In total knee arthroplasty, polyethylene wear has been a major cause of revision surgery. However, it is sometimes difficult to determine the time of revision surgery in elderly people due to their concomitant diseases. Therefore, the brace for measuring polyethylene wear under computed tomography was developed. The brace works by strapping a femoral component tightly to a polyethylene insert by applying compression force between the sole of the foot and the thigh. Holes of 1, 2, 5, 10 mm in diameter and 0.1, 0.2, 0.5 and 1 mm in depth were created in the posteromedial part of polyethylene inserts. The inserts were provided from Teijin-nakashima Co. ltd. (Jodo, Okayama, Japan). The Hi-tech knee artificial joint (Teijin-nakashima Co. ltd.) was applied to a cadaveric knee and CT images of the knee were taken with a combination of insets with varying diameters and depths holes, using Aquilion ONE (Toshiba Medical Systems Corporation, Ohtawara, Japan). The finding conditions were as follows, Voltage; 120V, Current; 5A, slice thickness; 0.5 mm helical. The patient, who received total knee arthroplasty over 15 years ago, wore the brace and was examined using computed tomography. Afterward, the patient received revision surgery to replace the worn insert into new one. The removed insert was measured with a three-dimensional measuring machine (Cyclon, Mitsutoyo Co. ltd., Kawasaki, Japan). At a 1.0 mm depth, all holes could be detected. At a 0.5 mm depth, holes of 2, 5, 10 mm in diameter could be detected. At a 0.1∼0.2 mm depth, there was no hole detected. After revision surgery, a three-dimensional measuring machine revealed a 1.8 mm thickness of the insert on the medial side. The CT reconstruction image showed a1.84 mm thickness similar to the virtually measured figure.Methods
Results
Revision hip arthroplasty for excessive bone loss because of osteolysis or infection is difficult theme. Bone grafting is essential technique for bone loss and need of allograft is increasing. Recently, many hospital bone banks are established in Japan. The aim of this study is investigate efficacy and safety of allograft in our hospital bone bank. We evaluated management, result and complication of allografts retrieved from living donors in our institute.Background
Material and method
In total knee arthroplalsties, there are risks of revision surgeries because of aseptic loosening, polyethylene wear, and metal component breakage. The data such as model, type, size, and manufacturing companies are required at the time of revision surgeries. However, it is sometimes difficult to acquire such data due to patient's change of address and the elimination and consolidation of hospitals in the long-term. Therefore, we try to use the Radio Frequency IDentification (RFID) in the total knee joint system. The FerVID family (Fujitsu Co. Ltd., Tokyo, Japan) was prepared as the RFID tag. It was radio-resistant below the dose of 50kGy, which allowed gamma sterilization. The RFID tags were embedded into the anterior side of GUR 1050 UHMWPE inserts and 0.3wt% vitamin E blended UHMWPE. The UHMWPE inserts were manufactured by thecompression molding method at the maximum temperature of 220°C and the maximum compressive force of 245kgf/cm2. The manufactured inserts were implanted in fresh cadaveric knees. The tibial base plate was made of Ti6Al4V. The femoral components were made of Co-Cr-Mo or Ti-6Al-4V. Communication Performance was measured with the interrogator (DOTR-920 MHz-band, Tohoku Systems Support Co. Ltd., Miyagi, Japan). The transmission output was up to 1W. Received Signal Strength Indicator (RSSI) was measured 500 times at 15 mm away from the surface of skin in the extension and 90° flexion of the knee (Fig1).Introduction
Materials and methods
The cement mantle thickness for cemented stem during total hip arthroplasty (THA) is different between the complete cement mantle technique and the line-to-line technique. In the line-to-line technique, the size of the rasp is same as that of the stem. We performed THA in321 hipsof 289 patientsusing a new designed triple-tapered polished cemented stem. We investigated the short-term result of these 321 hips clinically and radiographically. From February 2002 to December 2012, 321 THAs were performed in 289 patients with the use oftriple-tapered polished cemented stem (Trilliance). Of these, 306 hips in 274 patients who were followed over 6 months, were evaluated. All THAs were undergone with direct anterior approach in supine position. The third generation cementing technique was standardized. The mean age at surgery was 65.3 years and the mean follow-up period was 24.6 months. Clinical results were evaluated by Japanese Orthopaedic Association (JOA) hip score. Intra-postoperative complications were investigated. Radiographic examinations were performed to investigate the findings of stem loosening, stress shielding, radiolucent line, osteolysis, stem subsidence, stem alignmentand cementing grade on plain radiograph.Introduction
Materials and Methods
The bioactive polyetheretherketone (PEEK) was fabricated by the combination of PEEK and CaO-SiO2 particles, which formed hydroxyapatite on its surfaces in simulated body fluid and showed good mechanical propeties. The study revealed osteoblast-like cell proliferation and gene expression on the bioactive PEEK. Peek and bioactive PEEK discs (24 mm in diameter and 2 mm in thickness) were prepared. Bioactive PEEk was produced by the combination of 80 vol% Peek powder and 20 vol% CaO-SiO2 particles (30CaO · 70SiO2). Discs were sterilized with ethylene oxide gas. The study was approved by the ethics committee in Chiba University. Human osteoblast-like cells were used in the study. The cells at passage 3–5 were used in the experiments. 2 × 105cells /disc were culture at 37°C in a humidified atmosphere with 5% CO2, and the media was replaced every 3 days. At days 3, 7, 21, the culture media, cells and discs were collected respectively. Cell attachment assay was performed. Cells were seeded at a density of 4 × 105 cells /well and incubated for 2 hours at 37 C in a humidified atmosphere with 5% CO2. The cells on the discs were evaluated by DNA content. The real-time PCR was performed with regard to type I collagen (COLI), osteocalcin (OC), osteonectin (ON), osteopontin (OPN), and GAPDH. The alkaline phosphatase activity (ALP) was measeured at 3, 7, and 21 days, which samples as used in the DNA-content assay. Alizalin Red Staining was performed at day 21 to quantify calcification deposits in discs. Results were analyzed using Student's The content of DNA showed similar increases on PEEK and bioactive PEEK in the course of day 3, 7, 21. The cell attachment of bioactive PEEK was two times larger than that of PEEK. Real-time PCR results of human osteoblast-like cells cultured on PEEK and bioactive PEEK discs were shown in Fig. 1. There were no significant differences between cells on PEEK and bioactive PEEK with respect to COL I and ON mRNA expression. However, human osteoblast-like cells on bioactive PEEK presented higher expression of OPN and OCN mRNA at day 21. No significant differences were found in ALP activity of both discs. Calcification deposits were observed only on bioactive PEEK at day 21Materials and Methods
Results
The purpose of the present study was to describe the long-term results of THA for ONFH in patients with SLE. From 1994–2001, 18 cementless THAs (14 SLE patients) were included in the present study. Four hips (3 patients) were lost to follow-up. The remaining 14 hips (11 patients) were available for evaluation. The mean follow-up period was 13.1(range, 10.0–16.4) years. The follow-up rate was 77.8%. The mean age at the time of surgery was 35.2 (range, 27.4–51.0) years.Objectives
Methods
