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[Management of deep infection after total knee arthroplasty].

OBJECTIVE
To evaluate the clinical treatment methods of deep infection after total knee arthroplasty (TKA) and its effectiveness.


METHODS
Between January 2004 and January 2010, 32 cases (32 knees) of deep infection after TKA were treated, including 13 males and 19 females with an average age of 64.6 years (range, 52-79 years). The time from primary TKA to infection was 3 weeks to 10 years. The preoperative knee society score (KSS) was 104.6 +/- 9.1, and the visual analogue scale (VAS) score was 7.8 +/- 1.4. Open debridement and continuous irrigation were perfomed in 3 cases of acute infection, arthroscopic debridement and irrigation in 3 cases of acute haematogenous infection; in 26 cases of chronic deep infection, 9 cases underwent open debridement, 4 cases underwent antibiotics impregnated bone cement spacer, 12 cases received two-stage revision, and 1 case underwent conservative treatment by intravenous antibiotics.


RESULTS
All cases of acute infection failed to control deep infection; 1 case of acute haematogenous infection failed to treat; 7 cases of chronic infection undergoing debridement and 1 case of conservative treatment failed to treat; and all the failure cases were cured after symptomatic treatment. Thirty-two cases were followed up 2-8 years (mean, 4.6 years). At last follow-up, the KSS score and VAS score were 158.4 +/- 8.3 and 4.1 +/- 0.8, respectively, all showing significant differences when compared with preoperative scores (P < 0.05). Re-infection occurred in 3 patients who received two-stage revision during follow-up.


CONCLUSION
In patients with acute infection of methicillin-resistant Staphylococcus aureus after TKA, open debridement and liner change have low success rate; arthroscopic debridement can be performed to control acute haematogenous infection; and two-stage revision is an effective method to control chronic infection and restore the knee function, but two-stage revision has a potential risk of re-infection.