The fibula must not take weight, it is too slender. In high amputations it has a tendency to tilt outwards, causing the double inconvenience of widening the stump and of projecting through the skin. If only 4 or 5 cms. of the fibula remain it is perhaps best to disarticulate and remove it.
With a fitting arranged in this way, we consider that the convenience of walking with a free knee can be assured to patients whose stumps measure only 10 cms. from the lower border of the patella.
These principles can be applied to a limb constructed either of wood or of leather.
The leather appliance (French method) is formed of a leather cylinder, strengthened by two laternal steels which articulate at the level of the knee joint with two similar steels in the thigh corset. Its upper edge may be strengthened anteriorly by a metal plate, but in practice the latter cannot be made to fit with precision the bony prominences enumerated above. It is actually the edge of the leather, adjusted by lacing, which supports tibial tuberosities, and therefore the precision of the fit is soon lost.
For this reason, for amputation below the knee, the American method of construction with a wooden bucket is demonstrably superior.
These limbs are infinitely more durable than the French. They may last three years, whereas the French limb used by a young and active patient is worn out at the end of the first year, and it was for this reason that a limb with a free knee joint used to be considered a luxury.[9]
[9] That is the reason that amputation at four fingers' breadth below the knee used to be called for the working class, amputation at "the seat of election," a name which is no longer applicable and which is liable to mislead the operator.
This wooden bucket is shaped very accurately to the bony prominences, and by passing the fingers over its inner surface the three hollows corresponding to the points of pressure enumerated above can be distinctly felt.
It is important to describe the shape of the upper edge of the bucket in order to guard against two points which may interfere with flexion—