We used a polymerase chain reaction (PCR) lateral flow assay1) to rapidly diagnose joint infection. We evaluated the usefulness of multiplex-PCR (PCR lateral flow assay: PCR-LF) using detailed clinical data. A total of 35 synovial fluid samples were collected from 26 patients in whom bacterial infection was suspected, including 22 from knee joints, 11 from hip joints, and 2 from other joints. After purifying the DNA from the samples, multiplex PCR targeting two MRSA-associated genes (Aim
Method
The preparation of antibiotic-containing polymethyl methacrylate (PMMA), as spacers generates a high polymerization heat, which may affect their antibiotic activity; it is desirable to use bone cement with a low polymerization heat. Calcium phosphate cement (CPC) does not generate heat on polymerization, and comparative elution testings are reported that vancomycin (VCM)-containing CPC (VCM-CPC) exceeded the antibiotic elution volume and period of PMMA (VCM-PMMA). Although CPC alone is a weak of mechanical property spacer, the double-layered, PMMA-covered CPC spacer has been created and clinically used in our hospital. In this study, we prepared the double-layered spacers: CPC covered with PMMA and we evaluated its elution concentration, antimicrobial activity and antibacterial capability. We prepared spherical, double-layered, PMMA-coated (CPC+PMMA; 24 g CPC coated with 16 g PMMA and 2 g VCM) and PMMA alone (40 g PMMA with 2 g VCM) spacers (5 each). In order to facilitate VCM elution from the central CPC, we drilled multiple holes into the CPC from the spacer surface. Each spacer was immersed in phosphate buffer (1.5 mL/g of the spacer), and the solvent was changed daily. VCM concentrations were measured on days 1, 3, 7, 14, 28, 56, and 84. Antimicrobial activity against MRSA and MSSA was evaluated by the broth microdilution method. After measuring all the concentration, the spacers were compressed at 5 mm/min and the maximum compressive load up to destruction was measured.Aim
Method
Residual stress remains in bone tissues after press-fit-fixation of a joint prosthesis, recently employed for joint arthroplasty. The response of bone tissues to the residual stress is, however, unknown because it is not physiological. This unnatural stimulus may have adverse effects on bone tissues, including causing thigh pain or bone resorption. In the present study, we designed an experimental method to apply a stationary load from inside an animal femur using a loop spring of titanium alloy with super elasticity. The femoral response was assessed based on the migration of the wire into bone twelve weeks after implantation. As the results, wire migration was noted in 10 of 11 cases. We developed a method using a loop spring made of super elastic titanium alloy, which can maintain sufficient stress in a rat femur for a prolonged period. This titanium alloy, which contains 43.94% titanium and 56.06% nickel, was supplied as a wire (WDL1, Actment Co., Ltd., Kasukabe, Japan). In the present study, an experimental method was designed to apply a stationary load from inside a rat femur by inserting a loop spring made of super elastic wire.Background
Methods
Proximal humeral fracture occurs most frequently in elderly and usually unite within 12 weeks. Malunion is more common than nonunion. And even if nonunion occurs, we usually treat it by the blade plate. Norris et al. reported hemiarthroplasty is indicated for severe degenerative changes of the articular surface, osteonecrosis of the humeral head, or osteopenia severe enough to jeopardize fixation in order patients. Therefore, it is not common that hemiarthroplasty is used for primary treatment of the proximal humeral pseudoarthrosis. We report a case of proximal humerus pseudoarthrosis which was treated by hemiarthroplasty. A patients is 75 years old male. He was injured by falling from ladder. He was diagnosed proximal humeral fracture Neer type2. After he was followed conservatively for one year, he was referred to our hospital. In X-ray film and CT, the humeral head was scraped by the humeral shaft that was tucked inward to humeral head.(Figure 1) In MRI, rotator cuff muscles were left. The fatty infiltration was stage 1 in the Gourtallier classification. (Figure 2)And osteoarthritis of shoulder was not so severe. Therefore, we decided to do hemiarthroplasty. We used the SMR implant (Lima Corporate, Milano, Italy). Surgical reconstruction was done using a deltpectral approach. Lesser tuberosity was cut from greater tuberosity with subscaplaris muscle. We used the cementless stem. Each fragments and stem was fixed using FiberWire (Arthrex, Florida USA), after autograft which scraped from the reseceted humeral head was stuffed. After the operation, the shoulder was fixed by brace for 4weeks. The passive ROM exercise was started from 21 days later. The Active ROM exercise was started at 28 days later. Three months later, the pseudoarthrosis united successfully. (Figure 3) The active flexion was improved from 20 degrees to 110 degrees. The active abduction was from 20 degrees to 90 degrees. USLA score was improved from 10 to 26.Introduction
Case
According to proposal of Noble, the femoral bone marrow cavity form of patients who underwent Total Hip Arthroplasty (THA) can be classified under 3 categories; those are Stovepipe, Normal and Champagne-fluted. We developed typical sodium chloride femoral model was created by 3D prototyping technique. The purpose was to identify the relationship of pressure zone of the surrounding areas between femoral bone marrow cavity form and hip stem. As opponent clarified stem design concept Zweymüller type model was used. According to CT data with the patients who underwent THA, the sodium chloride femoral model was custom-made and selected as the representative model based on Noble's 3 categories. Eight models of each category were used to performed mechanical test.Introduction
Materials and Method
