Implant-associated infections are deep wound infections that occur at or near the site of an implanted device and frequently require a second surgery to remove the implant. (refs. 1,2) Retrospective studies of spinal surgery procedures involving implants report infection rates of 1.7% to 17%. (refs. 3-6) The highest incidences of implant-associated infections have been reported for spinal trauma procedures (9-17%) (ref. 7) and scoliosis/deformity procedures (1.7-11%) (refs. 8-11). The average cost of an orthopedic implant-associated infection is $15,000 (ref. 12), and the cost for scoliosis instrumentation is reported to be $65,000. (ref. 13) The cost of treating individual infections has been estimated as roughly $22,170 per occurrence. The cost of implant infections in spine surgery divided by the total number of spine patients is estimated to be about $2,400/patient. Third-party payers and patients assume some of these costs, but hospitals and physicians are asked to absorb the remainder.
This cost data suggests the need for a product that minimizes infection rates or mitigates the consequences of infections in spine surgery and that costs less than $2,400 per surgery. Such a product would be valuable to patients, surgeons, hospitals, and medical insurers while also having equitable benefits for healthcare economics.
There are no commercially available spinal products specifically designed to treat or manage implant-associated infections in spine surgery. Although technology exists in the areas of anti-infective coatings and drug-eluting materials, no technology has been developed that describes spinal device components with anti-infective properties.
Some conventional technologies for preventing or managing infection associated with implants are provided in the following patent documents: EP754064, entitled “Polymer Coating for Orthopedic Devices”; EP792654, entitled “Antimicrobial Pin Sleeve”; US2002/0029043, entitled “Silver Bone Screw” and assigned to Synthes; US2003/0036761, entitled “Pharmacological Pin Sleeve” and assigned to Smith & Nephew Richards; US2005/0031665, entitled “Orthopedic Screw Delivery System”; US2005/0059972, entitled “Screw Assembly with Antimicrobial Properties”; US2006/0093646, entitled “Drug Eluting Orthopedic Hip Implant”; U.S. Pat. No. 4,442,133, entitled “Preoperative Anti-Biotic Graft Coating”; U.S. Pat. No. 4,476,590, entitled “Silver Antimicrobial surgical implants”; U.S. Pat. No. 5,098,434, entitled “Porous Coated Bone Screw”; U.S. Pat. No. 6,514,517, entitled “Prevention of Biofilms” and assigned to Ethicon; U.S. Pat. No. 6,575,945, entitled “Prevention of Biofilms”; U.S. Pat. No. 6,663,634, entitled “Bone Screw” and assigned to Synthes; U.S. Pat. No. 6,921,390, entitled “Antibiotic Sleeve” and assigned to BostonScientific; U.S. Pat. No. 6,936,270, entitled “Orthopedic Screw Drug Delivery System and assigned to Control Delivery Systems, Inc; U.S. Pat. No. 7,066,938, entitled “Snap-On Rod Connector” and assigned to DePuy Spine;, and WO2002036175, entitled “Orthopedic Screw Drug Delivery System” and assigned to Control Delivery Systems.
WO1998003209, entitled “Screw Cap contoured” describes a non-load bearing screw cap that facilitates revision of the implanted screw.