Clinical Trial: Articulating Versus Static Antibiotic Loaded Spacers for the Treatment of Prosthetic Knee Infection

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Articulating Versus Static Antibiotic Loaded Spacers for the Treatment of Prosthetic Knee Infection

Brief Summary:

Infection remains a difficult-to-treat complication of total knee arthroplasty. The gold standard treatment is two-stage removal of the prosthesis with later replacement of permanent implants. The first stage consists of removal of the infected arthroplasty components and the surrounding devitalized tissue, copious pulsed irrigation, and placement of a temporary antibiotic-impregnated cement spacer. This spacer typically is left in place six weeks, during which time the patient receives intravenous antibiotics. After the surgeon feels that the infection has been eradicated, or if the patient requires repeat debridement, a second operative procedure is performed. While the use of an antibiotic-loaded spacer is well accepted, whether the spacer should immobilize the knee (a so-called "static" spacer) or allow for range of motion (a so-called "articulating" spacer) is controversial. Proponents of articulating spacers argue that they prevent scarring of the musculature surrounding the knee resulting in easier reimplantation, improved long-term knee function, and improved range of motion. Proponents of static spacers argue that immobilization of the periarticular soft tissues aids in clearance of the infection and is simpler to fashion intraoperatively. While good results have been described with both methods, comparative trials have been conflicting as to whether spacer design alters knee function, operative time, and range of motion. Equipoise exists within the literature, and no randomized clinical trial has been conducted to evaluate this issue.

The purpose of this study is to compare articulating and static antibiotic-impregnated spacers for the treatment of chronic periprosthetic infection complicating total knee arthroplasty through a prospective, randomized clinical trial. The goals of this trial are to determine the effect of spacer design upon era

Detailed Summary:

After diagnosis of infection and informed consent, patients will be taken to the operating room. After anesthetization, patients will be randomized to either an articulating spacer or a static spacer. Randomization will be performed by prepared opaque envelopes administered by a nonparticipant in the study. After a complete debridement of devitalized tissue, explantation of the infected components and any associated cement, either an articulating or static spacer will be placed. All spacers will be formed of 3 g of Vancomycin and 1 g of Tobramycin for each 40 g packet of cement. Articulating spacers will be formed of antibiotic impregnated cement using the Stage One system (Biomet, Warsaw, IN). Static spacers will be hand-made to fit the femoral and tibial exposed metaphyses as a solid block with associated antibiotic cement coated tibial and femoral intramedullary rod, such that knee motion will be minimized.

Post-operatively, all patients will be made touch-down weight bearing protected with a walker or crutches. If a static spacer is placed, patients will be immobilized using with a knee immobilizer. If an articulating spacer is utilized, range of motion will be allowed to the limits of stability as determined in the operating room and protected with a hinged knee brace. At the time of reoperation, the joint will be aspirated and multiple cultures obtained along with intraoperative histopathological analysis to evaluate for persistent infection.

Data collected preoperatively will include age, gender, laterality, etiology of knee degeneration, comorbidities, Knee Society score, and infecting organisms. The Knee Society score has been used extensively in the study of revision knee arthroplasty and has been found to be reliable and valid and will be determined pre-operatively and at all follow-up visits.

Same as current

Current Secondary Outcome:

  • Knee Society Score [ Time Frame: Outcomes will be collected until 2 years post-operatively. ]
  • Operative time [ Time Frame: Outcomes will be collected until 2 years post-operatively. ]


Original Secondary Outcome: Same as current

Information By: Rush University Medical Center

Dates:
Date Received: June 6, 2011
Date Started: December 2011
Date Completion: August 2018
Last Updated: April 10, 2017
Last Verified: April 2017