Short to midterm clinical and radiographic outcomes of the Salto total ankle prosthesis.

BACKGROUND

Total ankle arthroplasty (TAA) has become an increasingly effective treatment option for tibiotalar arthritis. The purpose of this study was to evaluate the short to midterm clinical and radiographic outcomes of the Salto fixed bearing total ankle prosthesis.

METHODS

We retrospectively reviewed the radiographs and patient records of 74 consecutive patients with 75 TAA implants from January 2007 to April 2011. The average age was 60.6 years (range, 41-82) with 41 females and 33 males. The average clinical follow-up was 43 months (range, 24-73 months). Radiographs were reviewed for areas of radiolucency and cystic changes around the talar and tibial implants, as well as for implant migration using standardized tibal, talar, talocalcaneal, and tibial slope angular measurements. The validated Foot and Ankle Outcome Score (FAOS), Short Form-12 (SF-12), and Visual Analog Scale (VAS) were used as subjective patient outcome measures. Kaplan Meier (K-M) curves were created for implant survivorship with revision of components as an endpoint and for return to the operating room for any reason.

RESULTS

Total ankle survivorship was 98%. Thirteen patients returned to the operating room for any reason. There was 1 deep infection, and no ankles were converted to an arthrodesis. Average ankle dorsiflexion and plantarflexion improved from 4.3 ± 3.3 to 8.7 ± 5.6 degrees (P = .0008) and 24 ± 11 to 29 ± 7 degrees (P = .04), respectively. Patients showed significant improvements in all subscales of the FAOS (P < .0001). The physical component of the SF-12 significantly improved from 30 ± 8 to 41 ± 13 (P < .0001), but this was not observed with the mental component (52 ± 1 vs 53 ± 1, P = .55). The mean VAS for patient satisfaction was 9 (range, 2-10). Two patients had component migration (1 tibial and 1 talar component), neither of which required a revision procedure. Six ankles had a total of 9 radiolucent lines with a radiographically stable implant, and no patients had cystic changes.

CONCLUSION

This is one of the first articles to report clinical and radiographic outcome data for the fixed bearing version of this prosthesis. We observed significant improvements in subjective outcome measures and range of motion with a 98% component survivorship at short to midterm follow-up. Longer follow-up will be necessary to determine the durability of this implant.

LEVEL OF EVIDENCE

Level IV, case series.