After more than 10 years' experience in France, the French Foot Surgery Association (Association française de chirurgie du pied [AFCP]) presents an update on mobile-bearing ankle prostheses, based on a multicenter study. META-ANALYSIS - BIOMECHANICS - ASSESSMENT AND INDICATIONS: A preliminary comparative meta-analysis of the literature studies on ankle and prosthesis biomechanics, reviews validated indications and contra-indications, and details clinical and radiological outcomes assessment protocols.
Sixty-three surgeons (95% AFCP members) answered a professional online survey, by email or regular post: 70% performed total ankle replacement (TAR), 39% of them at least two per year and 16% more than 10 per year, resulting in 317 TARs per year or 50% of the French activity and 312 arthrodeses per year or 17% of the French activity - which gave the survey considerable power. In 2004-2005, 46% of the TARs implanted were AES, 38% Salto and 9% Hintegra.
Gait analysis following tar:
This study included two series of patients (15 in Brussels and six in Paris) with laboratory gait analysis preoperatively and at 6 months' and 1 year's FU. Following TAR, speed, cadence and strides increased and mean total work approximated normal values. These two independent studies quantified the advantages of TAR over arthrodesis.
This retrospective study had a minimum follow-up of 1 year. Results were not distinguished between the four types of prosthesis (approved by the French Healthcare Agency [HAS]) involved. Inclusion criteria for operators were: AFCP membership, and experience of more than 20 prostheses of a given type. Twelve out of 15 centers responded and undertook to include continuous series. Data were centralized on a dedicated anonymous online site. Five hundred and ninety-two TARs (388 Salto, 173 AES, 22 Hintegra, nine Star) in 555 patients (mean age, 56.4 years; range 17-84 yrs) were included. Indications were post-traumatic arthritis (48%), arthritis associated with laxity (15%), inflammatory arthropathy (20%), primitive arthritis (9%), prosthetic revision (2%), and miscellaneous (5%). Sixty-one percent of operations included associated procedures: 208 Achilles lengthenings, 45 subtalar arthrodeses, nine calcaneal osteotomies and 45 lateral ligament reconstructions. Complications comprised 53 malleolar fractures, and 39 cutaneous and seven infections (9%). At a mean 37 months' FU, 87.5% of patients were satisfied or very satisfied; mean functional score was 82.1/100; radiographic mobility, 23.2 degrees ; and total SF 36 score (on the Short Form Health Survey), 66. X-ray found stable anchorage in 98% of cases, cysts in 15%, and calcification in 4%.
Revision for failure:
Overall cumulated survivorship was 88% at 71 months: 22 patients underwent arthrodesis (61% satisfied), and 10 implant replacement (50% satisfied).
This multioperator, multi-implant series of 592 patients confirmed literature data. Prospective follow-up of the cohorts managed in these expert centers is essential, in order to make available long-term data.