Surgeries are performed every day that help save budding sports careers, but you've never seen anything like this one.

Dugan Smith was just another 10-year-old baseball nut when doctors discovered a malignant tumor near his femur, and only chemotherapy and surgery would save his life. Because of the severity and location of the tumor, doctors elected to go with a rare yet long-established surgical procedure called a Van Nes rotationplasty. The procedure has been in use since the 1950s, but only a few are performed every year.

Here's what happens: The diseased portion of the leg is removed, and then the lower portion (containing the lower shin, ankle, and foot) is turned 180 degrees and grafted back onto the upper thigh. The ankle functions as a knee, the foot becomes the upper shin, and a prosthetic leg then fills out the lower portion.

After a successful surgery by Joel Mayerson, who specializes in musculoskeletal oncology at Ohio State University Medical Center and is one of the country's few experts in rotationplasty, Smith (now 13) is back playing youth baseball and functioning than like any other kid his age.

According to the Mayo Clinic, the surgery is most commonly performed on kids between the ages of 5 and 12, but afterward, the leg operates just as it would any other leg. You can bear weight on it, like any other knee joint. Because the nerves are left intact and the blood vessels can be easily reattached once the leg is amputated, all relative physiological function remains even without the prosthetic – albeit in a slightly different presentation.

[h/t Andrew Bucholtz via ThePostGame]