Patent US 5,606,590

A surgical alignment system employs a laser beam generating device and a lens system to convert the beam into a plane of light which is aligned along a desired axis of the human body to provide proper alignment to the surgeon to enhance the accuracy of orthopedic surgery such as total knee, hip or back surgery. The laser beam generating device is mounted on a bracket which is fixed to a cassette holder positioned beneath the patient and having a chamber designed to removably receive an x-ray film cassette. The cassette holder is made of a material which is transparent to x-rays. Straps incorporated into the cassette holder are designed to fix the patient to the cassette holder during surgery. The cassette holder includes a radio-opaque indicator with the bracket holding the laser beam generating device having a second radio-opaque indicator so that when an x-ray is taken of the patient affixed to the inventive device, compensation for parallax may be carried out.