AMIS Technology and the AMIS Method: Minimally Invasive Hip Surgery via an Anterior Approach for Hip Replacement

The core of the AMIS technique lies in the access route. It is the only approach to the hip that runs both intermuscularly and internervously. This means that access is gained through a gap between muscles innervated by different nerves, eliminating the risk of nerve damage due to traction.

The surgeon uses the direct anterior approach. To do so, the surgeon passes between the tensor fasciae latae muscle and the rectus femoris muscle. No muscles need to be cut to reach the hip joint; they are simply held aside with retractors. This clearly distinguishes the AMIS approach from the lateral (side) or posterior approaches.

The surgery is usually performed with the patient lying on their back on a special extension table. This makes it easier for the surgeon to maneuver the leg during implantation. The incision in this minimally invasive procedure is significantly smaller than in open surgery, which is also cosmetically advantageous. Since the muscles and tendons remain intact, hip stability is considerably better, and the risk of the prosthesis dislocating is minimized.

Patients can clearly feel the benefits of the AMIS method. Since no muscle tissue is damaged, there is significantly less postoperative pain. This reduces the need for pain medication and speeds up recovery.

Another advantage of the AMIS hip procedure is the reduced blood loss during surgery. Since blood vessels and tissue are spared, the strain on the circulatory system is lower. This is particularly important for older patients in orthopedics and trauma surgery.

Rehabilitation after hip surgery using the AMIS technique is usually much faster. Since the muscles essential for walking are immediately functional, patients are often able to bear full weight on the leg as early as the day after surgery. The length of the hospital stay is often reduced to just a few days. Many patients need crutches only for a very short time to help their gait return to normal.

For more information on this condition, see our article on hip osteoarthritis.

The most common indication for hip replacement surgery is joint wear and tear. When the cartilage on the femoral head and in the acetabulum is worn away, bone rubs against bone. A total hip replacement (THR) is often the only solution in such cases.

The AMIS technique is suitable for almost all patients who require a primary hip replacement. This anterior approach can also be safely performed in overweight patients. An experienced orthopedic surgeon or a specialist in orthopedics and trauma surgery selects the appropriate hip prostheses, which can be anatomically correctly implanted via the anterior approach.

Both cemented and cementless hip prostheses can be implanted via this approach to the hip joint. This surgical method allows for precise control of leg length even during the operation, which prevents a leg length discrepancy later on.

Read our article on hip replacements to learn more about these implants.

The postoperative phase is crucial. Patients who undergo the AMIS method benefit from immediate hip stability. Since the joint capsule and muscles remain intact, the risk of dislocation is very low.

Rehabilitation usually begins on the very day of hip replacement surgery. Under the guidance of physical therapy, patients quickly learn to walk safely again. Since the AMIS technique is considered a muscle-sparing procedure, the strict movement restrictions that apply with other approaches (e.g., no crossing the legs) are often not necessary.

In summary, hip replacement surgery using the AMIS technique is a procedure that quickly returns patients to an active lifestyle. The anterior approach and minimally invasive instruments make the AMIS method a gold standard in modern hip replacement surgery.

For general information on surgical procedures involving the musculoskeletal system, visit our Orthopedics and Trauma Surgery section.