title: The significance of calf thrombi after total knee arthroplasty.
abstract: We reviewed the records of 1257 patients having 1625 total knee arthroplasties; all had pre-operative and postoperative perfusion lung scans and postoperative venograms which were classified as showing no thrombi, calf thrombi or proximal thrombi. Patients with calf thrombi were found to have a significantly greater risk for both symptomatic and asymptomatic pulmonary embolism compared with patients with no venographic thrombi. There were positive lung scans in 6.9% of patients with calf thrombi compared with 2.0% of patients with negative venograms (p < 0.001). Symptomatic pulmonary embolism occurred in 1.6% of patients with calf thrombi compared with 0.2% of patients with negative venograms (p = 0.034). The risk of pulmonary embolism was not significantly different between patients with treated proximal thrombi, and those with calf thrombi. Patients who develop deep-vein thrombosis despite prophylaxis are at increased risk for pulmonary embolism; these patients should receive treatment, or undergo follow-up studies to detect proximal propagation.
authors.affiliation: Hospital for Special Surgery, New York, NY 10021.
authors.forename: S B
authors.initials: SB
authors.lastname: Haas
authors.forename: C B
authors.initials: CB
authors.lastname: Tribus
authors.forename: J N
authors.initials: JN
authors.lastname: Insall
authors.forename: M W
authors.initials: MW
authors.lastname: Becker
authors.forename: R E
authors.initials: RE
authors.lastname: Windsor
mesh_terms: D001241:Aspirin / Q000627:therapeutic use; D006801:Humans; D007720:Knee Prosthesis; D007866:Leg / Q000098:blood supply*; D010690:Phlebography; D011183:Postoperative Complications / Q000175:diagnosis; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000517:prevention & control
chemical_list: D001241:Aspirin