A long-term follow-up study of rheumatoid arthritis (RA) patients with a total ankle replacement (TAR) has shown a good prosthesis survival rate.
“The primary treatment choice for patients with disabling degenerative ankle joint disease has been arthrodesis, but there has been much debate over its efficacy,” write Niels Jensen and Frank Linde from the University Hospital of Aarhus in Denmark.
“An alternative treatment is TAR, which has a reported success rate of between 40 and 100% in RA patients,” they say.
To gain a better understanding of the life-span of ankle prostheses, the researchers followed 26 RA patients who received a Thomson, Prichard and Richards’ (TPR) type ankle replacement between 1980 and 1993.
Removal of the prosthesis and radiolucency were considered as endpoints. All patients were followed until death, prosthesis failure, or until January 2008 when the study ended.
As of January 2008, 18 patients with 23 prostheses had died with their prosthesis in place at a median of 9.5 years after operation. Two patients had their ipsilateral leg amputated due to unrelated causes 12 and 14 years after operation. Five prostheses in four patients had been removed 4.0–13.1 years after operation.
Two patients with three prostheses were still alive with their prosthesis in place at 22.5–23.7 years after surgery.
The 5-year cumulative prosthesis survival rate was 91%, after 10 years the survival rate was 85%, when removal was the endpoint. When radiolucency was the end-point, the 5-year prosthesis survival rate dropped to 75% and the 10-year survival rate was 64%.
Whilst discussing “better than expected” results where “the prosthesis survived the patient in many cases,” Jensen and Linde draw attention to the fact that “the present document is historic in the sense that the TPR-prosthesis has been withdrawn from the market, like many other prostheses used in the 80s.”
Despite this, “the long-term survival of this first generation type of TAR adds some optimism to the development of TAR,” they conclude in the journal Foot and Ankle Surgery.