To The Editor:
With regard to "Distal Femoral Varus Osteotomy for Osteoarthritis of
the Knee"
(2005;87:127-33), by Wang and
Hsu, the authors should be congratulated on a series of technically
well-executed osteotomies. However, because orthopaedists in training use this
journal as a foundation for their education, I am concerned about the message
that this paper delivers.
Specifically, the authors appear to have violated the traditional principle
that an osteotomy about the knee should be carried out on the side of the
deformity. The penalty for this violation is usually an oblique joint line,
persistent pain, and a challenging knee replacement.
Figures 2-A, 2-B, and 2-C show the knee of a patient in whom the valgus
deformity is secondary to an impressive deficit of the lateral plateau. The
distal part of the femur is normal. Yet, the authors have performed a femoral
osteotomy that predictably has led to an oblique joint line. The authors
report that the patient was doing well at eight years. We do not know if or
when the patient will need a joint replacement or how challenging that
arthroplasty will be. Would a relatively easy primary knee replacement not
have been preferable as the index procedure?
Should we no longer be teaching that an osteotomy is preferably performed
on the side of the joint where the deformity lies?
Either way, these principles should have warranted a serious discussion at
some point in the paper. Perhaps it is not too late.
Dr. Grelsamer has mentioned a very good point with regard to choosing the
site of osteotomy when correction of the valgus deformity of the knee is
indicated. Traditionally, a corrective osteotomy is performed at the site of
deformity to create a horizontal joint line. However, if the valgus deformity
of the knee exceeds 12° and there is depression of the lateral tibial
plateau, as depicted in Figure 2 of our article, the issue concerning the
proper site of corrective osteotomy is raised.
In two of the thirty knees in our series, the valgus deformity resulted
from an old fracture of the lateral tibial condyle. The tibiofemoral angles of
both knees were 15° of valgus before the osteotomy. At that time, we
followed the Coventry
principle1 that if
the valgus angulation of the knee exceeds 12°, the osteotomy should be
done in the supracondylar area of the femur. Both knees had adequate
correction of the deformity to 0° of tibiofemoral angulation immediately
after the osteotomy. At the time of the most recent follow-up (eight years
postoperatively), the tibiofemoral angles for these knees were 1° and
2° of varus and both patients were satisfied with the result.
We think that Dr. Grelsamer has raised a very good issue in this particular
situation, one that we believe has not been mentioned before. We believe that,
if an adequate correction is performed either by means of distal femoral or
proximal tibial varus osteotomy, a satisfactory clinical result can be
anticipated. We prefer to perform a distal femoral varus osteotomy, partly
because we are familiar with this technique and partly because we are
concerned about possible injury to the peroneal nerve if =15° of varus
correction is to be done. Importantly, if the deformity is not overcorrected,
the deformity may
recur2.
Coventry MB. Proximal tibial varus
osteotomy for osteoarthritis of the lateral compartment of the knee. J
Bone Joint Surg Am.1987;69:
32-8.6932
1987
Maquet PGJ. Biomechanics of the
knee: with application to the pathogenesis and the surgical treatment of
osteoarthritis. 2nd ed. New York: Springer; 1984. p
276.276
1984