The Effectiveness of Antibiotic Cement Compared to Regular Cement in Reducing the Rate of Infection Following Total Knee Arthroplasty: The ABC Feasibility Study

Rationale: Infection following total knee replacement (TKA) is a devastating complication that usually requires prosthesis removal, hospitalization while the infection is eradicated, and a second surgery to implant a revision prosthesis. For primary TKA, prophylactic antibiotic-loaded cement (ABC) may not only reduce the rate of infection it may also reduce the rate of revisions due to implant loosening. Current controversy about the use of ABC exists around the world. Without a definitive trial, patients will be exposed to a treatment of uncertain efficacy that may cause antibiotic resistant bacterial strains and will certainly generate high costs to the healthcare system. Purpose: To determine, 1) the extent to which ABC compared to regular cement reduces the infection rate in patients over the first two years following TKA and, 2) the resource use implications associated with the use of ABC for TKA. Methods: This is a randomized clinical trial in which 8,800 patients with undergoing primary TKA are allocated to either Simplex™ P with Tobramycin or Simplex™ P bone cement. We will exclude patients with a prior joint infection, an allergy to tobramycin, and those with no fixed address. All patients will be administered IV antibiotics immediately prior to surgery. Patients and surgeons will be blind to group allocation. The primary outcome measure is infection. Follow-up visits will take place at 6 weeks and 3, 12 and 24 months postoperative. A blinded adjudicator will review all reported infections and determine whether the putative infection is a study event. Blinded radiologists will interpret the 2 year series of radiographs for each patient. We will compare the rates of infection and implant loosening between the two treatment groups using survival analyses. This study includes a full economic analysis.