Viscosupplementation of the ankle: a prospective study with an average follow-up of 45.5 months

Providing pain relief for ankle osteoarthritis and delaying the need for a radical surgery procedure is difficult to achieve with analgesics that have limited efficacy or are not devoid of substantial side effects.

The goals of this study were to evaluate the efficacy of viscosupplementation, explore which factors better predict Patient's response and propose an injection protocol.

Eighteen patients (26 ankles) with ankle osteoarthritis were included, with seven of them having received multiple series of injections. The average age was 60 years. Series of three injections, performed in the operating room under fluoroscopy-guidance, were evaluated after 4 and 12 months and then annually with the AOFAS score; patient satisfaction was also assessed.

The average AOFAS score increased significantly from 61.8 ± 15 before the injections to 74.4 ± 14.5 and 73.7 ± 16.6 after 4 and 12 months, respectively. The average follow-up was 45.5 months and 73% of patients were satisfied or very satisfied. There were no adverse effects or intolerance. In patients receiving more than one series of injections, the average delay between series was 27.8 (range 15-43) months. Five patients had a radical surgery procedure after an average of 27 months of effective viscosupplementation.

This prospective study showed that viscosupplementation had a significant positive effect (P<0.05) in patients with ankle osteoarthritis when a three-injection protocol was used every two years on average. Neither etiology nor severity of the osteoarthritis was predictive of the response. In our opinion, fluoroscopy-guidance is essential for these injections.

Level IV cohort study.