Lateral Approach to the Hip

The direct lateral approach (or transgluteal approach) allows excellent exposure of the hip joint for joint replacement.25 It avoids the need for trochanteric osteotomy. Because the bulk of the gluteus medius muscle is preserved intact, it permits early mobilization of the patient following surgery. However, the approach does not give as wide an exposure as the anterolateral approach with trochanteric osteotomy. It is, therefore, difficult to perform revision surgery using this approach.

Position of the Patient

Place the patient supine on the operating table with the greater trochanter at the edge of the table. This allows the buttock muscles and gluteal fat to fall posteriorly away from the operative plane (see Fig. 8-26).

Landmarks and Incision

Landmarks

Palpate the anterior superior iliac spine upward from below. Palpate the lateral aspect of the greater trochanter and, below that, the line of the femur that feels like a resistance against the examining hand.

Incision

Begin the incision 5 cm above the tip of the greater trochanter. Make a longitudinal incision that passes over the center of the tip of the greater trochanter and extends down the line of the shaft of the femur for approximately 8 cm (Fig. 8-39).

Internervous Plane

There is no true internervous plane. The fibers of the gluteus medius muscle are split in their own line distal to the point where the superior gluteal nerve supplies the muscle. The vastus lateralis muscle is also split in its own line lateral to the point where it is supplied by the femoral nerve.

Superficial Surgical Dissection

Incise the fat and underlying deep fascia in line with the skin incision. Retract the cut edges of the fascia to pull the tensor fasciae latae anteriorly and the gluteus maximus posteriorly. Detach any fibers of the gluteus medius that attach to the deep surface of this fascia by sharp dissection.

The vastus lateralis and the gluteus medius are now exposed (Fig. 8-40).

Figure 8-39 Make a longitudinal incision centered over the tip of the greater trochanter in the line of the femoral shaft.

Deep Surgical Dissection

Split the fibers of the gluteus medius muscle in the direction of their fibers beginning in the middle of the trochanter. Do not go more than 3 cm above the upper border of the trochanter because more proximal dissection may damage branches of the superior gluteal nerve. Split the fibers of the vastus lateralis muscle overlying the lateral aspect of the base of the greater trochanter. Next, develop an anterior flap that consists of the anterior part of the gluteus medius muscle with its underlying gluteus minimus and the anterior part of the vastus lateralis muscle (Fig. 8-41). You will need to detach the muscles from the greater trochanter either by sharp dissection or by lifting off a small flake of bone. Continue developing this anterior flap, following the contour of the bone onto the femoral neck, until the anterior hip joint capsule is fully exposed. You will need to detach the insertion of the gluteus minimus tendon to the anterior part of the greater trochanter (Fig. 8-42). Develop the plane between the hip joint capsule and the overlying muscles, using a swab pushed into the potential space using a blunt instrument.

Enter the capsule using a longitudinal T-shaped incision (Fig. 8-43).

Osteotomize the femoral neck (Fig. 8-44). Extract the femoral head using a corkscrew. Complete the exposure of the acetabulum by inserting appropriate retractors around the acetabulum (Fig. 8-45).

Dangers

Nerves

The superior gluteal nerve runs between the gluteus medius and minimus muscles approximately 3 to 5 cm above the upper border of the greater trochanter. More proximal dissection may cut this nerve or may produce a traction injury. For this reason, insert a stay suture at the apex of the gluteus medius split. This will ensure that the split does not inadvertently extend itself during the operation (see Fig. 8-42).

The femoral nerve, the most lateral structure in the anterior neurovascular bundle of the thigh, is vulnerable to inappropriately placed retractors. Anterior retractors should be placed strictly on the bone of the anterior aspect of the acetabulum and should not infringe on the substance of the psoas muscle.

Figure 8-40 Divide the deep fascia in the line of the skin incision, retracting the fascial edges to pull the tensor fasciae latae anteriorly.

Figure 8-41 Split the fibers of gluteus medius above the tip of the greater trochanter and extend this incision distally on the lateral aspect of the trochanter until 2 cm of the vastus lateralis is also split.

Figure 8-42 Develop this anterior flap and divide the tendon of the gluteus minimus muscle to reveal the anterior aspect of the hip joint capsule.

Figure 8-43 Enter the capsule using a longitudinal T-shaped incision.

Figure 8-44 Osteotomize the femoral neck using an oscillating saw.

Vessels

The femoral artery and vein are also vulnerable to inappropriately placed anterior retractors.

The transverse branch of the lateral circumflex artery of the thigh is cut as the vastus lateralis is mobilized. It must be cauterized during the approach.

How to Enlarge the Approach

Extensile Measures

The approach can easily be extended distally. To expose the shaft of the femur, split the vastus lateralis muscle in the direction of its fibers (see Lateral Approach in Chapter 9). The incision cannot be extended proximally.

Figure 8-45 Extract the femoral head. Insert appropriate retractors to reveal the acetabulum.