ผลการศึกษาการวินิจฉัยภาวะการติดเชื้อภายหลังผ่าตัดข้อเข่าเทียมในโรงพยาบาลกระทุ่มแบน

บทคัดย่อ

A prospective descriptive study reviewed 195 patients with primary total knee arthroplasty (TKA) at Krathumbaen Hospital dunng 1^st  October 2007 to 31^st  March 2009. There were 24 males and 171 females. Mean body mass index was 25.4 (S.D. 4.3). Diseases of causes for TKA were secondary osteoarthritis 95%, rheu- matoid arthritis 3%, previous fracture around knee 2%. Patients were underlied by diabetic mellitus in 75% followed by hypertension 20%, chronic renal failure 3% and SLE 2% respectively. Range of motion before surgery was 80 degrees to -15 degrees. Poor dental hygiene found 1.5% at 6 months before surgery was improved by dentist. Mean allignment of knee before surgery was varus at 13 degrees (S.D. 10.5). Preoperative hematologic exam revealed mean ESR 18 mm/hr (range 5-40) and mean CRP 3.5 mg/L (range 0-10). Intrao-perative gram stain and culture of synovial fluid detected pathogens in 11 samples. Fluid exam showed leukocyte count > 1,100 cell/ul. with neutrophil > 64% in 12 samples. Among patients after TKA followed up at (least six months were found to have superficial infected TKA in 8 and deep infected TKA in 5 (4.1% and 2.5% respectively). The mean ESR and CRP of infected patients were 85 mm/hr and 110 mg/L, significantly higher (p <0.001) than the corresponding values at 22 mm/hr and 7 mg/L of the non infected knees. ln deep infected TKA groups (5 patients) septic loosening was found at mean duration of 2.4 months (S.D. 1.5) and intraoperative synovial fluid Gram stain and cultures detected pathogens in all 5 samples (Staphylococcus aureus, Klebsiella pneumonia, Enterococcus species, Acinetobacter and Pseudomonas aeuruginosa).

Fluid cell count also showed leukocyte > 1,100 cell/ul with neutrophil > 64% in al 5 samples. The mean ROM of non infected patients at 120 degrees to 0 degrees were significantly higher than infected patients mean ROM at 85 degrees to -10 degrees (p < 0.05). Accurate and early diagnosis is the first step in effective managing patients with periprosthetic joint infection. At present time, diagnosis remains dependent on clinical judgement, serologic test (ESR, CRP), analysis of joint fluid, interpretation of intra operative tissue and fluid and combination of these data.