Early treatment outcome of isolated calf vein thrombosis after total knee arthroplasty

Purpose: In contrast to proximal deep vein thrombosis (DVT), the treatment of isolated calf vein thrombosis (ICVT) remains controversial. This study aimed to investigate early treatment outcomes of ICVT after total knee arthroplasty (TKA). Methods: Medical records of 313 patients who underwent TKA from October 2007 to December 2009 were retrospectively reviewed. A DVT-computed tomography (CT) was performed 7 days after surgery. ICVT was identified in 76 limbs of 73 patients. Of them, follow-up DVT-CT was available in 39 limbs of 37 patients. The patients with ICVTs were categorized into two groups: oral anticoagulation group (group I, 17 patients with 18 limbs) and conservative treatment group (group II, 20 patients with 21 limbs). Group I received an oral vitamin K antagonist for 3 to 6 months following low molecular weight heparin. Change of thrombus extent and development of pulmonary embolism (PE) was assessed in follow-up DVT-CT. Results: Mean age was 68 years and 95% were female. Of 39 limbs with ICVT, 16 (41%) involved major lower leg veins (posterior tibial vein or peroneal vein), 13 (33%) involved muscular veins (soleal vein or gastrocnemius vein) and 10 (26%) involved both. During 1 to 6 months, follow-up DVT-CT revealed complete thrombus resolution in all limbs and there was no proximal propagation of thrombus or PE in both groups. Conclusion: There is no evidence of DVT propagation or newly developed PE in the conservative treatment group. This result suggests that anticoagulation therapy for ICVT patients without PE after TKA may not be mandatory.