Short-term Follow-up of Antibiotic-loaded Articulating Cement Spacers in Two-stage Revision of Infected Total Knee Arthroplasty: A Case Series

Objective: Infection of total knee arthroplasty (TKA) is a rare but devastating complication. Two-stage revision is an effective treatment for late infected TKA. This study aimed to assess the short-term results of two-stage revision using articulating antibiotic-loaded spacers. Methods: Twenty-five patients (10 men and 15 women) were diagnosed with late infections after TKA and treated with two-stage revision from April 2006 to August 2010; 19 of these patients had TKA for osteoarthritis and 6 for rheumatoid arthritis. Median age was 64.9 (range, 56-83) years. In the first-stage surgery, the prosthesis and all bone cement was removed. After thorough debridement, bone cement with vancomycin and tobramycin was put into a die cavity and made into temporary femoral and tibial spacers, respectively. In the cases of good knee range of motion, the temporary spacers were affixed to the bone surface using the same antibiotic bone cement. In the second surgery, gentamycin Refobacin Bone Cement with vancomycin was used to fix the prosthesis. After two-stage revision, patients were followed up clinically and radiologically at 1, 3, and 6 months, and then annually. Knee Society Score (KSS), knee function score, knee pain score, and knee range of motion (ROM) were assessed. Results: Among the group, all spacers were easily removed, and bone defect degree showed no obvious change compared with pre-implant, 24 (96%) patients had been debrided once, and 1 patient had been debrided twice before reimplant prosthesis. Mean follow-up was 64.2 (range, 52-89) months. There was no infection recurrence at final followup. Compared with preoperative data, the KSS (66 [59, 71], 83 [80, 88] vs 46 [43, 57], P < 0.01), knee function score (43 [42, 49], 78 [73, 82] vs 32 [25, 37], P < 0.01), knee pain score (34 [33, 37], 42 [40, 45] vs 18 [16, 23], P < 0.01), and knee ROM (92 degrees [86 degrees, 96 degrees], 94 degrees [90 degrees, 98 degrees] vs 78 degrees [67 degrees, 86 degrees], P < 0.01) were all improved during followup and at final visit. Three patients experienced complications in the interval period: one case had knee dislocation, one had knee instability, and one had a chip in the femoral component of the spacer. Conclusion: Using articulating antibiotic-loaded spacers showed benefits for treating infected TKA in selected patients. No infection recurrence was observed during follow-up.