Patent ID: 7959684
Filing Date: 2011-06-14
Classification: A61B

Abstract:
1. A method for forming a composite implant in a bone cavity comprising i) forming a first bone filler in a bone cavity; and ii) inserting a second bone filler into an unfilled space in said bone cavity, wherein the first bone filler has a higher compressive strength and slower bioresorption rate in comparison with the second bone filler wherein said forming in step i) comprises inserting a major portion of a perforated balloon in said bone cavity; injecting the first bone filler comprising a first orthopaedic paste into said perforated balloon, wherein said perforated balloon comprises a neck adapted to be mounted on an end of a tube through which said first bone filler is injected into the perforated balloon; and leaking perforations, wherein said leaking perforations have a size which is penetrable to liquid contained in said first orthopaedic paste but substantially impenetrable to powder contained in said orthopaedic paste under an expanded condition of said perforated balloon; letting the first orthopaedic paste harden in the perforated balloon under pressure, wherein said liquid contained in said first orthopaedic paste escapes from said perforated balloon through said perforations during said injection and hardening of said first orthopaedic paste; opening the perforated balloon when the first orthopaedic paste hardens or partially hardens; and retrieving the opened balloon from the bone cavity by pulling a tube on which said neck is mounted to leave the hardened or partially hardened orthopaedic paste in the bone cavity, wherein said opening comprises continuously or intermittently injecting a liquid or gas into the perforated balloon containing the hardened or partially hardened first orthopaedic paste therein until the perforated balloon is dilated to exceed a critical size, and thus ruptures.