A recent study showed that minor leg injuries, such as ankle sprains or a torn muscle, could lead to Venous Thrombo Embolism (VTE) or blood clots.

Researchers at Leiden University in Holland, led by Karlijn J. van Stralen, compared almost 2,500 patients who developed blood clots between 1999 and 2004 with more than 3,500 who did not. Patients completed questionnaire-describing injuries, surgical procedures, plaster casts or bed rest they had encountered within a year of developing blood clots.

The researchers were surprised to find that patients with minor leg injuries who did not need surgery, a plaster cast or extended bed rest, were three times more likely to develop a blood clot within three months than those who did not suffer injuries. About 11.7 percent (289) of the patients had had a minor injury during the three months leading up to the development of venous thrombosis, while 4.4 percent (154) of the controls had a minor injury in the three months before completing the questionnaire.

“Minor injuries that do not require surgery, a plaster cast or extended bed rest were associated with a three-fold greater relative risk of venous thrombosis. The association appeared to be local because injuries in the leg were associated strongly with thrombosis, while injuries in other locations were not associated with thrombosis. The association was strongest for injuries that occurred in the month before the venous thrombosis, suggesting a transient effect,” the researchers wrote.

Therefore, the researchers recommended that the individuals with minor injuries should contact the general practitioner first.

“Therefore, there may be an important task for general practitioners to identify subjects who are at a high risk of developing venous thrombosis and, subsequently, to provide prophylactic measures,” the researchers wrote.

The study also reports several reasons why minor injuries could lead to VTE. Although patients with minor injuries did not need to be completely immobilized during their recovery, most were less active because of their injury. This could have led to the developing of a blood clot. In addition, the damage to the blood vessel wall in the injured area could increase the risk of developing VTE.

The study was supported by the Netherlands Heart Foundation, the Dutch Cancer Foundation and the Netherlands Organization for Scientific Research. The findings were published in the Archives of Internal Medicine journal.