Postoperative lymphedema after primary total hip arthroplasty: prospective analysis of bikini incision-type direct anterior approach versus established standard approaches
Authors: Banasiak Sylwia , Hartel Maximilian , Frosch Karl-Heinz , Berger-Groch Josephine 
Published: January 2024

Abstract
Background
Minimally invasive approaches to the hip joint for total hip arthroplasty such as the DAA (“Direct Anterior Approach with bikini incision”) are increasingly utilized. According to the literature, this approach is more muscle-sparing, results in less postoperative pain, and achieves higher patient satisfaction. The existence of postoperative lymphedema after hip arthroplasty is hardly considered. The aim of this paper is to contribute to the evaluation of the different access methods related to postoperative lymphedema and their functional outcomes.

Methods
This is a prospective non-randomized study at an orthopedic specialist clinic in Northern Europe. The surgeons that performed the arthroplasties are high-volume surgeons in private practice affiliated to the clinic. The study included 188 patients with primary hip arthroplasty in a 1:1 ratio (DAA: standard accesses (posterior, transgluteal, and anterolateral access)). Epidemiologic data, Harris Hip Score, Oxford Hip Score, European Quality of Life 5, and Visual Analog Scale were collected preoperatively on admission day, 3rd and 5th postoperative day, and follow-up after 1 year. Furthermore, the range of motion, gait, and ability to climb stairs, as well as the presence of hypesthesia were assessed. To evaluate the edema situation, both legs were measured on the 3rd and 5th postoperative day. The prescription of manual lymphatic drainage and remaining swelling conditions 1 year postoperatively were recorded.

Results
For each group, 94 patients with a mean age of 61.7 years (DAA 60.7 and standard access 62.6) were included. All but one patient in the DAA group showed postoperative lymphedema (n: 93/94; 98.9%). In the standard surgery group, only n: 37/94 (39.4%) showed swelling symptoms requiring treatment. After 1 year, lymphedema persisted in 20 patients in the DAA group and 0 patients in the standard-OR group. Hypesthesia at the ventral thigh persisted in 16/94 (= 17%) patients of the DAA group versus 0/94 patients of the standard group after 12 months. Of these 16 cases, 10 had concomitant edema (62.5%). The DAA showed better results than the standard accesses in terms of Oxford Hip Score (p < 0.05) and ability to climb stairs (p < 0.05). In contrast, the Visual Analog Scale and patient quality of life results showed no significant difference (p > 0.05).

Conclusion
The present study demonstrated the increased incidence of postoperative lymphedema in patients operated on via DAA access using a Bikini-type skin incision. In the follow-up, significantly more hypesthesia of the ventral thigh occurred in the DAA group. Otherwise, the DAA proved to be superior to the standard approaches from a functional point of view at short-term follow-up. Future research is needed to compare the horizontally oblique to the longitudinal oblique skin incision technique in direct anterior hip surgery regarding the above-mentioned adverse effects found in this study.