Bikini Incision Modification of the Direct Anterior Approach.

Background: Although the direct anterior approach (DAA) represents an intermuscular and internervous approach to total hip arthroplasty (THA), it did not reach global acceptance until its adoption by large teaching centers. Today, >50% of primary THA procedures in Switzerland are performed via the DAA. Besides being truly minimally invasive, a key advantage of the DAA is the inherent stability that it provides. A shortcoming has been that the traditional longitudinal skin incision does not follow the skin tension lines Description: The bikini-type (skin-crease) incision only differs from the classic longitudinal approach used for DAA THA with respect to the skin and subcutaneous tissue. To avoid damage to the LFCN, our bikini-type incision has evolved over the last decade to being located entirely lateral to the ASIS (Video 1) Alternatives: The main alternative is the classic longitudinal incision used for DAA THA. Rationale: The bikini incision is a valuable alternative that improves wound healing and scar cosmesis in DAA THA in technically straightforward hips, which account for >90% of our cases. The procedure can be divided into 10 steps, as described in the videos. Today, indications include primary or secondary osteoarthritis, femoral neck fracture, and revision THA involving head and/or liner exchange, and simple socket loosening without the need for proximal extension of the approach. Particularly in patients prone to hypertrophic scar formation (i.e., patients who are younger, have a darker skin type, are obese, etc.), this incision is a helpful alternative to the classic longitudinal incision. The classic longitudinal incision is still preferred for complex primary or revision THA cases in which extensile distal and/or acetabular exposure might be required, revision cases with a preexisting longitudinal DAA incision, cases of inguinal skin infection, or cases in which the contralateral side has been treated utilizing a longitudinal incision. Expected Outcomes: A recent review assessed 8 double-armed studies that included a total of 952 bikini incision procedures and 1,361 longitudinal incision procedures. In 3 of the 4 studies reporting postoperative scar appearance and patient satisfaction, those outcomes were more favorable following the bikini incision compared with the longitudinal incision, with the fourth study showing comparable results. Postoperative hip function was similar between the incision types in 3 of 4 studies assessing that outcome Important Tips: Begin with the bikini incision in technically easier hips.Adjust the bikini incision according to radiographic hip morphology.Do not perform the skin incision too small, too distal, too proximal, or most importantly too medial.Secure the medial edge from tearing.Limit subcutaneous dissection.Change the dissection deep to the fascial sheath of the tensor from the oblique to the longitudinal direction.Appreciate that a bikini incision is less extensile. Acronyms and Abbreviations: ASIS = anterior superior iliac spineBMI = body mass indexCCD = caput column diaphysisDAA = direct anterior approachGT = greater trochanterLFCA = lateral femoral circumflex arteryLFCN = lateral femoral cutaneous nerveTFL = tensor fasciae lataeTHA = total hip arthroplastyOA = osteoarthritisROM = range of motion.