Positioning system makes replacement surgery more precise.

The number of Americans having hip replacement surgery has grown steadily over the past eighteen years. It’s estimated that this year, more than 300,000 people will undergo the procedure, up from 138,000 in 2000. The procedure, fortunately, has matured as well.

A recent advancement to hip replacement surgery was the release and FDA approval of a technology that helps surgeons determine the most accurate alignment of the replacement implants. This technology is the optimized positioning system or OPS™.

The inspiration behind OPS is the fact that no two people move the same way, and this can make a significant impact on the proper positioning of the hip implants. OPS is designed to account for the differences. It tailors the implant placement to each patient.

OPS factors in that no two people move the same way.

The hip joint has two essential parts, the ball and the socket. The ball of the joint is the head of the femur, or thigh bone. The socket, or acetabulum, is a concave depression in the pelvis, in which the ball sits. The ball and socket are the parts that are replaced during surgery and must be positioned appropriately for the best outcome.

To get the proper position, hip replacement surgery using OPS begins long before the procedure is performed. An extensive preoperative evaluation is first performed to determine how the patient’s femur, pelvis and spine work together during routine daily activities. This evaluation provides a specific functional simulation of the patient’s movement.

This information is essential to achieving optimum results during surgery. If the implants aren’t positioned precisely during surgery, there’s a greater risk for complications such as premature wear, implant loosening and dislocation, as well as nerve impingement.

The preoperative evaluation also includes imaging such as x-rays and CT scans to generate pictures of how the patient’s hip moves in three dimensions. The imaging captures the anatomical geometry around the person’s hip joint.

Using all of the information gathered from the preoperative evaluation, surgeons create exact 3-D models of the patients’ anatomy. They then use these models as guides to optimize implant position during the hip replacement procedure.

The preoperative evaluation is the first step in the hip replacement using OPS process. The second step is using the system during the procedure itself. During surgery, the 3-D model, which is unique to each patient, is combined with a laser guidance system. Surgeons match up the laser points to ensure the optimized plan is accurately recreated during surgery.

Need for OPS

The most common reason for needing hip replacement surgery with OPS is deterioration of the hip joint from arthritis. The most common type of arthritis is osteoarthritis, also known as “wear and tear” arthritis. Osteoarthritis generally develops with age. It’s estimated that more than 28 million Americans suffer from the disorder.

Osteoarthritis can develop in any joint in the body, but it most often affects weight-bearing joints such as knees and hips. The hip is one of the largest joints in the body, and like other joints, its surfaces are covered with a smooth cushioning material called articular cartilage. This cartilage enables the bones to slide over one another more easily.

Joints also contain another cushioning substance called synovial fluid. This fluid lubricates the joint cartilage and aids in movement. With osteoarthritis, the articular cartilage begins to wear away, and the synovial fluid begins to thin out. This results in the bones of the joint rubbing together without cushioning. Damaged bone may also start to grow. These resulting growths are called bone spurs.

All of the damage to the hip joint is degenerative; it gets worse over time. It also causes pain, swelling and other symptoms that get progressively more intense. Additional symptoms of osteoarthritis include tenderness around the hip, limited range of motion, a grating sensation with movement and difficulty walking.

The doctor can generally diagnose osteoarthritis through a complete history and physical exam. The doctor will confirm the findings with an x-ray of the patient’s hip.

Treatment for osteoarthritis generally begins with lifestyle modifications, such as switching from high-impact activities to lower-impact activities and losing weight. Other conservative treatments include doing physical therapy, using support such as a cane when walking and taking anti-inflammatory and/or pain medications.

If conservative treatments fail to relieve symptoms, the doctor may suggest surgery. Surgical options include hip resurfacing and total hip replacement.