Though uncommonly used in the United States, the anterior approach for total hip replacement provides definite advantages for patients, even those in need of bilateral procedures. Rehabilitation is simplified and accelerated, dislocation risk is reduced, leg length is more accurately controlled, and the incision is small.
Why, then, is this approach not more widely used by U.S. surgeons? There are several reasons: lack of familiarity, traditional teaching, and lack of the necessary instrumentation and equipment. The surgery is especially facilitated by a particular operating table with unique capabilities to position the leg. This procedure has been perfected and popularized by Dr. Joel Matta in LA. Thanks to his persistence to perfect this approach, we are able to do this today.
The anterior approach is an approach to the front of the hip joint as opposed to a lateral (side) approach to the hip or posterior (back) approach. It is a true anterior approach to the hip and should not be confused with the Harding approach which is often referred to as an anterior approach.
Rehabilitation is accelerated and hospital time decreased because the hip is replaced without detachment of muscle from the pelvis or femur. Other surgical approaches necessitate detachment of multiple muscles from the femur during surgery. In the anterior approach, by contrast, the hip is approached and replaced through a natural interval between muscles. The most important muscles for hip function, the gluteal muscles that attach to the posterior and lateral pelvis and femur, are left undisturbed.
Lack of disturbance of the lateral and posterior soft tissues also accounts for immediate stability of the hip and a low risk of dislocation. It is normal for patients undergoing lateral or posterior incisions to follow strict precautions that limit hip motion for the first two months after surgery. Most importantly, they are instructed to limit hip flexion to no more than 60 degrees. These limitations complicate a patient’s simple daily activities such as sitting in a chair or on the toilet or getting in a car. Following the anterior approach, however, patients are immediately allowed to bend their hip freely and avoid these cumbersome restrictions. Additionally, if patients are sexually active before surgery, there are no limitations on resumption of normal sexual activity after surgery.
The normal incision is about 5 inches but may vary (shorter or longer) according to a patient’s body size. Though small incisions are often considered desirable by patients, it should be kept in mind that the degree and type of tissue disturbance beneath the skin is a more important factor. Incisions of adequate length allow the necessary side-to-side separation of the incision without undue force. Too small an incision can be more traumatic to the tissues, particularly to muscles that can be damaged by stretching too hard.
With the anterior approach the patient lies supine (on their back) during surgery. X-rays taken during surgery with a fluoroscope ensure correct position, sizing and fit of the artificial hip components as well as correct leg length.
The OSI PROfx® Orthopedic Table
Evaluation and treatment by a physical therapist begins the day of surgery and leads to walking and functional activities. Patients may go home after achieving an initial degree of independence in walking with crutches or a walker as well as capabilities in basic day-to-day activities. Patients are commonly discharged 2 to 5 days following surgery depending on their degree of disability prior to surgery and their overall capabilities.