative controls under axial rotation and flexion and extension loading. Although the AGF + cage and autograft-alone treatments appeared to be statistically different from the intact spine during lateral bending, larger variances and smaller relative differences precluded a determination of statistical significance. Histomorphometric analysis of bone formation within the predefined fusion zone indicated quantities of bone within the interbody cage ranging from 21.3 +/- 14.7% for the AGF + cage group to 34.5 +/- 9.9% for the autograft-alone group. CONCLUSIONS: The results indicated no differences in biomechanical findings among the treatment groups and comparable levels of trabecular bone formation within the fusion site between specimens treated with autogenous bone and those filled with the ultra-concentrated AGF extract. In addition, interbody cage treatments appeared to maintain disc space height better than autograft-alone treatments.
-
BIOACTIVE TITANIUM CALCIUM PHOSPHATE COATING FOR DISK ARTHROPLASTY: ANALYSIS OF 68 VERTEBRAL ENDPLATES AFTER 6 TO 33 MONTHS IMPLANTATION
2006Co-Authors: P.c. Mcafee, N Hu, Bryan W Cunningham, Helen J. Beatson, Paul Tortolani, L PimentaAbstract:Introduction This is the largest analysis to date of any retrieved porous ingrowth disk replacement prostheses. In distinction to prior reports of retrieved implants which were conducted like “airplane crash” type pseudoanalyses, in this series the position of the components was known in vivo prior to implant removal. The digitized radiographs were used to determine if the components were in ideal, suboptimal, or poor position. There were thirty cervical disk replacements and thirty-eight lumbar disk replacements which comprised the basis of this analysis. Methods Quantitative histomorphometry, microradiography, and histology were performed on all 68 vertebral endplates. Scanning electron microscopy was performed on ten. All 24 Caprine Model, 34 non-human primates, and 10 human explants with titanium calcium phosphate porous ingrowth surface were manufactured by the same vendor, D.O.T., which provides the same porous ingrowth coating for several FDA approved total hip replacements. Group I – Ideal placement, was defined as Charite or PCM Artificial Disc replacement within 3 mm of exact central axis in both the coronal planes and mid-sagittal planes (2 mm posterior to the midpoint of the vertebral body in the sagittal plane for Charite only).The endplates of the prosthesis also had to be within 5 degrees of angulation of the bony end-plate or within 5 degrees of angulation of the perpendicular axis of the vertebral body. Group II – Suboptimal placement, was defined as Charite or PCM Artificial Disc placement from 3 mm to 5 mm from exact central placement in at least one axis In addition the prosthetic endplate had to be from 5 degrees to 10 degrees of perpendicular vertebral body orientation. Group III – Poor placement, was defined as greater than 5 mm from exact central placement in at least one axis or the endplate was greater than 10 degrees off angle. Three separate observers judged the measurements of axes and made a determination of prosthesis placement after correction for magnification error. Results The mean length of time in biologic conditions to monitor reabsorption and incorporation of the ingrowth surface was a mean of 10.5 months (range 6 to 33 months). This is the first study finding a correlation between the position of the components and amount of successful bony ingrowth. A representative group was: Ideal 50.9 +/− 13 % ingrowth, Suboptimal placement, 49.3 +/−18 % ingrowth, and Poor, 33.0 +/− 29.2 % ingrowth. There was trend but not statistically significant (F= 1.78, p = .186). The mean ingrowth of prostheses in poor and suboptimal position (defined by axis off by 3mm in either AP or Lateral plane) was 43.2 %. Whereas the mean ingrowth of prostheses inserted in “ideal position” within 3 mm of the optimal prosthesis axis in both planes was 46.4 %. The definition of successful biologic ingrowth in the extremities for total joint replacement is porous ingrowth over 30 %, which was achieved in 58 / 68 (85.3 %) of vertebral endplates. Discussion The porous ingrowth TiCaP bioactive technology permits osseointegration despite non-ideal positioning. The surgeon’s technical shortcomings to place the prosthesis in ideal position were more than compensated for as 85.3 % of the components were successfully ingrown and biologically fixed to the vertebral trabeculae at the time of explantation. There were no cases of osteolysis or biomaterial failure encountered in this retrieval study.
