Recent anthropometric studies have suggested that current design of total knee arthroplasty (TKA) does not cater to racial anthropometric differences. The purpose of this study was to investigate the exact sizing and rotational landmarks of the distal femur collected and its gender differences from a large group of healthy Southern Chinese using 3D-CT measurements, and then compare these measurements to the five total knee prostheses conventionally used in China. This study evaluated distal femoral geometry in 85 healthy Southern Chinese, included 39 females (78 knees) and 46 males (92 knees) with a mean age of 33.9 years,a mean height of 164.7 cm and a mean weight of 59.9 kg. The width of the articular surface as projected onto the transepicondylar line(ML), anteroposterior dimension (AP), the dimensions from medial/lateral epicondyle to posterior condylar (MEP/LEP) were measured. A characterization of the aspect ratio (ML/AP) was made for distal femur. The angles between the tangent line of the posterior condylar surfaces, the Whiteside line, the transepicondylar line, and the trochlear line were measured. The sulcus angle and hip center-femoral shaft angle were also measured [Fig. 1]. The data were compared with the five total knee prostheses conventionally used in China. In analyzing the data, best-fit lines were calculated with use of least-squares regression. The dimensions are summarized as the mean and standard deviation. Comparisons of dimensions between males and females were made with use of the two-sample t test. A p value of <0.05 indicated a significant effect.Background
Methods
Recent anthropometric studies have suggested that current design of total knee arthroplasty (TKA) does not cater to racial anthropometric differences. The purpose of this study was to investigate the exact sizing and rotational landmarks of the distal femur collected from a large group of healthy Southern Chinese using three dimensional computer tomographic measurements, and then compare these measurements to the known dimensions from Caucasian populations. This study evaluated distal femoral geometry in 125 healthy Southern Chinese, included 58 women (106 knees) and 67 men (134 knees) with a mean age of 35.2±8.11 years, a mean height of 165.5±7.94 cm, and a mean weight of 61.7±9.56 kg. The width of the articular surface as projected onto the transepicondylar line(ML), anteroposterior dimension (AP), the dimensions from medial/lateral epicondyle to posterior condylar (MEP/LEP)were measured. A characterization of the aspect ratio (ML/AP) was made for distal femur[Fig. 1]. The angles between the tangent line of the posterior condylar surfaces, the Whiteside line, the transepicondylar line, and the trochlear line were measured. The sulcus angle and hip center-femoral shaft angle were also measured. Known dimensions from Caucasian populations were compared with the morphologic data collected in this study[Fig. 2]. In analyzing the data, best-fit lines were calculated with use of least-squares regression. The dimensions are summarized as the mean and standard deviation. The differences of rotational landmarks and sizing between the Southern Chinese and Caucasians were assessed with use of the Student t test. A p value of <0.05 indicated a significant effect.Background
Methods
The purpose of this study was to understand the effects of terminal sterilisation and residual calcium on human demineralised bone matrix (DBM) in ectopic bone formation in nude rat. The intramuscular implantation of human DBM prepared by the Queensland Bone Bank (QBB) from four donors into eight male athymic rats was used to assess osteoinductivity. The DBM contained different levels of residual calcium and treated with or without gamma-irradiation at 11kGy. At 6 weeks post-implantation, calcium deposition was assessed by manual palpitation and radiological imaging. Tissue morphology and cellular interactions was analysed using various histological staining methods whilst protein expression of anabolic and catabolic biomarkers were examined through immunohistochemistry. All results were then analysed in qualitative, semi-quantitative and quantitative manners and tested for statistical significance. Bone formation was observed in all specimens at the gross level. This was confirmed by histology which revealed bony capsules surrounded by soft tissue in the muscle pockets and differences in tissue components. On a cellular level, variations in osteoclast expression were found between the two groups as well as amongst individual donors through statistical analysis which resulted in an imbalance of the expression of anabolic and catabolic markers. Furthermore, a positive relationship between residual calcium and new bone formation in gamma irradiated DBM samples was found. To date, no studies have compared the effect of calcium in gamma irradiated DBM. Our results suggest that gamma irradiation even at low doses and residual calcium may affect new bone formation. Taken together, this study stresses the importance of selecting ideal conditions for graft processing and the need to identify an optimal level of irradiation and remaining calcium levels that confers a balance between osteoinductivity and sterility.
