To prevent the reported side effects of rhBMP-2, an important cytokine with bone forming capacity, the sustained release of rhBMP-2 is highly important. Synthetic copolymer polylactic acid-polyethylene glycol (PLA-PEG) is already shown to be a good carrier for rhBMP-2. The nano-sized hydroxyapatite (nHAp) is mentioned to be superior to conventional hydroxyapatite due to its decreased particle size which increases the surface area, so protein-cell adhesion and mechanical properties concomitantly. In the literature no study is reported with PLA-PEG / rhBMP-2/ nHAp for bone regeneration. In this study, we assessed the controlled release profile of rhBMP-2 from the novel biomaterial of PLA-PEG / rhBMP-2 / nHAp in vitro and evaluated the bone forming capacity of the composite in rat posterolateral spinal fusion (PSF) model in vivo. Composites were prepared via addition of rhBMP-2 (0µg, 3µg or 10µg) and nHAp (12.5mg) into PLA-PEG (5mg) + acetone solution and shaping. The release kinetics of the cytokine from the composites with 5µg BMP-2 was investigated by ELISA. The effect of nHAp and nHAp with rhBMP-2 on cell differentiation (rat BMSC cells, passage 3) was tested with ALP staining. In vivo bone formation was investigated by PSF on L4-L5 in a total of 36 male SD rats and weekly µCT results and histology at 8th weeks post operation were used for assessment of the bone formation. All animal experiments was approved by the institutional review board confirming to the laws and regulations of Japan. The composite showed an initial burst release in the first 24 hours (51.7% of the total released rhBMP-2), but the release was continued for the following 21 days. Thus, the sustained release of rhBMP-2 from the composite was verified. ALP staining results showed nHAp with rhBMP-2 contributed better on differentiation than nHAp itself. µCT and histology demonstrated that spinal fusion was achieved either one or both transverse processes in almost all BMP 3µg and BMP 10µg treated animals. On the contrary, only small or no bone formation was observed in the BMP0µg group (bilateral non-union / unilateral fusion/ bilateral fusion, BMP0µg group; 9/0/0, BMP3µg group; 1/0/11, BMP10µg group; 0/1/11). We developed a new technology for bone regeneration with BMP-2/PLA-PEG/nHAp composite. With this composite, the required dose of BMP-2 for spinal fusion in rats (10µg) was decreased to 1/3 (3µg) which can be explained by the superior properties of nano-sized hydroxyapatite and by the achievement of sustainable release of rhBMP-2 from the composite. This study is supported by Japanese Society of the Promotion of Science (JSPS) and Scientific and Technological Research Council of Turkey (TUBITAK). [Project No: 215S834]
Bi-cruciate stabilized (BCS) TKA is the prosthesis that aims to substitute bi-cruciate ligament with post-cam engagement. We estimated to describe the
Our aim was to investigate whether it is possible to predict post-operative kinematics (Post-Ope) from intra-operative kinematics (Intra-Ope) after total knee arthroplasty. Our study were performed for 11 patients (14 knees) who underwent primary PS TKA using CT-based navigation system between Sept.2012 and Sept.2014. The mean subject age was 71.5 ± 5.5 years at the time of surgery. Intra-Ope was measured using the navigation system after implantation during passive full extension and flexion imposed by the surgeon. Under fluoroscopic surveillance, each patient was asked to perform sequential deep knee flexion under both non-weight bearing (NWB) and weight bearing (WB) conditions from full extension to maximum flexion. To estimate the spatial position and orientation, we used a 2- to 3- dimensional (2D3D) registration technique. Intra-Ope and Post-Ope had a common coordinate axis for bones. Evaluations were range of motion (ROM), external rotation angles (ER). The level of statistical significant difference was set at 0.05. Mean ROM in Intra-Ope(130°± 7.9°) was statistically larger than both NWB(121.1°±10.5°) and WB(124.0°±14.7°). No Statistically significant difference was found in the mean ER from 10° to 120° among Intra-Ope (11.2°± 8.5°) and NWB(7.1°±6.0°) and WB(5.3°±3.2°). It is suggested that we could predict Post-Ope from Intra-Ope by considering the increase of the range of motion due to the muscle relaxation condition and the amount of change in the ER.
