Antibiotic delivery system and method for treating an infected synovial joint during re-implantation of an orthopedic prosthesis

Abstract

An antibiotic delivery system including an intramedullary stem that is adapted to be removably mounted into a medullary canal of a bone. The stem includes a body having an inlet adapted to be in fluid communication with a source of liquid-borne antibiotic and a plurality of outlets disposed along the stem. A channel extends between the inlet and the plurality of outlets for delivering a fluid-borne antibiotic from the inlet to the plurality of outlets so as to distribute the antibiotic along the medullary canal in a controlled fashion. A method of treating an infected joint during a two-stage re-implantation of an orthopedic implant is also disclosed.

What is claimed is: 
     
       1. An antibiotic delivery system comprising:
 a femoral intramedullary stem adapted to be removably mounted into a medullary canal of a femur bone, said femoral intramedullary stem including a body having a proximate end and a distal end disposed remote from said proximate end, said body including a plurality of fins extending therealong and disposed in spaced angular relationship with respect to each other so as to define valleys that provide fluid flow spaces disposed between adjacent fins, said fins adapted to engage said medullary canal in a removably stable fashion, a femoral head and a neck extending from said proximal end of said body and between said body and said femoral head, said femoral intramedullary stem including at least one inlet, and a plurality of outlets disposed along said stem and between an outer surface of one of said plurality of adjacent fins in said valleys and in fluid communication with said fluid flow spaces and a channel extending between said inlet and said plurality of outlets, said femoral head having a plurality of outlets and a channel extending between said at least one inlet and said plurality of outlets for delivering fluid-borne antibiotics from said at least one inlet to said plurality of outlets so as to distribute said antibiotic along said intramedullary canal and the socket of a hip joint in a controlled fashion.   
     
     
       2. An antibiotic delivery system as set forth in  claim 1 , wherein said body includes an inlet and said femoral head includes an inlet, both inlets being in fluid communication with a source of fluid-borne antibiotic. 
     
     
       3. An antibiotic delivery system as set forth in  claim 1 , wherein said femoral head has a hemispherical shape so as to be complimentarily received in the socket of a hip joint. 
     
     
       4. A method of treating an infected joint during a two-stage re-implantation of an orthopedic implant, said method comprising the steps of: removing the infected implants mounted to the medullary canal of a bone; debriding the medullary canal; installing an intramedullary stem into the medullary canal where the stem includes an inlet, a plurality of outlets and a channel extending between the inlet and the plurality of outlets; said stem including a plurality of fins extending along a longitudinal axis of the stem and disposed in spaced angular relationship with respect to each other so as to define valleys that provide fluid flow spaces disposed between adjacent fins and a plurality of outlets disposed along said stem and between an outer surface of one of said plurality of adjacent fins in said valleys and in fluid communication with said fluid flow spaces providing a source of fluid-borne antibiotic to the inlet of the intramedullary stem so as to distribute the antibiotic into the medullary canal in a controlled fashion. 
     
     
       5. A method of treating an infected orthopedic implant as set forth in  claim 4 , wherein said step of installing an intramedullary stem includes installing a tibial intramedullary stem into the medullary canal of the tibia bone and installing a femoral intramedullary stem into the medullary canal of a femur bone. 
     
     
       6. A method of treating an infected orthopedic implant as set forth in  claim 5 , wherein the method further includes the step of positioning a coupler between the tibial intramedullary stem and the femoral intramedullary stem so as to provide axial stability between the tibial and femoral intramedullary stems. 
     
     
       7. A method of treating an infected orthopedic implant as set forth in  claim 6 , wherein the method further includes the step of establishing fluid communication between the coupler and the inlet of the tibial and femoral intramedullary stems and providing fluid communication between the coupler and a source of fluid-borne antibiotic so as to distribute the antibiotic through the tibial and femoral intramedullary stems and along the medullary canals in a controlled fashion. 
     
     
       8. A method of treating infected tissue in a patient, the method comprising:
 a) installing a first intramedullary stem into a first medullary canal of a first bone, said intramedullary stem comprising a longitudinal axis, wherein said installing comprises engaging an outer stem surface of the first intramedullary stem with said first medullary canal of the first bone, the outer stem surface comprising a plurality of fins extending along said first intramedullary stem, said plurality of fins disposed in spaced angular relationship so as to define a plurality of valleys, each of said plurality of valleys disposed between an adjacent pair of fins and providing a fluid-flow space between said adjacent pair of fins when said stem is installed in said first medullary canal, wherein the first intramedullary stem comprises a first inlet, a first plurality of outlets and a first channel therein and in fluid communication with each of said first inlet, said first plurality of outlets and the fluid-flow spaces, and further wherein said first plurality of outlets is disposed along said stem in said plurality of valleys; and   b) removing a first fluid from the first medullary canal.   
     
     
       9. The method of claim 8, wherein said removing the first fluid from the first medullary canal comprises using negative pressure in fluid communication with the first medullary canal to remove said first fluid. 
     
     
       10. The method of claim 9, wherein a pump applies said negative pressure to remove said first fluid from said first medullary canal. 
     
     
       11. The method of  claim 10 , wherein the pump pumps the fluid in a pulsatile fashion. 
     
     
       12. The method of claim 8, further comprising removing at least one implant from the first medullary canal before said installing said first intramedullary stem. 
     
     
       13. The method of claim 12, further comprising debriding the first medullary canal after removing said at least one implant from the first medullary canal and before said installing said first intramedullary stem. 
     
     
       14. The method of claim 8, further comprising delivering a second fluid to the first medullary canal via said first inlet, said first channel and said first plurality of outlets after said removing the first fluid. 
     
     
       15. The method of claim 14, wherein the second fluid comprises at least one of an antibiotic, a cleaning fluid, an irrigating fluid, a debriding fluid, and a fluid-borne agent for treating infected tissue. 
     
     
       16. The method of claim 8, further comprising installing a second intramedullary stem into a second medullary canal of a second bone, the second intramedullary stem comprising a second channel therein and in fluid communication with a second plurality of outlets disposed along the second intramedullary stem. 
     
     
       17. The method of claim 16, further comprising removing the first fluid from the second medullary canal. 
     
     
       18. The method of claim 17, comprising irrigating the first medullary canal and the second medullary canal prior to removing the first fluid. 
     
     
       19. The method of claim 17, further comprising delivering a second fluid to the second medullary canals via said second channel and said second plurality of outlets after removing the first fluid from said second medullary canal. 
     
     
       20. The method of claim 19, wherein the second fluid comprises at least one of an antibiotic, a cleaning fluid, an irrigating fluid, a debriding fluid, and a fluid-borne agent for treating infected tissue. 
     
     
       21. The method of claim 16, wherein the second intramedullary stem comprises a plurality of fins extending therealong and disposed in spaced angular relationship so as to define a plurality of valleys, each of said plurality of valleys disposed between an adjacent pair of fins and providing a fluid flow space between said adjacent pair of fins when said stem is installed in said first medullary canal, wherein each of the fluid flow spaces is in fluid communication with the second plurality of outlets. 
     
     
       22. The method of claim 16, further comprising coupling the first intramedullary stem to the second intramedullary stem with a coupler. 
     
     
       23. The method of claim 10, further comprising delivering a second fluid to the first medullary canal via said first inlet, said first channel and said first plurality of outlets after said removing the first fluid. 
     
     
       24. The method of claim 23, wherein said pump for applying said negative pressure is also adapted to deliver said second fluid to said first medullary canal.