Patients with Revision Modern Megaprostheses of the Distal Femur Have Improved Disease-Specific and Health-Related Outcomes Compared to Those with Primary Replacements.

Abstract

We asked whether there would be any difference between primary and revision modern cemented fixed hinge megaprosthesis of the distal femur in function and activity-related outcomes following treatment of a bone tumor. An identical custom-made fixed hinge cemented megaprosthesis with a hydroxyapatite collar was used in all cases. The main outcomes were joint-specific function, disease-specific activity, and health-related quality of life. Implant survival was also evaluated. Patients in the revision group performed slightly better than patients in the primary group on disease-specific (Toronto Extremity Salvage Score, <i>p</i> = 0.033; Musculoskeletal Tumor Society, <i>p</i> = 0.072) and health-related outcomes (Short Form 36 [SF-36] physical component, <i>p</i> = 0.085; SF-36 mental component, <i>p</i> = 0.069) but not on joint-specific outcomes (Knee Society Score, <i>p</i> = 0.94). The cumulative probabilities of revision for any reason were 14.5% (7-25%) at 5 years with no statistically significant difference between primary and revision procedures (<i>p</i> = 0.77). In conclusion, patients undergoing a revision have similar joint-specific functional outcome but improved disease-specific and health-related outcomes. Implant survival are similar between groups.