GMRS Oncological Prosthesis with a Porous Coating Collar: A Good Option for Revision of Aseptic Loosening in the Lower Extremity

Abstract

Background: Revisions for oncological prosthesis are especially challenging due to the limited bone quantity and poor quality that the patients still possess. The aims of this study were to ask (1) what is the cumulative survival of the Global Modular Replacement System (GMRS) prosthesis after revision? and (2) what are the long-term functional outcomes of these patients? Methods: We retrospectively reviewed 16 patients who developed aseptic loosening of a lower extremity prosthesis. There were nine males and seven females with a mean age of 28 years (range, 14–55 years). The 5-year and 8-year survivorship of the prosthesis were calculated. Function outcome was evaluated according to the score of the Musculoskeletal Tumor Society (MSTS). Results: At a mean of 90 months follow-up (range, 52–118 months), the cumulative survival of all revision prosthesis was 94% at both 5 and 8 years. There were two prosthesis failures including one infection and one repeated aseptic loosening. At the last follow-up, except for the infection case, 93.3% (14/15) of the patients did not develop repeated aseptic loosening. The mean MSTS score was 27.7 (range, 24–30). Conclusions: GMRS prosthesis demonstrated significant satisfactory long-term outcomes for revisions of lower extremity oncological prosthesis.