The function of the anterior cruciate ligament was investigated for different conditions of kinem... more The function of the anterior cruciate ligament was investigated for different conditions of kinematic constraint placed on the intact knee using a six-degree-of-freedom robotic manipulator combined with a universal force-moment sensor. To do this, the in situ forces and force distribution within the porcine anterior cruciate ligament during anterior tibial loading up to 100 N were compared at 30, 60, and 90 degrees of flexion under: (a) unconstrained, five-degree-of-freedom knee motion, and (b) constrained, one-degree-of-freedom motion (i.e., anterior translations only). The robotic/universal force-moment sensor testing system was used to both apply the specified external loading to the intact joint and measure the resulting kinematics. After tests of the intact knee were completed, all soft tissues except the anterior cruciate ligament were removed, and these motions were reproduced such that the in situ force and force distribution could be determined. No significant differences in the magnitude of in situ forces in the anterior cruciate ligament were found between the unconstrained and constrained testing conditions. In contrast, the direction of in situ force changed significantly; the force vector in the unconstrained case was more parallel with the direction of the applied tibial load. In addition, the distribution of in situ force between the anteromedial and posterolateral bundles of the ligament was nearly equal for all flexion angles for the unconstrained case, whereas the anteromedial bundle carried higher forces than the posterolateral bundle at both 60 and 90 degrees of flexion for the constrained case. This demonstrates that the constraint conditions placed on the joint have a significant effect on the apparent role of the anterior cruciate ligament. Specifically, constraining joint motion to one degree of freedom significantly alters both the direction and distribution of the in situ force in the ligament from that observed for unconstrained joint motion (five degrees of freedom). Furthermore, the changes observed in the distribution of force between the anteromedial and posterolateral bundles for different constraint conditions may help elucidate mechanisms of injury by providing new insight into the response of the anterior cruciate ligament to different types of external knee loading.
The objective of this study was to assess the long-term stability and mechanical strength of a no... more The objective of this study was to assess the long-term stability and mechanical strength of a novel unidirec-tional porous hydroxyapatite (UDPHAp). Thirty-five Japanese white rabbits were used in the study. A cylindrical piece of UDPHAp was implanted in the femoral marrow. The animals were sacrificed 6, 12, 52 and 104 weeks after implantation. Compression strength was measured in a direction parallel to that of the unidirectional pores. The mean compression strength of the control sample before implantation was 13.4 MPa. The mean compression strength was 29.5 MPa, 43.5 MPa, 49.2 Mpa, 39.4 MPa and 45.8 MPa at 6, 12, 26, 52 and 104 weeks after implantation, respectively. Statistically significant differences were observed between the control samples and the implanted samples at all time points and between the im-planted samples tested at 6 and 26 weeks after implantation. UDPHAp offers an advantage with regard to mechanical strength in that the compression strength in the direction p...
Marginal resection during resection of a spinal metastasis is frequently difficult because of the... more Marginal resection during resection of a spinal metastasis is frequently difficult because of the presence of important tissues such as the aorta, vena cava, and dura mater, including the spinal cord adjacent to the vertebral body. Thus, there is an urgent need for novel intraoperative imaging modalities with the ability to clearly identify bone metastasis. We have proposed a novel nanocarrier loaded with indocyanine green (ICG) (ICG-lactosome) with tumor selectivity attributable to its enhanced permeation and retention (EPR) effect. We studied its feasibility in intraoperative near-infrared (NIR) fluorescence diagnosis with ICG-lactosome for imaging spinal metastasis. A rat model of subcutaneous mammary tumor and a rat model of spinal metastasis of breast cancer were used. Fluorescence emitted by the subcutaneous tumors and the spinal metastasis were clearly detected for at least 24 h. Moreover, imaging of the dissected spine revealed clear fluorescence emitted by the metastatic le...
In the present study, we have newly developed an artificial bone substitute, which is unidirectio... more In the present study, we have newly developed an artificial bone substitute, which is unidirectional porous β-tricalcium phosphate (UDPTCP). The objective of this study was to examine the effects of high and low porosity substitutes on the balance between new bone formation and β-TCP absorption. Materials and Methods Six male Japanese white rabbits (weight 3.1–3.5 kg, approximately 18– 21 weeks old) were used for this study. Intra-venous injection of pent barbiturate was administered and the both medial and lateral femoral condyle were exposed. A hole of 5 mm diameter was drilled to a depth of 12 mm in the metaphysis, perpendicular to the long axis of the femur. (Figure 1) Figure 1. Operation procedureIn the next step, a cylindrical UDPTCP test piece measuring 4.8 × 11 mm was implanted in the holes. Within the bone substitute, unidirectional pores ranging from 100 to 300 μm in diameter were made. This unique architecture fostered transmission of fluids and cells into the piece. In t...
