Wylie Lopez - Department of Orthopaedic Surgery, Massachusetts General Hospital, MA, USA
Kayoumars Azizpour - Harvard Medical School, Boston MA, USA
Kevin Raskin - Department of Neurosurgery, Leiden University Medical Center, Leiden, The Netherlands
Lozano-Calderon Santiago A.M.D. - Massachusetts General Hospital, Boston, MA, USA

Background: This study evaluates mega-endoprosthetic survival after revision for periprosthetic joint infection (PJI)and two-staged reconstruction using a cement spacer. Mega-endoprosthetics offer patients an important treatmentoption for limb salvage. However, PJI is a devastating complication which affects between ۲-۱۰% of patients. Itcommonly results in revisions, amputation, and sometimes death. Literature in terms of success rates, limb salvageand Megaprostheses survival after revision for infection is limited. We present here our experience and the impact oflength of the spacer in prostheses survival.Methods: A retrospective chart review was implemented using Fisher’s exact test for categorical data and the Kaplan-Meier method for prosthesis survival. Patient information was acquired through our institution’s electronic medicalrecords. Variables such as diagnosis, complications, length of cement spacer, and number of surgeries were recorded.We analyzed spacer length and prosthesis survival based on these variables.Results: Fisher’s Exact test showed no correlation between length of spacer and amount of repeat surgery (P = ۰.۲۴۵).After two-stage revision and mega-prosthesis insertion, there was a ۶۳.۲% chance of complication and a ۲۶.۳% chanceof amputation. This indicates a ۷۳.۷% probability for limb salvage in this sample (Kaplan-Meier).Conclusion: These data suggest long-term viability of mega-endoprostheses after two-stage revision despite a highcomplication rate.Level of evidence: IV

Limb salvage, Mega-endoprosthesis, Periprosthetic joint infection, two-stage revision