Anterior Approach to Hip Joint

The anterior approach to hip joint, also known as the Smith-Petersen approach, gives safe access to the hip joint and ilium.

The anterior approach to hip joint is used for:

1. Total hip arthroplasty.
2. Open reduction of congenital hip dislocations.
3. Synovial biopsies.
4. Intra-articular fusions.
5. Excision of pelvic tumors.
6. Irrigation and debridement of infected, native hip.
7. The upper part of the anterior approach to hip may also be used for the pelvic osteotomies.

The approach does not expose the acetabulum as completely as other incisions unless muscles are extensively stripped off the pelvis.

Position of the Patient

• Place the patient supine on the operating table.
• If the anterior approach to hip is to be used for pelvic osteotomy, place a small sandbag under the affected buttock to push the affected hemipelvis forward.

Landmarks and Incision

• Landmarks:
  1. Anterior superior iliac spine.
  2. Iliac crest .
• Incision:
  • Make incision from anterior half of iliac crest to anterior superior iliac spine.
  • From Anterior superior iliac spine curve inferiorly in the direction of the lateral patella for 8-10 cm.

Internervous plane

The anterior approach to hip joint (Smith-Petersen approach) has a Superficial and Deep internervous plane:

1. Superficial Internervous plane lies between:
   • Sartorius muscle: which is innervated by the femoral nerve.
   • Tensor fasciae latae muscle: which is innervated by the superior gluteal nerve.
2. Deep Internervous plane lies between:
   • Rectus femoris muscle which is innervated by the femoral nerve.
   • Gluteus medius muscle which is innervated by the superior gluteal nerve.

Superficial dissection

• Externally rotate the leg to stretch the sartorius muscle, making it more prominent and identify the gap between sartorius and tensor fasciae latae.
• Dissect through subcutaneous fat (avoid lateral femoral cutaneous nerve).
• Incise fascia on medial side of tensor fascia latae.
• Detach the iliac origin of the tensor fasciae latae to develop the internervous plane.
• The large ascending branch of the lateral femoral circumflex artery crosses the gap between the two muscles below the anterior superior iliac spine. It must be ligated or coagulated.

Deep dissection

• Identify plane between rectus femoris and gluteus medius.
• Detach rectus femoris from both its origins.
• Retract rectus femoris and iliopsoas medially and gluteus medius laterally to expose the hip capsule.
• Adduct and externally rotate the hip to place the capsule on stretch.
• Incise capsule with a longitudinal or T-shaped capsular incision.
• Dislocate hip with external rotation after capsulotomy is complete.

Approach Extension

Proximal extension:

• Anterior Approach to Hip Joint can be extended proximally for Bone graft harvest.
• It’s done by extend the proximal incision posteriorly along the iliac crest.

Distal extension:

• Anterior Approach to Hip Joint can be extended distally for Intra-operative fracture of distal femur.
• lengthen skin incision downward along anterolateral aspect of thigh, and incise fascia latae in line with skin incision (Stay in the interval between the vastus lateralis and rectus femoris muscles).

Dangers

The structures at risk during the anterior approach to hip joint  include:

1. Lateral femoral cutaneous nerve:
   • Lateral femoral cutaneous nerve reaches thigh by passing under inguinal ligament. The course is variable and the lateral femoral cutaneous nerve can be seen passing medial or lateral to anterior superior iliac spine.
   • It’s most commonly seen when incising fascia between the sartorius and the tensor fascia latae.
   • Its Injury may lead to painful neuroma or decreased sensation on lateral aspect of thigh.
2. Femoral nerve: The Femoral nerve should remain protected as long as you stay lateral to sartorius muscle.
3. Ascending branch of lateral femoral circumflex artery:
   • It’s found proximally in the internervous plane between the tensor fascia latae and sartorius muscles.
   • Be sure to ligate it to prevent excessive bleeding.

References

• Surgical Exposures in Orthopaedics book – 4th Edition
• Campbel’s Operative Orthopaedics book 12th