https://ispub.com/IJSS/9/1/21527 Background Although percutaneous endoscopic debridement and drai... more https://ispub.com/IJSS/9/1/21527 Background Although percutaneous endoscopic debridement and drainage (PEDD) has been shown to be useful for septic spondylodiscitis, there are no reports regarding the effectiveness of this technique for patients with marked bone destruction. Purposes To determine the clinical outcomes of PEDD for septic spondylodiscitis with peridiscal destructive bony defect of the infected vertebrae by quantitatively evaluating the severity of bone destruction. To determine the appropriate candidates for PEDD. Patients and Methods Twelve consecutive patients (mean age, 76.3 years; range, 58-88 years) with thoracic/lumbar septic spondylodiscitis with marked bone destruction treated with PEDD between April 2008 and March 2013 were retrospectively analyzed. Most patients had serious comorbid medical problems. A good treatment outcome was defined as infection control with PEDD. Results Eight out of 12 patients had good treatment outcomes. In these patients, the depth ...
ABSTRACT We recently synthesized a novel unidirectional porous hydroxyapatite (UDPHAp) material w... more ABSTRACT We recently synthesized a novel unidirectional porous hydroxyapatite (UDPHAp) material with a microstructure consisting of cross-sectional oval pores (diameter, 100-300 μm) . The unidirectional pores of UDPHAp are expected to facilitate the ingrowth of new tissues at sites of implantation. Here, we estimated the osteoinductive capacity of UDPHAp following its implantation in the dorsal muscles of dogs, and also investigated the affinity of UDPHAp for muscle and connective tissues. As a reference material, the HAp porous ceramic product Apaceram® (HOYA, Tokyo, Japan), which is commercially available in Japan and has a different microstructure from UDPHAp, was also used. A cylinder-shaped UDPHAp block was implanted in the dorsal muscles of two beagle dogs. At 1 and 2 years post-implantation, muscle and connective tissues had directly attached to UDPHAp at the upper and lower perforated surfaces. Histological assessment, revealed the direct invasion of fibrous tissues and small capillaries into the unidirectional pores of UDPHAp. Notably, no osseous tissue had formed within UDPHAp. Our findings suggest that the unidirectional pores of UDPHAp are advantageous for the vascularization and invasion of fibrous tissues. However, this unique structure does not contribute to osteoinductive capacity.
Journal of materials science. Materials in medicine, 2014
The purpose of this study was to clinically and radiologically evaluate the availability, osteoco... more The purpose of this study was to clinically and radiologically evaluate the availability, osteoconductivity, and resorption of a novel unidirectional porous hydroxyapatite (UDPHAp) used as an artificial substitute for open wedge high tibial osteotomy (OWHTO). Our hypothesis was that UDPHAp is a safe and useful bone substitute for OWHTO. Seven patients (2 men and 5 women aged 34-72years) who underwent OWHTO and were followed up for more than 12months were retrospectively studied. After the osteotomy, the gap created was filled with UDPHAp(REGENOS® Kuraray Co.Ltd). Radiography and computed tomography(CT) were performed, and gap healing was assessed postoperatively. The Japanese Orthopaedic Association (JOA) knee score was determined pre- and post-operatively for clinical evaluation. Neither gross displacement nor collapse of the UDPHAp block graft was observed within 12 months after surgery. Both radiographs and CT showed attenuation of lucency and increasing sclerosis over time. JOA ...
The purpose of the present study was to fabricate fibroblast growth factor (FGF)-2-apatite compos... more The purpose of the present study was to fabricate fibroblast growth factor (FGF)-2-apatite composite layers on titanium (Ti) pins in one step at 25 °C using a supersaturated calcium phosphate (CaP) solution, and to evaluate the physicochemical characteristics and biological effects of the coated Ti pins compared with coated Ti pins fabricated at 37 °C. Ti pins were immersed in a supersaturated CaP solution containing 0.5, 1.0, or 2.0 µg/mL FGF-2 at 25 °C for 24 h (25F0.5, 25F1.0, and 25F2.0) or containing 4.0 µg/mL FGF-2 at 37 °C for 48 h (37F4.0). Except for the 25F0.5, the chemical compositions and the mitogenic activity levels of FGF-2 of the composite layers formed by these two methods were similar, except for the Ca/P molar ratio, which was markedly smaller at 25 °C (1.55-1.56±0.01-0.02, p=0.0008-0.0045) than at 37 °C (1.67±0.11). Thus, either the apatite was less mature or the amount of amorphous calcium phosphate was higher in the composite layer formed at 25 °C. In vivo, the...
Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine, 2014
The influence of circadian rhythms has recently been considered in advanced studies of chronophar... more The influence of circadian rhythms has recently been considered in advanced studies of chronopharmacology and chronotherapeutics. Although emerging studies have reported the usefulness of platelet-rich plasma (PRP), no reports have described the diurnal variations in PRP growth factor levels. In the present study, we hypothesized that growth factor levels in PRP show a significant diurnal variation. Controlled laboratory study. Institutional. Ten adult male volunteers (mean age, 30.0 ± 2.6 years; range, 26-34 years). Each subject donated a 20-mL sample of fasting blood, 4 times per day (7 AM, 11 AM, 3 PM, and 7 PM). Each blood sample was processed to produce PRP. Complete blood counts of peripheral blood (PB) and PRP, as well as quantitative determination of PRP growth factor levels (platelet-derived growth factor and transforming growth factor) were performed. Statistical analyses were conducted using a one-way repeated measures analysis of variance. No significant differences were...
Idiopathic spinal cord herniation is a rare disease, and surgical treatment is recommended for pa... more Idiopathic spinal cord herniation is a rare disease, and surgical treatment is recommended for patients with motor deficits or progressive neurological symptoms. Surgery is performed to release and reposition the tethered spinal cord. In terms of repositioning and prevention of reherniation, various procedures have been proposed; enlargement of the ventral dural defect, primary closure of the defect with sutures, and insertion of a ventral patch for duraplasty. We treated 3 patients with idiopathic spinal cord herniation, using a ventral patch for duraplasty with an expanded polytetrafluoroethylene pericardial membrane (the Hammock method), and all 3 cases had good clinical outcome. The specific important technical aspects are described and illustrated. If this procedure is performed meticulously under the microscope by following the specific techniques, the Hammock method is safer and more effective for prevention of reherniation than simple enlargement of the dural defect.
The function of the anterior cruciate ligament was investigated for different conditions of kinem... more The function of the anterior cruciate ligament was investigated for different conditions of kinematic constraint placed on the intact knee using a six-degree-of-freedom robotic manipulator combined with a universal force-moment sensor. To do this, the in situ forces and force distribution within the porcine anterior cruciate ligament during anterior tibial loading up to 100 N were compared at 30, 60, and 90 degrees of flexion under: (a) unconstrained, five-degree-of-freedom knee motion, and (b) constrained, one-degree-of-freedom motion (i.e., anterior translations only). The robotic/universal force-moment sensor testing system was used to both apply the specified external loading to the intact joint and measure the resulting kinematics. After tests of the intact knee were completed, all soft tissues except the anterior cruciate ligament were removed, and these motions were reproduced such that the in situ force and force distribution could be determined. No significant differences in the magnitude of in situ forces in the anterior cruciate ligament were found between the unconstrained and constrained testing conditions. In contrast, the direction of in situ force changed significantly; the force vector in the unconstrained case was more parallel with the direction of the applied tibial load. In addition, the distribution of in situ force between the anteromedial and posterolateral bundles of the ligament was nearly equal for all flexion angles for the unconstrained case, whereas the anteromedial bundle carried higher forces than the posterolateral bundle at both 60 and 90 degrees of flexion for the constrained case. This demonstrates that the constraint conditions placed on the joint have a significant effect on the apparent role of the anterior cruciate ligament. Specifically, constraining joint motion to one degree of freedom significantly alters both the direction and distribution of the in situ force in the ligament from that observed for unconstrained joint motion (five degrees of freedom). Furthermore, the changes observed in the distribution of force between the anteromedial and posterolateral bundles for different constraint conditions may help elucidate mechanisms of injury by providing new insight into the response of the anterior cruciate ligament to different types of external knee loading.
