A mechanical arthroscopic leg holder for supporting and clamping a patient's leg in a desired position for examination or operation, the holder having an adjustable mounting post engageable with a standard operating table side rail holder. The mounting post supports a positioning plate and connected moveable base plate having a medial pad and a sled guide for a sliding lateral pad carriage. The sliding carriage transports an adjustable lateral pad and includes a clamping lock mechanism which permits a manually determined clamping force for controlled retention of the patient's leg in an optimized operating position with maximized patient comfort.
