Stern S H, Insall J N
Department of Orthopaedic Surgery, Northwestern University, Chicago, Illinois.
Clin Orthop Relat Res. 1993 Jan(286):10-4.
In a prospective evaluation of 41 patients (57 knees) treated with index cemented total knee arthroplasty, perioperative blood testing was performed on blood counts, fibrinogen, and fibrin degradation products (FDP). The preoperative platelet count averaged 314/nl (range, 160-502/nl), whereas postoperatively, the count nadired at an average of 173/nl (range, 60-305/nl). Fibrinogen levels increased from 304 mg/dl (range, 170-442 mg/dl) to an average high of 647 mg/dl (range, 317-1018 mg/dl). Patients were also classified according to whether they had been treated with unilateral or bilateral procedures. Postoperatively, unilateral patients had an average 32% decrease in the platelet count, compared with the 64% decrease seen in bilateral patients. Analysis of fibrin split products revealed a trend toward greater elevation of these degradation products after bilateral procedures. The hematologic changes represented evidence of activation of the coagulation and fibrinolytic systems. These changes tended to be more pronounced in patients treated with bilateral procedures, and were manifested in postoperative elevation of fibrinogen and fibrin degradation products, with reductions in the platelet count. The degree of relative thrombocytopenia raises concerns about careful evaluation of candidates for bilateral arthroplasty, especially when determining the preoperative platelet count.
在一项对41例患者（57个膝关节）进行初次骨水泥型全膝关节置换术的前瞻性评估中，对血细胞计数、纤维蛋白原和纤维蛋白降解产物（FDP）进行了围手术期血液检测。术前血小板计数平均为314/μl（范围160 - 502/μl），而术后计数最低平均为173/μl（范围60 - 305/μl）。纤维蛋白原水平从304mg/dl（范围170 - 442mg/dl）升至平均高水平647mg/dl（范围317 - 1018mg/dl）。患者还根据接受单侧或双侧手术进行分类。术后，单侧手术患者的血小板计数平均下降32%，而双侧手术患者下降64%。对纤维蛋白裂解产物的分析显示，双侧手术后这些降解产物有更大升高的趋势。血液学变化代表了凝血和纤维蛋白溶解系统激活的证据。这些变化在接受双侧手术的患者中往往更明显，表现为术后纤维蛋白原和纤维蛋白降解产物升高，血小板计数降低。相对血小板减少的程度引发了对双侧关节置换术候选者进行仔细评估的关注，尤其是在确定术前血小板计数时。
