The Second World War gave rise to a previously inconceivable number of
peripheral nerve injuries. Only later on did these injuries occasion
renewed intensive research in this field of neurosurgery. Among the
factors which have promoted this development is the operating microscope
with more refined surgical techniques. Of course, surgery of peripheral
nerve injuries in peacetime is not to be compared with that in wartime.
Only rapid wound healing enables a secondary suture to be performed at a
favorable time, after about four weeks. Besides in most cases the defect
of substance is not as great as in war injuries, in which the so-called
"critical resection length" (Seddon) was the cause of the greatest
difficulties and consti- tuted the crucial obstacle to good success. The
experienced surgeons of the Second World War always knew that the
specified dimensions were far too great for the critical resection
length. They could only resort to attempting a suture even when there
was a great gap be- tween the ends of the nerves. Precise information
was not available on direct damage to the axis cylinder or alteration
due to vascular factors when stretching the various nerves, above all
during the later mobilization of joint decompressions. In my opinion,
the experimental investigations of the author can make a contribution
here. The precisely executed and afterwards carefully analyzed
experiments appear very likely to be applicable to human conditions as
regards their percentages of total nerve length.