A knee disarticulation (sometimes called a ‘through knee’) is an amputation that involves keeping the femur intact. However, the tendons and ligaments attaching the femur (thigh bone) to the tibia (shin bone) are detached.
There are several advantages of the knee disarticulation over the traditional transfemoral (above-knee) amputation. The first is, decreased rehabilitation time since there is less trauma to the femur. Secondly, the adductor group of muscles (the muscles that bring the leg towards the body) are still intact. This results in the patient having more control over his/her residual limb. The third advantage is, the end of the femur can take some weight bearing instead of through the ischium (sitting bone).
The length of the residual limb is as long as possible (the entire femur) which equals more control over the prosthesis. This can translate into more stability and a better gait.
Despite the advantages, the knee disarticulation level presents an interesting challenge to the patient and the prosthetist. The end of the femur is larger than the area above it, which means it can be difficult to accommodate this area. Since the femur is fully intact, it can lower the person’s knee center compared to the opposite side and limit componentry options.
Due to these kinds of challenges, few prosthetists, when consulted prior to amputation by a surgeon or patient, will recommend this level over the traditional transfemoral level.
While there are challenges with this level, our prosthetists have many years of experience fitting this unique level of amputation. Contact us to find out more.