Location of Incision

The most obvious difference between anterior and posterior hip replacement surgeries is the location of the incisions:

• Anterior hip replacement surgery uses an incision at the front of the hip. This incision typically starts at the top of the pelvic bone (iliac crest) and extends down toward the top of the thigh. Less commonly, the incision is made horizontally.
• Posterior hip replacement surgery uses a curved incision on the side and back of the hip. The incision curves just behind the greater trochanter, the knobby bit of bone that sticks out at the side from the top of the femur (thigh bone).

  See Total Hip Replacement for Hip Arthritis

The location of the incision determines the where the postsurgical scar will be.

Muscles Affected

Once the surgical incision is made, the muscles must be pushed aside or cut to access the hip’s ball-and-socket.

• Anterior hip replacement requires the surgeon to work between the muscles, pushing them aside to get to the hip joint. This natural separation allows ready access to the hip joint with minimal or no muscle cutting. The surgeon works in between muscles supplied by different nerves.
• The posterior hip replacement approach requires surgeons to cut muscles and other soft tissue at the back of the hip, including:
  1. The tensor fascia lata, which is a wide piece of fibrous soft tissue at the top of the outer thigh. It works with the iliotibial band (IT band) to help stabilize the hip and knee.
  2. The large gluteus maximus muscle, which is attached to the fascia lata. The gluteus maximus allows a person to extend and rotate the thigh outward. It also helps stabilize the pelvis and keep the body erect.
  3. The external rotators of the hip, which are small, short muscles that connect the top of the femur to the pelvis. These muscles provide hip stability, preventing the femur from dislocating out the back of the hip socket.

See Total Hip Replacement Surgical Procedure

Like the posterior approach, the direct lateral approach to hip replacement also requires the cutting of muscles. In that surgical approach, the abductor muscles (gluteus medius and minimus) are affected. Any muscles that are cut during posterior or lateral surgeries are repaired and reattached at the end of the surgery.