Feasibility and Safety of a Novel Leg Exercise Apparatus for Venous Thromboembolism Prophylaxis After Total Joint Arthroplasty of the Lower Extremities

Abstract

Background: Venous thromboembolism (VTE) is a severe complication of orthopedic surgeries. Although mechanical measures such as graduated compression stockings and intermittent pneumatic compression are widely used for VTE prevention, complications (e.g. lower limb pain or skin disorders) may result from prolonged usage. Early postoperative ambulation and active ankle movements are recommended but have low patient acceptance due to surgical pain and the lack of motivation. To overcome these limitations, we developed a novel leg exercise apparatus (LEX) to encourage limb movement in bedridden patients in the early postoperative period in order to prevent VTE. Here, we aimed to evaluate the feasibility and safety of the LEX in individuals at high risk of deep vein thrombosis (DVT) postoperatively. Methods: Twenty subjects (4 men, 16 women) who underwent total joint arthroplasty in the lower extremity were enrolled in this prospective study. Exercise using LEX was performed for 5 minutes at 30 cycles/min, four times per day from postoperative days 1 to 7. Clinical assessments included the evaluation of vital signs before and after exercise with LEX, venous ultrasonography and blood tests within 7 days postoperatively, and evaluation of adverse events, including pulmonary embolism and cerebral hemorrhage.Results: Overall, 16/20 (80%) patients completed the exercise regimen of 7 days, while 4 dropped out. All four subjects who dropped out had undergone total hip arthroplasty; three of them refused to start exercises with LEX because of leg pain related to surgery. No severe adverse events occurred. There were no severe changes in vital signs. No DVT of the lower extremities was confirmed during postoperative week 1. The average preoperative D-dimer level was 0.85 µg/mL (range, 0.4-2.2), whereas the corresponding value in postoperative week 1 was 7.93 µg/mL (range, 2.0-13.8).Conclusions: In this study, no DVT cases or severe adverse events occurred postoperatively in patients undergoing total joint arthroplasty of the lower extremities who performed exercises with LEX. A study protocol analyzing the efficacy of this tool to prevent VTE after joint arthroplasty of the lower extremities may be safe and feasible.