eTable 2. Classification of current ankle implant types.
| Surgical access | Inlay type | Replaced surfaces | Internal implant surfaces | Inlay materials | Sulcus type | Surface morphology | |
|---|---|---|---|---|---|---|---|
| AAA | Anterior | Mobile | Superior | HA | UHMWPE | None | Trapezoidal |
| AES | Anterior | Mobile | Superior | HA | UHMWPE | Deep | Trapezoidal |
| Agility | Anterior | Fixed | Superior/medial/ lateral | Titanium | UHMWPE | None | Trapezoidal |
| BOX | Anterior | Mobile | Superior | HA | UHMWPE | Normal | Ellipsoidal |
| Buechel-Pappas | Anterior | Mobile | Superior | Titanium | UHMWPE | Deep | Ellipsoidal |
| ESKA | Lateral/medial | Fixed | Superior | Titanium | UHMWPE | Normal | Ellipsoidal |
| INBONE | Anterior | Fixed | Superior | Titanium | UHMWPE | Normal | Spheroidal |
| HINTEGRA | Anterior | Mobile | Superior/medial | HA | UHMWPE | None | Conical |
| Mobility | Anterior | Mobile | Superior | Titanium | UHMWPE | Deep | Trapezoidal |
| Ramses | Anterior | Mobile | Superior | HA | UHMWPE | None | Ellipsoidal |
| Salto | Anterior | Mobile | Superior/medial | HA | UHMWPE | Normal | Conical |
| STAR | Anterior | Mobile | Superior | HA | UHMWPE | None | Cylindrical |
| TNK | Anterior | Fixed | Superior | HA | UHMWPE, ceramic | None | Cylindrical |
| TM Total Ankle | Lateral | Fixed | Superior | Porous metal | Highly cross-linked UHMWPE | None | Conical |
AAA: Alpha Ankle Arthroplasty; AES: Ankle Evolutive System; BOX: Bologna–Oxford; HA: hydroxyapatite; STAR: Scandinavian Total Ankle Replacement; TM: Trabecular Metal; UHMWPE: ultra-high-molecular-weight polyethylene