Expandable device for insertion between anatomical structures and a procedure utilizing same

An interspinous implant for insertion between upper and lower spinous processes, comprising:

• a spacer having first and second protrusions extending substantially upwardly and third and fourth protrusions extending substantially downwardly, the spacer further comprising posterior and anterior surfaces;
• the first and second protrusions forming an upwardly facing concave saddle and the third and fourth protrusions forming a downwardly facing concave saddle, wherein the saddles extend to the posterior and anterior surfaces;
• a strap extending circumferentially around the spacer such that the strap extends around the posterior and anterior surfaces and extends substantially transverse to the first, second, third and fourth protrusions;
• the strap coupled to the spacer such that tightening the strap causes the upwardly and downwardly facing concave saddles to move away from each other;
• wherein the spacer is configured such that, when the implant is inserted between the upper and lower spinous processes such that the saddles receive the upper and lower spinous processes, the posterior and anterior surfaces extend through a sagittal plane defined by the upper and lower spinous processes.