To The Editor:
I wish to comment on the article "Flexible Intramedullary
Nailing for the Treatment of Unicameral Bone Cysts in Long
Bones" (82-A: 1447-53, Oct. 2000), by Roposch
et al. While this study represents an extraordinary experience (thirty-two
cases in eight years) and includes an exemplary review of the literature,
certain elements of and deficiencies in the article deserve attention,
as they should arouse doubts in the reader about whether the treatment described
should be followed in all cases of simple unicameral bone cysts. One
problem is the lumping together of lesions situated mostly
in the humerus (twenty-one cases) or femur (nine cases). The latter
group, which is more prone to fracture, would be more appropriately
given the treatment described. It is regarding the former group
that questions arise. Surely this is a highly selected group of
patients, since most of them (thirty of thirty-two with cysts in
all locations) presented with a pathological fracture. In my experience,
many patients with humeral lesions do not have pathological fractures
(and with conservative care, they do not incur that complication).
Moreover, most of those patients, in my experience, are much younger
than those described in the article. It would have been better if
the authors had provided the ages of the patients and other data
(e.g., the size of the lesion and its location in relation to the
epiphyseal plate) and the correlations between patient
age and those data.
The main deficiency in the article is a lack of critical evaluation
of the extraordinary nature of the data on the two counts mentioned
above. One conclusion that many readers would draw from the article
would be that all unicameral cysts would benefit from the nailing
treatment described. In my view, femoral lesions would undoubtedly
qualify because they occur in older children and because the displacement and
angulation of the pathological fracture are so often major therapeutic problems.
However, in a young child with an "inactive" cyst
of the humerus, much can be said for conservative treatment even
if there is an undisplaced fracture, especially one adjacent to
the epiphyseal plate.
A. Roposch, V. Saraph, and W.E. Linhart reply:
We wish to thank Dr. Cohen for his comments. He has expressed
concern that our paper seems to advocate intramedullary nailing
as the treatment for all unicameral cysts and that the majority
of the cases in our series involved humeral cysts that could also be
treated effectively conservatively. In addition, he also states
that, in his experience, most patients with a humeral lesion do
not have a pathological fracture. With due respect to Dr. Cohen,
we do not fully agree with his statement. Although femoral lesions
obviously have a higher risk of pathological fracture and displacement,
humeral lesions are also prone to and do present with pathological
fractures, which has been well documented in the literature1-3. We are of the opinion that the
risk of pathological fracture with unicameral cysts depends on the
extent of bone destruction and the level of activity of the patient.
Regarding our choice of intramedullary nailing as a treatment
for unicameral bone cysts, we wish to emphasize that we do not perform
intramedullary nailing for all patients with a unicameral bone cyst
presenting at our clinic. We perform intramedullary nailing in patients
who have had a pathological fracture. In those rare cases that were diagnosed
during other routine x-rays or after minor trauma where
there was no pathological fracture but the destruction of the bone
was such that there was a risk of fracture, prophylactic nailing was
done. We strongly believe that nailing in such cases avoids displacement should
a fracture occur subsequently. Although such lesions can be managed very
well with bracing until the cyst heals in a few years, we found
that the patients preferred minor surgery with minimal incisions
to wearing cumbersome braces. From our previous experience of treating
these lesions with bracing for several years until the cyst showed
some healing, we found that bracing imposed a substantial psychological
burden on the affected children. Needless to say, "inactive
cysts" or cysts with thick, sclerotic margins do not require
intramedullary nailing and can be managed conservatively.
The mean age of the patients in our series was 9.8 years, which
seems to compare with that of the cohorts in other reports4,5. It was interesting to learn from
Dr. Cohen that femoral lesions occur in older children; we could
not find any significant correlation between age and the location
of lesions in either our hospital records or the literature. As
the majority of these lesions are diagnosed only after a pathological
fracture, we believe that it is difficult to document the
observation that femoral lesions occur in older children.