Pot-(K)Cast trials

Thrombosis prophylaxis after knee arthroscopy or during plaster cast lower leg immobilisation: determining the balance between benefits and risks

Project managers

Prof. dr S.C. Cannegieter 

Prof. dr R.G.H.H. Nelissen

Prof. dr I.B. Schipper

Collaboration

Alrijne Hospital, Leiderdorp

Groene Hart Hospital, Gouda

Haga Hospital, The Hague

Isala Hospital, Zwolle

Medical Center Haaglanden Hospital, The Hague

Reinier de Graaf Hospital, Delft

Orthopedium Clinic, Delft

Park Medical Center, Rotterdam

We conducted two parallel, pragmatic, multicenter, randomized, controlled, open-label trials with blinded outcome evaluation: the POT-KAST trial, which included patients undergoing knee arthroscopy, and the POT-CAST trial, which included patients treated with casting of the lower leg. Patients were assigned to receive either a prophylactic dose of low-molecular-weight heparin (for the 8 days after arthroscopy in the POT-KAST trial or during the full period of immobilization due to casting in the POT-CAST trial) or no anticoagulant therapy. The primary outcomes were the cumulative incidences of symptomatic venous thromboembolism and major bleeding within 3 months after the procedure.

In the POT-KAST trial, 1543 patients underwent randomization, of whom 1451 were included in the intention-to-treat population. Venous thromboembolism occurred in 5 of the 731 patients (0.7%) in the treatment group and in 3 of the 720 patients (0.4%) in the control group. Major bleeding occurred in 1 patient (0.1%) in the treatment group and in 1 (0.1%) in the control group. In the POT-CAST trial, 1519 patients underwent randomization, of whom 1435 were included in the intention-to-treat population. Venous thromboembolism occurred in 10 of the 719 patients (1.4%) in the treatment group and in 13 of the 716 patients (1.8%) in the control group. No major bleeding events occurred. 

The results of both trials showed that prophylaxis with low-molecular-weight heparin for the 8 days after knee arthroscopy or during the full period of immobilization due to casting was not effective for the prevention of symptomatic venous thromboembolism. 

Additional studies are being performed to determine coagulation profiles in these patients and to further develop models that predict thrombosis risk in both high risk groups.

The Pot-(K)Cast trial was nominated for the "Zinnige Zorg Award 2018" of VGZ  with “minder prikken na beenbreuk”. Watch the short promotion film (in dutch).