Highly cross-linked polyethylene (HXLPE) was developed to reduce the wear of articular-bearing surfaces in total hip arthroplasty (THA). This study aimed to compare the mean linear wear of HXLPE with a 22.225 mm diameter zirconia head with that of conventional polyethylene (CPE) with a 22.225 mm diameter ortron head. A prospective cohort study performed on 93 patients (113 hips) who had undergone primary cemented THAs at our hospital between January 2001 and December 2003. The subject population included 85 females and 8 males with a mean age of 58.0 years (22 to 78) at the time of surgery. The mean follow-up period was 10.2 years (9 to 12). We randomly used two types of implants: the HXLPE cup with a 22.225 mm diameter zirconia head (Kyocera Medical, Osaka, Japan) in 60 hips (HXLPE group), and the CPE cup with a 22.225 mm diameter ortron head (DePuy International, Leeds, UK) in 53 hips (CPE group). Linear wear (penatration) by computer-assisted method with PolyWare software (Draftware Inc, Indiana, USA) was measured at 10 years. Anteroposterior radiographs were evaluated for osteolysis or component loosening defined by the criteria of Hodgkinson et al. Analysis of covariance using the general linear models procedure was carried out to determine the linear wear rate difference between the groups after adjusting for variables (age at surgery, sex, body mass index, vertical distance, horizontal distance, cup inclination, and cup anteversion) as covariates. The differences were considered significant when the p value was <0.05.Introduction
Materials and Methods
Antibiotic-loaded acrylic cement (ALAC) is employed in the treatment or prevention of infected total hip arthroplasty (THA). We have administered vancomycin (VCM) as the ALAC for the treatment of THAs with methicillin-resistant Staphylococcus aureus, or for the prevention of THAs with high risks. This study aimed to evaluate the serum concentration of VCM from ALAC in THA or cement beads. Between December 2013 and February 2014, 16 hips (16 patients) underwent application of the ALAC including VCM at our institution. Two hips were used for the treatment of infection, in the first stage of two-staged revision THAs (i.e., cement beads). Two hips were used for the both treatment and prevention of infection, in one-staged revision THAs. Twelve hips were used for the prevention of infection, in aseptic revision THAs or primary THAs with high risks. Patients were classified into two groups depending on the VCM concentration of ALAC, as follows: high-dose group (2 hips), average 4.4% (3.8–5.0%); low-dose group (14 hips), average 1.6% (1.3–2.5%). The amount of VCM placed as ALAC into the hip was calculated by using the remaining ALAC. The serum concentration of VCM was evaluated at 1 day, 4 days, 7 days, and 28 days after surgery. Statistical analysis was performed by using the Introduction
Methods
The diagnosis of implant-associated infections is challenging, and the conventional culturing of periprosthetic tissue has been the gold standard for diagnosis of implant-associated infections. However, conventional diagnostic tests are inaccurate because the pathogenesis of implant-associated infection is related to microorganisms growing in biofilms. We compared culture of samples obtained by sonication of explanted implants to dislodge adherent bacteria from implants with conventional culture of periprosthetic tissue. The purpose of this study is to evaluate the results of sonication that is microbiological diagnostic method for implant-associated infections. Between January 2013 and April 2013, a total of 19 consecutive patients underwent the removal of implants at our institution. There were 15 women and 4 men with a mean age of 71 years (32 to 90) at the time of the operation. Implants were removed because of aseptic loosening in 9 patients, infection in 6 patients, necrosis in 2 patients, dislocation in 1 patient and implant fracture in 1 patient. Removed implants, including 17 joint prostheses and 2 fracture fixation devices, were subjected to sonication in a BactoSonic (BANDELIN, Germany). Preoperative bacterial culture, intraoperative conventional culture of periprosthetic tissue, intraoperative culture of sonicate-fluid, and pathological examination were assessed.Introduction:
Materials and Methods:
