Bone implants for the treatment of infection

Abstract

Described herein are devices, systems and methods for treating disease and/or infection by the release of silver from an implant over an extended period of time. In particular, the devices described herein may be used to treat infections such as osteomyelitis by the controlled release of silver ions from multiple sites of an extended-use implant. This implant typically includes a plurality of arms that both anchor and help distribute the released ions within the tissue. Power may be applied to release the silver ions into the tissue.

What is claimed is: 
     
         1 . A method of treating or preventing infection in a bone, the method comprising:
 inserting a silver-releasing implant into a bone in a collapsed configuration;   expanding the implant into the bone from the collapsed configuration into an expanded configuration having multiple pathways through the bone;   releasing silver ions from one or more silver reservoirs on the implant into the bone over an extended period of time at a sustained level; and   removing the implant after a predetermined period of time that is longer than a week.   
     
     
         2 . The method of  claim 1 , wherein inserting comprises pre-forming passageways for the implant. 
     
     
         3 . The method of  claim 1 , wherein inserting comprises inserting a passage forming implant having a plurality of expandable members to pre-form the multiple pathways. 
     
     
         4 . The method of  claim 1 , wherein expanding the implant comprises driving a plurality of arms of the implant through the bone by extending the arms from the implant, wherein the arms are sufficiently stiff and/or sharp to penetrate bone. 
     
     
         5 . The method of  claim 4 , wherein inserting comprises inserting the implant with a delivery device configured to hold one region of the implant while longitudinally moving another region of the implant to extend the arms. 
     
     
         6 . The method of  claim 4 , wherein removing comprises removing the implant with a delivery device configured to secure a proximal region of the implant while longitudinally moving another region of the implant to contract the arms. 
     
     
         7 . The method of  claim 1 , further comprising anchoring the implant in the bone. 
     
     
         8 . The method of  claim 1 , wherein releasing silver ions comprises applying energy to drive the release of ions. 
     
     
         9 . The method of  claim 1 , wherein releasing silver ions comprises applying less than 50 microAmps of power to release ions. 
     
     
         10 . The method of  claim 1 , wherein releasing silver ions comprises applying pulsatile energy to release ions. 
     
     
         11 . The method of  claim 1 , wherein releasing silver ions comprises applying energy in pulses to maintain a silver ion concentration above a minimum inhibitory concentration. 
     
     
         12 . The method of  claim 1 , wherein releasing silver ions comprises releasing silver ions to maintain a silver ion concentration above a minimum inhibitor concentration in a region of the bone surrounding the implant for a period of at least one week. 
     
     
         13 . The method of  claim 1 , wherein releasing silver ions comprises releasing silver ions to maintain a silver ion concentration above a minimum inhibitor concentration in a region of the bone surrounding the implant for a period of at least one month. 
     
     
         14 . The method of  claim 1 , wherein releasing silver ions comprises releasing silver ions to maintain a silver ion concentration above a minimum inhibitor concentration in a region of the bone surrounding the implant for a period of between about one day and six months. 
     
     
         15 . The method of  claim 1 , further comprising sampling a patient tissue when removing the implant. 
     
     
         16 . The method of  claim 1 , further comprising sampling a patient tissue using a sampling member on the implant when removing the implant. 
     
     
         17 . The method of  claim 1 , wherein the method is a method of treating osteomyelitis. 
     
     
         18 . A method of treating or preventing infection in a bone, the method comprising:
 inserting a silver-releasing implant into a bone in a collapsed configuration;   expanding a plurality of arms from the implant into the bone from the collapsed configuration into an expanded configuration wherein the expanded arms extend in a pattern having multiple pathways through the bone;   galvanically releasing silver ions from one or more silver reservoirs on the arms into the bone over an extended period of time at a sustained level; and   removing the implant after a predetermined period of time that is longer than a week.