Abstract: A self-supporting surgical retractor is provided for retracting soft tissue and anatomy at a spinal surgical site. The retractor includes a tubular base defining an upper rim and a lower rim and a working channel there between the upper and lower rims, in which the base and lower rim are sized and configured to be seated on adjacent vertebral bodies spanning an intervertebral space. At least two elongated legs are provided, each projecting from the upper rim and each including a fixation feature at a free end thereof. Each of the legs has a length sufficient for the fixation feature to be outside the body of a patient when the lower rim is seated on adjacent vertebral bodies of the patient. The retractor is formed of a radio-transparent or radio-lucent material.

Abstract: A material measuring device has a base and a support, in which the base is provided with a mounting system adapted to hold the support in one or more fixed positions over material to be measured, in which the base has a first end, and in which the fixed positions are spaced apart from the first end.