The authors present two cases of checkrein deformity, a tethering of the flexor hallucis longus (FHL) tendon, following ankle surgery. The first case was treated by tenolysis and tendon lengthening posterior to the ankle. The second case was treated by lengthening of the FHL at the midfoot, a more simple procedure which produced a better outcome and faster recovery. The authors recommend this latter treatment should be considered to treat this problem.