The DAA has become increasingly popular not only for primary total hip arthroplasty (THA) but also for more complex THA revision surgeries. Familiarity with extensile anterior exposures is necessary because many benefits of primary DAA are also applicable to revision THA, such as ease of component evaluation with fluoroscopy, accurate intraoperative leg length assessment, and shortened recovery resulting from preservation of the hip deltoid and the posterior soft tissues. Furthermore, the supine position and anterior incision permit access to both sides of the ilium. This allows for easy removal of intrapelvic implants and an accurate assessment of screw position.

Performing DAA THA revision surgery requires a particular set of skills, extensile exposure tricks, and occasionally special instruments to facilitate implant removal and implantation.^1,2,3,4,5 In this chapter, we discuss tips and techniques for advanced acetabular revision through the DAA, including the use of augments, cup-cage constructs, and custom triflange components.

THA revisions through the DAA can be performed using a dedicated traction table (Hana orthopaedic table, Mizuho OSI, Union City, CA, USA) or a standard operating room (OR) table. The traction table allows for good femoral exposure with the lifting hook. In addition, the leg can be locked in extension, external rotation, and adduction, which supports femoral elevation. However, all of this is done with assistants manipulating the extremity in the holder. In addition, it is difficult to assess the soft tissue tension and implant stability when using the Hana table. For these reasons, our preference is to use a radiolucent flat-top operating table (Modular Table System, Mizuho OSI) or a standard operating table AMSCO Surgical Table, Steris Healthcare, Dublin, Ireland, UK). Fluoroscopy through a radiolucent table allows for extensive fluoroscopic imaging without table impingement when inlet, outlet, and rollover-type imaging is required to judge placement of anterior, posterior, or pubis screws. However, it can be difficult to extend the femur to gain exposure because of the inability to perform hyperextension on the flat table.

In case fluoroscopic landmarks are no longer available, leg length assessment on a regular OR table is more easily accomplished. Exposure of the acetabulum with both legs draped free is quite simple because a lazy figure-4 leg position allows for slight hip flexion and adduction. This facilitates posterior-lateral retraction of the femur with a retractor behind the posterior wall. Femoral elevation can be facilitated with hyperextension of the hip on a regular OR table. This is helpful when performing combined femoral and acetabular revision. The main drawback is that the bed can interfere with fluoroscopic imaging. To use a regular table for fluoroscopic-assisted DAA, the patient is moved slightly more distal from the support pedestal and hip break and a table extender is added at the foot of the bed.

Careful preoperative assessment with optimal patient and fluoroscopy positioning is important. We prefer to use a regular OR table for most acetabular revisions, but it can require added effort from scrubbed assistants to manipulate the leg. Prepping and draping bilateral extremities can take more time with a potential for contamination, especially early in the learning curve.

The extensile direct anterior approach to the acetabulum is also described in this chapter. In our experience, mobilization of the tensor fascia lata (TFL) is crucial to facilitate posterior retraction of the femur to fully access the acetabulum (Figure 26.1). The first step is to curve the proximal part of the incision to parallel the iliac crest. This allows for identification of the origin of the TFL on the outer table of the ilium just posterior to the anterior superior iliac spine. A tenotomy leaving a cuff of soft tissue on the ilium is then performed. A whipstitch is placed through the proximal muscle belly and tendon to act as a rip-stop for later repair. If further femoral mobilization is needed (eg, due to abundant scar tissue or proximal migration into the pelvis), the exposure is extended distally by curving the incision posterolaterally. The TFL can then be dissected out and traced into where it becomes the iliotibial band. Incising the fascia at this level further relaxes the TFL proximally. The pubofemoral and medial iliofemoral ligaments are routinely released from the medial and posteromedial femoral neck.

Once the femur is adequately mobilized, the pelvic structures are exposed. If we are reconstructing the acetabulum with an augment, a cup-cage, or a triflange construct, it is necessary to expose the outer table of the ilium. The TFL release exposes the underlying abductor musculature (Figure 26.2). These muscles can be subperiosteally elevated at their iliac origin in a single sleeve to allow placement of a cup-cage or triflange construct. Because the abductors are not being longitudinally split, there is little risk to the superior gluteal neurovascular bundle.⁶

In the case of an intrapelvic cup or pseudotumor, the sartorius and external oblique muscles can be taken down from the anterior superior iliac spine in a single sleeve to work onto the inner table. This can be extended to include elevation of the iliacus depending on the exposure needed. Finally, we have encountered situations in which the cup and femoral head are trapped under the rectus femoris. In these situations, we tag the rectus femoris and perform a tenotomy. This release allows the femur to externally rotate to bring the entire construct out of the pelvis. By following a stepwise process to performing the extensile DAA approach, we have found that nearly any acetabular defect can be reconstructed. We present examples of the reconstructive ladder in the following sections.

We use “orange peel” augments in the case of superior (Figure 26.3) and superolateral (Figure 26.4) deficiencies that create an eccentric defect because these defects are not amenable to reconstruction with a hemispherical cup. The use of acetabular augments via the DAA was first described in 2017 by Honcharuk et al⁷ whereby a “cup-first” or an “augment-first” instrumentation technique can be used for lateral acetabular reconstruction. As noted in that case series, surgeons can use a trapezoidal bone wedge cut from the native femoral head or instead use a porous metal augment for the reconstruction.