Dose response and toxicity of doxorubicin microspheres in a rat tumor model.

The therapeutic response and toxic effects of chemotherapy using several doses of doxorubicin in conventional solution form or bound to an ion-exchange resin were compared in a rat tumor model, to assess the relationship of drug dose to therapeutic efficacy and associated toxicity. Single bolus injections of 3.0, 4.5, 6.0, 7.5 and 9.0 mg/kg were administered via the abdominal aorta to rats bearing hindlimb tumors. Tumor size was measured serially and the growth rates of treated groups were compared with a control growth curve. In addition, the effect of empty microspheres on tumor growth rate was assessed. The levels of circulating white blood cells were measured and compared to control levels to provide an indication of the severity of bone marrow toxicity experienced by each form of treatment. Finally, any difference in the distribution of doxorubicin to tumor, hindlimb and cardiac tissue following administration of doxorubicin as free drug or on microspheres was ascertained. Empty ion-exchange resin exerted a small although significant detrimental effect on tumor growth which may be explained by the embolization of microspheres in the precapillary blood vessels of the tumor resulting in a transient delay in tumor growth rate. The lowest dose of doxorubicin produced a significantly better therapeutic response when administered in the free drug form, but higher doses elicited an equivalent delay in tumor growth for both drug microsphere and free drug groups in a dose-dependent manner, with the maximum anti-tumor response occurring at the highest dose. Treatment with free doxorubicin at high doses resulted in significant reductions of circulating white blood cells suggesting the occurrence of bone marrow toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recurrent locking of knee joint caused by intraarticular migration of bioabsorbable tibial interference screw after arthroscopic ACL reconstruction

Two cases are reported in which, after ACL reconstruction with autologous hamstring grafts, tibial polylactide interference screws migrated into the knee joint. Clinically, both patients presented with recurrent locking of the joint. In one case, a broken 15 mm-long tip of the screw was found intra-articularly. In the other case, the whole screw had migrated into the joint cavity. The degradation process of polylactic acid, operative technique and bone quality are discussed as possible reasons for these complications.     

Intraosseous ganglion about to cause a fracture of the glenoid: a case report

Intraosseous ganglia of the glenoid are rare, and their etiology is unknown. This report describes a case of an intraosseous ganglion about to cause fracture of the glenoid. The patient was a 61-year-old woman with a painful left shoulder with a limited range of motion. Her symptoms did not improve after non-operative treatment. Arthroscopic examination showed a cartilage defect and erosion in the posteroinferior portion of the glenoid, behind which computed tomography (CT) showed a cystic lesion of the glenoid. There was no communication between the cyst and the joint space. The patient was treated by curettage and an autogenous cancellous bone graft from the iliac crest. Two years after the operation, the patient was almost free from pain, and CT showed good integration of the bone graft.