This paper introduces the RAM classification for adult-acquired flatfoot (AAFF). It independently grades deformity at three zones — Rearfoot (R), Ankle (A), and Midfoot (M) — each on a I–IIIa/b scale. The system was developed because prior single-axis staging systems (Johnson-Strom, Myerson Stage IV) assumed linear progression and could not capture patients whose zones were discordantly involved.
The Johnson-Strom and Myerson systems organized AAFF around PTT dysfunction as the central driver, with deformity progressing linearly from tendon disease through rearfoot collapse to ankle valgus (Stage IV). That framework works for the classic presentation but breaks down when a patient has severe midfoot collapse with a strong PTT, or ankle valgus from tibial plafond erosion rather than deltoid laxity.
When you evaluate an adult flatfoot, RAM tells you to assess all three zones independently before picking an operation. A patient coded as R-IIb A-Ia M-IIIb needs midfoot fusion as the primary procedure, not the osteotomy-and-tendon-transfer construct you would build for R-IIb A-Ia M-Ia.
The most high-yield decision rule: before finalizing any rearfoot correction, passively reduce the hindfoot and assess whether midfoot supination persists. If it does and you ignore it, the rearfoot will drift back into valgus — the paper explicitly names this as a mechanism of treatment failure.
The ankle zone distinction matters most in operative planning: a patient with lateral plafond bone loss (A-III) needs that bony deformity addressed at arthrodesis or arthroplasty, not just a soft tissue deltoid reconstruction that would be applied to A-II.
This paper introduces the RAM classification for adult-acquired flatfoot (AAFF). It independently grades deformity at three zones — Rearfoot (R), Ankle (A), and Midfoot (M) — each on a I–IIIa/b scale. The system was developed because prior single-axis staging systems (Johnson-Strom, Myerson Stage IV) assumed linear progression and could not capture patients whose zones were discordantly involved.
The Johnson-Strom and Myerson systems organized AAFF around PTT dysfunction as the central driver, with deformity progressing linearly from tendon disease through rearfoot collapse to ankle valgus (Stage IV). That framework works for the classic presentation but breaks down when a patient has severe midfoot collapse with a strong PTT, or ankle valgus from tibial plafond erosion rather than deltoid laxity.
When you evaluate an adult flatfoot, RAM tells you to assess all three zones independently before picking an operation. A patient coded as R-IIb A-Ia M-IIIb needs midfoot fusion as the primary procedure, not the osteotomy-and-tendon-transfer construct you would build for R-IIb A-Ia M-Ia.
The most high-yield decision rule: before finalizing any rearfoot correction, passively reduce the hindfoot and assess whether midfoot supination persists. If it does and you ignore it, the rearfoot will drift back into valgus — the paper explicitly names this as a mechanism of treatment failure.
The ankle zone distinction matters most in operative planning: a patient with lateral plafond bone loss (A-III) needs that bony deformity addressed at arthrodesis or arthroplasty, not just a soft tissue deltoid reconstruction that would be applied to A-II.