In a follow-up study of 239 consecutive patients with fractures of the
femoral neck treated by six surgeons in one hospital by Pugh nailing,
Austin Moore prosthesis, or Knowles pinning, 96 per cent could be followed
for a minimum of two years or until a definitve result had been reached.
The incidence of unsatisfactory results was 39.3 per cent after Pugh
nailing, 18.2 per cent after prosthetic replacement, and 14.2 per cent
after Knowles pinning (mostly undisplaced or impacted fractures).
Thirty-five unsatisfactory results following Pugh nailing were due to:
aseptic necrosis which was definite in eighteen cases and probable in two;
early mechanical failure in twelve cases; infection in one; and late
non-union in two. Eight poor results followed prosthetic replacement and
were due to erosion of the acetabulum in six and dislocation in two. The
four poor results that followed Knowles pinning were due to aseptic
necrosis in three and to pain, probably the results of aseptic necrosis, in
another. From this study it was concluded that aseptic necrosis was more
influenced by the original displacement than by the accuracy of reduction
or fixation, and that in displaced femoral-neck fractures in the elderly,
prosthetic replacement gave a more reliable result.