How to do DAA THA well? There are 10 key points!

The DAA approach is currently a popular approach for total hip replacement surgery. How to make a DAA THA well requires attention to the following 10 key points:

Part.1 Patient Selection

According to the DAA learning curve, when selecting patients, select patients who are thin and have a long femoral neck at an early stage, and gradually increase the patient's BMI and increase the difficulty of surgery step by step.

• 1. Low BMI, less musculature, long everted femoral stem
• 2. Slightly increased BMI, slightly thicker musculature, long everted femoral neck
• 3. Low BMI, less musculature, short?varus femoral neck
• 4. Slightly increased BMI, slightly thicker musculature, short varus femoral neck
• 5. Deformity, dysplasia, bone loss
• 6. Revision surgery

Part.2 Incision position

The longitudinal incision was made from 2 cm lateral to ASIS and 1 cm distal, obliquely to the distal end, parallel to the TFL and the rectus femoris space but more lateral (2-4 cm).

Part.3 Surgical Exposure

Exposure is the hardest part of DAA THA, and successful exposure is especially important for a successful procedure and avoiding complications.

① Find the tensor fascia lata: Identify and confirm by color and thickness. Generally, the fascia over the tensor fascia lata appears whiter than the surrounding tissue running posterolaterally, and there are usually 2-3 perforating vessels.

② Expose the hip joint:

After incising the tensor fascia lata myofascial, bluntly separate the tensor fascia lata from its fascia medially, including superficial and inferior separation.

A Cobra retractor is placed on the lateral femoral neck, and a Hohmann retractor is placed posterior to the rectus femoris muscle along the medial femoral neck.

After the "L" shaped capsulotomy, the hip joint was fully exposed.

Part.4 Femoral Neck Osteotomy and Head Removal

Angle: 45° to the anatomical axis of the femoral shaft;

Height: Determined by measuring the distance from the lesser trochanter;

Carefully protect the TFL muscle belly to avoid being pulled by the retractor when exposed and damaged by the sharp osteotomy edge when the head is removed.

Part.5 Acetabular Exposure

Use 2-3 retractors: anteriorly, the retractor tip is placed on the medial side of the iliopsoas muscle notch; anteriorly and superiorly, it is beneficial for acetabular labrum resection; The round ligament and remaining labrum can be resected before rasp; The transverse ligament and?Horseshoe fossa are exposed until direct visualization is possible.

Part.6 Acetabular reaming

Grind the file from the small file to the inside and bottom to confirm the inner wall; Change to a large size, make sure to file inward to the previous depth and then adjust the upward file.

Part.7 Acetabular Cup Placement

Use of offset acetabular reamer handles, and the driver handles. The abduction and anteversion angles were reconfirmed before the final implantation.

Part.8 Proximal Femur Exposure

• Maximize external rotation of the femur but avoid excessive force;
• Operating table repositioning;
• Moderate adduction, extension, and external rotation lift the femoral neck out of the incision.

Part.9 Femoral preparation and femoral stem placement

• Maximize external rotation of the femur but avoid excessive force;
• Operating table repositioning;
• Moderate adduction, extension, and external rotation lift the femoral neck out of the incision.

Part.10 Repositioning

Irrigate adequately before repositioning, verify stability, and check lower extremity length.

Summarize

• In the learning stage, there may be problems such as greater bleeding, longer operation time, and a higher incidence of complications. Paying attention to the exposure steps can help reduce the incidence of complications;
• Femoral exposure requires the release of the posterolateral capsule from the femur; do not start femoral reaming until adequate exposure is achieved;
• Starting with a thin, mobile patient allows for easier exposure of the acetabulum and femur.

Just Medical provides prosthetic designs and special instruments suitable for DAA THA.

MINI minimally invasive femoral stem design

1. Restoring natural hip biomechanics to ensure optimal function;
2. Focus on proximal stress distribution to prevent stress shielding and thigh pain;
3. Preserve bone stock for possible future revision.