Abstract: An extension foot sleeve is formed with an L-shaped foot-receiving shell having an external adapter block for arranging on an operating table and having quick-release clasps and detent tabs for securing a patient's foot. The foot sleeve makes it possible to easily clamp a patient's foot without turning it in the L-shaped foot-receiving shell and without moving cushioning material laterally, and also reliably prevents an accidental release of the quick-release clasps or undesirable contact between the operating team and same. The quick-release clasps are arranged in pairs to the right and left on side edges of the foot-receiving shell in an edge region of the L angle close to the heel and in an edge region of the upper end of the foot-receiving shell. The extension foot sleeve is associated with clamps having detent tabs on both sides, which can be inserted in parallel into the quick-release clasps.