Survivorship and clinical evaluation of cementless, meniscal-bearing total ankle replacements

A porous-coated, cementless, congruent-contact, meniscal-bearing total ankle replacement with a centrally placed trochlear groove and a cylindrical articulating axis representing the lateral talar curvature was developed and used clinically over a 10-year period. An initial clinical series of 40 ankle replacements involved the use of cobalt-chromium-molybdenum tibial and talar components with sintered-bead porous coating of 275-mum pore size and a shallow-sulcus trochlear groove with a central fixation fin for the talar onlay component. The congruent meniscal bearing, made of ultrahigh molecular-weight polyethylene (UHMWPe), was flat superiorly and matched the shallow-sulcus and cylindrical geometry inferiorly. Two bearings in two patients subluxed laterally and required revision within 2 years. The overall cumulative survival at the 10-year interval for this group using revision as an end point was 94.75%. The clinical results, using a strict ankle evaluation scoring scale, demonstrated 85% overall good to excellent results. Three patients required further treatment for intermalleolar exostoses, one patient required a debridement for infection, two ankles had medially subluxed bearings, eight ankles developed talar component subsidence, and two patients suffered from chronic reflex-sympathetic dystrophy. A second clinical series of 14 ankle replacements involved the use of polished titanium-nitride-coated titanium-6 aluminum-4 vanadium tibial and talar components with sintered-bead porous coating of 350-mum pore size and a deep-sulcus trochlear groove with two lateral fixation fins for the talar onlay component. The bearing element was similar to the initial series except that it had a deeper engagement in the trochlear groove to prevent subluxation.(ABSTRACT TRUNCATED AT 250 WORDS)