6. Authors’ preference
For the past decade, we have focused on the studies about the role of the drainage system
after total knee arthroplasty. In the first observational study, we found then most of the
blood loss in TKA occurs during the first four postoperative hours.(Jou IM 1993; Senthil
Kumar et al. 2005) Then we conducted a randomized controlled trial to check the
effectiveness of four-hour temporary clamping drainage and found it is an effective method
to reduce postoperative blood loss after total knee arthroplasty.(Shen et al. 2005) We also
published a meta-analysis of the randomized controlled trials comparing outcomes between
the various drain-clamping methods and immediately open drainage after TKA.(Tai et al.
2010b) We focused on blood loss and complications to evaluate the pros and cons of drain
clamping. A trial comparing four-clamping drainage and non-drainage was conducted and
revealed the role of drainage is still questionable after total knee arthroplasty.(Tai et al.
2010a) Despite clamping the drain for the first four hours after TKA, we found that the
patients with drainage showed more blood loss and gained no other benefit compared with
those without a drain. Although the clamping drainage was superior to the conventional
drainage according to previous literature, we found no advantage of using this method
compared with non-drainage. Thus, we did not routinely use the drainage system in
primary total knee arthroplasty in our daily practice.