Performance of 3 gelatine-based resorbable cement plugs: a study on 15 synthetic femurs and a prospective randomized study on 103 patients

Background: Intramedullary plugs are key factors in improving cement fixation of the femoral component. We investigated the performance of 3 commercially available resorbable cement restrictors in vitro and in vivo. Methods: We measured the migration of the SEM II, the C-plug, and the REX plug in 15 Sawbones synthetic femurs and in 103 patients during total hip surgery. Cement pressures were also measured distally and proximally in vitro. Results and interpretation: Our in vitro results showed poor performance of the C-plug compared with the REX and SEM II plugs. In vivo, the mean migration was least for the SEM plug and most for the C-plug. The smaller sizes performed significantly better than the larger ones for all 3 plug types. The overall in vivo performance of all 3 plug types was unsatisfactory. Differences between the SEM II and REX plugs were small and therefore not significant. The SEM II performed better than the REX, the former being much cheaper and easier to insert. The Rex plug looks promising; however, the insertion device must be improved for better results. The C-plug proved to be unstable.