The use of antibiotic-impregnated polymethylmethacrylate (PMMA) cement beads for the local delivery of antibiotics in the treatment of chronic osteomyelitis has become a standard orthopaedic practice. The increasing resistance to antibiotics of organisms associated with orthopaedic infections has led to interest in the incorporation of more effective antibiotics into PMMA cement. Ciprofloxacin, a synthetic fluoroquinolone, is potent against a broad spectrum of bacteria associated with osteomyelitis. In this study, strands of ciprofloxacin-impregnated PMMA cement beads were prepared with 0.2, 0.5, or 1.0 g of ciprofloxacin per 40 g of PMMA. The elution concentration of ciprofloxacin was at least 1-2 mcg/ml for 7 days (0.2 g), 30 days (0.5 g), and 42 days (1.0 g). This concentration is equivalent to the minimum inhibitory concentration for the common pathogens associated with osteomyelitis. Concurrent systemic and local ciprofloxacin therapy appears to be a method for the treatment of chronic osteomyelitis.

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A 74-year-old man underwent total knee arthroplasty in 1996 and subsequent revision total knee arthroplasty for aseptic loosening in 2005. During revision, an all-polyethylene, 7-mm, second-generation, highly cross-linked ultra-high-molecular-weight polyethylene patellar component (Durasul; Zimmer, Warsaw, Indiana) was used. The patient recovered well, but he presented with severe acute pain after a popping feeling was detected during a game of golf in postoperative year 4. Radiographs demonstrated a fracture of the patellar component. At re-revision surgery, polyethylene fragments were encountered without visual evidence of wear. Appropriate rotational and axial alignment of the components was confirmed. Patellar revision was performed. To the authors' knowledge, this is the first report of an acute posttraumatic catastrophic fracture of a second-generation, highly cross-linked ultra-high-molecular-weight polyethylene patellar component. Although no malposition of the components was noted, abnormal tensile forces across the patellar component can be transmitted by altered patellofemoral kinematics. This combination could lead to a small surface crack that propagates deeper into the component with continued impaction and an eventual acute fracture of the entire component. The patellar component failed in a piecemeal fashion following acute trauma. Although many advantages exist to the enhancement of polyethylene patellar components, including the potential for improved wear characteristics, cross-linking has reduced resistance to crack initiation and propagation. Therefore, fracture risk should be considered when using second-generation, highly cross-linked ultra-high-molecular-weight polyethylene.

Variations exist in the manual preparation and delivery of cement during primary total hip arthroplasty. The incorporation of a power source may standardize cement mantle manufacturing. This study prospectively compared the use of a new power-operated polymethylmethacrylate vacuum mixing and delivery system to a commonly used manually powered industry standard. The study did not reveal a significant difference in the quality of cement mantle grades when comparing the use of this power-operated system to an industry standard manual system. However, the benefit of the new preparation and delivery system may be in consistent porosity reduction and not in the improvement of cement mantle grading.