Outcomes following total ankle total talus replacement: A systematic review

Abstract

Background: Prosthetic substitution of the talus presents a significant challenge to the foot and ankle surgeon. The shear and compressive forces on the talus and its tenuous blood supply lead to high rates of avascular necrosis and eventual talar collapse. The purpose of this systematic review is to evaluate whether total ankle total talus replacement (TATTR) leads to improved clinical and radiographic outcomes with appropriate safety metrics in patients with a history of avascular necrosis or significant trauma.

Methods: We searched the concepts of talus, prosthesis, and arthroplasty in MEDLINE (PubMed), Embase (Elsevier), CINAHL Complete (EBSCOhost), and Scopus (Elsevier) from the database's inception through March 9, 2023. Inclusion Criteria were 1) previous trauma to the talus, 2) post-traumatic arthritis to the tibiotalar joint, 3) avascular necrosis of talus, 4) multiple failed prior interventions, 5) degenerative osteoarthritis to the tibiotalar joint, and 6) inflammatory arthropathy to tibiotalar joint. Patients less than 18 years of age and manuscripts in non-English languages were excluded.

Results: Of the 7625 references, 16 studies met the inclusion criteria, yielding data from 136 patients (139 ankles). The studies varied in design, with case reports and retrospective case series being predominant. The overall weighted average modified Coleman Methodology Score (mCMS) was 70.4 out of 100, indicating moderate flaws in study design that may be subject to various forms of bias and possible confounders. Demographics showed a diverse range of etiologies, with alumina ceramic being the primary prosthesis material. Functional scores demonstrated improvements in dorsiflexion and plantarflexion, although patient-reported outcome measures (PROs) were inconsistently reported. Complications included fractures, heterotopic ossification, prolonged wound healing, and infections. Revision details were sparsely reported.

Conclusion: TATTR is a promising treatment modality for improving short-term functional outcomes for patients with avascular necrosis or trauma-related issues. However, this systematic review underscores the need for standardized reporting, longer-term follow-ups, and further research to establish the procedure's efficacy and safety, particularly in comparison to other treatment modalities.

Level of evidence: III, Systematic Review of Level IV Studies.

Keywords: 3D printing; Avascular necrosis; Osteonecrosis of the talus; Total ankle total talus replacement.