THR REVISIONS USING DELTA ALUMINA SLEEVED HEADS: A PROSPECTIVE STUDY

Abstract

The new technology using femoral heads with sleeves allows conservative procedures for revision hip arthroplasty. The implantation of classical ceramic heads on a previously used femoral taper is not recommanded. When there is no loosening of the femoral implant, the use of sleeves is a good solution for using an alumine on alumine couple, specially in young and active patients.

Material and methods: 25 hips in 25 patients were included. In 12 cases the cause of revision was an acetabular osteolysis with or without loosening in metal on metal cimented THR.

In 13 patients the revision was performed for a loosening and a wear of the PHE cup with osteolysis (4 zyrcon and 9 chrome-cobalt heads). The mean age was 49 years for the metal on metal revisions (36 to 75) and 54 years for the prosthesis using a polyethylen socket.

Cementless cups were implanted using XLW delta alumina inserts. The 32 mm delta alumina sleeved heads were adjusted on the existing femoral 12–14 tapers. Patients were evaluated preoperatively and followed-up with clinical and radiological examinations.

Results: At 2 years mean follow-up, average Harris Hip Score was significantly improved (97 vs 54, p< 0.05). We did not observe ceramic fracture or squeaking. The radiographic results did not demonstrate acetabular loosening, osteolysis, or femoral abnormalities.

Concerning the metal on metal revisions, the aseptic loosening of the socket was combined with high rates of cobalt and chromium serum levels. Mean delay before revision was 4 years (2 to 11). Unipolar acetabular revisions were only decided after a carefull inspection of the remaining stems to detect any taper alteration or impingement lesions.

Postoperative cobalt and chromium serum levels significantly decreased postoperatively.

Concerning the metal on PHE and the zyrcon on PHE revisions, the mean delay before revison was 11 years (4 to 21).

At this short follow up, we did not notice any parasitic impingement due to the additional sleeve or any ceramic fracture or squeaking. The radiographic results did not demonstrate acetabular loosening, osteolysis, or femoral abnormalities.

Discussion: Failures of metal-on-metal or metal on PHE hip arthroplasties raise new technical problems. Conversion to ceramic on ceramic has been suggested in case of hypersensibility reactions or high rate of serum metal ions, and in case of osteolysis in young population. This prospective study evaluates a revision strategy using ceramic cups and delta ceramic heads with titanium adapter sleeves when a femoral revision is not required. Despite the limitation due to short follow-up, this technical option should be considered when wear surfaces exchange is decided.