Radiological evaluation is crucial for interpretation of experimental osteomyelitis studies. Current scoring systems for radiologic evaluation of experimental osteomyelitis have limitations to demonstrate differences among treatment groups. Response of bone tissue to infection is a dynamic process; each radiological sign of osteomyelitis becomes prominent at different time points of disease. Analysing radiological criteria separately at different stages of the disease may provide better quantification of the response to treatment in experimental osteomyelitis rather than summation of these grades together.

Osteomyelitis was induced with S.aureus in left tibias of 72 adult, wistar albino rats. Rats were assigned into six different treatment groups. Their radiograms were graded according to previously defined scoring systems, and each radiological criterion separately, at the third week of induction, and at the third and sixth week after treatment.

Although periosteal reaction and diaphyseal widening demonstrate significant differences with three weeks of treatment, previously defined scoring systems could not find significant differences. At the sixth week of treatment, only one of the previously defined grading scales was able to differentiate significance among the treatment groups. Individual values of diaphyseal widening, osteolysis, BMC values were pointed out differences among the groups in the presence of osteomyelitis, confirmed by osteomyelitis.

Formulation of radiological grading scales requires evaluation of periosteal elevation, diaphyseal widening, bone deformation, osteolysis, and osteosclerosis, individually. However, evaluation of these scores separately will multiply interpretations of future studies, and will make them more meaningful.

Bisphosphonates are systemically used for the treatment of metabolic bone diseases such as osteoporosis or aseptic loosening after joint replacement surgeries, and there are limited studies on their effects when applied locally. Furthermore, effects of biphosphonates in osteomyelitis treatment are not well-known. A prospective longitudinal randomised controlled study was designed for the rat tibia to test the efficacy of local or systemically administered bisphosphonates for controlling the localised osteolytic reactions and possible effects on local infection control.

Osteomyelitis was induced in the tibia of 72 Wistar albino rats with S. aureus ATCC 25923 strain. All rats in all treatment groups were given curettage and debridement surgery. Rats in Group I were left without any bone grafting. In Group II, dead space was grafted with plain bone graft, while in Group III rats were treated with vancomycin-loaded bone grafts. In group IV, defects were filled with vancomycin-loaded bone grafts, and this was combined with weekly subcutaneous alendronate application at a dose of 240 μg/kg/wk. At Group V defects were grafted with alendronate impregnated bone graft. Finally, rats in Group VI received vancomycin + alendronate impregnated grafts. Dependent variables were groups (n=6) and time (n=2) whereas independent variables were swab cultures, radiology, quantitative computerised tomography, dual energy X-ray absorptiometry and histopathology.

Within three weeks, S.aureus was isolated in all groups. Within six weeks, S.aureus was eradicated in Groups II and IV according to the results of swab cultures. Radiological diaphyseal widening was significantly lower (p=0.037) in Group VI at three weeks. Bone deformation, diaphyseal widening and osteolysis scores were lower in this group at six weeks. Bone mineral content and density measured by quantitative computerised tomography were significantly higher (p=0.001) in Groups IV and VI at six weeks. Bone mineral density measured by dual energy X-ray absorptiometry was significantly higher in Group IV at six weeks. Histology revealed marked osteoblastic activity in Groups IV and VI at six weeks.

Hydatid disease of bone is rare. It probably represents between 0.5% and 4% of all human shydatid disease and, in about 60% of patients, affects the spine or pelvis. Between 1986 and 1998, we treated 15 cases of bone hydatidosis. Curettage, swabbing with povidone iodine and filling the defect with polymethylmethacrylate (PMMA) were carried out in ten patients. Three of these had a recurrence after five years, but seven had no signs of relapse during a mean follow-up of 52 months. We believe that the combination of antihelminthic therapy, wide resection and the use of PMMA gives the best outcome in the treatment of bone hydatidosis.