Is there a preferred articulating spacer technique for infected knee arthroplasty? A preliminary study.

BACKGROUND: Periprosthetic infection in TKA is a devastating and challenging problem for both patients and surgeons. Two-stage exchange arthroplasty with an interval antibiotic spacer reportedly has the highest infection control rate. Studies comparing static spacers with articulating spacers have reported varying ROM after reimplant, which could be due to differences in articulating spacer technique.

QUESTIONS/PURPOSES: We therefore determined whether one of three articulating spacer techniques was superior in terms of (1) infection control, (2) final ROM, and (3) cost.

PATIENTS AND METHODS: We retrospectively reviewed 53 patients with infected TKAs who had two-stage exchange arthroplasty with one of three techniques with articulating spacers: autoclaving an original component (n = 15), a new femoral component (n = 16), and a silicone mold component (n = 22). We compared infection control, ROM, and cost. Minimum followup was 12 months (mean, 39 months; range, 12-105 months).

RESULTS: We found no difference in infection control among the three techniques. Infection control was achieved in 13 of 15 (86.7%) autoclaved original component spacers at mean 73 months (range, 37-105 months), 15 of 16 (93.8%) new femoral component spacers at mean 19 months (range, 12-32 months), and 20 of 22 (90.9%) silicone mold component spacers at mean 32 months (range, 14-56 months). Mean final flexion was 95.7°, 98.3°, and 93.8°, respectively. Direct costs for all implants, molds, cement, and antibiotics were $932, $3589, and $3945, respectively.

CONCLUSIONS: We found comparable infection control and ROM for the three techniques. Direct cost was least for the autoclaved original component technique.