To The Editor:
I read with interest "Proximal Femoral Osteotomy as the Primary
Operation for Young Adults Who Have Osteoarthrosis of the Hip" (80-A: 1428-1438,
Oct. 1998), by D'Souza et al.
I fully agree that proximal femoral osteotomy is a valuable option
for the management of young adults who have osteoarthrosis of the
hip. By improving joint congruency and limb alignment and by redistributing
forces across the hip, osteotomy can provide long-lasting improvement and
offer a biological alternative to total hip replacement in well
selected patients. The authors recommended that proximal femoral
osteotomy be used routinely in the treatment of young adults with
osteoarthrosis of the hip if the results of stress radiography indicate
that such a procedure is appropriate. They reported that 60 percent
(fifteen) of the twenty-five hips had radiographic improvement postoperatively
and approximately half of those had marked improvement. They stated
that no additional refinements would have improved their results.
Less attention was paid to the anatomical and biomechanical factors
of the disease process. The patients basically formed two distinct
diagnostic groups. The first group included patients who had residual
deformity as a result of hip dysplasia, and the second group included
those who had osteoarthrosis due to other causes. It is important
to study these different groups separately because the biomechanics
of the joint and the nature of the osteoarthrotic process are so different.
If the same procedure is employed in the treatment of primary osteoarthrosis,
Perthes disease, avascular necrosis, trauma, and congenital dysplasia,
the outcomes are bound to be different because of the differences
in the composition of the bone in such individuals. The data seemed
to show that the result of proximal femoral osteotomy for the treatment
of osteoarthrosis of the hip in patients with congenital dysplasia
or acetabular dysplasia was not as good as that for patients with
a different etiology. I reviewed the results of proximal femoral
osteotomy in eight patients who had hip dysplasia. The mean pain
score improved from 2.7 points preoperatively to 4.2 points at the
most recent follow-up examination; the mean score for walking ability,
from 4.2 to 5.0 points; and the mean score for range of motion,
from 3.3 to 3.7 points. Only three of the eight patients had minimal joint-space
improvements on radiographic examination. In the study by D'Souza
et al., four hips were converted to a total hip replacement and
three of them had had dysplasia.
The authors acknowledged that reports in the literature have
shown that intertrochanteric osteotomy can be an effective treatment
for osteoarthrosis of the hip in carefully selected young patients
but that it is less effective in patients who have primary hip disease2-5. This is consistent
with the findings of their study. I agree with Poss4 who has suggested
that pelvic osteotomy with or without a femoral osteotomy might
be the procedure of choice when acetabular insufficiency is considered
to be the primary cause of joint incongruity. The procedure provides
coverage of the femoral head with an acetabular roof consisting
of hyaline cartilage, a physiological substance with optimal load-bearing
capacity, which might improve the results.
Nusret Köse, M.D.
Department of Orthopaedics and Traumatology, Osmangazi University
Medical Faculty, Meselik, Eskisehir 26480, Turkey
Mr. Northmore-Ball, Mr. D'Souza,
Mr. Sadiq, and Mr. New reply:
We are grateful for Dr. Köse's comments on our study. We note,
with interest, that he also thinks that proximal femoral osteotomy
is a valuable option for the management of young adults who have
osteoarthrosis of the hip. While the altered biomechanics resulting
from this procedure can provide long-lasting improvement and offer
a biological alternative to hip replacement in well selected patients,
it would be wrong to say that we "recommended that proximal femoral
osteotomy be used routinely" in this group of patients. We simply
suggested that this operation has certain advantages in very carefully
selected patients, with appropriate indications, and should be given
serious consideration after appropriate investigation. We outlined
the decision-making process in our paper; many patients did not
fulfill the necessary criteria and were managed expectantly or with
hip resurfacing or a total hip replacement.
It is true that three of the four conversions to a total hip
replacement in our series were performed in patients with congenital
hip dysplasia. Nevertheless, we do not think that the underlying
diagnosis was the chief reason for these failures. Although we agree
that the outcome is likely to be affected by the original diagnosis, we
think that the overwhelmingly greatest influence on the results
is the morphology of the hip and the distribution of the degenerative
change immediately prior to the osteotomy. Similar morphology and
patterns of degeneration can result from widely different initial
causes. We are interested in the results of Dr. Köse's own series,
though more detail would, of course, be needed in order to comment
further.
Finally, we strongly support the view that acetabular dysplasia
now is often better treated with an operation on the acetabular
side of the hip rather than with an intertrochanteric osteotomy. Recently,
the senior one of us (M. D. N.-B.) has observed very satisfactory
results with use of a periacetabular osteotomy carried out according to
the method of Ganz et al.,
as noted in the Materials and Methods section of our study (p. 1430).
We had not yet started to use this procedure during the period of
our study. However, the indications for the procedure are quite
clearly defined and there are many patients with other types of
hip pathology, as outlined in our study, who we think can still
be legitimately considered for intertrochanteric osteotomy.
M. D. Northmore-Ball, M.A., M.B., B.Chir., F.R.C.S., C.I.Mech.E.
S. R. D'Souza, M.S., M.Ch.(Orth), F.R.C.S., F.R.C.S.(Orth)
S. Sadiq, M.B., B.S., M.D., F.R.C.S.
A. M. R. New, Ph.D., B.Eng., A.R.S.M.
Corresponding author: M. D. Northmore-Ball, M.A., M.B., B.Chir.,
F.R.C.S., C.I.Mech.E. , The Robert Jones and Agnes Hunt Orthopaedic Hospital
Oswestry, Shropshire SY10 7AG, United Kingdom