Prosthetic joint infection (PJI) is a complex disease that causes significant damage to the peri-implant tissue. Developing an animal model that is clinically relevant in depicting this disease process is an important step towards developing novel successful therapies. In this study, we have performed a thorough histologic analysis of peri-implant tissue harvested post Staphylococcus aureus (S. aureus) infection of a cemented 3D-printed titanium hip implant in rats. Sprague-Dawley rats underwent left hip cemented 3D-printed titanium hemiarthroplasty via posterior approach under general anesthesia. Four surgeries were performed for the control group and another four for the infected group. The hip joint was inoculated with 5×109 CFU/mL of The histologic analysis revealed strong resemblance to tissue changes in the clinical setting of chronic PJI. IHC demonstrated the extent of bacterial spread within the peri-implant tissue away from the site of infection. The H&E and MT stains showed 5 main features in infected bone: 1) increased PMNs, 2) fibrovascular inflammation, 3) bone necrosis, and 4) increased osteoclasts 5) fibrosis of muscular tissue and cartilage. Micro CT data showed significantly more osteolysis present around the infected prosthesis compared to control (surgery with no infection). This is the first clinically relevant PJI animal model with detailed histologic analysis that strongly resembles the clinical tissue pathology of chronic PJI. This model can provide a better understanding of how various PJI therapies can halt or reverse peri-implant tissue damage caused by infection.
Recent studies have indicated that healthy and willing patients above 80 years have similar outcomes as younger patients following arthroplasty. We wished to investigate the outcomes in a cohort of patients above 80 years who underwent medial unicompartment knee replacement (UKA). 46 patients (51 knees) with UKA aged 80 or more formed the study group. For comparison rest of the UKA patients in the database were divided into groups according to their age. Patients were reviewed and KSS, complication rates and patient satisfaction information was collected. Revision for any cause was considered an endpoint. Significance was set at < 0.05.Introduction
Material/methods
Despite being from different manufacturers, Exeter stem and Ogee cup are commonly used together as cemented ‘cross breed’ combination in United Kingdom. The purpose of this study was to evaluate the long-term outcome of this combination. The ten years outcome of 131 primary hip replacements using an Exeter stem and an Ogee cup combination were studied retrospectively from clinical audit data and radiographs.Introduction
Materials and methods