The objective of this study was to assess the long-term stability and mechanical strength of a no... more The objective of this study was to assess the long-term stability and mechanical strength of a novel unidirec-tional porous hydroxyapatite (UDPHAp). Thirty-five Japanese white rabbits were used in the study. A cylindrical piece of UDPHAp was implanted in the femoral marrow. The animals were sacrificed 6, 12, 52 and 104 weeks after implantation. Compression strength was measured in a direction parallel to that of the unidirectional pores. The mean compression strength of the control sample before implantation was 13.4 MPa. The mean compression strength was 29.5 MPa, 43.5 MPa, 49.2 Mpa, 39.4 MPa and 45.8 MPa at 6, 12, 26, 52 and 104 weeks after implantation, respectively. Statistically significant differences were observed between the control samples and the implanted samples at all time points and between the im-planted samples tested at 6 and 26 weeks after implantation. UDPHAp offers an advantage with regard to mechanical strength in that the compression strength in the direction p...
Marginal resection during resection of a spinal metastasis is frequently difficult because of the... more Marginal resection during resection of a spinal metastasis is frequently difficult because of the presence of important tissues such as the aorta, vena cava, and dura mater, including the spinal cord adjacent to the vertebral body. Thus, there is an urgent need for novel intraoperative imaging modalities with the ability to clearly identify bone metastasis. We have proposed a novel nanocarrier loaded with indocyanine green (ICG) (ICG-lactosome) with tumor selectivity attributable to its enhanced permeation and retention (EPR) effect. We studied its feasibility in intraoperative near-infrared (NIR) fluorescence diagnosis with ICG-lactosome for imaging spinal metastasis. A rat model of subcutaneous mammary tumor and a rat model of spinal metastasis of breast cancer were used. Fluorescence emitted by the subcutaneous tumors and the spinal metastasis were clearly detected for at least 24 h. Moreover, imaging of the dissected spine revealed clear fluorescence emitted by the metastatic le...
In the present study, we have newly developed an artificial bone substitute, which is unidirectio... more In the present study, we have newly developed an artificial bone substitute, which is unidirectional porous β-tricalcium phosphate (UDPTCP). The objective of this study was to examine the effects of high and low porosity substitutes on the balance between new bone formation and β-TCP absorption. Materials and Methods Six male Japanese white rabbits (weight 3.1–3.5 kg, approximately 18– 21 weeks old) were used for this study. Intra-venous injection of pent barbiturate was administered and the both medial and lateral femoral condyle were exposed. A hole of 5 mm diameter was drilled to a depth of 12 mm in the metaphysis, perpendicular to the long axis of the femur. (Figure 1) Figure 1. Operation procedureIn the next step, a cylindrical UDPTCP test piece measuring 4.8 × 11 mm was implanted in the holes. Within the bone substitute, unidirectional pores ranging from 100 to 300 μm in diameter were made. This unique architecture fostered transmission of fluids and cells into the piece. In t...
https://ispub.com/IJSS/9/1/21527 Background Although percutaneous endoscopic debridement and drai... more https://ispub.com/IJSS/9/1/21527 Background Although percutaneous endoscopic debridement and drainage (PEDD) has been shown to be useful for septic spondylodiscitis, there are no reports regarding the effectiveness of this technique for patients with marked bone destruction. Purposes To determine the clinical outcomes of PEDD for septic spondylodiscitis with peridiscal destructive bony defect of the infected vertebrae by quantitatively evaluating the severity of bone destruction. To determine the appropriate candidates for PEDD. Patients and Methods Twelve consecutive patients (mean age, 76.3 years; range, 58-88 years) with thoracic/lumbar septic spondylodiscitis with marked bone destruction treated with PEDD between April 2008 and March 2013 were retrospectively analyzed. Most patients had serious comorbid medical problems. A good treatment outcome was defined as infection control with PEDD. Results Eight out of 12 patients had good treatment outcomes. In these patients, the depth ...
ABSTRACT We recently synthesized a novel unidirectional porous hydroxyapatite (UDPHAp) material w... more ABSTRACT We recently synthesized a novel unidirectional porous hydroxyapatite (UDPHAp) material with a microstructure consisting of cross-sectional oval pores (diameter, 100-300 μm) . The unidirectional pores of UDPHAp are expected to facilitate the ingrowth of new tissues at sites of implantation. Here, we estimated the osteoinductive capacity of UDPHAp following its implantation in the dorsal muscles of dogs, and also investigated the affinity of UDPHAp for muscle and connective tissues. As a reference material, the HAp porous ceramic product Apaceram® (HOYA, Tokyo, Japan), which is commercially available in Japan and has a different microstructure from UDPHAp, was also used. A cylinder-shaped UDPHAp block was implanted in the dorsal muscles of two beagle dogs. At 1 and 2 years post-implantation, muscle and connective tissues had directly attached to UDPHAp at the upper and lower perforated surfaces. Histological assessment, revealed the direct invasion of fibrous tissues and small capillaries into the unidirectional pores of UDPHAp. Notably, no osseous tissue had formed within UDPHAp. Our findings suggest that the unidirectional pores of UDPHAp are advantageous for the vascularization and invasion of fibrous tissues. However, this unique structure does not contribute to osteoinductive capacity.
