Molded, Gamma-radiated, Argon-processed Polyethylene Components of Rotating Hinge Knee Megaprostheses Have a Lower Failure Hazard and Revision Rates Than Air-sterilized, Machined, Ram-extruded Bar Stock Components

Limited Revision with a Newly Designed Hinge Device for the Treatment of Mega-Prosthesis Hinge Failure: Two Case Reports

BACKGROUND

Surgical treatment for hinge failure in mega-prosthesis continues to be a challenge. This study introduces a new method for treating hinge failure by using a unilateral prosthesis and hinge revision.

CASE PRESENTATION

We here present two patients who underwent mega-prosthesis reconstruction after resection of osteosarcoma in the distal femur. To address the issue of knee hyperextension after mega-prosthesis reconstruction, one patient underwent three revision surgeries, two surgeries were performed using the original hinge, and one surgery involved a newly designed hinge. To resolve the problem of dislocation, one patient underwent three revisions, with the first two revisions not involving hinge replacement and the third revision involving a newly designed hinge. Two replacements of unilateral prosthesis and hinge renovations were successful.

CONCLUSIONS

Unilateral prosthesis and newly designed hinge device revision are effective in treating the failure of old-fashioned mega-prosthesis hinges.