Heterotopic Ossifications in Anterior and Lateral Approach Total Ankle Replacement: A Retrospective Evaluation

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Degenerative arthropathy of the tibio-tarsal joint is a condition that afflicts about 1% of the world's population, with consequences in terms of impact on the quality of life of the patients. In recent decades, ankle prosthetic replacement has seen an important spread with increasingly promising results. Among the most frequent complications described in the short to medium term of primary ankle prosthesis we find the formation of periarticular heterotopic ossifications. However, the clinical impact of these findings remains highly debated in the literature, and the need for prophylactic treatments is controversial, due to the paucity of scientific evidence in the literature. Methods: 105 treated total ankle prosthetic replacement patients at a minimum radiological follow-up of 12 months were included in the study, the patients were retrospectively analysed by dividing them into two subgroups, 43 patients treated of ankle prosthesis with lateral access and 62 patients treated with anterior access. Patients were evaluated radiographically by assessing the presence, location, and severity of periarticular heterotopic ossifications according to modified Brooker's classification; and they were evaluated clinically by NRS and FAAM score and rate of re-interventions due to the presence of heterotopic ossifications. Individual and procedural risk factors has been taken into consideration. Results: 84 patients (80%) developed radiographic findings of HO. A surgical intervention was required because of HO in 19 of these 84 patients which is 23 %. Intervention for HO would be considered only in those patients who had HO. The AA group consisted of 62 patients, forty-five (73% of 62) developed HO and 10 of these 45 patients had sufficient symptoms which was treated with arthrolysis. The LA group consisted of 43 patients, thirty-nine (91%) developed HO and 9 of these 39 patients had sufficient symptoms which was treated with arthrolysis. LA group had a higher prevalence of HO than the AA group (91% vs 73%). Conclusion: There is a direct correlation between clinical scores and degree of HO (FAAM and Pain Score). Prosthesis with LA more frequently develop HO than AA. In addition, young patients, delayed ankle mobilization and weightbearing can be accounted as risk factors in the development of HOs; conversely smoking, BMI, duration of surgery and post-traumatic arthritis were not found to have a significant impact. Demographics characteristics and mean score results at the end of follow-up