Case 5: Below Knee DVT

35 year old Female presented with ultrasound confirmed diagnosis of right below knee DVT.

She ruptured her ACL 2 weeks ago while playing netball. After the injury, she had a MRI and saw an orthopaedic surgeon. She wanted to have the knee reconstruction ASAP.

Few days ago, she started to feel throbbing pain in her right leg. Incidentally, she had an appointment with another GP at a different clinic for skin cancer check. During the consultation, she mentioned her lower limb swelling and an ultrasound was ordered which confirmed the below knee thrombus.

She was started on clexane and sent back to you.

Question 1
Other than clexane, what are other options?

Question 2
How long will you put her on anti-coagulation for?

Question 3
She is extremely concerned about her ruptured ACL. She wants to have it fixed ASAP. What do you tell her ?

Answer 1

I still remember prescribing clexane and warfarin for people with below knee DVT when I was an intern 5 years ago. With the new oral anticoagulants, there are many more options.

The available treatments (1):

• Subcutaneous low molecular weight heparin such as clexane in this case
• The oral factor Xa inhibitors rivaroxaban or apixaban
• Bridging clexane then warfarin 
• Dabigatran or edoxaban. (requiring 5 to 10 days course of heparin prior to commencement of treatment)

The standard practice now at most hospitals is rivaroxaban (starting with 15 mg for 3 weeks, then increase to 20 mg). Interestingly, therapeutic guideline in Australia is till recommending clexane and warfarin as first line treatment. 

Of course, there is no hard and fast rule in selecting anticoagulants. If in doubt, use clexane for the first few days so that you and the patient can have time to think about the options.

Answer 2

According to therapeutic guideline, a person with provoked DVT, the minimum length of treatment is 3 months. Usually we will re-assess with ultrasound to ensure the resolution of the thrombus prior to ceasing the anti-coagulation.

Answer 3

Many patients have a fixed perception that ruptured ACLs have to be fixed ASAP. They probably get the idea from the media. It often reports Australian footy player receives surgery right away after an ACL rupture, and 2 months later, they are playing on the field again! (They forgot to mention the players are getting paid few hundred thousand dollars per game.)

So far, there is no evidence that early ACL repairs improve outcome. The rehabilitation time after an ACL repair is long, usually 6 - 12 months. It takes motivation and effort to return to pre-injury level activities. I have seen many people with poor outcome from ACL re-constructions.

Many people can continue playing sports without ACLs. In short, there is absolutely no indication for an urgent ACL repair. (Of course, unless you are getting paid 100,000 per game)

I told her that no orthopaedic surgeon will risk her life (the chance of developing a PE from having the surgery) with an ACL reconstruction.

References:

Lip G, Hull R. Overview of the treatment of lower extremity deep vein thrombosis (DVT). In: UpToDate, Post TW(Ed), UpToDate, Waltham, MA. (Accessed on April 26,2017)

Friedberg R. Anterior cruciate ligament injury. In: UpToDate, Post TW(Ed), UpToDate, Waltham, MA. (Accessed on April 26, 2017)