Short-Term Complications, Reoperations, and Radiographic Outcomes of a New Fixed-Bearing Total Ankle Arthroplasty.

BACKGROUND

With the increasing use of total ankle arthroplasty (TAA), new implants with varied configurations are being developed every year. This study aimed to assess the early complications, reoperations, and radiographic and clinical outcomes of the Infinity TAA. To date, clinical results of this novel implant have not been published.

METHODS

A retrospective analysis of 64 consecutive ankles that underwent a primary Infinity TAA from July 2014 to April 2016 was performed. Patients had an average follow-up of 24.5 (range, 18-39) months. Medical records were reviewed to determine the incidence of complications, reoperations, and revisions. Radiographic outcomes included preoperative and postoperative tibiotalar alignment, tibial implant positioning, the presence of periprosthetic radiolucency and cysts, and evidence of subsidence or loosening. Additionally, patient-reported outcomes were analyzed with the Foot and Ankle Outcome Score (FAOS).

RESULTS

Survivorship of the implant was 95.3%. Fourteen ankles (21.8%) presented a total of 17 complications. A total of 12 reoperations were necessary in 11 ankles (17.1%). Revision surgery was indicated for 3 ankles (4.7%) as a result of subsidence of the implant. Tibiotalar coronal deformity was significantly improved after surgery ( P < .0001) and maintained during latest follow-up ( P = .81). Periprosthetic radiolucent lines were observed around the tibial component in 20 ankles (31%) and around the talar component in 2 ankles (3.1%). A tibial cyst was observed in 1 ankle (1.5%). Outcome scores were significantly improved for all FAOS components analyzed ( P < .0001), from 39.0 to 83.3 for pain, from 34.0 to 65.2 for symptoms, from 52.3 to 87.5 for activities of daily living, and from 15.7 to 64.2 for quality of life.

CONCLUSION

Most complications observed in the study were minor and successfully treated with a single reoperation procedure or nonoperatively. Failures and radiographic abnormalities were most commonly related to the tibial implant. Further studies with longer follow-up are needed to evaluate the survivorship of the tibial implant in the long term.

LEVEL OF EVIDENCE

Level IV, retrospective case series.