Please select the eligibility criteria that correspond to the clinical trial below.
Title: Pot-Kast: Thrombosis Prophylaxis After Knee Arthroscopy: Determining the Balance Between Benefits and Risks
Brief Summary: Currently, guidelines and clinical practice differ considerably with respect to use of anticoagulant treatment after arthroscopy of the knee. Trials that have been carried out were aimed at efficacy only, had small sample sizes and therefore mainly used asymptomatic thrombosis as endpoint. From these trials an overall risk benefit-balance could not be established, hence the current controversy. In the proposed study the investigators will use relevant symptomatic endpoints in a large cohort of patients. Furthermore the investigators will follow subjects with an adverse event for a longer period, during which the investigators will assess the long term sequelae of these events. Lastly, the investigators will determine high risk groups that will benefit most from anticoagulant treatment.

Objective: Comparative effectiveness research to determine cost-effectiveness of two existing policies, i.e. treatment with low molecular weight heparin (LMWH) after arthroscopy of the knee. In addition the investigators will investigate personalized prophylaxis based on genetic and acquired risk factors.


Options:
A: Inclusion Criteria:

* Meniscectomy
* Diagnostic Arthroscopy
* Removal of corpora libera

Exclusion Criteria:

* Contra-indications for LMWH use (recent major bleeding, bleeding disorder, allergy)
* Pregnancy
* Pre-existent indication for anticoagulation therapy, either LMWH or vitamin K antagonists.
* History of venous thromboembolism (indication for anticoagulation therapy for prophylaxis of recurrence)
* Mental of physical disability to fulfill study requirements
* Insufficient knowledge of the Dutch language
* Previous participation in the Pot-(K)Cast study
B: Inclusion Criteria:

* Age \> 16 years
* Unilateral or bilateral, closed or open, fractures of the lower extremity distal to the knee including:

  1. Isolated fractures of the tibia including tibial plateau, shaft and plafond and medial malleolus
  2. Isolated fractures of the fibula including fibular head, fibular diaphysis,distal fibula and lateral malleolus
  3. Combined fractures of the tibia and fibula
* Tibia and/or fibula fractures may be accompanied by fractures of the patella and/or foot as well as ligamentous injuries as long as either the tibia or the fibula is involved
* Patients must be scheduled to undergo surgery (internal or external fixation) for repair of their fracture during the current admission

Exclusion Criteria:

* Patients presenting greater than 72 hours after injury
* Major injury involving other site(s)
* Lower extremity vascular injury requiring surgical repair
* Known systemic bleeding disorder or INR \> 1.5, aPTT \> 40 sec, or platelets \< 50 x 109/L at baseline
* Active, uncontrolled bleeding (as determined by the attending surgeon or delegate)
* Intracranial or other major bleed in the previous 4 weeks
* Ongoing need for anticoagulation for other reasons
* Previous DVT or PE (objectively proven or treated with anticoagulants)
* Known molecular hypercoagulable state
* Active cancer
* Inability to receive contrast dye because of pregnancy, contrast allergy, or renal failure (serum creatinine \> 300 mmol/L)
* Hypersensitivity to heparin or LMWH (including history of HIT)
* Inability to arrange out-of-hospital study medication administration
* Anticipated inability to undergo endpoint duplex ultrasound or follow-up (day 14 ± 2, 6 weeks, 3 months)
* Inability or refusal to provide informed consent· Previous participation in this study
* Estimated weight less than 40 kg
C: Inclusion Criteria:

All patients in need of immobilization of the lower leg with a plaster cast (or equivalent of a cast) for a minimum of one week for the following indications:

* Trauma of the lower leg
* Surgery of the lower leg followed by lower leg immobilization with a plaster cast
* Non-traumatic indications

Exclusion Criteria:

* Contra-indications for LMWH use (recent major bleeding, bleeding disorder, allergy)
* Pregnancy
* Pre-existent indication for anticoagulation therapy, either LMWH or vitamin K antagonists.
* History of venous thromboembolism (indication for anticoagulation therapy for prophylaxis of recurrence)
* Mental of physical disability to fulfill study requirements
* Insufficient knowledge of the Dutch language
* Previous participation in the Pot-(K)Cast study
D: Inclusion Criteria:

* at least 18 years
* with a nonsurgical fracture of the lower extremity requiring immobilisation in a below-knee plaster cast for a minimum of 4 weeks.

Exclusion Criteria:

* Delay between injury and Emergency Department visit greater than three days
* Pregnancy/ lactation
* Body weight \< 50 kg
* Severe hepatic impairment
* Severe renal impairment (creatinin-clearance \< 30 ml/min)
* Known hypersensitivity to nadroparine or fondaparinux
* Pre-existing venous thromboembolism
* Pre-existing post-thrombotic syndrome
* Documented congenital or acquired bleeding tendency/disorder(s)
* Active, clinically significant bleeding
* Clinically significant bleeding within the past six months
* Previous or active bleeding from the digestive tract by peptic ulcer, tumours, hiatus hernia or diverticulosis
* Severe hypertension (systolic blood pressure above 180 mmHg or diastolic blood pressure above 110 mmHg)
* Bacterial endocarditis
* Haemorrhagic stroke within the previous two months
* Severe head injury within the previous three months
* Intraocular, spinal, and/or brain surgery within the previous twelve months
* Major surgery within the previous two months
* Treatment with LMWH or other anticoagulants
* Anticoagulant therapy required or likely to be required during the study period (e.g. planned surgery justifying pharmacological thromboprophylaxis)

Answer: A