Total hip arthroplasty (THA) has been applied to treat pain and disability in patients with post-traumatic arthritis after acetabular fracture for many years. However, the midterm and long-term results of THA for this unique population are still controversial. According to previous studies, we found that uncemented acetabular reconstructions were usually performed in patients who were most likely to have the best results and an abnormal acetabular structure was usually the reason for THA failure. In this study, we evaluated the midterm results of using uncement acetabular components to treat posttraumatic arthritis after acetabular fracture. In addition, we investigated the effects of different acetabular fracture treatments and fracture patterns on THA. Between January 2000 to December 2003, 34 uncemented acetabular reconstructions were performed in 34 patients for posttraumatic arthritis after acetabular fractures. Among them, 31 patients underwent complete clinical and radiographic follow-up for an average of 6.3 years (range, 3.1–8.4 years). There were 22 men and 9 women. The patients' average age was 51 ± 12 years (range, 27–74 years) at the time of arthroplasty. The average interval from fracture to THA was 5.58 ± 4.42 years (range, 0.75–17.5 years). Of the 31 patients, 19 had undergone ORIF (open-reduction group) and 12 had received conservative treatment for the acetabular fractures (conservative-treatment group). Then, 14 had simple pattern fractures (simple group) and 17 had complex pattern fractures (complex group). After midterm follow-up, the radiographic and clinic results of the different groups were compared.Background and Objective
Materials and Methods
To set up an osteosarcoma mouse model with spontaneous lung metastasis and to identify a marker of osteosarcoma metastasis and to inhibit the marker against the invasive ability of an osteosarcoma cell line. A human osteosarcoma orthotopic mouse model was set up by injecting 143B human osteosarcoma cells into mouse tibia. Type I insulin-like growth factor receptor (IGF-1R) and its downstream signalling factors were measured in samples from the primary tumor and the lung secondaries by immunohistochemistry. Human Alu mRNA expression was tested using in situ hybridization assay. A Matrigel assay was used to assess cell invasion ability under the interference of a MEK/ERK pathway specific inhibitor, U0126. All fifteen mice showed tumour mass at the left tibia and lung metastasis. Human Alu expression in the primary and secondary tumours confirmed human origin of the tumour cells. Total IGF-1R, MEK, Akt, p38 and phosphorylated MEK (p-MEK), but not p-Akt and p-p38, were positive in both local tumours and lung secondaries. Leiomyosarcoma controls expressed p-Akt and p-MEK, but not p-p38. The 143B cells treated with U0126 had significantly lower in vitro invasion ability compared with controls. The IGF-1R-MEK signalling pathway, particularly Ras/Raf/MEK/ERK, may play an important role in osteosarcoma lung metastasis, and the targeting MEK/ERK by its specific inhibitor may have a potential use in the effective treatment of osteosarcoma.
We aimed to analyze the clinical results of the patients according to joint line change who underwent navigation assisted cruciate ligament retention type mobile bearing total knee arthroplasty. From September 2004 to January 2006, cruciate ligament retention type mobile bearing total knee arthroplasties using navigation system(Orthopilot®, Aesculap) were performed for 50 knees in 45 patients (2 men, 43 women). The mean follow up period was 46(39~55) months and the mean age was 65. There was one case with rheumatoid arthritis and all other were degenerative arthritic cases. All surgeries were performed using navigation system. Proximal tibia resection was performed at the sclerotic level of medial tibial plateau. The distance from the lowest point of lateral tibial plateau (registered point) to the proximal resection plane was measured. Clinical outcome were compared between joint line elevation with more than 3 mm(20cases) and less than 3mm (30cases). The mean joint line elevation was 1.93 mm (range −1~5mm). There were no significant difference in the clinical results according to the joint line change (p>
0.05). It may be suggested that the change of joint line in the range of −1 to 5mm in cruciate ligament retention type mobile bearing total knee arthroplasty result in satisfactory clinical outcome.
This prospective study reports the midterm outcome of total hip arthroplasty performed in a consecutive series of patients using a tapered uncemented femoral component. From Nov. 2001 to Apr. 2006, total hip arthroplasties were performed in 138 patients (150hips). The clinical records and the routine serial radiographs of these patients were monitored closely over a 1-year period. Clinical evaluation was done by Harris hip score before surgery and at last follow-up. Radiological evaluation was done on plain radiographs. The average follow up period was 4.05 years. There was a significant improvement in functional outcome of these patients as measured by Harris hip score. There were no revisions for aseptic loosening of the femoral component in this series, accounting for an overall survivorship of 100%. The study confirms that the midterm outcome of this stem is excellent, with no revisions.
