Postoperative swelling: influence of a negative pressure application in comparison to manual lymphatic drainage after total knee arthroplasty-a randomized controlled trial.

Abstract

Postoperative soft tissue swelling is a significant factor influencing outcome after total knee arthroplasty (TKA). This prospective study aims to investigate the influence of technical device assisted negative pressure therapy (NP) on early functional outcome after TKA. NP was therefore compared to manual lymphatic drainage (MLD). A total of 50 consecutive patients undergoing primary TKA were enrolled. 25 subjects per group were either treated by conventional MLD or NP. Primary outcome parameter was defined as circumference of the affected limb in cm postoperative up to seven days postoperatively. Secondary outcome parameters were: Duration of hospitalization, subjective perception of pain (measured via visual analogue scale, VAS), affected limb's ROM. NP showed an overall equivalent influence compared to MLD in reducing lower limb swelling, recovering of mobility and length of hospital stay after TKA. Moreover, the application of NP showed a significant decrease in overall pain perception compared to manual lymphatic drainage on day 2 and forth after surgery (p < .05). Our findings show that NP could be a useful device in clinical routine treating postoperative swelling after TKA. Its application is simple and effective for the patient. Particularly given the shortage of healthcare workers and physical therapists, there is a need for supportive measures that NP could fulfil.