TRABECULAR TANTALUM CUPS WITH IMPACTED MORCELLIZED BONE GRAFT IN ACETABULAR REVISION AND RECONSTRUCTION AFTER ACETABULAR FRACTURES

Abstract

Reconstruction and revision of the acetabulum component in loose hip implants may be conducted with several techniques, depending on the entity of the defects and of the surgeon’s experience. Impaction grafting with cemented cups or associated to rings or non cemented cups with flanges are some of the options. Rings or cages may have a containment effect but usually do not osteo-integrate.

Since 2001 we performed 28 acetabular revisionswith trabecular tantalum metal cups (Zimmer) for Paprosky type II and IIId efects. All the patients but three needed fresh frozen morcellized allograft. Eight patients had less than 50 years; twelve had a previous acetabular fracture that ended in an improper reduction or an infection.Three had a previous infected joint implant, one an infected non-union; this group before the definitive reconstruction had one to three débridement procedures. Six patients without infection had three to six previous surgeries including hip reconstruction. Medial containment disks were used in six patients, to contain bone defects. All patients had a trabecular metal cup fixed with screws or stabilized with press fit alone , associated to a cemented poly cup.

Dislocations were not observed. The cemented cup was oriented to overcorrect the head coverage only in four cases. Three patients had a high hip center, but only one has shorter limb. At short follow up no lyseswere observed with adequate osteointegration. Infection did not recurred in any patient.

TMT cups simplify complex reconstructive procedures, and in spite of cementing a poly cup, osteointegration occurred in all patients. Lysis was readable in three patients but it was marginal and restricted. Great attention should be kept when an additional hole is done in the cup to confine metal dissemination to the soft tissues.