The surgical instrument includes a shaft having a distal end portion and a proximal end portion; an operative device is disposed on the distal end portion. A hand mechanism has a first handle and a second handle and is disposed on the proximal end portion. Movement of the second handle relative to the first handle actuates the operative device. A ratchet, attached to the second handle, locks the operative device and moves with the second handle. The ratchet is pivotally attached to the second handle and pivots between a locked position and an unlocked position. A biasing device biases the ratchet toward the locked position and a release mechanism for moves the ratchet from the locked position. At least one of the release mechanism and the ratchet has a feature permitting relative movement between the release mechanism and the ratchet.