Posterior Approach to Hip Joint (Moore Approach) indications:
- The posterior approach to hip joint is the most common and practical of those used to expose the hip joint. Popularized by Moore it is often called the southern approach.
- It was first popularized by Moore, it is often called the southern approach.
The posterior approach to hip joint is used for:
- Total hip replacement, including revision surgery.
- Hip hemiarthroplasty.
- Open reduction and internal fixation of posterior acetabular fractures.
- Open reduction of posterior hip dislocations.
- Removal of loose bodies.
- Dependent drainage of septic hip.
- Pedicle bone grafting.
All posterior approaches allow easy, safe, and quick access to the joint and can be performed with only one assistant. Because they do not interfere with the abductor mechanism of the hip, they avoid the loss of abductor power in the immediate postoperative period.
Posterior approaches allow excellent visualization of the femoral shaft, thus are popular for revision joint replacement surgery in cases in which the femoral component needs to be replaced.
Position of the Patient
- Place the patient in the true lateral position, with the affected limb uppermost.
- It is important to protect the bony prominence of the legs and pelvis with pads placed under the lateral malleolus and knee of the bottom leg and a pillow between the knees.
Landmarks and Incision
- Greater trochanter.
- The posterior edge of the trochanter is more superficial than the anterior and lateral portions, and, as such, it is easier to palpate.
- Make 10 to 15 cm curved incision one inch posterior to posterior edge of greater trochanter (GT):
- Begin 7 cm above and posterior to greater trochanter.
- Curve the Incision posterior to the greater trochanter and continue down the shaft of femur.
- Mini-incision approach shows no long-term benefits to hip function.
- There is No internervous plane for The posterior approach to hip joint.
- Intermuscular plane:
- Gluteus maximus: it’s innervated by inferior gluteal nerve.
- Incise fascia lata to uncover vastus lateralis distally.
- Lengthen fascial incision in line with skin incision.
- Split fibers of gluteus maximus in proximal incision:
- Cauterize vessels during split to avoid excessive blood loss.
- Internally rotate the hip to place the short external rotators on stretch.
- Place stay suture in piriformis and obturator internus tendon (short external rotators).
- Evidence shows decreased dislocation rate when short external rotators repaired during closure.
- Detach piriformis and obturator internus muscle close to femoral insertion.
- Reflect backwards to protect sciatic nerve.
- Incise capsule with longitudinal or T-shaped incision.
- Dislocate hip with internal rotation after capsulotomy.
- Proximal extension:
- The posterior approach to hip joint may be extended proximally towards iliac crest for exposure of ilium.
- Distal extension:
- The posterior approach to hip joint may be extended distally down line of femur down to level of knee.
- Vastus lateralis may either be split or elevated from lateral intermuscular septum.
The structures at risk during posterior approach to hip joint includes:
- Sciatic nerve: it can be damaged if it is compressed by the posterior blade of a self-retaining retractor used to split the gluteus maximus. Extend the hip and flex the knee to prevent injury to sciatic nerve.
- Inferior gluteal artery.
- First perforating branch of profunda femoris.
- Femoral vessels.
- Superior gluteal artery and nerve.
Gluteus Maximus Muscle:
- Origin: From posterior gluteal line of ilium and that portion of the bone immediately above and behind it; from posterior surface of lower part of sacrum and from side of coccyx; and from fascia covering gluteus medius.
- Insertion: Into iliotibial band of fascia lata and into gluteal tuberosity.
- Action: Extends and laterally rotates thigh.
- Nerve supply: Inferior gluteal nerve.
The following five muscles insert into it:
- The gluteus medius attaches by a broad insertion into its lateral aspect. Below this insertion, the bone is covered by the beginnings of the iliotibial tract.
- The gluteus minimus is attached to the anterior aspect of the trochanter, where its tendon is divided in the anterolateral approach.
- The piriformis inserts via a tendon into the middle of the upper border of the greater trochanter. Its insertion forms a surgical landmark for the insertion of certain types of intramedullary rods into the femur.
- Obturator externus tendon: Immediately below the insertion of the piriformis lies the trochanteric fossa, a deep pit that marks the attachment of the obturator externus tendon.
- The obturator internus tendon inserts with the two gemelli into the upper border of the trochanter, posterior to the insertion of the piriformis
- Surgical Exposures in Orthopaedics book – 4th Edition