-
bioactive titanium calcium phosphate coating for disc arthroplasty analysis of 58 vertebral end plates after 6 to 12 month implantation
The Spine Journal, 2006Co-Authors: Bryan W Cunningham, N Hu, Candace M Zorn, Paul C McafeeAbstract:Abstract Background context From a biomechanical perspective, the successful outcome of total disc replacement is largely based on the mechanisms of acute fixation obtained at the index procedure and the extent of porous biological osseointegration at the prosthesis-bone interface, ensuring long-term device fixation. Purpose The present retrospective investigation quantifies the extent of porous osseointegration in cervical and lumbar disc arthroplasty implants containing a bioactive titanium/calcium phosphate coating. Study design Based on radiographic analysis and quantitative histomorphometry, the study was designed to determine the extent of porous osseointegration and whether osseointegration was affected by arthroplasty implant position. Outcome measures Quantitative histomorphometric analysis of trabecular apposition in metallic backed cervical and lumbar arthroplasty devices. Methods Twenty-nine disc arthroplasty devices underwent radiographic and histomorphometric analysis after 6- to 12-month implantation. The specimens included 12 cervical porous-coated motion devices implanted in a Caprine Model, and 17 lumbar Charite devices implanted in a non-human primate baboon. The two prosthetic-bone surfaces (superior and inferior) of each implant were examined for a total of 58 vertebral end plates. The operative motion segments were processed using undecalcified histologic technique with production of high-resolution light photomicrographs and microradiographs used for histomorphometric quantification of trabecular bone area at the implant interface. Based on plain film radiographs and histologic microradiographs, the technical accuracy of implant placement was classified as Ideal, Suboptimal, or Poor, with alignment referenced to the sagittal and coronal planes. Results The technical accuracy of implant placement in the cervical spine based on histologic microradiographs ranged from poor=8% (2 out of 24), suboptimal=17% (4 out of 24), to ideal=75% (18 out of 24), whereas accuracy of lumbar disc arthroplasty ranged from poor=20% (7 out of 34), suboptimal=52% (18 out of 34), and ideal=26% (9 out of 34). Based on histomorphometric analysis of the inferior and superior end plate surfaces, the trabecular apposition ranged from poor placement 21%±30% ingrowth, suboptimal 26%±33%, to ideal=44%±23% (p>.05). Similar findings were observed for the lumbar region; however, the suboptimal and ideal positions were closer in values with regard to trabecular apposition. Poor placement was 34%±29%, suboptimal 49%±19%, and ideal 51%±13%, but this was not statistically significant (p>.05). Conclusions The present study represents the largest analysis to date of any retrieved porous ingrowth disc replacement prostheses. A trend was observed of increase porous osseointegration with improved implant positioning; however, the small sample size and high standard deviations account for lack of statistical significance. Although osseointegration occurs despite nonideal intraoperative positioning, it remains imperative that surgeons strive for Ideal implant position.
-
porous coated motion cervical disc replacement a biomechanical histomorphometric and biologic wear analysis in a Caprine Model
Spine, 2006Co-Authors: N Hu, J C Sefter, A Cappuccino, Paul C Mcafee, Bryan W Cunningham, L PimentaAbstract:STUDY DESIGN: The biomechanical, histopathologic, and histomorphometric characteristics of cervical disc replacement were assessed in a Caprine animal Model. OBJECTIVE: To investigate the biomechanical, porous ingrowth, and histopathologic characteristics of the Porous Coated Motion (PCM) Cervical Disc replacement (Cervitech, Inc., Rockaway, NJ). SUMMARY OF BACKGROUND DATA: As an alternative to anterior cervical interbody arthrodesis, an artificial cervical disc serves to replace the symptomatic degenerated disc, restore the functional biomechanical properties of the motion segment, and preserve neurologic function. METHODS: There were 12 mature Nubian goats divided into 2 groups based on postoperative survival periods of 6 (n = 6) and 12 months (n = 6). Using an anterior surgical approach, a complete discectomy was performed at the C3-C4, followed by implantation of the PCM device. Functional outcomes of the disc prosthesis were based on computerized tomography (CT), multidirectional flexibility testing, undecalcified histology, histomorphometric, and immunocytochemical analyses. RESULTS: There was no evidence of prosthesis loosening, or neurologic or vascular complications. CT showed the ability to image and assess the cervical spinal canal for the presence of compressive pathology in the area of the CoCrMo prosthesis. Multidirectional flexibility testing under axial rotation and lateral bending indicated no differences in the full range of intervertebral motion between the disc prosthesis and nonoperative controls (P > 0.05). Based on immunohistochemical and histologic analysis, there was no evidence of particulate debris, cytokines, or cellular apoptosis within the local or systemic tissues. Moreover, review of the spinal cord at the operative levels indicated no evidence of cord lesions, inflammatory reaction, wear particles, or significant pathologic changes in any treatment. Histomorphometric analysis at the metal-bone interface indicated the mean trabecular ingrowth of 40.5% +/- 24.4% and 58.65% +/- 28.04% for the 6 and 12-month treatments, respectively. CONCLUSION: To our knowledge, this serves as the first in vivo time-course study investigating the use of the PCM device for cervical arthroplasty. All 12 animals undergoing cervical disc replacement had no evidence of implant loosening, subluxation, or inflammatory reactions. PCM cervical arthroplasty permits unobstructed visualization of the spinal canal based on CT imaging. Segmental intervertebral motion was preserved under axial rotation and lateral bending loading conditions, while at the same time permitting porous osseointegration at the prosthesis-bone interface. Based on histopathologic review of all local and systemic tissues, there was no evidence of particulate wear debris, cytokines, cellular apoptosis, or significant pathologic changes in any treatment.
-
Cervical disc replacement-porous coated motion prosthesis: a comparative biomechanical analysis showing the key role of the posterior longitudinal ligament.
