Secondary degenerative changes of the knee are a well recognized complication of Giant Cell Tumor (GCT). Osteoarthritis (OA) may be a consequence of the lesion itself or its treatment. Total Knee Arthroplasty (TKA) is a treatment option for end stage knee arthritis. In the current study we describe the short term follow up of three patients that underwent TKA for treatment of GCT related OA between 2006–2007. The records of 180 consecutive patients treated for giant cell tumor of the knee between 1989 and 2007 in our institution were reviewed. Three patients were identified that had total knee arthroplasty following treatment of giant cell tumor of the knee, confirmed by tissue biopsy. The review included all clinical notes, pathology and operative reports. Outcomes were assessed based on knee scores and functional scores calculated according to the clinical rating system of The Knee Society, with the assignment of a maximum of 100 points for each. Patient ages range from 29–75 years of age. Assessment occurred pre-operatively as well as post-operatively at six weeks, three months, six months and then yearly. The development of osteoarthritis with severe knee pain was the primary indication for performing TKA.Purpose
Method
To evaluate the mechanism by which orthopedic implant wear particles induce apoptosis in immature osteoblasts in an in-vitro setting. Stromal cells from femurs of thirty day-old Swiss Webster Mice were isolated, cultured in-vitro, and incubated with orthopedic wear particles in the micrometer size range. After incubation with wear-particles, the cells were assessed for Caspase three expression and activity in the presence or absence of specific inhibitor(s) in order to delineate potential mechanism for cellular changes previously reported. Here we report the induction of caspase three protein expression and activity with incubation of stromal cells with titanium wear particles. Caspase three activity however was not demonstrated to be up regulated in a time dependent manner or at lower concentration of particles (2 x 107 particles/ml). However, there was a significant (P<
0.05) increase in caspase three activity with titanium particle at higher concentration (4 x 107 particles/ml) that was not reversible when the extrinsic arm of the apoptotic pathway was blocked with anti-TNFƒa antibodies. Our previous studies have suggested that aseptic loosening of orthopedic implants may be independent of inflammatory processes, and may be associated with induction of programmed cell death. Our current results would strengthen this idea by demonstrating induction of expression and activity of caspase three involved in apoptosis in cells incubated with wear particles. In addition, titanium wear particles may induce apoptosis through direct cellular effects rather than through the extrinsic TNFƒa pathway. Delineating the mechanism by which wear particles induce apoptosis in immature osteoblasts will allow for the selection and/or development of inhibitors to the process of asceptic loosening by targeting a specific pathway.