This study was to investigate the effect of posterior tibial slope (PTS) on the kinematics in the cruciate-retaining total knee arthroplasty (CR-TKA) using 2- to 3- dimensional registration technique. A total of 75 knees in 58 patients were recruited and categorized into the following two groups according to PTS. Group A was categorized PTS under 7degrees (n = 33) and group B was categorized PTS over 7 degrees (n = 42). The average age of group A and group B at the time of fluoroscopic surveillance date was 73.5 ± 7.4 years and 74.3 ± 4.5 years, respectively and the average follow-up period from operation date to fluoroscopic surveillance date was 13.8 ± 9.3 months and 16.7 ± 8.6 months, respectively. In vivo kinematics during sequential deep knee bending under weight-bearing condition were evaluated using fluoroscopic image analysis and 2- to 3- dimensional registration technique. Range of motion (ROM), axial rotation, anteroposterior (AP) translations of medial and lateral nearest points of the femoral component relative to the tibial component were measured and compared between the two groups. The nearest points were determined by calculating the closest distance between the surfaces of femoral component model and the axial plane of coordinate system of the tibial component. We defined external rotation and anterior translation as positive. P values under 0.05 was defined as statistically significant.Purpose
Material & Methods
We hypothesized that using the navigation system, intra-operative knee kinematics after implantation measured may predict that post-operative kinematic in activities of daily living. Our aim was to compare intra-operative knee kinematics by a computed tomography (CT)-based navigation system and post-operative by the 2- to 3-dimensional registration techniques (2D3D). This study were performed for 8 patients (10 knees, medial osteoarthritis) who underwent primary PS TKA using CT-based navigation system. The median follow-up period from operation date to fluoroscopic surveillance date was 13 months (range 5 – 37 months). Navigation and 2D3D had a common coordinate origin for components. Medial and lateral femoral condyle anterior-posterior translation (MFT and LFT) were respectively defined as the distance of the projection of the points (which was set on the top of the posterior femoral pegs) onto the axial plane of the tibial coordinate system. Intraoperative kinematics was measured using the navigation system after final implantation and closure of the retinaculum during passive full flexion and extension imposed by the surgeon. Under fluoroscopic surveillance in the sagittal plane, each patient was asked to perform sequential deep knee flexion under both weight bearing (WB) and non-weight bearing (NWB) conditions from full extension to maximum flexion. Repeated two-way ANOVA (tasks × flexion angles) were used, and then post-hoc test (paired t-tests with Boferroni correction) were performed. The level of statistical significant difference was set at 0.05 on two-way ANOVAs and 0.05 / 3 on post-hoc paired t-tests. Mean range of motion between femoral and tibial components were Intra-operative (Intra): 28.0 ± 9.7, NWB conditions: 120.6 ± 11.1, WB conditions: 125.1 ± 12.9°, respectively. Mean ER (+) / IR (−) from 0° to 120° were Intra-operative (Intra): 9.3 ± 10.2°, NWB conditions: 8.1 ± 8.9, WB conditions: 5.2 ± 7.0, respectively. Mean MFT /LFT from 0° to 90° were Intra; 4.4 ±14.8/ 4.2± 8.5mm, NWB; 6.2 ± 6.9 / 9.2 ± 3.1 mm, WB; 9.2 ± 3.5 / 7.4 ± 2.8 mm, respectively. Mean MFT /LFT from 90° to 120° were Intra; −4.4 ± 2.5 / −5.7 ± 2.9 mm, NWB; −5.5 ± 1.8 / −8.2 ± 0.6 mm, WB; −4.0 ± 1.9 / −5.4 ± 2.3mm, respectively. Mean ADD/ABD from 0° to 120° were Intra;-4.2 ± 3.0, NWB; −0.2 ± 2.1, WB; −0.1 ± 0.8, respectively. Repeated two-way ANOVA showed a significant all interaction on kinematic variables (p<0.05). No statistically significant difference at post-hoc test was found in ER/ IR of all tasks and MFT /LFT of Intra vs NWB and Intra vs WB from 0° to 120° (p>0.05 / 3). The Conditions of these tasks were different from each others. Our study demonstrated that intra-operative kinematics could predict post-operative kinematics.
