Infections in orthopaedic surgery are a serious issue. Antibiotic-loaded bone cement was developed for the treatment of infected joint arthroplasties and for prophylaxes in total joint replacement in selected cases. Despite the widespread use of the antibiotic-loaded bone cement in orthopedics, many issues are still unclear or controversial: bacterial adhesion and antibiotic resistance, modification of mechanical properties which follows the addition of the antibiotic, factors influencing the release of the antibiotic from the cement and the role of the surface, the method for mixing the cement and the antibiotic, the choice and the effectiveness of the antibiotic, the combination of two or more antibiotics, and the toxicity. This review discusses all these topics, focusing on properties, merits, and defects of the antibiotic loaded cement. The final objective is to provide the orthopaedic surgeons clear and concise information for the correct choice of cement in their clinical practice.

Ultra-high molecular weight polyethylene (UHMWPE) is the most common bearing material in total joint arthroplasty due to its unique combination of superior mechanical properties and wear resistance over other polymers. A great deal of research in recent decades has focused on further improving its performances, in order to provide durable implants in young and active patients. From “historical”, gamma-air sterilized polyethylenes, to the so-called first and second generation of highly crosslinked materials, a variety of different formulations have progressively appeared in the market. This paper reviews the structure–properties relationship of these materials, with a particular emphasis on the in vitro and in vivo wear performances, through an analysis of the existing literature.

Wear debris related osteolysis is recognised as being the main cause of failure in joint replacements based on UHMWPE inserts. However, many solutions and “new” polyethylenes have been suggested in order to address this issue. This review discusses “historical” issues associated with UHMWPE, such as oxidation, sterilization method and storage, as well as “new” topics, such as crosslinking and stabilization. The final aim is to aid orthopaedic surgeons in their selection of polyethylene inserts and in the information given to the patients. The main problem for the polymer is degradative oxidation, which is caused by the combination of the irradiation used for sterilization and oxygen, and which leads to a decrease in wear resistance and mechanical properties. Irradiation and packaging in the absence of oxygen can only reduce the oxidation, while sterilization with gas (EtO or gas plasma) is the only method that effectively eliminates it. Manufacturing processes are of great relevance to the clinical duration and must be considered by surgeons. Crosslinked polyethylene has been developed for joint inserts due to its superior wear resistance compared to conventional UHMWPE; to prevent the oxidation, crosslinked polyethylene requires post-irradiation thermal treatment, which reduces its mechanical properties and which depends on the producer. Several good clinical results from the use of crosslinked acetabular cups have reported at mid-term, while early results for knee replacements are also encouraging. Recently, the use of the antioxidant vitamin E (alpha-tocopherol) has been introduced for joint prostheses in order to prevent the oxidation of both crosslinked and noncrosslinked UHMWPE.

Polymethyl methacrylate (PMMA)-based bone cement is a biomaterial that has been used over the last 50 years to stabilize hip and knee implants or as a bone filler. Although PMMA-based bone cement is widely used and allows a fast-primary fixation to the bone, it does not guarantee a mechanically and biologically stable interface with bone, and most of all it is prone to bacteria adhesion and infection development. In the 1970s, antibiotic-loaded bone cements were introduced to reduce the infection rate in arthroplasty; however, the efficiency of antibiotic-containing bone cement is still a debated issue. For these reasons, in recent years, the scientific community has investigated new approaches to impart antibacterial properties to PMMA bone cement. The aim of this review is to summarize the current status regarding antibiotic-loaded PMMA-based bone cements, fill the gap regarding the lack of data on antibacterial bone cement, and explore the progress of antibacterial bone cement formulations, focusing attention on the new perspectives. In particular, this review highlights the innovative study of composite bone cements containing inorganic antibacterial and bioactive phases, which are a fascinating alternative that can impart both osteointegration and antibacterial properties to PMMA-based bone cement.