Achieving the correct amount of femoral component rotation has become the basic objective of surgical techniques in total knee arthroplasty and this can be done either with a measured resection technique or indirectly by flexion/extension gap equalization technique. We demonstrated the variabilities of the reference axes (PCA, WSL, TEA) when soft tissue tension was managed intraoperatively by navigation system. The mean angle of transepicondylar line, Whiteside’s line, posterior condylar line from the proximal tibia resection plane were 1.29 ± 3.67 (mean ± SD; range 7 to 10.5), 3.90 ± 4.17 (mean ± SD; range 3 to 15.5), −4.03 ± 2.71 (mean ± SD; range 9.5 to 1.0) respectively. Coefficient of variation(CV(%); std/mean × 100) were 283, 106, 67 respectively. Out of the 3 reference axes widely used for femoral component rotation, angles from proximal tibia resection plane to posterior condylar line showed the least range of variance.
Fracture healing involves many local and systemic regulatory factors. Progress in identifying signaling events downstream has been made with the discovery of a novel family of proteins, the Smad, as TGF-ß/activins/BMPs signal transducers. Smads are the vertebrate homologs of Eighteen 3-month old female CD-COB rats were used. A standard closed fracture was made in the mid-shaft of right femur using a 3-point bending device. The left limb served as the non-fracture control. The rats were divided into 3 groups (6 per group) and sacrificed at day 3, 10 and 28 after fracture. The femurs were harvested, fixed in buffered formalin for 48 hours and decalcified with 10% formic acid-formalin solution. The decalcified tissues were embedded in paraffin and 5μm sections were cut onto silane-coated slides. Representative slides from each block were stained with routine haematoxylin and eosin (H&
E). Sections were cut for immunohistochemistry for protein marker expression by a standard procedure for Smads and BMP 4 and 7. Sections were viewed and analysed by colour video image analysis using a 40x objective, a 10x eyepiece, and a fixed frame of 128 × 128 pixels (49152.0 μm2). Ten fields per slide were examined. Smad proteins (Smads 1, 4, and 6) were expressed during the early stages (day 3) of fracture healing by bone marrow stromal cells, osteoblasts, fibroblasts and chondrocytes located in the intramembranous and endochondral ossification regions around the fracture site. Differential expressions of individual Smads, particularly Smad 1 and Smad 6, at different time-points (Smad-1 was higher than Smad-6 at day 3, whilst Smad-6 was much higher than Smad-1 at day 10) suggest that Smad proteins are not simply BMP signal transducers. Smads may also be responsible for up- and/or down-regulation of transcriptional events during the intramembranous and endochondral ossification. Smad-4, a Co-SMAD, expression newly formed bone and cartilage suggests an additional function beyond the signal transduction in rat fracture healing. BMP-4 and BMP-7 were highly expressed at day 3 and 10. BMP-7 expression was greater than BMP-4 at day 3 but switched by day 10 (BMP-4 >
BMP-7). Smads represent a new level where specific therapeutic strategies can be targeted considering the interactions with a number of BMPs.
The rate of success of transtrochanteric rotational osteotomy for osteonecrosis of the femoral head may be improved if patients are preselected using MRI. We have used three criteria for selection for osteotomy (i) minor collapse of the infarcted area, loss of congruity or the crescent sign, without narrowing of the joint space or acetabular involvement (ii) patients younger than 55 years and with a painful hip (iii) patients with an intact area constituting an arc of more than 120° between the central vertical line of the femoral head and the posterior or anterior margin of the necrotic portion as seen on a midsagittal MRI. Seventeen patients were selected, with a follow-up of more than 42 months. A bone scan four weeks after operation showed adequate perfusion of the proximal segment in all hips. The hip score of Merle d’Aubigné et al improved from 13.5 points before operation to 17.2 points at the latest follow-up. Further collapse of the femoral head did not occur. The use of MRI instead of plain radiographs for the selection of patients has improved the success rate of transtrochanteric rotational osteotomy.