The purpose of this study is to investigate the three-dimensional (3D) kinematics of normal knees in deep knee-bending motions like squatting and kneeling. Material & Methods: We investigated the in vivo kinematics of 4 Japanese healthy male volunteers (8 normal knees in squatting, 7 normal knees in kneeling). Each sequential motion was performed under fluoroscopic surveillance in the sagittal plane. Femorotibial motion was analyzed using 2D/3D registration technique, which uses computer-assisted design (CAD) models to reproduce the spatial position of the femur and tibia from single-view fluoroscopic images. We evaluated the femoral rotation relative to the tibia and anteroposterior (AP) translation of the femoral sulcus and lateral epicondyle on the plane perpendicular to the tibial mechanical axis. Student's t test was used to analyze differences in the absolute value of axial rotation and AP translation of the femoral sulcus and lateral epicondyle during squatting and kneeling. Values of P < 0.05 were considered statistically significant. During squatting, knees were gradually flexed from −2.8 ± 1.3° to 145.5 ± 5.1° on average. Knees were gradually flexed from 100.8 ± 3.9° to 155.6 ± 3.2° on average during kneeling. Femurs during squatting displayed sharp external rotation relative to the tibia from 0° to 30° of flexion and it reached 12.5 ± 3.3° on average. From 30° to 130° of flexion, the femoral external rotation showed gradually, and it reached 19.1 ± 7.3° on average. From 130° to 140° of flexion, it was observed additionally, and reached 22.4 ± 6.1° on average. All kneeling knees displayed femoral external rotation relative to the tibia sharply from 100° to 150° of flexion, and it reached 20.7 ± 7.5° on average. From 100° to 120° of flexion, the femoral external rotation during squatting was larger than that during kneeling significantly. From 120° to 140° of flexion, there was no significant difference between squatting and kneeling. The sulcus during squatting moved 4.1 ± 4.8 mm anterior from 0° to 60° of flexion. From 60° of flexion it moved 13.6 ± 13.4 mm posterior. The sulcus during kneeling was not indicated significant movement with the knee flexion. The lateral epicondyle during squatting moved 39.4 ± 7.7 mm posterior from 0° to 140° of flexion. The lateral epicondyle during kneeling moved 22.0 ± 5.4 mm posterior movement from 100° to 150° of flexion. In AP translation of the sulcus from 100° to 140° of flexion, there was no significant difference between squatting and kneeling. However in that of the lateral epicondyle, squatting groups moved posterior significantly. Even if they were same deep knee-bending, the kinematics were different because of the differences of daily motions. The results in this study demonstrated that in vivo kinematics of deep knee-bending were different between squatting and kneeling.
Excessive mechanical stress on synovial joints causes osteoarthritis
(OA) and results in the production of prostaglandin E2 (PGE2), a
key molecule in arthritis, by synovial fibroblasts. However, the
relationship between arthritis-related molecules and mechanical
stress is still unclear. The purpose of this study was to examine
the synovial fibroblast response to cyclic mechanical stress using
an Human synovial fibroblasts were cultured on collagen scaffolds
to produce three-dimensional constructs. A cyclic compressive loading
of 40 kPa at 0.5 Hz was applied to the constructs, with or without
the administration of a cyclooxygenase-2 (COX-2) selective inhibitor
or dexamethasone, and then the concentrations of PGE2, interleukin-1β (IL-1β),
tumour necrosis factor-α (TNF-α), IL-6, IL-8 and COX-2 were measured.Objective
Method
The effect of the geometry of the tibial polyethylene insert was investigated in vivo loaded conditions. The decision to choose CR (cruciate retaining) insert or CS (condylar stabilised) insert during TKA remains a controversial issue. Triathlon CS type has a condylar stabilised insert with an increased anterior lip that can be used in cases where the PCL is sacrificed but a PS insert is not used. The difference of the knee kinematics between CR and CS insert remains unclear. This study measured knee kinematics of deep knee flexion under load in two insert designs using 2D/3D registration technique.Summary
Introduction
