The Direct Anterior Approach to Hip Reconstruction

SECTION VI Outpatient Arthroplasty and Case Efficiency Using the Direct Anterior Approach 376

Electrocautery is then used to tease the capsule off the inner aspect of the greater trochanter from anterosupe rior to posterior while the hip is gently further adducted, extended, and externally rotated to deliver the femoral neck into the wound ( Figure 44.8 ). The release should not continue past the piriformis fossa in order to pre serve the posterior capsular structures. When the release is complete, the operative leg should end up in a lazy figure-4 position under the well leg and between the assistant’s legs ( Figure 44.9 ). The table-mounted femoral elevator is then used to lift the femoral neck out of the wound. Femoral Preparation and Stem Insertion The lateral aspect of the femoral neck is used as the starting point to open the canal with the box osteo tome. A femoral starter rasp is then used to con firm the longitudinal axis of the femur. With the leg extended and externally rotated, the canal trajectory will be more lateral and toward the ground than if the patient’s limb was in neutral alignment. The femur is then sequentially broached to an appropriately sized femoral implant. With the femoral broach in place, any remaining femoral neck is leveled using the calcar pla nar. The hip is then trialed starting with the shortest available neck length and templated offset. The oper ative leg is brought out of the figure-4 position while removing the now contaminated outer stockinette. This must be done anytime the leg is brought out of

the figure-4 position. The hip is reduced using internal rotation and traction with a hip skid placed deep to the rectus femoris. Hip stability is checked dynamically with combined hip external rotation and extension. Keep in mind that the hip is already extended 15° relative to the floor from the table Trendelenburg. Leg length can be checked using direct comparison to the well leg ( Figure 44.10 ). To check the leg length radiographically, an alignment rod is placed at the level of the ischial tuberosities on an appropriately rotated anteroposterior image of the pelvis. The relationship between the alignment rod and the two lesser trochanters can help determine restoration of the desired leg length. Furthermore, femoral offset can be assessed during this step. At this point, the final stem size and neck length are selected. The hip is dislocated using a bone hook combined with hip extension and external rotation. The retractors are placed back in the original position with the leg in the figure-4 position. The femoral trial is removed, and the final femoral component is then placed. The final head component can be placed at this time, or the hip can be retrialed to verify neck length before selecting the final

FIGURE 44.8 For femoral preparation, the table is repositioned, the bone elevator is secured to the table, and the hook is posi tioned around the femoral shaft. The operative hip is adducted and extended to place gentle tension on the capsule, and addi tional retractors are placed. The capsule is teased off the inner aspect of the greater trochanter from anterosuperior to posterior using electrocautery, while the hip is gently adducted, extended, and externally rotated to deliver the femoral neck into the wound. FIGURE 44.9 When capsular release is complete, the operative leg is maneuvered into a lazy figure-4 position under the patient’s well leg and between the assistant’s legs. The femoral neck is lifted out of the wound using the table-mounted elevator. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2024