The FDA approved a prosthetic device Thursday that implants in the thigh bone of an amputee. The prosthesis, Osseo Anchored Prosthesis for the Rehabilitation of Amputees (OPRA), is designed for amputees whose remaining limb is not long enough for traditional ball-and-socket prostheses. It's now available for all adults with above-the-knee leg amputations.

The OPRA device is surgically attached to a patient’s remaining bone with two procedures. The first procedure involves surgically implanting a cylinder-shaped titanium fixture directly into the bone, Popular Science reported. For six months following the operation, patients are observed to make sure that the tissue has grown correctly around their new implant. After this waiting period, a second operation is conducted to implant a rod from the bone through the skin. This rod is then used to insert and fit a prosthetic limb.

The Swedish-made device allows amputees to attach a prosthetic limb directly to their remaining limb by attaching it to screws and a fixture implanted directly into the bone itself. The first-of-its-kind device will drastically improve the quality of life for amputees who are not viable for traditional prosthetics or who have had problems with other methods of rehabilitation. According to a 2014 study, along with storing an amputee’s mobility, OPRA also offers amputees with more comfort and a greater amount of control over their prosthesis’ function than available in current prosthetic models.

Initial designs for OPRA have been around for years, but it wasn’t until the implementation of Intraosseous Transcutaneous Amputation Prosthesis (ITAP), anti-infection technology, in 2013 that the FDA began to take the innovation seriously. Engineers modeled ITAP’s design after the porous bone underneath deer antlers. The addition of ITAP to the OPRA not only helped to improve mobility but also seriously reduced the risk of infection by using the pores to help soft tissue seal off the connection between the bone and skin.

Following the two operations, OPRA recipients are required to undergo six months of physical therapy. This involves the patient gradually putting his weight on the OPRA device while simultaneously learning how to move with a small training prosthesis limb. Only after this training period will amputees be fitted with their own customized prosthesis, according to the FDA press release.

Although OPRA is built to be used on both upper and lower appendages, for now the FDA has restricted its use to individuals with leg amputations above the knee. According to Mark O’Leary, one of the first amputees to be fitted with the new technology, the device has drastically improved his mobility.

"It's like they've given me my leg back,” he told The Guardian.