Ankle Arthroplasty—Does Preoperative Fixed Equinus Affect Patient-Reported Outcomes

Abstract

Postoperative sagittal range of motion, in particular degree of dorsiflexion, is critical for satisfactory outcomes in total ankle arthroplasty (TAA). Although there is literature discussing techniques to treat a preoperative fixed equinus we are not aware of any papers presenting patient outcomes. We present patient-reported outcomes for our cohort of patients undergoing TAA with preoperative fixed equinus compared to plantigrade ankles. This is a single surgeon, cohort study of consecutive cases. Cases of primary TAA were identified from a local joint registry which prospectively records Foot and Ankle Outcome Scores (FAOS), Short Form-36 (SF-36), and patient satisfaction. Revision cases or those with inadequate data were excluded. Patients were classified as fixed equinus or neutral based on both preoperative weightbearing lateral radiographs and clinical records. Overall 259 cases were identified, 92 were excluded leaving 167 cases for analysis (mean follow-up 81.7 months), 147 were classified as neutral and 20 fixed equinus. The fixed equinus group were significantly younger (neutral 63.9 vs equinus 52.9, p < .001). Stiffness was the only FAOS domain that was detectibly different at baseline (neutral 36.6 vs equinus 25.6, p=.044). Final FAOS scores, change from baseline and patient satisfaction was the same in all domains for both groups. There was no difference in revision rates. With the numbers available we did not demonstrate a postoperative difference in outcomes for patients with preoperative fixed equinus.