Imaging periprosthetic osteolysis around total knee arthroplasties using a human cadaver model.

We examined the sensitivity and accuracy of measuring osteolysis around total knee arthroplasty (TKA) on radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) in a cadaver model. Fifty-four simulated osteolytic defects ranging from 0.7 to 14 cm(3) were created in 6 cadaver knees implanted with either a cemented or an uncemented TKA. Three blinded investigators assessed the presence, location, and volume of defects on radiographs and CT and MRI scans with metal reduction protocols. Both CT and MRI had significantly higher sensitivities and specificities than did plain radiographs (P < .005). Overall, there was no difference in the accuracy of defect volume measurements between CT and MRI (P = .574). This study demonstrates the limitations of radiographs and the high sensitivity and specificity of both CT and MRI in assessing osteolysis around TKA.

Complications of trans arterial embolization during the resuscitation of pelvic fractures.

INTRODUCTION: Trans arterial embolization (TAE) can stem uncontrolled bleeding associated with pelvic fractures, but is associated with potential complications. This study investigated and compared the early to midterm complications in two patient cohorts: one who did and one who did not undergo TAE. METHODOLOGY: The results of 14 patients who underwent TAE in the resuscitation phase, and then had their pelvic fractures managed non-operatively, the study group (Group 1), were compared with those of a control group (Group 2) of 14 patients matched for age, sex, injury and management, that did not undergo TAE. All patients were examined clinically and answered a questionnaire on bowel and urinary function, pain and limp. Gluteus medius structure and volume were assessed on MRI. The hip girdle muscle function was assessed using a hand held dynamometer, surface electromyography as well as quantitative gait analysis. RESULTS: Seven patients in Group 1 (50%), but none in Group 2, had persistent urological dysfunctions, in the absence of any recognized previous pathology or urologic trauma at the time of injury. No gluteal muscle demonstrated fibrosis or fatty infiltration. The median gluteal muscle volume was not significantly decreased compared with the uninjured side in either group (P=0.421). The muscle strengths of gluteus maximus, gluteus medius, tensor fasciae latae and iliopsoas when compared to the uninjured side were significantly less in Group 1 compared to Group 2. However, no patient had a discernable limp and gait analysis showed no significant differences between the left and right sides in the study and control groups in the gluteal activation timing (p=0.171 and 0.354) and duration (p=0.622 and 0.435). There were no skin complications, and no patient reported any persistent bowel dysfunction. CONCLUSION: TAE was associated with a high rate of persistent urological dysfunction. TAE could lead to decreased hip muscles strength, however this does not seem to affect gait.