1/6. Wear debris from total hip arthroplasty presenting as an intrapelvic mass.A granulomatous reaction to the small particles worn off from an implanted prosthesis is a common complication in arthroplasty. The chronic inflammatory response to the wear debris from either the polyethylene or the metal components is thought to be responsible for osteolysis, implant loosening, and finally mechanical failure. Formation of an extra-articular granulomatous tissue mass is uncommon, however. We report a case of a huge granulomatous mass that presented as an intrapelvic tumor. The prosthesis was an Anatomical Medullary Locking (AML) hip arthroplasty with cementless fixation. The polyethylene insert was manufactured by ram extrusion and sterilized with gamma irradiation in air. Fragments of the insert were among the contents in the cystic mass together with black metallic debris. There was no loosening of the prosthesis, and the acetabulum floor was preserved.- - - - - - - - - - ranking = 1keywords = black (Clic here for more details about this article) |
2/6. Black holes on MR images of the brain of patients with Bjork-Shiley heart valves: additional observation in three cases.We report the cases of three patients with Bjork-Shiley convexo-concave heart valves with unusual black holes shown on cerebral MR images. For two patients, these findings were associated with fracture of the Bjork-Shiley convexo-concave heart valve, and for the third, with worn surfaces on the heart valve. Susceptibility changes shown by MR imaging suggest the possibility that these black holes may be associated with microscopic metallic particles, although, the exact cause of these black holes remains undetermined.- - - - - - - - - - ranking = 3keywords = black (Clic here for more details about this article) |
3/6. Cementless or hybrid total elbow arthroplasty with titanium-alloy implants. A study of interim clinical results and specific complications.Twenty-six patients (32 elbows) with rheumatoid arthritis had a total elbow arthroplasty with insertion of a cementless prosthesis. The humeral component was made of titanium alloy and it was fixed without cement in all elbows. The patients were followed for an average of 3 years 1 month (range, 2 years 2 months to 4 years 4 months). A good result was seen in 25 elbows, a fair result in 2, and a poor result in 5. The reason for the poor results was a breakage of the humeral component at the junctional portion of its stem. In all five of these elbows a marked resorption of bone mass within the condylar portion of the humeral component was observed on the lateral radiograph. The five elbows with a poor result had a revision operation, and in each of these black staining of the soft tissues within the joint was seen. This tissue metallosis due to wear debris of the titanium alloy was responsible for the osteolysis within the condylar portion. It became clear from this study that even in a non-weight-bearing joint, such as the elbow, titanium alloy may wear and result in tissue metallosis when used as a bearing surface of the implant. However, it was also found that in the majority of the elbows an establishment of the biologic fixation of the porous-coated stem could be achieved by use of this alloy.- - - - - - - - - - ranking = 1keywords = black (Clic here for more details about this article) |
4/6. Severe metallosis caused by shaving down of the stem neck due to outer cup impingement of a bipolar endoprosthesis. A case report. off.The authors report on a patient with severe metallosis caused by shaving down of the stem neck due to outer cup impingement. A primary arthroplasty was performed using an Omnifit bipolar endoprosthesis (Stryker) with an acetabular bone graft fixed by ceramic screws. At the time of revision surgery the synovium was stained black. Two ceramic screws were broken, but no scratch was observed on the metal surfaces of the outer cup and the inner head. The ultra-high molecular weight polyethylene (UHMWPE) of the inner-bearing collar was worn and flat. During the operation, a groove was observed at the stem neck where the outer cup impinges. An analysis of the black pseudocapsule by scanning electron microscopy with electron prove microanalysis (SEMEPMA) revealed that the pseudocapsule contained titanium metal particles. To our knowledge, metallosis caused by the same mechanism has only been reported in four joints, which were replaced by a Zimmer BHP bipolar endoprosthesis and Howmedica bicentric cup.- - - - - - - - - - ranking = 2keywords = black (Clic here for more details about this article) |
5/6. Failure of a carbon fiber implant. A case report.STUDY DESIGN: Case report. OBJECTIVES: Failure of a carbon fiber implant. SUMMARY OF BACKGROUND DATA: To simplify the procedure of posterior lumbar interbody fusion, a carbon-fiber-reinforced polymer implant has been developed. The implant has ridges to resist retropulsion, struts to support weight, and a hollow area to allow packing of autologous bone graft. So far, no complications have been reported from the use of carbon implant as a fusion aid in spine surgery. methods: A patient with postoperative infection has been followed with computed tomography images and histologic examination from a reoperation. RESULTS: An entire nonunion across the width of the disc space and a clearly broken cage was visualized with computed tomography. The spinal canal was explored during a reoperation and the tissue surrounding the dura and nerves were all black. Microscopic examination showed a large quantity of carbon particulate debris. The authors have operated on approximately 100 patients so far and no other carbon cage has broken, to their knowledge. CONCLUSIONS: carbon cages can break if a nonunion occurs and as a result free carbon particles move out to the spinal canal.- - - - - - - - - - ranking = 1keywords = black (Clic here for more details about this article) |
6/6. Severe metallosis in an isoelastic hip prosthesis.Severe black staining due to metallic wear debris has been reported in metal-on-metal hip prosthesis(3). This problem is not commonly seen because of the popular use of metal-on-polyethylene component and has not been previously reported with the use of isoelastic femoral prosthesis. We report a case of severe metallosis in an isoelastic prosthesis, four years after implantation.- - - - - - - - - - ranking = 1keywords = black (Clic here for more details about this article) |