Article

Knee rotationplasty (KRP) is a type of surgery in which the rotated ankle serves
as a new knee after being removed for bone tumor. Although this limb salvage
surgery is rarely indicated in properly selected patients, it may offer
functional advantages over transfemoral amputation, and more durable results
compared with a prosthesis.
The walking mechanics of adult patients after KRP is
believed to be close to that of below-knee amputees. In this study, we evaluated
steady-state walking of KRP patients from the viewpoint of the overall muscle
power needed to keep the body centre of mass in motion.
Three adult patients
after KRP, all athletes, were evaluated. Ground reactions during walking were
recorded during six subsequent strides on a force treadmill.
The positive
mechanical work and power sustaining the motion of the centre of mass and the
recovery of muscle energy due to the pendulum-like mechanism of walking were
computed and compared with those obtained in previous studies from above-knee,
below-knee amputees and healthy individuals. In KRP patients, walking was
sustained by a muscle power output which was 1.4-3.6 times lower during the step
performed on the rotated limb than on the subsequent step. The recovery of muscle
energy was slightly lower (0.9)
or higher (1.3-1.4 times) on the affected side.
In two out of the three KRP patients, our findings were more similar to those
from above-knee amputees than to those from below-knee amputees. After KRP, the
rotated limb does not necessarily provide the same power provided by below-knee
amputation. This may have a relevance for the paralympic classification of KRP athletes.

Langue : ANGLAIS