By Jonathan Yerasimides, M.D
All hip replacements are not created equal. This statement has never been truer than now. The days of large incisions, extensive tissue dissection and long periods of rehabilitation are over. The materials we use for hip replacement are much better than in years past and the implants can be expected to last considerably longer.
In the past decade, more attention has been turned to the surgery itself and minimizing trauma to the muscles and soft tissue around the hip. By preserving the soft tissues, patients can expect a faster recovery and return of function.
Many so-called “minimally invasive” procedures are available today for patients to choose from. It is important that patients research the specific approach a surgeon wants to use and ask questions about the surgery. The term “minimally invasive surgery” is somewhat of a misnomer in general. As I tell patients, there is nothing minimally invasive about someone cutting bone, removing your hip joint and putting in metal implants. Some of these procedures are simply “minimal incision” surgery, where the incisions are small, but the same muscles and tendons are cut under the skin. These procedures offer no more than a cosmetic incision. Patients should inquire about the procedure they are having and what is actually done under the skin.
A good general rule to remember in trying to determine whether muscles are cut or not during hip replacement is whether you will have hip dislocation precautions after surgery. When muscles are cut away from the femur bone, the artificial hip is less stable and surgeons will prescribe limits to hip range of motion to prevent dislocation of the artificial joint. The anterior approach truly causes fewer traumas to the muscles and tendons around the hip and should be considered less invasive compared to traditional hip replacement. This results in faster recovery and no restrictions following surgery.
The anterior approach to hip replacement allows the surgeon to replace the hip joint from the front as opposed to the back or side of the hip. By exposing the hip from the front, no muscles have to be detached from the bone as in traditional hip replacement techniques. By not disturbing the normal muscle attachments, the hip maintains stability and strength returns much faster. Patients who have anterior approach hip replacement do not have restrictions or dislocation precautions. Patients are allowed to sleep on their side or stomach, cross their legs, bend over and do not require elevated toilet seats or chairs. Full weight bearing is allowed immediately after surgery and walking is encouraged. The typical stay in the hospital is one to three days, with physical therapy twice daily in the hospital. On average, patients leave the hospital with a walker or crutch and are walking without either by two weeks after surgery.
Along with dislocation risks, leg length inequality has long been a problem with traditional hip replacement surgery. The most common reason for patient dissatisfaction after hip replacement is leg length discrepancy. With the anterior approach, the patient lies on their back during the surgery. In this position, fluoroscopy is used to determine leg lengths, correct position and proper sizing of the implants. The trial implants are interchanged in the operating room until the proper leg length is found. This ensures that every patient leaves the operating room with the artificial hip components most suited for their body.
With all the advantages the anterior approach provides, some patients ask why orthopaedic surgeons do not commonly use it across the country. Most surgeons do not have access to the special orthopaedic table. Without the table, the surgery can be extremely difficult to perform. The main reason orthopaedic surgeons don't commonly use the approach, however, is lack of training. Orthopaedic surgeons in the United States are routinely taught the posterior and anterolateral approaches for hip replacement, but very few know the anterior approach. The other two approaches have been used for many years by many surgeons and are felt to be fundamentally sound for total hip replacement. This is true, and these approaches are very good, but both require cutting natural muscle attachments that can lead to increased dislocation rates and longer rehabilitation compared to the anterior approach. The anterior approach is not widely taught and should only be performed after appropriate training. It is a time tested and safe procedure and should not be considered experimental or more dangerous than other traditional approaches.
Overall, the anterior approach offers advantages over other hip replacement procedures and allows patients to rehabilitate and return to activity more quickly.
