Mechanical prophylaxis after hip fracture: what is the risk of deep vein thrombosis? A retrospective observational study.

ABSTRACT

Graduated compression stockings carry a potential risk of pressure, vascular and other complications. Current understanding of deep vein thrombosis (DVT) risk leaves it uncertain whether patients with hip fracture should wear stockings on both legs. OBJECTIVES: To determine the association between the side of the hip fracture and the subsequent occurrence of symptomatic lower limb DVT. SETTING: Single tertiary trauma centre, Wales. PARTICIPANTS: All 3657 patients presenting with hip fracture between 2007 and 2013 were identified from our unit's National Hip Fracture Database. We excluded 404 patients (11.0%) resident outside our catchment area, leaving a total of 3253. Median age was 83 years (±12.4). PRIMARY/SECONDARY OUTCOME MEASURES: We cross-linked patient details with Medical Physics records, to identify 634 (19.5%) who had undergone one or more lower-limb Doppler-ultrasound scans at some point during the study period. The distribution rates of DVT were calculated from this resulting data set. RESULTS: Many of the total 634 scans were unrelated to the hip fracture, including 225 (35.5%) performed prior to the fracture. We calculated a baseline rate of DVT of 3.7/1000 patients per year, for the 3-month period immediately before the hip fracture. Scans performed following hip fracture showed DVT risk to be highest in the 3-month period after fracture (35.7/1000 patients per year). This resulted from a six-fold increase in DVTs on the side of the fracture (29.5/1000 patients per year, p<0.01). We found only a very small non-significant increase in DVT on the contralateral leg (6.1/1000 patients per year) CONCLUSIONS: The additional risk of DVT after hip fracture is essentially confined to the fractured limb-the leg to which it is most painful to apply stockings. There appears little justification for the cost and potential risk of using stockings on the contralateral leg.