Lesion location and volume are critical factors to select patients with osteonecrosis for whom resurfacing arthroplasty is appropriate. However, no reliable surgical planning system which can assess relationship between necrotic lesions and the femoral component has been established. We have developed a 3D-MRI-based planning system for resurfacing arthroplasty. The purpose of the present study was to evaluate its feasibility. The subjects included five patients with osteonecrosis of ARCO stage 3 or 4 who had undergone resurfacing THA at our institute. All patients had an MRI before surgery using 3D-SPGR sequences and fat suppression 3D-SPGR sequencea. In cases where it was difficult to distinguish bone marrow edema and reparative zone on 3D-SPGR images, fat suppression 3D-SPGR sequences were used. Simulation of resurfacing arthroplasty was performed on image analysis software where multidirectional oblique views could be reconstructed. The femoral neck axis was determined by drawing line through centers of two spheres which were fitted to the normal portion of the femoral head and the mid-portion of femoral neck. A femoral component was virtually implanted to align the femoral neck axis and match the implant center and femoral head center.Introduction
Methods
In osteonecrosis of the femoral head (ONFH), progression of collapse is influenced by a repair reaction, especially bone resorptive activity, around the necrotic bone. Alendronate is a potent inhibitor of bone resorption by inhibiting osteoclast activity. We performed a clinical study to test if systemic alendronate treatment would prevent the development of collapse in patients with ONFH. Thirty-three hips in 22 ONFH patients with initial ARCO Stage 1 to 3 were included. Fourteen patients (20 hips) received daily administration of oral alendronate 5mg/day (alendronate group) and 8 patients (13 hips) did not receive alendronate administration (Control group). Baseline investigations included anteroposterior and lateral plain radiographs, T1-weighted magnetic resonance imaging (MRI), and biochemical markers (urinary NTX and serum BAP). Examination of the biochemical markers were repeated at 3, 6, and 12 months, and MRI imaging was repeated at 12 months. At 3 years, clinical symptoms and findings on plain radiographs were compared between the 2 groups. Advancement of ARCO stages or increase of collapse by more than 2 mm were considered as development of collapse.Introduction
Methods
Femoral neck fracture (FNF) is a common trauma in the elderly individuals. When the blood supply to the femoral head is impaired with a fracture event, the reduction or disruption of blood supply to the bone, hypoxia, leads to death of the bone marrow and trabecular bone, and eventual late segmental collapse. In the reparative process, osteoblasts and osteoclasts perform the important function of repairing the fracture site at the femoral neck. However, the reparative reaction including angiogenesis and osteogenesis remains unknown. In order to investigate the reparative reaction in patients with FNF, the distribution of tartrate resistant acid phosphatase (TRAP)-positive cells and expression of HIF-1 alpha, VEGF, and FGF-2 were observed in 36 hips in 35 patients. There were 6 men and 30 women who had a mean age of 79 years (range, 58 to 94 years). There were 10 hips with Garden stage 3, and 26 hips with Garden stage 4. The mean duration from onset to the surgery was 12 days (range: 1 to 82 days). Hematoxylin eosin staining, TRAP staining, immunohistochemistry using anti HIF-1 alpha, anti VEGF, and anti FGF-2 antibodies were performed for retrieved whole femoral heads. As a control, one femoral head in a patient who underwent wide resection for metastatic acetabular tumor was used.Introduction
Methods
We investigated the rates of expression of bone morphogenetic protein-2 (BMP-2) in 29 adult patients with high-grade malignant fibrous histiocytoma of soft tissue, using the BMP-2-specific monoclonal antibody, AbH3b2/17, and found that they ranged from 1.9% to 78.9%. The survival at five years of the groups expressing high (≥30%) and low (<
30%) levels of BMP-2 was 85.7% and 36.3%, respectively. Multivariable analysis showed that only BMP-2 had prognostic significance for continuous disease-free survival and for overall survival (p <
0.05). Our findings indicate that over-expression of BMP-2 in malignant fibrous histiocytoma of soft tissue is the most reliable prognostic indicator of the parameters assessed.
