Ultrasound assessment of the efficacy of wound drains.

We report the use of ultrasound in the assessment of the efficacy of wound drains in preventing wound haematoma. 171 patients with proximal femoral fractures who underwent AO dynamic hip screw or hemiarthroplasty were randomized as to whether or not they should receive wound drainage. Patients then underwent ultrasound examination on the 5th postoperative day to localize and quantify any wound haematomas. Results show that drains are effective in preventing wound collections, but only while in situ; following the removal of drains the size of resulting wound collections is the same whether the wound has been drained or not (Student's t-test; t = 0.19, NS). This study questions current theories on the mechanisms by which wound drainage is thought to influence wound healing.