Journal of materials science. Materials in medicine, 2014
The purpose of this study was to clinically and radiologically evaluate the availability, osteoco... more The purpose of this study was to clinically and radiologically evaluate the availability, osteoconductivity, and resorption of a novel unidirectional porous hydroxyapatite (UDPHAp) used as an artificial substitute for open wedge high tibial osteotomy (OWHTO). Our hypothesis was that UDPHAp is a safe and useful bone substitute for OWHTO. Seven patients (2 men and 5 women aged 34-72years) who underwent OWHTO and were followed up for more than 12months were retrospectively studied. After the osteotomy, the gap created was filled with UDPHAp(REGENOS® Kuraray Co.Ltd). Radiography and computed tomography(CT) were performed, and gap healing was assessed postoperatively. The Japanese Orthopaedic Association (JOA) knee score was determined pre- and post-operatively for clinical evaluation. Neither gross displacement nor collapse of the UDPHAp block graft was observed within 12 months after surgery. Both radiographs and CT showed attenuation of lucency and increasing sclerosis over time. JOA ...
The purpose of the present study was to fabricate fibroblast growth factor (FGF)-2-apatite compos... more The purpose of the present study was to fabricate fibroblast growth factor (FGF)-2-apatite composite layers on titanium (Ti) pins in one step at 25 °C using a supersaturated calcium phosphate (CaP) solution, and to evaluate the physicochemical characteristics and biological effects of the coated Ti pins compared with coated Ti pins fabricated at 37 °C. Ti pins were immersed in a supersaturated CaP solution containing 0.5, 1.0, or 2.0 µg/mL FGF-2 at 25 °C for 24 h (25F0.5, 25F1.0, and 25F2.0) or containing 4.0 µg/mL FGF-2 at 37 °C for 48 h (37F4.0). Except for the 25F0.5, the chemical compositions and the mitogenic activity levels of FGF-2 of the composite layers formed by these two methods were similar, except for the Ca/P molar ratio, which was markedly smaller at 25 °C (1.55-1.56±0.01-0.02, p=0.0008-0.0045) than at 37 °C (1.67±0.11). Thus, either the apatite was less mature or the amount of amorphous calcium phosphate was higher in the composite layer formed at 25 °C. In vivo, the...
Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine, 2014
The influence of circadian rhythms has recently been considered in advanced studies of chronophar... more The influence of circadian rhythms has recently been considered in advanced studies of chronopharmacology and chronotherapeutics. Although emerging studies have reported the usefulness of platelet-rich plasma (PRP), no reports have described the diurnal variations in PRP growth factor levels. In the present study, we hypothesized that growth factor levels in PRP show a significant diurnal variation. Controlled laboratory study. Institutional. Ten adult male volunteers (mean age, 30.0 ± 2.6 years; range, 26-34 years). Each subject donated a 20-mL sample of fasting blood, 4 times per day (7 AM, 11 AM, 3 PM, and 7 PM). Each blood sample was processed to produce PRP. Complete blood counts of peripheral blood (PB) and PRP, as well as quantitative determination of PRP growth factor levels (platelet-derived growth factor and transforming growth factor) were performed. Statistical analyses were conducted using a one-way repeated measures analysis of variance. No significant differences were...
Idiopathic spinal cord herniation is a rare disease, and surgical treatment is recommended for pa... more Idiopathic spinal cord herniation is a rare disease, and surgical treatment is recommended for patients with motor deficits or progressive neurological symptoms. Surgery is performed to release and reposition the tethered spinal cord. In terms of repositioning and prevention of reherniation, various procedures have been proposed; enlargement of the ventral dural defect, primary closure of the defect with sutures, and insertion of a ventral patch for duraplasty. We treated 3 patients with idiopathic spinal cord herniation, using a ventral patch for duraplasty with an expanded polytetrafluoroethylene pericardial membrane (the Hammock method), and all 3 cases had good clinical outcome. The specific important technical aspects are described and illustrated. If this procedure is performed meticulously under the microscope by following the specific techniques, the Hammock method is safer and more effective for prevention of reherniation than simple enlargement of the dural defect.
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Papers by Masataka Sakane