Abstract
Numerous techniques are used for the fusion of failed TAR. We wish to report our results of the revision of failed TAR to fusion.
Between July 2005 and February 2011 the senior author had performed 20 arthrodeses in 19 patients (13 male and 6 female) who had failed total ankle arthroplasty (TAR). Their mean age was 63.5 years. All of them had the AES total ankle replacement. (Biomet UK). The mean period from the original TAR to fusion was 51 months (6 to72). The indication for revision of TAR to fusion was septic loosening in 4 patients and osteolysis and or aseptic loosening in 16 cases. Three types of fusion techniques were used.
The mean follow-up was 15 months. All 3 tibiotalar arthrodeses with screws alone fused successfully. Of the 13 patients where the fusion was augmented with an Ilizarov frame, 4 were done for septic loosening. There were 2 non unions of which one was stable without pain and the other required a further revision fusion with a frame and subsequently fused. Of the 9 patients who had a fusion with a frame for osteolysis and or aseptic loosening, there was one non union which was revised to a tibiotalocalacaneal fusion with a hind foot nail. The nail fractured at the level of the posterior oblique screw hole. The patient subsequently developed a relatively pain free non-union of the tibiotalar joint and not required further surgical intervention. The remaining 8 ankles fused at a mean of 5 months. The average time of frame removal was 17 weeks. There was four pin-site infection all of which settled with oral antibiotics. 5 patients had tibiotalocalacaneal fusion with a hind foot nail. The indication for the hind foot nail was significant osteolysis and loss of talar bone stock. The average shortening as a result of the fusion for the failed TAR was 1.5cms.
Our results were comparable to the previous reports of arthrodesis for failed total ankle replacement. We recommend the use of tibiotalocalcaneal fusion with a hind foot nail in the presence of severe osteolysis or accompanying subtalar arthritis. In the presence of good bone stock an ankle fusion supplemented with a circular frame gives a good predictable outcome.
