New Modular Hip Prosthesis Designed with Women in Mind

A new gender-specific hip replacement implant has been specifically designed to cater to women's needs.

The M/L Taper Hip Prosthesis implant is a system comprised of modular stem and neck components designed to help the surgeon restore the hip joint center intraoperatively by addressing leg length, offset, and version independently. The implant comes in three separate sections: a stem, the head, and the neck, so that it is adjustable for a woman's size and shape. During the surgery, all three sections are connected. The pieces lock in place but can be easily changed, allowing orthopedic surgeons to independently adjust leg length and offset after stem implantation to optimize each dimensional factor without affecting the other, according to the patient's leg length, muscle tension, and hip stability. Another advantage of the gender-specific hip is that it is inserted via minimally invasive surgery, requiring only several small incisions to place each of the separate components; and because there is no need to cut through muscles and tendons, recovery time is significantly reduced.

An additional feature of the new system is proprietary Kinectiv technology; the geometry of each neck component can be specifically optimized for strength and range of motion based on head section length. Kinectiv technology also eliminates the use of skirted femoral heads that are necessary for the longer offset options of other designs. In addition, the anteverted and retroverted necks of the implant allow the surgeon to also adjust the neck version intraoperatively after cup and stem implantation, and thus further fine-tune the range of motion for the patient. The M/L Taper Hip Prosthesis implant is made by Zimmer (Warsaw, IN, USA).

"The traditional artificial hip is based on a man's anatomy. Women are built differently than men,” said the developer of the new implant, Richard Berger M.D., an orthopedic surgeon at Rush University Medical Center (Chicago, IL, USA). "Women tend to be shorter than men, more petite, and have smaller bones and shorter hips.”

When a conventional hip replacement implant is placed, surgeons need to make adjustments during the surgical procedure. The results are not always perfect for women as well as men for men shorter than 165 cm. In some cases, the stem of the implant may be too long and can cause the hip to push out and the leg to be slightly longer than normal. The stress from the mismatch can cause the new hip to fail or lead to significant pain and disability, requiring another replacement.

Related Links:
Zimmer
Rush University Medical Center