Modular diaphyseal anchor stems with locking screws in the hip revision with massive femoral defects

Complex femoral defects with insufficient isthmus (Paprosky III and IV) and Vancouver B3 periprosthetic fractures determines the fixation of the revision stems. The objective is to evaluate the results of the modular revision stems with diaphyseal anchor and distal block (Revitan Zimmer Biomet GmbH, Winterthur, Switzerland). Our hypothesis is that this procedure offers a stable primary fixation in cases of alteration of the femoral isthmus.

Retrospective cohort study of 38 patients, minimum follow-up of 12 months (12-94) with severe femoral defects treated with Revitan stems distally blocked. An endofemoral or transfemoral approach was used. The subsidence was assessed according to Callahan's method and bone neoformation according to Nordin. Merle d'Aubigné-Postel was used and complications and reoperations were collected. A statistical analysis was performed with SPSS and a significance level p < 0.05 was considered.

Between 2009 and 2017, 147 revisions were carried out with Revitan stem, 38 locked, 23 men and 15 women, with an average age of 74 years and an average follow-up of 64 months. The cause of the review was: 15 septic loosenings, 14 aseptic, two fractures and seven stable fibrous unions. Right fixation was obtained in 27 cases, there were four loosenings, three screw breakages, three infections, one of dislocation and one of femoral nerve injury. The MDP increased significantly from 11.26 to 14.98.

Distally locked conical modular stems are a good alternative in femoral defects with isthmus involvement if proper canal filling and bicortical screw fixation are achieved.