*The Direct Anterior Approach: A Comprehensive Guide for the Learner and Educator DOI: http://dx.doi.org/10.5772/intechopen.104398*

surgical table. The patient is positioned supine with a triangular bump under the hip to assist with hip extension. The bump should be placed proximal 1/3 and middle 1/3 of the femur making sure that a hand can be freely moved over the bump.

The surgical incision is marked out 2 cm distal and 3 cm lateral to the ASIS (**Figure 1**); the top of the incision is typically at the midpoint between the ASIS and the tip of the GT. The superficial dissection is performed down to the level of the TFL fascia which can be identified based on the blue tint of the muscle belly deep to the fascia (**Figure 2**). Using electrocautery or a scalpel, the TFL fascia is incised in-line with the muscle fibers and carefully separated from the muscle belly. It is important to stay parallel with the muscle fibers to ensure minimal bleeding and muscle damage. Retracting the released TFL laterally completes the superficial dissection and should expose the fascial floor of the TFL. The TFL is a digastric muscle, therefore, it is critical to make sure that both muscle bellies are retracted laterally.

#### **Figure 1.**

*Incision placement for the direct anterior approach. The trajectory of the incision follows the muscle belly of the tensor fascia latae (TFL) (Right hip).*

#### **Figure 2.**

*Following the superficial dissection, the rectus femoris is visible. The deep layer of the dissection beneath the rectus is accessed by making a facial incision at the red-yellow junction (dotted white line) and retracting the rectus muscle belly medially (Right hip).*

After retracting both the TFL and the rectus femoris muscle belly, the reflected head of the rectus (pars reflecta) can be seen inserting proximally on the anterior acetabulum (**Figure 3**). There is typically a fat pad with a small vessel at the insertion site. In cases where the pars reflecta is going to be released to allow the rectus femoris to relax and enhance surgical exposure, the fat pad needs to be resected and the vessel cauterized. *We recommend releasing the pars reflecta in all cases early on in the learning curve.* Carefully dissect the investing fascia over the rectus femoris to retract the rectus medially and expose the lateral femoral circumflex vessels (**Figure 4**). Once identified, these vessels need to be tied-off or thoroughly coagulated; electrocautery alone is typically not adequate.

After appropriately addressing the circumflex vessels, the peri-capsular fat is removed and the anterior hip capsule is exposed. While most surgeons are familiar with posterior capsular exposure, the anterior capsule creates a bare triangle between the iliocapsularis muscle medially, the gluteus medius laterally and the vastus lateralus distally. At this point, the option is to perform a capsulotomy (author's preferred technique) or a capsulectomy (**Figure 5**).

In addition to strong foundation of anatomy and surgical technique the use of retractors with appropriate placement is paramount for exposure and safety during the procedure. During acetabular exposure and preparation, the principal author utilizes two, 45 degree, pointed homan retractors for capsular exposure, placing one retractor inferior femoral neck space between the capsule and the muscle and the other retractor over the superior femoral neck protecting the gluteus medius muscle. Both retractors should be extracapsular; following capsulotomy, the retractors should be repositioned intracapsular. Additionally, a charnley retractor is used for hands free acetabular exposure. For right sided procedure, the anterior blade should be placed in the 1 o'clock position and the posterior blade in the 7 o'clock position. For femoral exposure, the use of a dark and stormy retractor placed over the posterior femoral neck, distal to the obturator externus muscle to elevate the femur for broaching.

#### **Figure 3.**

*The yellow circle denotes the pars reflects tendon as it originates from the anterior lip of the acetabulum (Right hip).*

*The Direct Anterior Approach: A Comprehensive Guide for the Learner and Educator DOI: http://dx.doi.org/10.5772/intechopen.104398*

#### **Figure 4.**

*The lateral circumflex vessels are typically visible just proximal to the vastus lateralis and course proximal lateral to distal medial. The artery typically courses with two accompanying venae comitantes (Right hip).*

#### **Figure 5.**

*The bare area in the anterior hip capsule is bordered by these muscles. This image shows the femoral head and neck after a triangular anterior capsulotomy has been performed (Right hip).*

## **3. Methodological transition**

The decision to transition from an alternative surgical approach is not one to take lightly. A surgeon must acknowledge that although they may have significant experience with performing a THA from an alternate surgical approach, the DAA THA is an entirely different procedure, especially if transitioning from a posterior approach – the anterior approach is oriented 90 degrees from your normal surgical view. Several reports highlight the dangers of inadequate preparation/planning for surgeons starting to perform the DAA leading to significantly increased surgical times and higher intra/post-operative complications [14]. Therefore, any surgeon deciding to take this step should create a comprehensive and thorough plan involving self-learning, mentorship, and cadaver sessions.

Once the decision to transition to the DAA has been made, and familiarization with the anatomy and surgical steps has been completed, the focus should be on proper surgical indications, common pitfalls, and understanding why you may struggle with portions of the procedure. E-learning (technique guides, digital modeling, online tutorials, surgical videos) has emerged as a powerful tool with many diverse teaching modalities, 24/7 access, and real-time measures progress through testing [15].

Surgical mentorship has been a pivotal aspect of training, emphasized by the Halstedian model of educating new surgeons [16]. Identifying a mentor is critical and it should be someone that is equally invested in you [17]. Observation of the surgical technique should be accompanied by creating a detailed, annotated surgical technique guide. This is the most critical part of making the transition and decreasing the learning curve. Similar to the sequence of surgical steps, the process of creating this surgical technique guide requires patience, diligence, and attention to detail. Additionally, this document should be used to acquaint the surgical team with the procedure, so they too can participate in minimizing the learning curve.

After an extensive observership and creating of a technique guide, hands-on cadaveric training is the next step in the sequence. The senior author assisted his mentor in the lab during a cadaveric demonstration of the procedure. Following the demonstration, the senior author performed a DAA THA on the contralateral hip with the assistance of his mentor. This cadaveric workshop helped to translate what was seen in the operating room during observation into the tangible ability of performing the procedure prior to going live on an actual patient.

After selectively identifying patients that should be considered candidates for a DAA THA (**Table 1**), reverse surgical observation by the mentor was arranged. The first two DAA THAs were observed by the mentor with real-time feedback and guidance provided during the operation. This portion of the training significantly decreased the anxiety associated with performing a DAA for the first time. The mentor should help with identifying your tendencies and anticipating difficulties (e.g. improper retractor placement or limb positioning) before they arise.

All team members should be a part of the learning process. This is not limited to the surgical team performing the procedure (surgeon, Fellow/Resident, advanced practice provider) but should include the scrub technician, circulating nurse, radiology technician, and the anesthesia team. A pre-operative planning session with the entire team can be very helpful early on in the learning curve. More importantly, a post-operative debrief after every case should be conducted with the team to determine what went well, what didn't go well, what did we learn, and what should we should do differently for the next case. This process allows for iterative improvements with performing the DAA safely and reproducibly.

*The Direct Anterior Approach: A Comprehensive Guide for the Learner and Educator DOI: http://dx.doi.org/10.5772/intechopen.104398*


**Table 1.**

*Indications and contraindications to guide patient selection during the learning curve.*
