Letter to the Editor concerning “Pre-operative predictors of lower extremity swelling following total knee arthroplasty in patients with venous insufficiency and osteoarthritis”

To the Editor,

We read with great interest the article by Cansabuncu, G. and F. Gumus regarding the “Pre-operative predictors of lower extremity swelling following total knee arthroplasty in patients with venous insufficiency and osteoarthritis” [1]. Based on the results of the research, the author suggests that a detailed pre-operative evaluation of the venous system could contribute to the post-operative satisfaction following TKA and could give the chance of treating underlying venous pathology earlier and increasing the functionality. We really appreciate the interesting observation for their conclusion. However, after reading this article, we would like to highlight some important questions that it raises.

First, through this research, we have some questions about the post-operative oedema. We know that, due to the specific anatomy of the circulatory system in the lower limbs, and to the physiology of venous blood and lymph return, these two problems will both lead to post-operative lower limb oedema [2]. The impairment of venous and/or lymphatic microcirculation is both one of the main complications of orthopaedic surgery. However, the problem of post-operative lymphedema was not mentioned in this study. Several studies indicate that besides affecting the venous system, an injury of the lymphatic system with subsequent tissue fluid and lymph stagnation is likely an additional cause for post-traumatic oedema [3]. I wonder whether the author took this into account when designing this experiment and why it was not mentioned in the article. I would like to know the details of the author’s consideration in this respect.

Second, the author listed many ways that have been described in current literature to deal with post-operative swelling and oedema, such as cryotherapy, the application of a compressive bandage, and extremity elevation, but the effect of these methods remains controversial. According to the authors, this is the most crucial reason for them to do this research. What I want to say is that the authors seem to ignore a very important method to deal with post-operative oedema, physical therapy. Physical therapy performed by a physiotherapist (PT) is an essential means for the functional recovery of patients after TKA, which has many ways to deal with the post-operative swelling and oedema, such as aquatic physiotherapy, muscle training, and manual lymphatic drainage. Ankle pumping exercise, as one of the most commonly used methods to treat the lower limb swelling, has been proved to be effective by many studies [4]. Furthermore, a recent study found that exercise training is a valuable tool for treatment of mild and advanced chronic venous insufficiency conditions, since it promotes haemodynamic and musculoskeletal improvements that improve functionality [5]. Therefore, in my opinion, this should be concerned.

Thirdly, relevant data showed that bed rest time will cause the patient’s limbs to be passively braked, the patient’s blood flow slows down, and the adhesion of white blood cells increases, which in turn activates the thrombin system in the patient’s body, aggravates the hypercoagulable state of the blood, and promotes thrombosis [6]. It can be speculated that this may affect the venous reflux duration also. Therefore, I would like to ask whether the author considered this point after surgery, because it may affect the data of post-operative measurements.

Once again, we complement the authors for their work and hope that the readers may benefit from it. And we hope that this discussion can assist future researchers who may be interested in post-traumatic or post-operative oedema studies.