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.