Deep Vein Thrombosis

Procedure

Patient lying on their back with the knee straight. Gently and passively dorsiflex the ankle. Do not squeeze or massage the calf.

Positive Finding

Pain in the calf or behind the knee as the ankle is dorsiflexed.

Interpretation

A historical sign that is no longer used to decide whether DVT is present. It does not reliably separate DVT from calf strain, a Baker's cyst or other calf problems. Use the Wells score and refer. Any suspicion of DVT means stopping manual treatment of that leg and arranging same-day medical assessment. A 2005 meta-analysis of clinical findings in suspected DVT (Goodacre et al.) found that only cancer, previous DVT, recent immobilisation or surgery, and a difference in calf diameter usefully raised the chance of DVT. Homans' sign was not among them, so it should not be used to rule DVT in or out. The 48% / 83% previously stored could not be traced to a study (Europe PMC search, September 2026), so no figure is shown.

Procedure

Score 1 point for each: active cancer (treatment ongoing, within the last 6 months, or palliative); paralysis, weakness or recent plaster cast of the leg; bedridden for 3 days or more, or major surgery in the last 12 weeks; tenderness along the deep veins; whole leg swollen; calf more than 3 cm larger than the other side (measured 10 cm below the tibial tuberosity); pitting oedema in the symptomatic leg only; visible collateral superficial veins (not varicose veins); previous DVT. Subtract 2 points if another diagnosis is at least as likely as DVT.

Positive Finding

Score of 2 or more: DVT likely. Score of 1 or less: DVT unlikely.

Interpretation

A way of estimating how likely DVT is before any test. It does not confirm or exclude DVT on its own: 'unlikely' plus a normal D-dimer blood test can exclude DVT without a scan; 'likely', or a raised D-dimer, needs an ultrasound. Any suspicion of DVT means stopping manual treatment of that leg and arranging same-day medical assessment. This applies whatever the score. Wells is a probability score, not a yes/no test, so a single sensitivity and specificity does not describe it. In a 2006 review of 14 studies with more than 8,000 outpatients (Wells et al.), DVT was found in 5% of people scored low probability, 17% moderate and 53% high. A 2005 meta-analysis (Goodacre et al.) found a high score raised the odds of DVT about five-fold (likelihood ratio 5.2) and a low score lowered them (0.25). A low score with a negative D-dimer allows DVT to be ruled out without a scan. The 86% / 60% previously stored is not reported in either review.

Procedure

Patient lying down. Mark a point 10 cm below the tibial tuberosity on both legs and measure the calf circumference at the mark with a tape measure.

Positive Finding

The symptomatic calf is more than 3 cm larger than the other.

Interpretation

One of the Wells criteria. Calf swelling has many causes (cellulitis, a ruptured Baker's cyst, muscle injury, lymphoedema, venous insufficiency), so it raises suspicion rather than making the diagnosis. New one-sided calf swelling without a clear cause needs same-day medical assessment. In a 2005 meta-analysis (Goodacre et al.), a difference in calf diameter raised the likelihood of DVT only modestly (likelihood ratio 1.80), and no difference lowered it modestly (0.57); no calf swelling gave 0.67. Calf measurement adds to the Wells score and ultrasound; it cannot replace them. No sensitivity or specificity is shown.

Procedure

Done by a sonographer or doctor. The probe is pressed over the leg veins (at least the common femoral and popliteal veins; a whole-leg scan also includes the calf veins) to see whether each vein squashes flat.

Positive Finding

A vein that will not compress fully, or clot seen inside it.

Interpretation

The standard imaging test for DVT. A limited scan of the thigh and knee veins can miss clot confined to the calf, so a repeat scan about a week later, or a whole-leg scan, is used when suspicion remains. It is the test to refer for, not one done in osteopathic practice.

Procedure

A blood test ordered by a doctor. It measures fragments released when a blood clot breaks down.

Positive Finding

A level above the laboratory's cut-off.

Interpretation

Mainly useful for ruling DVT out: a normal result in someone with a low Wells score makes DVT very unlikely. Levels are commonly raised after surgery or injury, with infection or cancer, in pregnancy and in older people, so a raised result needs an ultrasound; it does not confirm DVT.

Procedure

Ask about new pain, swelling, heaviness, warmth or redness in one leg and when it started. Ask about risk factors: recent surgery or hospital stay, plaster cast or immobilisation, long-distance travel, cancer, previous DVT or pulmonary embolism, pregnancy or recent birth, oestrogen-containing pill or HRT, and family history of clots.

Positive Finding

New one-sided calf or thigh pain or swelling, especially with risk factors.

Interpretation

History alone cannot confirm or exclude DVT, but it sets the level of suspicion and feeds into the Wells score. Always ask about breathlessness, chest pain or coughing up blood: these suggest pulmonary embolism and need an ambulance. Any suspicion of DVT means stopping manual treatment of that leg and arranging same-day medical assessment. This is part of the history rather than a test. A 2005 meta-analysis (Goodacre et al.) found individual symptoms and signs changed the likelihood of DVT only modestly; the Wells score, which combines them, performed better. No figure is shown.