If both hips are replaced, can you add height to my body?

Yes. If both hips are replaced, it is possible to increase the leg length on one side and increase it by the same amount on the other side. However, any gain in height is about an inch or less. The limiting factor includes the muscles, tendons and nerves, which only have so much stretch before there is injury or damage.

Will my leg be longer or shorter after surgery?

This is an important topic, and should be understood before you embark on any hip replacement, no matter where you have the surgery done.

Hip resurfacing is an operation similar to replacement. During resurfacing, the arthritic ball is capped with metal, and an artificial socket is placed in the pelvis. Any bone removed is replaced with an equivalent thickness of metal in hip resurfacing, so there is no noticeable gain or loss in leg length during hip resurfacing.

In contrast to hip resurfacing, during hip replacement the arthritic ball is removed and replaced with a new ball. Since the artificial ball comes in different neck lengths, the surgeon is able to adjust muscle tension, leg length and ball-socket stability during the hip replacement. These adjustments reflect complex decision-making and trade-offs during surgery. Rarely, because of anatomic constraints or other patient-specific reasons, slight leg lengthening may occur. If this is completely unacceptable, you should not consider hip replacement surgery.

In the overwhelming majority of cases, there is no change in leg length after hip replacement. In most cases where the patient feels a change in leg lengths, that perception disappears over several months as the muscle and tissues stretch.

Can leg length be changed during hip replacement surgery?

Yes. An example would be a patient with a leg that was shortened from injuries after a motor vehicle accident, who now needs a new hip. In such cases, it is possible to restore the original leg length during surgery. The decision-making is complex, requires professional judgment and is specific to each situation.

Likewise, if the patient has too long a leg before surgery, it is possible to shorten it during hip replacement, using specific surgical techniques that keep muscle tension within safe limits. Again, the exact steps taken and the decision-making are specific to each patient.

My leg ended up too long after a hip replacement. Can anything be done?

In most cases, with exercise, stretching and healing over 6 to 12 months, the perception of a leg length difference disappears on its own. During this time, to avoid a limp and facilitate walking, a shoe-lift built into the shoe can help.

The reason for waiting is that the majority of leg-length discrepancy after surgery is not a true difference in skeletal lengths. Rather, the discrepancy is from pelvic tilt, tight muscles, altered biomechanics and even spinal arthritis that can lead to a curvature in the back. With muscle stretching, exercises and time, such discrepancy likely resolves in a few months.

If leg length discrepancy is permanent, additional surgery may be an option. During such surgery, the femoral stem component is removed, and the bone at the top of the femur is removed to equalize the leg lengths. Then, a new femoral stem is implanted.

While this sounds easy, additional steps must be taken to avoid improper muscle tensioning and to reduce the risk of creating hip instability and a limp. Recovery from this type of surgery is about six to 12 weeks.

How can we know if my leg is truly longer after a hip replacement?

Special X-ray studies can help determine if the perceived difference in leg lengths is really in the bone or arising from some other source, such as a tilted pelvis, a curvature in the back or tight muscles. These X-rays – called scanograms – involve imaging the entire length of both legs with a measuring ruler that leaves no doubt about the actual length of each leg, from the top of the pelvis to the ankle.

Learn more about hip replacement surgery at MU Health Care.