Spine, 2003Co-Authors: Paul C Mcafee, Bryan W Cunningham, Anton E. Dmitriev, Niabin Hu, Andy Cappuccino, L PimentaAbstract:STUDY DESIGN: Benchtop cadaveric biomechanical comparative testing and Caprine animal Model in vivo implantation. OBJECTIVE: To evaluate the role of the posterior longitudinal ligament in cervical arthroplasty and to understand the relative contribution of this ligament in nonfusion applications. SUMMARY OF BACKGROUND DATA: Rauschning refers to the posterior longitudinal ligament as "The Kleenex Ligament" due to its apparent anatomic insignificance. White and Panjabi found the posterior longitudinal ligament ranked only fourth in importance in tensile load-to-failure biomechanical testing. In the postoperative situation following anterior cervical diskectomy fusion, posterior longitudinal ligament integrity is overlooked by physicians because the entire disc space usually fuses into a homogeneous block of bone. PURPOSE: This biomechanical study was undertaken to determine the relative importance of the posterior longitudinal ligament following two different degrees of anterior decompression, anterior disc replacement, and anterior arthrodesis procedures. METHODS: A total of seven fresh frozen human cadaveric cervical spines (C3-C7) (mean age 68 +/- 19 years) were used for biomechanical testing. Each vertebra was equipped with three non-colinear light emitting diodes designed for detection by an optoelectronic motion measurement system (3020 Optotract System). To determine the multidirectional flexibility, six pure moments (flexion, extension, right + left lateral bending, right + left axial rotation) and axial compression were applied using a servohydraulic 858 Bionix testing device configured with a six-degree-of-freedom spine simulator. Range of motion was defined as the peak displacement from the initial neutral position to the maximum load, whereas the neutral zone represents the motion from the initial neutral position to the unloaded position at the beginning of the third cycle. Seven groups of (N = 7 each) constructs at C5-C6 were: 1) intact "native" C5-C6 level; 2) anterior diskectomy (posterior longitudinal ligament intact); 3) a Low Profile Porous Coated Motion cervical disc replacement; 4) posterior longitudinal ligament resected; 5) Porous Coated Motion cervical disc replacement fixed with anterior flanges and screws; 6) tricortical structural allograft; and 7) an anterior cervical translational plate + allograft. The Caprine Model was evaluated for suitability as an animal Model with 12 goats undergoing C3-C4 anterior cervical Porous Coated Motion disc replacement. RESULTS: Group 2 (anterior diskectomy alone) was significantly more stable than Group 4 (anterior diskectomy + posterior longitudinal ligament resection) in flexion-extension, 18.7 +/- 4.76 degrees versus 24.8 +/- 4.42 degrees (P < 0.05) and in lateral bending, 5.9 +/- 1.79 degrees versus 10.7 +/- 2.8 degrees (P < 0.05). The comparison for the two conditions for axial rotation, 10.4 +/- 13.9 degrees versus 13.9 +/- 2.7 degrees, and axial compression, 1.19 +/-.98 degrees versus 1.52 +/- 1.14 degrees, showed the same trend. Twelve goats undergoing porous coated motion cervical disc replacement had no evidence of prosthesis loosening, neurologic complications, or experienced inflammatory reactions from particulate wear debris after 6 months of implantation. DISCUSSION: This study confirms the pivotal role of the posterior longitudinal ligament in postsurgical stability of the cervical spine following anterior diskectomy. This is because the lateral anulus, uncovertebral ligaments, and lateral capsular ligaments are stretched and plastically deformed in the surgical distraction process of restoring the disc space height following anterior surgical decompression. There should be a separate determination of the range of motion of cervical disc replacements depending of the integrity and the amount of the posterior longitudinal ligament that has been resected. CLINICAL RELEVANCE: There are two basic types of total knee replacements, posterior cruciate ligament-preserving and posterior cruciate ligament-sacrificing designs. In the cervical spine, an analogous situation exists biomechanically depending on whether the posterior longitudinal ligament needs to be removed in its entirety as part of the spinal cord decompression part of the procedure--it may be helpful to conceptually differentiate between posterior longitudinal ligament-preserving and posterior longitudinal ligament-sacrificing total cervical disc replacements.
A. Toshimitsu Yokobori - One of the best experts on this subject based on the ideXlab platform.
-
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a Caprine Model.
Journal of neurosurgery, 1999Co-Authors: T Takahashi, Naohito Watabe, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Takayuki YoshimotoAbstract: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. Fourteen mature goats underwent three-level anterior discectomies after induction of endotracheal anesthesia. Porous HA grafts that contained 0, 5, and 50 microg 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. Through osteogenesis at the fusion site, the addition of rhBMP-2 to a porous HA ceramic graft enhances the rate of anterior cervical fusion.
-
use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein 2 for cervical fusion in a Caprine Model
Journal of Neurosurgery, 1999Co-Authors: T Takahashi, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Noriaki Watabe, Takashi YoshimotoAbstract: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 ...
-
Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a Caprine Model.
Journal of neurosurgery, 1999Co-Authors: T Takahashi, Naohito Watabe, Hiroyuki Sasada, A. Toshimitsu Yokobori, Teiji Tominaga, Takayuki YoshimotoAbstract: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.
