Salvage of infected total knee arthroplasty with Ilizarov external fixator.

Sir,

We read with interest the article titled “Salvage of infected total knee arthroplasty with Ilizarov external fixator” by Reddy et al.1 The indications or inclusion criteria for Ilizarov external fixator as a salvage procedure are not clear, particularly when antibiotic sensitive bacteria are present with a potential for a revision joint replacement instead.2 In the third paragraph under the section Materials and Methods, the authors had mentioned that in the two-stage procedure for salvage with Ilizarov external fixator, antibiotic impregnated bone cement were used, but postoperatively they routinely used suction drain. The local antibiotic concentration is highest in the first 48–72 hours after antibiotic cement implantation and a postoperative drain is therefore better avoided.2–5 If at all used, the drain should be used only to limit the volume of hematoma and should be removed as soon as possible.2 Thus, drains cannot be a blanket recommendation here since the eluted antibiotic will come out of the postoperative wound against the intended high local concentration of eluted antibiotics.2 Since the local antibiotic concentration is highest in the first 48–72 hours after antibiotic cement implantation,1 judicious drainage only may be recommended.35 It is unclear as to how exactly and meticulously the bone cement (used in primary surgery for implant fixation) needs to be removed during debridement, particularly if the implant was well fixed on one side (tibial or femoral), since these are potential sources of bacterial biofilm and nonunions. Lastly, the clinical picture with ambulatory and functional status of the cases (besides the status of radiological union) is quite important but is not mentioned in this paper.