A backwards foot prosthetic is what is used after a rotationplasty surgery, in which the lower leg and foot are rotated 180 degrees and then attached to the thigh.
Because the ankle joint bends in the opposite direction of a knee, rotating the lower leg 180 degrees allows your ankle to act as a functional knee joint.
And the backward facing foot and ankle fit inside of a custom lower leg or socket prosthetic, which enables you to bend, walk, run and play sports much more naturally than with a standard above the knee amputation.
And the main nerves and blood vessels are also kept intact during the rotationplasty surgery, allowing you to feel and control the new knee using your foot.
Rotationplasty surgery is most commonly performed in children that have bone cancer, like osteosarcoma, around the knee joint.
A rotationplasty may also be used for congenital conditions like proximal femoral focal deficiency or PFFD when upper femur is missing or severely deformed and in growing children, the rotated ankle can also be matched to the other leg over time, and prosthetics can easily be lengthened as the child grows.
Rotationplasty was invented by German orthopedic surgeon Joseph Borggreve in 1927.
Joseph Borggreve performed the original rotationplasty operation on a 12 year old boy that had a knee destroyed by tuberculosis.
And then Dutch orthopedist Cornelis Pieter van Nes further developed and reported on the rotationplasty procedure in 1950, who helped made it well known, which lead to the term Van Nes rotationplasty.
The different types of rotationplasty surgery are Type A Knee Rotationplasty (Distal Femur & Proximal Tibia) and Type B which is proximal femur & hip Rotationplasty.
In Type A rotationplasty surgical procedures, the knee joint is removed, your lower limb is rotated 180 degrees, and our ankle joint is repositioned to function as a knee ("neo-knee"0 inside of a specialized prosthesis.
Type AI rotationplasty is used for tumors or defects that are located around the distal femur (lower thigh bone).
Your lower leg and foot are rotated and attached to the remaining upper femur.
And type AII rotationplasty is used for tumors or defects that are located around your proximal tibia, (upper shin bone).
The remaining lower limb is rotated and attached higher up your leg.
In Type B proximal femur & hip rotationplasty, these are more complex and involve resections around your upper femur, hip joint, or lower pelvis.
Type BI rotationplasty involves tumors around the proximal femur without hip joint involvement.
Type BII rotationplasty involves tumors of the proximal femur that extend into your involve your lower pelvis/hip region.
Type BIII rotationplasty involves total femur resection, which is removing the entire thigh bone and is further divided based on age.
Type BIIIa Rotationplasty (Children): The lateral tibial plateau is reshaped and placed into the acetabulum (hip socket) to act as a ball-joint substitute for the missing hip.
Type BIIIb Rotationplasty (Adults): The total femur is replaced using a femoral prosthesis combined with rotationplasty mechanics.
And there's also historical and congenital variants of rotationplasty which include:
Van Nes / Borggreve Rotationplasty: Originally designed to treat congenital femoral deficiency (such as Proximal Femoral Focal Deficiency, or PFFD) or severe limb-length discrepancies from childhood conditions like tuberculosis.
The Van Nes / Borggreve Rotationplasty, rotates the lower leg 180 degrees so the ankle can compensate for a missing or non-functional knee joint.
Rotationplasty is a specialized, life-changing surgical procedure used primarily for children and young adults who have a malignant bone tumor (such as osteosarcoma or Ewing's sarcoma) near the knee joint, or a severe congenital lower-limb deficiency.
Bone healing after a rotationplasty procedure typically takes 3 to 6 months (or longer if post-operative chemotherapy is required).
A cast or external fixator is often worn during the initial weeks.
After the bone heals and swelling subsides, a specialized prosthetist builds a custom transtibial (below-the-knee style) prosthesis that accommodates the backward-facing foot.
Intensive physical therapy is also essential to help the patient retrain their brain and nerves, building strength in the hip and ankle to master walking and balance with the new joint.