To The Editor:
I read with great interest "Extended Slide Trochanteric Osteotomy
for Revision Total Hip Arthroplasty"(82-A: 1215-19,
Sept. 2000), by Chen et al.
I congratulate the authors on the excellent results obtained
with this technique, which I also use for the same indications.
In their description of the operative technique and in the legend
to Figure 1, they stated that after the extended osteotomy was performed,
a sling consisting of the gluteus medius and minimus muscles proximally
and the vastus lateralis muscle distally was left attached to the
fragment.
I agree with the insertion of the proximal muscles, but distally
it is anatomically impossible to have the vastus lateralis muscle still
attached to the fragment.
Attachment of the vastus lateralis distally can be obtained only
when the anterior lateral cut is performed from the inside to the
outside of the femur, but this is impossible for technical reasons.
As this is an important and valuable technique, other colleagues
should know that, notwithstanding this partial insertion of the
muscles (only proximally), incorporation and healing of this fragment
is very well documented.
W.-M. Chen, J.P. McAuley, C.A. Engh Jr., R.H. Hopper
Jr., and C.A. Engh Sr. reply:
We are pleased to respond to Dr. Tonino’s letter, and
we apologize for any confusion caused by our description of the
surgical technique. It is possible, and quite easy, to maintain
the vastus lateralis attachment to the osteotomy fragment. Dr. Tonino must
be under the impression that the vastus lateralis is reflected circumferentially
from the posterior aspect of the osteotomy to the anterior cut.
In fact, the vastus lateralis is dissected subperiosteally from the
posterior to the anterior cortex only at the level of the transverse
portion of the osteotomy. The distal and posterior cuts of the osteotomy are
performed under direct vision, maintaining the attachment of the
vastus lateralis to the fragment.
There are three ways to complete the anterior portion of the osteotomy
without sacrificing the attachment of the vastus lateralis to the
fragment. Multiple drill-holes can be made through the substance
of the muscle into the anterior cortex along the chosen plane of
the osteotomy, and a controlled fracture can be produced by levering
the osteotomy open with broad osteotomes that are inserted through
the posterior cut. A second option, which we typically perform,
is simply to pass a thin osteotome from the distal transverse cut
proximally and from the anterior femoral neck region distally under
the vastus lateralis, without stripping the muscle for direct
visualization. Third, when the stem can be removed easily prior
to the osteotomy, the longitudinal cut can extend across the femur
and through the anterior cortex from the inside out.
In simple terms, the posterior cortex is exposed longitudinally anterior
to the linea aspera, the lateral cortex is exposed only at the level
of the transverse osteotomy, and the anterior cortex is never exposed,
so that muscle attachments are maintained.