Rotating, locking, middle-expanded intervertebral disk stabilizer

Apparatus for inserting between adjacent vertebrae after removal of a portion of the intervertebral disk from therebetween with an elongate applicator comprising:

• an elongate implant having a substantially rectangular cross-sectional shape perpendicular to the elongate length thereof, comprised of first and second substantially flat sides defining the height of said implant and third and fourth sides defining the width of said implant, the third and fourth sides being arched to provide said implant with a bi-convex shape having a width greater in the middle portion than at the ends thereof, the height of said implant being less in dimension than the width of said implant;
• means formed in one end of said implant for detachably mounting an applicator to said implant;
• and
• a lock detachably secured to said implant to prevent rotation of said implant in the space between the adjacent vertebrae after (a) inserting said implant when mounted to said applicator into the space between the adjacent vertebrae with the first and second sides of said implant contacting the adjacent vertebrae, (b) rotating said applicator having said implant mounted to the applicator approximately 90.degree. to cause the third and fourth sides of said implant to contact the adjacent vertebrae, and (c) detaching said applicator from said implant.