F Sangiorgi, A Mazzotti, S O Zielli, A Arceri, G Di Paola, F Sgubbi, L Langone, C Faldini
A 100% incidence of HO, with posterior quadrant predominance and progressive development throughout the first postoperative year, was observed after an anterior approach TAA. Descriptive trends suggested lower HO burden with selected low-impact activity combinations and greater HO severity with more intensive regimens, although these findings were not statistically significant. Further investigations are warranted.
PURPOSE: Heterotopic ossification (HO) is a well-known complication after joint arthroplasty but remains poorly characterized following total ankle arthroplasty (TAA). This study evaluated the temporal progression and anatomical distribution of HO after an anterior approach TAA and explored the potential influence of postoperative rehabilitation protocols on its development.
METHODS: This retrospective observational study included a consecutive series of patients undergoing primary TAA via an anterior approach. Standardized clinical and radiographic assessments were performed from 12 months postoperatively. HO was evaluated radiographically, graded, and analysed according to anatomical quadrant and temporal evolution. Postoperative rehabilitation protocols were recorded and examined as potential factors influencing HO severity.
RESULTS: Radiographic HO was observed in all patients, yielding a 100% incidence at 12 months. HO was consistently more prevalent and severe in the posterior quadrant, whereas anterior involvement remained limited throughout follow-up. Serial radiographs demonstrated progressive HO formation in all four quadrants between 6 weeks and 12 months, with mean grades increasing from 0.8 to 1.9 laterally, 0.675 to 2.125 medially, 0.15 to 0.675 anteriorly, and 1.6 to 2.975 posteriorly, without evidence of stabilization during the first postoperative year. No statistically significant association was found between HO severity and rehabilitation protocols.
CONCLUSIONS: A 100% incidence of HO, with posterior quadrant predominance and progressive development throughout the first postoperative year, was observed after an anterior approach TAA. Descriptive trends suggested lower HO burden with selected low-impact activity combinations and greater HO severity with more intensive regimens, although these findings were not statistically significant. Further investigations are warranted.