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Journal of Bone and Joint Surgery - British Volume, Vol 88-B, Issue SUPP_II,
207.
Copyright © 2006 by British Editorial Society of Bone and Joint Surgery
Pfäffikon, Switzerland 2527 May, 2006 President Beat R. Simmen
S13 PROBLEMS OF ANKLE JOINT ENDOPROSTHETICS AS A DRIVING FORCE OF TECHNICAL DEVELOPMENTTillmannK.Bad Bramstedt
The ankle joint offers adverse conditions to any prosthetic replacement: high loads on small surfaces, only vague landmarks for the insertion, complex and individually very different functional anatomy. Despite these obstacles many excellent short- and some long-term results have been published, giving little way to a learning curve. This contrasts with our own experiences over at all 29 years now: 24 % failures of cemented two-component EPs after 14,6 (6,121,2) years (n=67) and 8,7 % failures of uncemented tri-component EPs after 3,7 (0,67,6) years (n=92). We analyze and explain special problems and typical failures by a brief historical review of ankle joint replacement: as a logical sequence of various concepts, each of them basing on the knowledge of preceding insufficiencies. The general concern of the functionally useful, but limited mobility after the implantation will be discussed, also on the basis of own early and medium-term results: ROM ranging on average from 26° for TPR-(n=35) and 29° for New Jersey LCS-(n=30) up to 35° for S. T. A. R.-prostheses (n=12). Possible solutions of problems will be considered, respecting assumed causalities. Basing on the literature and own earlier investigations, especially the long-term results will be compared critically. The incertitude of an exact implantation has been partly compensated by the actual "meniscal" concept of tricomponent prostheses. It should be favourable for their fixation to the bone and moreover reduce polyethylene-wear. But as before the discrepancy of high loads on a small area threatens the durability of ankle joint prostheses. Prosthetic replacement has become indispensable in the treatment of painfully destructed ankle joints, but it demands a careful and critical indication.
Correspondence should be addressed to ERASS Office, Schulthess Klinik, Lengghalde 2, CH-8008 ZURICH, Switzerland.
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