DEEP-VEIN THROMBOSIS AFTER HIP OR KNEE ARTHROPLASTY - PREVENTION AND DUPLEX ULTRASONOGRAPHIC PREVALENCE

Purpose. Duplex ultrasound scanning was performed to detect deep venou s thrombosis (DVT) after hip or knee arthroplasty and evaluate applica tion of the postoperative thromboprophylaxis consensus. Patients and m ethods. A prospective multicenter study was conducted between April 19 95 and April 1996 in 16 centers. Thirty angiologists included 505 pati ents (370 in private clinics and 135 in university hospitals). Mean pa tient age was 71 years. There were 288 women. Hip arthroplasty was per formed in 396 patients (78 %) and knee arthroplasty in 109 (22 %): und er general anesthesia in 323. The postoperative thromboprophylaxis con sensus was recalled prior to study onset and DVT was detected 8 and 10 days after surgery by duplex ultrasonography. Results. Thromboprophyl axis was prescribed by the anesthesiologist (57 %), the surgeon (23 %) or an angiologist (20 %). Anticoagulation dosage was lower than the r ecommended dosage in 181 patients (36 %). The prevalence of detected d eep venous thrombosis was 14 % (range 11-17 %), including 21 cases of proximal DVT (4.2 %), 33 of distal DVT (6.5 %) and 17 of distal muscul ar DVT (3,4 %). The risk of having a DVT was 1.6-fold higher in patien ts over 70 years of age (p = 0.04), 2.2-fold higher in case of general anesthesia (p = 0.03) and 2.1-fold higher in case of reduced mobility (p = 0.01). When heparin dosage was lower than the recommended consen sus dosage, prevalence of DVT was 19 % compared with 11 % for patients who received the right dosage (RR = 1.7, p = 0.01). Conclusion. Much progress is needed in the application of the postoperative consensus o n thromboprephylaxis. The high prevalence of DVT despite preventive tr eatment indicates that systematic detection of DVT is useful, particul arly in high-risk patients or when the recommended thromboprophylaxis cannot be applied.